United States
Environmental Protectior
Agency
Air And
Radiation
(ANR-459)
EPA 520/1-75-001-A
January 1990
Manual Of Protective Actions
For Nuclear Incidents
                                  Primed on Recycled Paper

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MANUAL OF PROTECTIVE ACTION GUIDES AND PROTECTIVE ACTIONS

                   FOR  NUCLEAR  INCIDENTS
               Office of Radiation Programs
       United  States  Environmental  Protection Agency
                   Washington,  DC   20460
                           1989

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                                 FOREWORD
     Public officials are charged with the responsibility to protect the
health of the public during hazardous situations.  The purpose of this
manual is to assist these officials in establishing emergency response
plans and in making decisions during a nuclear incident.  It provides
radiological protection guidance that may be used for responding to any
type of nuclear incident or radiological emergency.  In addition, it
provides advice on implementation, with particular emphasis on application
to nuclear power facilities.

     Under regulations governing radiological emergency planning and
preparedness issued by the Federal Emergency Management Agency
(47 FR 10758, March 11, 1982), the Environmental Protection Agency's
responsibilities include, among others, (1) establishing Protective Action
Guides (PAGs), (2) preparing guidance on implementing PAGs, including
recommendations on protective actions, (3) developing and promulgating
guidance to State and local governments on the preparation of emergency
response plans, and (4) developing, implementing, and presenting training
programs for State and local officials on PAGs and protective actions,
radiation dose assessment, and decision making.  This document is intended
to respond to the first two responsibilities.

     The manual begins with a general discussion of Protective Action
Guides (PAGs) and their use in planning for protective actions to
safeguard public health.  It then presents PAGs for specific exposure
pathways and associated time periods.  These PAGs apply to all types of
nuclear incidents.  This is followed by guidance for the implementation of
PAGs that emphasizes their application to nuclear power facilities.
Finally, appendices provide definitions, background information on health
risks, and other information supporting the choice of the numerical values
of the PAGs.

     PAGs for protection from an airborne plume during the early phase of
an incident at a nuclear power plant were published in the 1980 edition of
this manual.  These are reprinted as Chapters 2 and 5 in this edition.
They should continue to be used pending publication of revised PAGs for
the early phase that will apply to a much broader range of situations, and
are currently under development.  Recommendations and background
information for protection from ingestion of contaminated food were
published by the Food and Drug Administration in 1982.  These are
reprinted here as Chapter 3 and Appendix D and should continue to be
used.  Draft recommendations for PAGs for relocation have been developed
recently, and are presented in Chapters 4 and 7.  Additional PAGs for
water and radiation protection guidance for recovery will be developed at
a later date.
                                    iii

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     This manual Is being re-published to consolidate existing
recommendations with the new draft recommendations for relocation  in  a
single volume.  As the above-noted revised and additional recommendations
are developed, they will be issued as revisions to this manual.  The  new
PAGs for relocation are appropriate for incorporation into emergency
response plans when they are revised or when new plans are developed.
After experience is gained in the application of these recommedations,
they will be reexamined and refined as necessary, proposed for review,  and
then recommended to the President as Federal radiation protection
guidance.  It is important to recognize that regulatory requirements  for
emergency response are not provided by this manual; they are established
by the cognizant agency (e.g., the Nuclear Regulatory Commission in the
case of commercial nuclear reactors, or the Department of Energy in the
case of their contractor-operated nuclear facilities).

     Users of this manual are encouraged to provide comments and
suggestions for improving its contents.  Comments should be sent to Joe E.
Logsdon, Guides and Criteria Branch (ANR-460), Criteria and Standards
Division, Office of Radiation Programs, U.S. ^vironmental Protection
Agency, Washington, DC 20460.
                                         Richard J. Guomond, Director
Washington, D. C.                        Office of Radnation Programs
                                    iv

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                                 CONTENTS

                                                                       page
Foreword	iii

1. Overview	1-1
   1.0  Introduction	1-1
   1.1  Nuclear Incident Phases and Protective Actions  	  1-3
   1.2  Basis for Selecting Protective Action Guides  	  1-6
   1.3  Planning	1-7
   1.4  Implementation of Protective Actions  	  1-8
        References	1-9

2. Protective Action Guides for the Early Phase 	  2-1
   2.0  Introduction	2-1
   2.1  Whole Body External Exposure  	  2-2
   2.2  Inhalation Dose	2-4
        2.2.1  Exposure to Radioiodines in a Plume	2-4
        2.2.2  Exposure to Particulate Material in a Plume  	  2-6
   2.3  Intepretation of PAGs	2-6

3. Protective Action Guides for the Intermediate Phase
        (Food and Water) Accidental Radioactive Contamination of
        Human Food and Animal Feeds; Recommendations for State and
        Local Agencies	3-1

4. Protective Action Guides for the Intermediate Phase
        (Deposited Radioactive Materials) 	  4-1
   4.1  Introduction	4-1
        4.1.1  Exposure Pathways  	  4-3
        4.1.2  The Population Affected	4-3
   4.2  The Protective Action Guides for Deposited Radioactivity  .  .  4-4
        4.2.1  Longer Term Objectives of the Protective Action Guides  4-5
        4.2.2  Applying the Protective Action Guides for Relocation  .  4-6

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                                                                       page

   4.3  Exposure Limits for Persons Re-entering the Restricted Zone    4-7
        References	    4-8
5. Implementing the Protective Action Guides for the Early Phase . .   5-1
   5.0 Introduction	   5-1
   5.1 Release Assumptions 	   5-2
        5.1.1 Radioactive Noble Gas and Radioiodine Releases ....   5-4
        5.1.2 Radioactive Particulate Material Releases  	   5-5
   5.2 Sequence of Events	   5-5
        5.2.1 Accident Notification  	   5-7
        5.2.2 Immediate Actions  	   5-8
   5.3 Establishment of Exposure Rate Patterns 	   5-9
   5.4 Dose Projection	   5-12
        5.4.1 Duration of Exposure	   5-14
        5.4.2 Whole Body Dose Projection	   5-15
        5.4.3 Thyroid Dose Projection	   5-18
              5.4.3.1 Concentrations Based on Release Rates  ....   5-21
              5.4.3.2 Concentrations Based on Gamma Exposure Rate
                      Measurements 	   5-24
   5.5 Protective Action Decisions 	   5-30
        References	   5-35

6. Implementing the Protective Action Guides for the Intermediate
        Phase (Food and Uater)	   6-1

7. Implementing the Protective Action Guides for the Intermediate
        Phase (Exposure to Deposited Materials) 	  7-1
   7.1  Introduction	7-1
        7.1.1  Protective Actions 	  7-2
        7.1.2  Areas Involved	7-2
        7.1.3  Sequence of Events	7-5
   7.2  Establishment of Isodose-rate Lines 	  7-8
                                    VI

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                                                                       page
   7.3  Dose Projection	7-9
        7.3.1  Projected External Gamma Dose  	  7-10
        7.3.2  Inhalation Dose Projection	7-18
   7.4  Priorities	7-21
   7.5  Reentry	7-23
   7.6  Surface Contamination Control 	  7-23
        7.6.1  Considerations and Constraints 	  7-24
        7.6.2  Numerical Relationships  	  7-25
        7.6.3  Recommended Surface Contamination Limits 	  7-26
        References	7-30

8. Radiation Protection Guidance for the Late Phase (Recovery)
   (reserved)	8-1
                                  TABLES
   1-1  Exposure Pathways, Incident Phases, and Protective Actions  .  1-5
   2-1  Protective Action Guides for Whole Body Exposure to Airborne
        Radioactive Materials 	  2-3
   2-2  Protective Action Guides for Thyroid Dose Due to Inhalation
        from a Passing Plume	2-5
   4-1  Protective Action Guides for Exposure to Deposited
        Radioactivity During the Intermediate Phase of a Nuclear
        Incident	4-5
   5-1  Recommended Protective Actions to Reduce Whole Body and Thyroid
        Dose from Exposure to a Gaseous Plume	5-31
   7-1  Gamma Exposure Rate and Effective Dose Equivalent (Corrected
        for Radioactive Decay and Weathering) due to an Initial
                                        2
        Uniform Concentration of 1 pCi/m  on Ground Surface 	  7-12
                                    Vll

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                                                                    page
7-2  Exposure Rate and the Effective Dose Equivalent (Corrected
     for Radioactive Decay) due to an Initial Concentration of
     of 1 pCi/m on Ground Surface 	   7-13
7-3  Example Calculation of Dose Conversion Factors for Gamma
     Exposure Rate Measurements Based on Measured Isotopic
     Concentrations  	  7-16
7-4  Dose Conversion Factors for Inhalation of Resuspended
     Material  	7-20
7-5  Skin Beta Dose Conversion Factors for Deposited
     Radionuclides 	  7-22
7-6  Recommended Surface Contamination Screening Levels for
     Emergency Screening of Persons and Other Surfaces at
     Screening or Monitoring Stations in High Background
     Radiation Areas 	  7-28
7-7  Recommended Surface Contamination Screening Levels for Persons
     and Other Surfaces at Monitoring Stations in Low Background
     Radiation Areas  	  7-29
                               FIGURES

5-1 Projected Whole Body Gamma Dose as a Function of Gamma Exposure
     Rate, or Radioiodine Concentration in Air and the Projected
     Exposure Time	5-17
5-2 Projected Thyroid Dose as a Function of Either Gamma Exposure
     Rate, or Radioiodine Concentration in Air and the Projected
     Exposure Time	5-19
5-3 Typical Values for XU/Q as a Function of Atmospheric Stability
     Class and Downwind Distance	5-22
5-4 Radioiodine Release Correction Factor  	    5-27
5-5 Gamma Exposure Rate Finite Cloud Correction Factor 	  5-28
                                vm

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                                                                    page
7-1  Response Areas	7-3
7-2  Time Frame of Response to a Major Nuclear Reactor Incident   .  7-6
                               APPENDICES

A.  Glossary

B.  Risks to Health From Radiation Doses That May Result From
     Nuclear Incidents

C.  Protective Action Guides for the Early Phase:  Supporting
     Information (Reserved)

D.  Background for Protective Action Recommendations:  Accidental
     Contamination of Food and Animal Feeds

E.  Protective Action Guides for the Intermediate Phase
     (Relocation)  Background Information

F.  Radiation Protection Criteria for the Late Phase:  Supporting
     Information (Reserved)
                                 IX

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                                 CHAPTER 1

                                 Overview
1.0  Introduction

     Public officials, in discharging their responsibility to protect  the
health of the public during hazardous situations, will usually be faced
with decisions that must be made in a short period of time.  A number  of
factors influencing the choice of protective actions will exist, so  that
the decisions may be complex.  Further, all of the information needed  to
make the optimum choice will usually not be immediately available.   In
such situations, it will therefore be helpful if the complexity of the
decisions needed can be reduced by careful planning during the formulation
of emergency response plans.

     The U.S. Environmental Protection Agency has developed this manual in
order to assist public officials in planning for nuclear incidents.   In
the context of this manual, a nuclear incident is defined as an event  or a
series of events, either deliberate or accidental, leading to the release,
or potential release, into the environment of radioactive materials  in
sufficient quantity to warrant consideration of protective actions.   (The
term "incident" includes accidents, in the context of this manual.)  A
radiological emergency may result from an incident at a variety of types
of facilities, including, but not limited to, those that are part of the
nuclear fuel cycle, defense and research facilities, and facilities  that
produce or use radioisotopes, or from an incident connected with the
transportation or use of radioactive materials at locations not classified
as "facilities".  This manual provides radiological protection criteria
intended for application to all nuclear incidents requiring consideration
of protective actions, other than nuclear war.  It is designed for the use
of those in Federal, State, and local government with responsibility for
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emergency response planning.  The manual also provides guidance for
implementation of the criteria.  This has been developed primarily for
incidents at nuclear power facilities.  Although this implementation
guidance may also be useful for application to other facilities, or uses
of radioactivity when the radionuclides involved or their physical
characteristics are different from those addressed here, emergency
response plans will usually require the development of additional
implementation procedures.

     The decision to advise members of the public to take an action to
protect themselves from radiation from a nuclear incident involves a
complex judgment in which the risk avoided by the protective action must
be weighed in the context of the risks involved in taking the action.
Furthermore, the decision may have to be made under emergency conditions,
with little or no detailed information available.  Therefore, considerable
planning is necessary to reduce to a manageable level the complexity of
decisions required to effectively protect the public at the time of an
incident.

     An objective of emergency planning is to simplify the choice of
possible responses so that judgments are required only for viable and
useful alternatives when an emergency occurs.  During the planning process
it is possible to make some value judgments and to determine which
responses are not required, which decisions can be made on the basis of
prior judgments, and which judgments must be made during an actual
emergency.  From this exercise, it is then possible to devise operational
plans which can be used to respond to the spectrum of hazardous situations
which may develop.

     The main contribution to the protection of the public from abnormal
releases of radioactive material is provided by site selection, design,
quality assurance in construction, engineered safety systems, and the
competence of staff in safe operation and maintenance.  These measures can
reduce both the probability of an accident and the magnitude of potential
consequences.  Despite these measures, the occurrence of nuclear incidents
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cannot be excluded.  Accordingly, emergency response planning to mitigate
the consequences of an incident  is a necessary supplementary level of
protection.

     During a nuclear incident, when the source of exposure of the public
is not under control, the public usually can be protected only by some
form of intervention which will disrupt normal living.  Such intervention
is termed protective action.  A Protective Action Guide (PAG) is the
projected dose to standard man, or other defined individual, from an
unplanned release of radioactive material at which a specific protective
action to reduce or avoid that dose is warranted.  The objective of this
manual is to provide such PAGs for the principal protective actions
available to public officials during a nuclear incident, and to provide
guidance for their use.

1.1  Nuclear Incident Phases and Protective Actions

     It is convenient to identify three time phases which are generally
accepted as being common to all nuclear incident sequences; within each,
different considerations apply to most protective actions.  These are
termed the early, intermediate, and late phases.  Although these phases
cannot be represented by precise periods and may overlap, they provide a
useful framework for the considerations involved in emergency response
planning.

     The early phase (also referred to as the emergency phase) is the
period at the beginning of a nuclear incident when immediate decisions for
effective use of protective actions are required and must therefore usually
be based primarily on the status of the nuclear facility (or other incident
site) and the prognosis for worsening conditions.  When available, predic-
tions of radiological conditions in the environment from the condition of
the source or actual environmental measurements may also be used.
Protective actions based on the PAGs may be preceded by precautionary
actions during this period.  This phase may last from hours to days.
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     The intermediate phase is the period beginning after the  source  and
releases have been brought under control and reliable environmental
measurements are available for use as a basis for decisions on additional
protective actions.  It extends until these additional protective  actions
are terminated.  This phase may overlap the early and late phase and  may
last from weeks to many months.

     The late phase (also referred to as the recovery phase)  is the period
beginning when recovery action designed to reduce radiation levels in the
environment to acceptable levels for unrestricted use are commenced,  and
ending when all recovery actions have been completed.  This period may
extend from months to years.

     The protective actions available to avoid or reduce radiation dose
can be categorized as a function of exposure pathway and incident  phase,
as shown in Table 1-1.  Evacuation and sheltering (supplemented by bathing
and changes of clothing), are the principal protective actions for use
during the early phase to protect the public from exposure to  direct
radiation and inhalation from an airborne plume.  It may also  be
appropriate to initiate protective action for milk during this period, and
in cases where emergency response plans include procedures for the
issuance of stable iodine (FE-85), this may be an appropriate  protective
action for the early phase.

     Some protective actions are not addressed by these PAGs.   Although
the use of simple, ad hoc respiratory protection may be applicable for
supplementary protection in some circumstances, this protective action is
primarily for use by emergency workers.  The control of access to  areas is
a protective action whose introduction is coupled to a decision to
implement one of the other early or intermediate phase protective  actions
and is not discussed separately.

     Relocation and decontamination are the principal protective actions
for protection of the public from whole body external exposure due to
deposited material and from inhalation of any resuspended radioactive

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       TABLE  1-1.   EXPOSURE  PATHWAYS,  INCIDENT  PHASES,
                        AND  PROTECTIVE  ACTIONS.
          POTENTIAL EXPOSURE PATHWAYS
               AND INCIDENT PHASES
                        PROTECTIVE
                         ACTIONS
1.  External radiation from
    facility


2.  External radiation from plume
3.   Inhalation of activity in
    plume
4.   Contamination of skin and
    clothes
5.   External radiation from
    ground deposition of activity
6.  Ingestion of contaminated
    food and water
7.   Inhalation of resuspended
    activity
                                     Early
Intermediate
                                                Late
Sheltering
Evacuation
Control of access

Sheltering
Evacuation
Control of access

Sheltering
Administration of stable iodine
Evacuation
Control of access

Sheltering
Evacuation
Decontamination of persons

Evacuation
Relocation
Decontamination of land
 and property
                  Food and water controls
                  Relocation
                  Decontamination of land
                   and property
Note:  The use of stored animal feed and uncontaminated water to limit the uptake of radionuclides
      by domestic animals in the food chain can be applicable in any of the phases.
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participate materials during the intermediate and late phases.   It  is
assumed that decisions will be made during the intermediate phase
concerning whether relocated areas will be decontaminated and reoccupied,
or condemned and the occupants permanently relocated.  The second major
type of protective action during the intermediate phase encompasses
restrictions on the use of contaminated food and water.  This protective
action, in particular, may overlap the early and late phases.

     It is necessary to distinguish between evacuation and relocation with
regard to incident phases.  Evacuation is the urgent removal of  people
from an area to avoid or reduce high-level, short-term exposure, usually
from the plume or deposited activity.  Relocation, on the other  hand, is
the removal or continued exclusion of people (households) from
contaminated areas to avoid chronic radiation exposure.  Conditions may
develop in which some groups who have been evacuated in an emergency may
be allowed to return based on the relocation PAGs, while others  may be
converted to relocation status.

1.2  Basis for Selecting Protective Action Guides

     The PAGs in this manual incorporate the concepts and guidance
contained in Federal Radiation Council (FRC) Reports 5 and 7 (FR-64 and
FR-65).  One of these is that the decision to implement protective  actions
should be based on the projected dose that would be received if  the
protective actions were not implemented.  However, since these reports
were issued, considerable additional guidance has been developed on the
subject of emergency response  (IC-84, IA-89).  EPA considered the
following four principles in establishing values for the PAGs:

     1.   Acute effects on health (those that would be observable within  a
          short period of time and which have a dose threshold below which
          such effects are not likely to occur) should be avoided.
     2.   The risk of delayed effects on health (primarily cancer and
          genetic effects for which linear nonthreshold relationships to
          dose are assumed) should not exceed upper bounds that  are judged

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          to be adequately protective of public health  under  emergency
          conditions, and are reasonably achievable.

     3.   PAGs should not be higher than justified on the basis  of
          optimization of cost and the collective risk  of effects on
          health.  That is, any reduction of risk to public health
          achievable at acceptable cost should be carried out.
     4.   Regardless of the above principles, the risk  to health from a
          protective action should not itself exceed the risk to health
          from the dose that would be avoided.

     The above principles apply to the selection of any PAG.  Similar
principles have been proposed for use by the international community
(IA-89).  Appendices C and E demonstrate their application to the choice
of PAGs for evacuation and relocation.  Although in establishing the PAGs
it is prudent to consider a range of source terms to assess the  costs
associated with their implementation, the PAGs are chosen so  as  to  be
independent of the magnitude or type of release.

1.3  Planning

     The planning elements for developing radiological  emergency response
plans for nuclear incidents at commercial nuclear power facilities  are
provided in NUREG-0654 (NR-80), which references the PAGs in  this Manual
as the basis for emergency response.  Planning elements for other types of
nuclear incidents should be developed using similar types of
considerations.

     NUREG-0396 (NR-78) provides guidance for nuclear power facilities on
time frames for response, the types of releases to be considered,
emergency planning zones (EPZ), and the effectiveness of various
protective actions.  The size and shape of the recommended EPZs were only
partially based on consideration of the numerical values of the  PAGs.  A
principle additional basis was that the planning zone for evacuation and
sheltering should be large enough to encompass urban and rural areas and
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involve the various organizations needed for emergency response.  This
consideration is appropriate for any facility requiring an emergency
response plan involving offsite areas.  Experience gained in exercises  is
then expected to provide an adequate basis for expanding the response to
an actual incident to larger areas, if needed.  It is also noted that the
10-mile radius EPZ for evacuation is large enough to avoid exceeding the
evacuation PAGs at its boundary for low-consequence, nuclear reactor,
core-melt accidents and to avoid early fatalities for high-consequence,
nuclear reactor core-melt accidents.  The 50-mile EPZ for ingestion
pathways was selected to account for the proportionately higher doses via
ingestion compared to inhalation and whole body external exposure pathways.

1.4  Implementation of Protective Actions

     The sequence of events during the early phase includes evaluation  of
conditions at the location of the incident, notification of responsible
authorities, prediction or evaluation of potential consequences to the
general public, recommendations for action, and implementing protection of
the public.  In the early phase of response, the time available to
implement the most effective protective actions may be limited.

     Immediately upon becoming aware that an incident has occurred that
may result in exposure of the population, responsible authorities should
make a preliminary evaluation to determine the nature and potential
magnitude of the incident.  This evaluation should determine whether
conditions indicate a significant possibility of a major release and, to
the extent feasible, determine potential exposure pathways, population  at
risk, and projected doses.  The incident evaluation and recommendations
should then be presented to emergency response authorities for action.  In
the absence of recommendations for protective actions in specific areas
from the official responsible for the source, the emergency plan should,
where practicable, provide for protective action in predesignated areas.

     Contrary to the usual situation during the early phase, dose
projections used to support protective action decisions during the
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intermediate and late phases will be based on measurements of environmental
radioactivity and dose models.  Following relocation of the public from
affected areas to protect them from exposure to deposited materials, it
will also be necessary to compile radiological and cost of decontamination
data to form the basis for radiation protection decisions for recovery.

     The PAGs do not imply an acceptable level of risk for normal
(nonemergency conditions).  They also do not represent the boundary
between safe and unsafe conditions, rather, they are the approximate
levels at which the associated protective actions are justified.
Furthermore, under emergency conditions, in addition to the protective
actions specifically identified for application of PAGs, any other
reasonable measures available should be taken to minimize radiation
exposure of the general public and of emergency workers.
                                References
FE-85     FEDERAL EMERGENCY MANAGEMENT AGENCY.  Federal Policy on
          Distribution of Potassium Iodide around Nuclear Power Sites for
          Use as a Thyroidal Blocking Agent.  Federal Register 50-142, p.
          30256, July 24, 1985.
FR-64     FEDERAL RADIATION COUNCIL.  Radiation Protection Guidance for
          Federal Agencies.  Federal Register, Volume 29, pp. 12056-7,
          August 22, 1965.
FR-65     FEDERAL RADIATION COUNCIL.  Radiation Protection Guidance for
          Federal Agencies.  Federal'Register, Volume 30, pp. 6953-5, May
          22, 1965.
IA-89     INTERNATIONAL ATOMIC ENERGY AGENCY.  Principles for Establishing
          Intervention Levels for the Protection of the Public in the
          Event of a Nuclear Accident or Radiological Emergency.  Safety
          Series No. 72, revision 1, in press.  International Atomic
          Energy Agency, Vienna, Austria.
IC-84     INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION.  Protection
          of the Public in the Event of Major Radiation Accidents:
          Principles for Planning, ICRP Publication 40, Pergamon Press,
          Oxford, England, 1984.

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NR-78     NUCLEAR REGULATORY COMMISSION.  Planning Basis for the
          Development of State and Local Government Radiological Emergency
          Response Plans in Support of Light Water Nuclear Power Plants.
          (1978).  U.S. Nuclear Regulatory Commission, Washington, D. C.
          20555.

NR-80     NUCLEAR REGULATORY COMMISSION.  Criteria for Preparation and
          Evaluation of Radiological Emergency Response Plans and
          Preparedness in Support of Nuclear Power Plants.  (1980).  U.S.
          Nuclear Regulatory Commission, Washington, D. C.  20555.
                                   1-10

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                           CHAPTER  2
         Protective Action Guides  for  the Early Phase*
         (Exposure  to  Airborne Radioactive Materials)
2.0  Introduction

          Following an incident  involving a release of radioactive

     material to the atmosphere,  there may be a need for rapid action

     co protect the public  from  radiation exposure from inhalation

     and/or from whole body external  radiation.  This chapter provides

     Protective Action Guides  (PAGs)  for whole body external gamma

     radiation and for inhalation of  radioactive material  in an air-

     borne plume.   A person who  is exposed to the plume of airborne

     radioactive materials  may also be exposed at a later date from

     contaminated food,  water, or other pathways.  However, the PAGs

     in this chapter refer  only  to the exposure received directly

     from the airborne plume.  The emergency response situation addressed

     in this chapter is the period from initiation of an atmospheric

     release until perhaps  two to four days after the event occurs.

     During this period, the principal effort would be directed toward

     protection of the public  from direct exposure to the  plume or from

     inhalation of radioactive material in the plume.

          Ic is important to recognize that the PAGs are defined in

     terms of projected dose.  Projected dose is the dose  that would be

     received by the population  if no protective action were taken.  For
     This Cnapter appears here in  the  form it was published  in  1980;  a
     revised  version  with broader  applicability than this version,  which
     applies  primarily to airborne plumes  for power reactors,  is  currently
     under review.
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     these PAGs, the projected dose does not include dose that may have




     been received prior to the time of estimating the projected dose.




     For protective actions to be most effective, they must be instituted




     before exposure to the plume begins.  PAGs should be considered




     mandatory values for purposes of planning, but under accident con-




     ditions, the values are guidance subject to unanticipated conditions




     and constraints such that considerable judgment may be required for




     their application.




2.1  Whole Body External Exposure




          A radioactive plume will consist of gaseous and/or particulate



     material.  Either of these can result in whole body external expo-




     sure.  Measurements or calculations of environmental levels of




     radioactivity are usually in terms of exposure.  To translate from



     whole body gamma exposure to whole body dose requires a correction




     factor of approximately 0.67.  However, due to the many uncertain-




     ties in projecting dose from exposure to a plume, it is generally



     conservatively assumed that gamma exposure and whole body gamma




     dose are equivalent.



          Recommended PAGs for emergency response in the case of whole




     body external exposure to radionuclides in the atmosphere are




     summarized in table 2.1.  These guidelines represent numerical



     values as to when, under the conditions most likely to occur,




     intervention is Indicated to avoid radiation exposure that would




     otherwise result from the incident.  When ranges are shown, the
                                     2.2

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     Table 2.1  Protective Action Guides for Whole Body
         Exposure to Airborne Radioactive Materials
                                        Projected Whole Body
  Population at Risk                      Gamma Dose (Rom)
General population                             1 to 5'*'


Emergency workers                                25


Lifesaving activities                            75
   (&)wiien ranges are shown, the lowest value should be used if
there are no major local constraints in providing protection at
that level, especially to sensitive populations.  Local con-
straints may make lower values impractical to use, but in no
case should the higher value be exceeded in determining the need
for protective action.
                            2.3

-------
       lowest value should be used if there are no major local constraints




       in providing protection at that level, especially to sensitive popu-



       lations.  Local constraints may make lower values impractical to use,



       but in no case should the higher value be exceeded in determining the



       need for protective action.  The rationale and technical bases for the



       numerical guides and their ranges are described in greater detail in



       Reference (4_) and are summarized In Appendix C.  It is recommended



       that anyone responsible for applying these guides In a nuclear emergency



       become familiar with the rationale on which the guidance was based.



  2.2  Inhalation Dose



            The gaseous portion of a radioactive plume may consist of



       noble gases and/or vapors such as radioiodines.  The noble gases



       will not cause as much dose from Inhalation as from whole body



       external exposure and therefore need not be considered as a



       separate contributor to inhalation exposure.  The principal



       inhalation dose will be from the iodines and partlculate material



       In the plume.



2.2.1  Exposure to Radioiodines in a Plume



            Due to the ability of the thyroid to concentrate Iodines,



       the thyroid dose due to Inhaling radioiodines may be hundreds



       of times greater than the corresponding whole body external



       gamma dose that would be received.  The PAGs for thyroid dose



       due to inhalation from a passing plume are shown in table 2.2.



       The technical support for their development is provided in



       reference (4) and is summarized in Appendix C.
                                       2.4

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    Table 2.2  Protective Action Guides for Thryoid Dose
           Due to Inhalation from a Passing Plume
                                       Projected Thyroid Dose
  Population at Risk                             rem
General population                              5-25


Emergency workers                               125


Lifesaving activities                           (b)
   'a'When ranges are shown, the lowest value should be used if
there are no major local constraints in providing protection at
that level, especially to sensitive populations.  Local con-
straints may make lower values impractical to use. but in iio
case (mould cne nignei vaxue be exceeded IB uetermining me need
for protective action.

      No specific upper limit is given for thyroid exposure
since in the extreme case complete thyroid loss might be an
accent-able penalty for a life saved.  However, this should
not be necessary if respirators and/or thyroid protection for
rescue personnel are available as the result of adequate
planning.
                              2.5

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2.2.2  Exposure to Particulate Material in a Plume




            This section is being developed.



  2.3  Interpretation of PAGs



            The guides for the general population listed in tables



       2.1 and 2.2 were arrived at in consideration of protection of



       the public from early effects of radiation and maintaining the



       delayed biological effects at a low probability.  Consideration



       has been made of the higher sensitivity of children and pregnant



       women and the need to protect all members of the public.  Con-



       sideration has also been made that personnel may continue to




       be exposed via some pathways after the plume passes, and that



       additional PAGs may have to be applied to these exposure pathways.



            Where a range of values is presented, the lower guide is a



       suggested level at which the responsible officials should consider



       initiating protective action particularly for the more sensitive



       populations Indicated above.  The higher guide is a mandatory



       level at which the respective governmental agency should plan to



       take effective action to protect the general public unless the



       action would have greater risk than the projected dose.



            At projected doses below the lower guide, responsible



       officials may suggest voluntary action available to the public



       at risk.  This should be done with the philosophy that popula-



       tion doses be kept as low as possible as long as the effects of
                                       2.6

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action are not more hazardous Chan Che projected dose.  The



concept of voluntary action and the types of action that may be



considered were discussed In Chapter 1.



     The need for selected populations, such as emergency response



team members and persons involved in lifesaving activities, to be



allowed higher exposures than the general public is in line with



policies wherein these categories of individuals normally accept



greater risk.  Public safety and nuclear plant personnel will be



essential to provide services for the public even though they may



receive a greater radiation exposure.



     In the event greater exposures to selected populations are



required to save lives, these should be taken.  However, if the



radiation Injury In these lifesaving activities Is excessive,



the harm may exceed the good, so some restrictions must be made.



     Because of the variations in sensitivity of Che population



to radiation effects and in local conditions (weather, etc.), a



range of values is recommended for the general population.  Where



selective protective actions (i.e. evacuation) for the general



population is possible, children and women of childbearing age



should be protected at the lower levels of the range.  A further



interpretation of the range is that plans should be made to consider



organized protective action at the lower end of the range whereas it



is mandatory that plans be made to implement protective action at the



upper end.  However, if no constraints existed, the lower range should
                                2.7

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always be used.  Since constraints exist on a local basis under



different conditions, the range allows adjustment by local.



officials during the planning stage for special local problems



as discussed in Chapter 1.



     The values given for emergency workers recognize the need



for some civil functions to continue in the event of an evacu-



ation of the general population.  The risks are considered to be



warranted when necessary on the basis of the individual exposure



and the benefits derived.  In such cases, precautions should be



taken to minimize exposures to emergency workers.



     PAGs for lifesaving missions are given for those persons



whose normal duties might involve such missions, i.e., police,



firemen, radiation workers, etc.  These guides would normally



be limited to healthy males.  No specific upper limits are



given for thyroid exposure since in the extreme case, complete



thyroid loss might be an acceptable penalty for a life saved.



However, this should not be necessary if appropriate protective



measures for rescue personnel are available as the result of



adequate planning.  For example, respiratory protection and/or



stable iodine for blocking thyroid uptake of radlolodine should



be available to the extent possible for personnel involved in



lifesaving missions and other emergency actions.  The issuance



of stable iodine must be in accordance with state medical procedures.
                                2.8

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                                CHAPTER 3
          Protective Action Guides for the  Intermediate Phase*
                            (Food and Mater)
    a)  Accidental Radioactive Contamination of Human Food and Animal

          Feeds;  Recommendations for State  and Local Agencies*
    b)  Drinking Water**
* These recommendations were published by FDA in 1982.
**Protective action recommendations for drinking water are under
    development by EPA.

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Federal Register / Vol. 47,  No. 205 / Friday, October  22. 1982 / Notices            47073
                                                         DEPARTMENT OF HEALTH AND
                                                         HUMAN SERVICES

                                                         Food and Drug Administration

                                                         (Docket No. 76M-0050]

                                                         Accidental Radioactive Contamination
                                                         o1 Human Food and Animal Feed*;
                                                         Recommendatlona tor State and Local
                                                         Agencies
                                                         AGENCY: Food and Drug Administration.
                                                         ACTION; Notice.	

                                                         SUMMARY: The Food and Drug
                                                         Administration (FDA) is publishing this
                                                         notice to provide to State and local
                                                         agencies responsible for emergency
                                                         response planning for radiological
                                                         incidents recommendations for taking
                                                         protective actions in the event that an
                                                         incident causes the contamination of
                                                         human food or animal feeds. These
                                                         recommendations can be used to
                                                         determine whether levels of radiation
                                                         encountered in food after a radiological
                                                         incident warrant protective action and
                                                         to suggest appropriate actions that may
                                                         be taken if action is warranted. FDA has
                                                         a responsibility to issue guidance on

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47074             Federal Register / Vol. 47, No.  205 / Friujy. October 22. 1902  /  Notices
appropriate planning actions necessary
for evaluating and preventing
contamination of human food and
animal feeds and on the control and use
of these products should they become
contaminated.
FOR FURTHER INFORMATION CONTACT:
Gail D. Schmidt, Bureau of Radiulogic.il
Health (HFX-1). Food and Drug
Administration. 5600 Fishers Lane.
Rockville, MD 20857. 301-443-2050.
SUPPLEMENTARV INFORMATION:

Background
  This guidance on accidental
radioactive contamination of food from
fixed nuclear facilities,  transportation
accidents, and fallout is part of a
Federal interagency effort coordinated
by the Federal Emergency Management
Agency (FEMA). FEMA issued a final
regulation in the Federal Register of
March 11,1982 (47 FR 10758). which
reflected governmental  reorganizations
and reassigned agency  responsibilities
for radiological incident emergency
response planning. A responsibility
assigned to the Department of Health
and Human Services (HHS) (and in turn
delegated to FDA) is the responsibility
to develop and specify  to State and local
governments protective actions and
associated guidance for human food and
animal feed.
  In the Federal Register of December
15,1978 (43 FR 58790), FDA published
proposed recommendations for State
and local agencies regarding accidental
radioactive contamination of human
food and animal feeds.  Interested
persons were given until February 13,
1979 to comment on the proposal.
Twenty-one comments  were received
from State agencies, Federal agencies,
nuclear utilities, and others. Two of the
comments from environmentally
concerned organizations were received
after the March 28.1979 accident at
Three Mile Island, which increased
public awareness of protective action
guidance. Although these comments
were received after the  close of the
comment period, they were considered
by the agency in developing these final
recommenda tiona.
  The Office of Radiation Programs.
Environmental Protection Agency (EPA),
submitted a detailed and exhaustive
critique of the proposed
recommendations. EPA addressed the
dosimetry data, the agricultural models
used in calculating the derived response
levels, and the philosophical basis for
establishing the numerical value of the
protective action guides. FDA advises
that, to be responsive to the EPA
comments, FDA staff met with staff of
the Office of Radiation  Programs. EPA,
during the development of these f.nul
recommendations. Although EPA's
formal comments are responded to in
this notice, EPA stdff reviewed a draft of
the final recommendations, and FLJA
has considered their additional  informal
comments. These contacts were
considered appiopnate because EPA
has indicated that it intends to use the
recommendations as the basis for
revising its guidance to Federal  agencies
on protpctive a< lion guides for
radioactivity in food.

Protective Action Guidance
  Although not raised  in the comments
received, FDA has reconsidered its
proposal to codify these
recommendations in 21 CFR Part 1090.
Because these recommendations are
voluntary guidance to Slate and local
agencies (not regulations). FDA has
decided not to codify the
recommendations; rather, it is issuing
them in this notice. Elsewhere in this
issue of the Federal Register, FDA is
withdrawing the December 15.1978
proposal.
  The recommendations contain basic
criteria, defined as protective action
guides (PAG's), for establishing the level
of radioactive contamination of human
food or animal feeds at which action
should be taken to protect the public
health and assure the safety of food. The
recommendations also contain specific
guidance on what emergency protective
actions should be taken to prevent
further contamination of food or feeds or
to restrict the use of food, as well as
more general guidance on the
development and implementation of
emergency action. The PAG's have been
developed on the basis of
considerations of acceptable risk to
identify that level of contamination at
which action is necessary to protect the
public health.
  In preparing these recommendations.
FDA has reviewed and utilized the
Federal guidance on protective actions
contained in Federal Radiation Council
(FRC) Reports No. 5. July 1964 (Ref. 1)
and No. 7. May 1965 (Ref. 2]  The
Federal guidance provides that each
Federal agency, by virtue of its
immediate knowledge or its operating
problems, would use the applicable FRC
guides as a basis for developing detailed
standards to meet the particular needs
of the agency. FDA's recommendations
incorporate the FRC concepts and the
FRC guidance that protective actions, in
the event of a contaminating accident,
should be based on estimates of the
projected radiation dose that would be
received in the absence of taking
protective actions. Similarly, protective
actions should be implemented for a
s jfficicnt time to avoid most of the
projected radiation dose. Thus, the
PAC's define the numerical value of
projected radiation doses for which
protective actions are recommended.
  FDA has reviewed the recent report of
Ihc National Academy of Sciences/
Nutionul Rcsc;irch Council (Ref. 3) on
radiation risks and biological effects
data thiil became available after
publication of the  FRC guidance and has
reviewed the impact of taking action m
Ihc pjisture/cow/milk/person pathway
;r. light of the current concerns in
rudiiition protection. Based on these
considerations and the comments
received on the proposed
recommendations, FDA has concluded
that protective actions of low impact
should be undertaken at projected
radiriliun doses lower than those
recommended by FRC (Refs. 1 and 2).
Accordingly, FDA is recommending low-
impact protective actions (termed the
Preventive PAG) at projected radiation
doses of 0.5 rem whole body and 1.5 rem
thyroid. FDA intends that such
protective actions be implemented to
prevent the appearance of radioactivity
in food at levels that would require its
condemnation. Preventive PAG's
include the transfer of dairy cows from
fresh forage (pasture) to uncontaminated
stored feed and the diversion of whole
milk potentially contaminated with
short-lived radionuclides to products
with a long shelf life to allow
radioactive decay of the radioactive
material.
  In those situations where the only
pi elective actions that are feasible
present high dietary and social costs or
impacts (termed the Emergency PAG)
action is recommended  at projected
radiation doses of 5 rem whole body
and 15 rem thyroid. At the Emergency
PAG level responsible officials should
isolate food to prevent its introduction
into commerce and determine whether
condemnation or other disposition is
appropriate. Action at the Emergency
PAG level is most  likely for the
population that is near to the source of
radioactive contamination and that
consumes home-grown produce and
milk.
  The PAG's represent FDA's judgment
as to that level of food contamination
resulting from radiation incidents at
which action should be taken to protect
the public health. This is based on the
agency's recognition that safety involves
the degree to which risks are judged
acceptable. The risk from natural
disasters (approximately a one in a
million annual individual risk of death)
and the risk from variations in natural
background radiation have provided

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                   Federal Register / Vol. 47. No.  205 / Friday. October 22. 1982 / Notices	47075
perspective in selecting the PAG values.
This issue is further discussed in the
responses to specific comments later in
this notice, especially in paragraph 9. A
more detailed treatment of the rationale.
risk factors, dosimetric and agricultural
models, and methods of calculation is
contained in the "Background for
Protective Action Recommendations;
Accidental Radioactive Contamination
of Food and Animal Feeds" (Ref. 22).

Organ PAG Values
  Current scientific evidence, as
reflected by BEIR-I [Ref. 18).
UNSCEAR-1977 (Ref. B). and BEIR-III
(Ref. 3). indicates that the relative
importance of risk due to specific organ
exposure is quite different from the
earlier assumptions. The International
Commission on Radiological Protection
(ICRP) clearly recognized this in its 1977
recommendations (ICRP-26 (Ref. 6)).
which changed the methodology for
treating external and internal radiation
doses and the relative importance of
specific organ doses. ICRP-26 assigned
weighting factors to specific organs
based on considerations of the
incidence and severity (mortality) of
radiation cancer induction For the
radionuclides of concern for food PAG's.
ICRP-26 assigned weighting factors of
0 03 for the thyroid and 0.12 for red bone
marrow. Thus, the organ doses equal in
risk to l rem whole body radiation dose
are 33 rem to the thyroid and 8 rem to
Red bone marrow. (The additional
ICRP-26. nonstochastic limit, however.
restricts the thyroid dose to 50 rem or 10
times the whole body occupational limit
of 5 rem.)
  In the Federal Register of January 23.
1981 (46 FR 7836], EPA proposed to
revise the Federal Radiation Protection
Guidance for Occupational Exposures
using the ICRP approach for internal
organ radiation doses, modified to
reflect specific EPA concerns. The EPA
proposal has been subject to
considerable controversy. Also, the
National Council on Radiation
Protection and Measurements (NCRP)
curently is evaluating the need to revise
its recommendations. FDA does not.
however, expect the protection model
for internal organ  radiation doses to be
resolved rapidly in the United States
and has based the relative PAG dose
assignments in these recommendations
on current U.S. standards and the 1971
recommendations in NCRP-39 (Ref. 19).
Thus, the red bone marrow is assigned
the same PAG dose as the whole body
(0.5 rem Preventive PAG), and the
thyroid PAG is greater by a factor of
three (l.S rem Preventive PAG). This
results in PAG assignments for the
thyroid and  red bone marrow that are
lower by factors of 3.3 and 8.
respectively, than values based on
ICRP-26 (Ref. 6). FDA advises that it
will make appropriate changes in
recommendations for internal organ
doses when a consensus in the United
States emerges.

Analysis of Comments
  The following is a summary of the
comments received on the December 15,
1978 proposal and the agency's response
to them:
  1. Several comments requested
clarification of the applicability and
compatibility of FDA's
recommendations with other Federal
actions, specifically the PAG guidance
of EPA (Ref. 7). the FRC Reports No. 5
(Ref. 1) and No. 7 (Ref. 2). and the
Nuclear Regulatory Commission (NRC)
definition of "Extraordinary Nuclear
Occurrence" in 10 CFR Part 140. A
comment recommended that the term,
"Protective Action Guide (PAG)", not be
used because that term traditionally has
been associated with the FRC. and the
general public would confuse FDA's
recommendations with Federal
guidance.
  The FRC Report No. 5 specifically
recommended that the term, "protective
action guide." be adopted for Federal
use. The report defines the term as the
"projected absorbed dose to the
individuals in the general population
which warrants protective action
following a contaminating event." a
concept that is addressed by FDA's
recommendations. To use the concept
with a different description would, in
FDA's opinion, be unnecessanly
confusing to State and local agencies as
well as Federal agencies.
  These recommendations are being
issued to fulfill the HHS responsibilities
under FEMA's March 11.1982
regulation. FDA fully considered FRC
Reports No. 5 and No. 7 and the basic
concepts and philosophy of the FRC
guidance form the basis for these
recommendations. The specific PAG
values are derived response levels
included in these recommendations are
based on current agricultural pathway
and radiation dose models and current
estimates of risk. The FRC guidance
provided that protective actions may be
justified at lower (or higher) projected
radiation doses depending on the total
impact of the protective action. Thus,
FDA's recommendation that protective
actions be implemented at projected
radiation doses lower than those
recommended by FRC doses is
consistent with the FRC guidance. The
FRC guidance is applicable to Federal
agencies in their radiation protection
activities. FDA's recommendations are
for use by Slate and local agencies in
response planning and implementation
of protective actions in the event of a
contaminating incident. Further. FDA's
recommendations would also be used by
FDA in implementing its authority for
food in interstate commerce under the
Federal Food. Drug, and Cosmetic Act.
  FDA's recommendations are being
forwarded to EPA as the basis for
revising Federal guidance on food
accidentally contaminated by
radionuclides. EPA has advised FDA
that it intends to forward the FDA
recommendatiojis to the President under
its authority to "advise the President
with respect to radiation matters
directly or indirectly affecting health,
including guidance for all Federal
agencies  in the formulation of radiation
standards *  * *". (This authority was
transferred to EPA in 1970 when FRC
was abolished.)
  The recommendations established in
this document apply only to human food
and animal feeds accidentally
contaminated by radionuclides. They
should not be applied to any other
source of radiation exposure. EPA
already has issued  protective action
guidance for the short-term accidental
exposure to airborne releases of
radioactive materials and intends also
to forward the EPA guides to the
President as Federal guidance. EPA also
is considering the development of
guidance for acidentally contaminated
water and for long-term exposures due
to contaminated land, property, and
materials. Guidance for each of these
exposure pathways is mutually
exclusive. Different guidance for each
exposure pathway is appropriate
because different criteria of risk, cost.
and benefit are involved. Also, each
exposure pathway may involve different
sets of protective or restorative actions
and would relate to different penods of
time when such actions would be taken.
  2. Several comments expressed
concern about radiation exposure from
multiple radionuclides and from multiple
pathways, e.g., via  inhalation, ingestion.
and external radiation from the cloud
(plume exposure) and questioned why
particular pathways or radionuclides
and the does received before
assessment were not addressed in the
recommendations.  Several comments
recommended that the PAG's include
specific guidance for tap water (and
potable water).  Other comments noted
that particular biological forms of
specific radionuclides (i.e.,
cyanocobalamin Co 60). would lead to
significantly different derived response
levels.

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•J7076
Federal  Register / Vol. 47. No. 205 / Friday. October 22, 1982  /  Notices
  FDA advises that the PAG's and the
protective action concepts of FRC apply
to fictions taken to avoid or prevent
projected radiation dose (or future
dose). Thus, by definition, the PAG's for
food do not consider the radiation closrs
already incurred from the plume
pathway or from other sources. The
population potentially exposed by
ingestion of contaminated food can be
divided into that population near the
source of contamination and a generally
much larger population at distances
where the doses from  the cloud are not
significant. The NRC regulations provide
thdt State and local planning regarding
plume exposure should extend for 10
miles and the ingestion pathway should
extend for 50 miles (see 45 FR 55402;
August 19.1980). The total population
exposed by ingestion. however, is a
function of the animal feed and human
food production of any given area and is
not limited by distance from the source
of contamination. Exposure from
multiple pathways would not be a
concern for the more distant population
group Further, individuals in this larger
population would most likely receive
doses smaller than that projected for
continuous intake because the
contaminated food present in the retail
distribution system would be replaced
by uncontaminated food.
  FRC Report No. 5 states that, fur
repetitive occurrences, the total
projected radiation dose and the total
impact of protective actions should be
considered. Similar considerations on a
case-by-case basis would then appear to
be appropriate in the case of multiple
exposures from the plume and the
ingestion pathway. Accordingly, the
final recommendations are modified to
note that, specifically in the case of the
population near the site that consumes
locally grown produce, limitations of the
total dose should be considered (see
paragraph (a)(2)). The agency concludes.
however, that a single unified PAG
covering multiple pathways, e.g..
external radiation, inhalation, and
ingestion is not practical because
different actions and impacts are
involved. Further. FDA's responsibility
in radiological incident emergency
reapon.se planning extends only to
human food and animal feeds.
  The agency's primary charge is to set
recommended PAG dose commitment
limits for the food pathway. Thus.
deriving response  levels for only the
radionuclides most likely to enter the
food chain and deliver the highest dose
to the population permits FDA to
establish recommendations that are
practical for use in an emergency. In
discussing with EPA the list of definitive
                    models, FDA and T.PA si.iffs ajjroi'd Hint
                    further pathway studies would be
                    useful  Elsewhere in this notice. FDA
                    references models for other
                    radionur.lides. providing a resource fur
                    thosr requiting more details.
                      Thr chemic.-il form of radionuc lides in
                    the environment may he important wh»n
                    considering the derivation of an
                    appropriate "response level" in specific
                    situations, but would not change the
                    PAC's. which are in terms of projected
                    dose commitments. Cyanocobalamm Co
                    60 has not been identified as a likely
                    constituent of health importance to be
                    released from a nuclear reactor accident
                    and. therefore,  the agency rejects the
                    recommendation that it provide derived
                    response levels for this radionuchde.
                    However, after reviewing current
                    agricultural and dose models, the
                    agency concludes that cesium-134 would
                    likely be released and has added it to
                    the tables in paragraph (d) of the
                    recommendations identifying
                    radionuclide concentrations equivalent
                    to the PAG response levels,
                      FDA rejects the comment
                    recommending that the PAG's include
                    guidance for water. A memorandum of
                    understanding  between EPA and FDA
                    provides  that FDA will have primary
                    responsibility over direct and indirect
                    additives and other substances in
                    drinking water (see 44 FR 42775: July 20.
                    1979). Thus. FDA defers to EPA for
                    developing guides specifically for
                    drinking water.
                      3. Three comments requested
                    clarification of the proposed
                    recommendations, including the time
                    over which the guides apply, the time of
                    ingestion required to reach the PAG. and
                    the time that protective actions should
                    be implemented.
                      FDA advises that the
                    recommendations are intended to
                    provide guidance for actions to be
                    implemented in an emergency, and the
                    duration  of protective action should not
                    exceed 1  or 2 months. The agency
                    believes that the actions identified in
                    paragraphs (a) and (h) of the
                    recommendations should be continued
                    for a sufficient time to avoid most of the
                    emergency radiation dose and to assure
                    that the remaining dose is less than the
                    Preventive PAG. This period of time can
                    be estimated by considering the
                    effective  half-life of the radioactive
                    material taking into account both
                    radioactive decay and weathering. Each
                    case must be examined separately
                    considering the actual levels of
                    contamination and the effective half-life
                    of the radioactive material present. For
                    the paslure/cow/milk pathway, the
                    effective  half-lives are 5 days for iodine-
131 
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                   Federal Register / VoL 47. No.  205 / Friday. October 22. 1982 / Notices
                                                                    47077
shipment of contaminated foods from
Slates without sufficient resources and
what would be the applicable PAC.
  FEMA. as the lead agency for the
Federal effort, is providing to Slates
guidance and assistance on emergency
response planning including evaluation
of projected doses. Also. NRC requires
nuclear power plant licensees to have
the capability to assess the off-site
consequences of radioactivity releases
and to provide notification to State and
local agencies (45 FR 55402: August 19.
1S80). FDA has authority under the
Fuderdl Food. Drug, and Cosmetic Act to
remove radioactively contaminated food
from the channels of interstate
commerce. In this circumstance. FDA
would use these PAG recommendations
as the basis for implementing
regulatory action.
Risk Estimates
  7. Many comments questioned the risk
estimates on which FDA based the
proposed PAG's. The comments
especially suggested that risk estimates
from WASH-1400 (Ref. 4) were of
questionable validity. Other comments
argued that the proposed
recommondarions used an analysis of
only lethal effects: that they used an
absolute nsk model: and that genetic
effects were not adequately considered.
The nsk estimates themselves were
alleged  to be erroneous because recent
studies show that doubling doses are
lower than are those suggested  by
WASH=1400. The tinea capitis study by
Ron and Modan, which indicates an
increased probability of thyroid cancer
at an estimated radiation dose of 9 rem
to the thyroid (Ref. 5). was ated as
evidence that the PAG limits for the
thyroid  were too high. The comments
requasred further identification and
support for using the cnbcal population
selected
  Most  of these issues were addressed
in tha preamble to the FDA proposal.
The final recommendations issued in
this notice employ the most recent nsk
estimates (somatic and genetic) of the
National Academy of Sciences
Committee on  Biological Effects of
Ionizing Radiuti«n (Ref. 3).
  The thyroid PAG limits are based on
the relative radiation protection guide
for thyroid compared to whole body
contained in NRC's current regulations
(10 CFR Part 20]. The denved response
levels for thyroid are based on nsk
factors for external x-ray irradiation.
Therefore, the criticism of the PAG
limifc for the thyroid is not applicable.
no "credit" having been taken for an
apparent lower radiation risk due to
iodine-131 irradiation of the thyroid
gland. Further, as discussed above
under "ORGAN PAG VALUES", the use
of BEIR-IU risk estimates or the ICRP-26
recommendations would result in jn
increase of the thyroid PAG relative to
the whole body PAG. For these  reasons.
FDA believes the PAC limits for
projected dose commitment to the
thyroid are conservative when
considered in light of current knowledge
of radiation to produce equal health
risks from whole body and specific
organ doses.
  Although it may be desirable  to
consider total health effects, not just
lethal effects, there is a lack of data for
total health effects to use in such
comparisons. In the case of the
variability of natural background, as an
estimate of acceptable risk.
consideration of lethal effects or total
health effects is not involved because
the comparison is the total dose over a
lifetime.
Rational
  8. Several comments questioned the
rational FDA used in setting the specific
PAG values included in the December
1978 proposal A comment from EPA
stated that the guidance levels should be
justified on the grounds that it is not
practical or reasonable to take
protective actions at lower risk  levels.
Further. EPA argued that the protective
action concept for emergency planning
and response should incorporate the
principle of keeping radiation exposures
as low as reasonably achievable
(ALARA]. EPA noted that the principle
of acceptable risk involves a perception
of nsk that may vary from person to
person and that the implication that an
acceptable genetic risk has been
established should* be avoided.
  FDA accepts and endorses the
ALARA concept but the extent to which
a concept, which is used in occupational
settings, should be applied to emergency
protective actions is not clear. To use
the ALARA concept as the basis for
specific PAG values and also require
ALARA during the implementation of
emergency protective actions appears to
be redundant and may not be practical
under emergency conditions.
  FDA advises that these guides do not
constitute acceptable occupational
radiation dose limits nor do they
constitute acceptable limits for  other
applications (e.g., acceptable genetic
nsk). The guides are not intended to be
used to limit the radiation dose  that
people may receive but instead  are to be
compared to the calculated projected
dose. i.e.. the future dose that the people
would receive if no protective action
were taken in a radiation emergency. In
this respect, the PAG'» represent trigger
levels calling for the initiation of
recommended protective actions. Once
the protective action IB initiated, it
should be executed so as to prevent as
much of the calculated projected dose
from being received as is reasonably
achievable. This does not mean.
however, that all doses above guidance
levels can be prevented.
  Further, the guides are not intended to
prohibit taking actions at projected
exposures lower than the PAC values.
They have been derived for general
cases and are just what their name
implies, guides. Aa provided in F5C
Reports No. 5 and No. 7 ondaa
discussed in paragraph 1 of thi« notice.
in the absence of significant constraints.
responsible authority may End it
appropriate to implement low-impact
protective actions at projected radiation
doses less than those specified in the
guides. Similarly, high impact actions
may be justified at higher projected
doses. These judgments-must be made
according to the facts of each situation.
Paragraphs (a) (2) and (3) have been
added to the final recommendationa to
Incorporate this concept.
  9. Several comments questioned the
adequacy of the level of Tiak judged
acceptable in deriving the proposed
PAG values. A comment stated that the
estimated one in a million annual
Individual nsk of death from natural
disasters is extremely conservative. EPA
suggested that comparative risk is
appropriate for perspective but not for
establishing the limits. EPA further
suggested that the population-weighted
average of the variability in natural
background dose or the variation in
dose due to the natural radioactivity in
food should be the basis for judging
acceptable risk.
  FDA concludes that the differences
between EPA's suggested approach and
that employed by FDA largely involve
the semantics of the rationale
descriptions. Aa discussed in the
preamble to the proposal. FDA'believes
that safety (or a safe level of nakj needs
to be defined as the degree to which the
risks are judged acceptable, because it
is not passible to achieve zero risk from
human endeavors. Further. ICSP (Ref. 6)
recommends that, for a given
application involving radiation, the net
benefit to society should be positive.
considering the total costs and impacts
and the total benefit (this is termed
"justification"]. FDA believes that to
establish a PAC. the primary concern is
to provide adequate protection (or safe
level of nsk) for members of the public.
To decide on safety or levels of
acceptable risk to the public from a
contaminating event FDA introduced
the estimates of acceptable risk from

-------
47078
Federal  Register / Vol  47. No 205  / Friday. October 22. 1982 /  Notices
ndtural disastrrs and background
radiation These values provided
bcickground or perspective for FDA s
ludgment that the proposed PAG's
represent that level of food or feed
rddiation contamination at which
protective actions should be taken to
protect the public health: judgment
which, consistent with FRC Report No.
5, also involves consideration of the
impacts of the action and the possibility
of future events. The recommendations
are based on the assumption that the
occurrences of environmental
contamination requiring protective
actions in a particular area is an
unlikely event, that most individuals
will never be so exposed, and that any
individual is not likely to be exposed to
projected doses at the PAG level more
than once in his or her lifetime.
  FDA continues to believe that the
average risks from natural disasters and
variation of background radiation
provide appropriate bases for judging
the acceptability of risk represented by
the Preventive PAG. These
recommendations incorporate the
philosophy that action should be taken
at the Preventive PAG level of
contamination to avoid a potential
public health problem. Should this
action not be wholly successful, the
Emergency PAG provides guidance for
taking action where contaminated food
is encountered. FDA expects that action
at the Emergency PAG level of
contamination would most likely
involve food produced for consumption
by the population near the source of
contamination. As discussed in
paragraph 2, this is also the population
which might receive radiation doses
from multiple pathways. Thus, the
Emergency PAG might be considered  to
be an upper bound for limiting the total
radiation dose to individuals. FDA
emphasizes, however, that the
Emergency PAG is not a boundary
between safe levels and hazardous or
injury levels of radiation. Individuals
may receive an occupational dose of 5
rem each year over their working
lifetime with the expectation of minimal
increased risks to the individual.
Persons in high elevation areas such as
Colorado receive about 0.04 rem per
year (or 2.B rem in a lifetime) above the
average background radiation dose for
the United States population as a whole.
The Emergency PAG is also consistent
with the upper range of PAG's proposed
by EPA for the  cloud (plume) pathway
(Ref.7j.
  FDA agrees that a population-
weighted variable is as applicable to the
evaluation of comparative risks as is a
geographic variable. Arguments can be
                    m.idc for using either variable Because
                    prrsons rather than geographic arr.is
                    are the important parameter in the
                    evaluation of risk associated with these
                    guidrs, FDA has used populdtion-
                    weiyhhng in estimating the variability of
                    the annual external dose from ndtural
                    rddiation A recent EPA study (Ref  20)
                    indicates that the average population
                    dose from external background
                    radiation dose is 53 millirem [mrcm] per
                    year, and the variability m lifetime  dose
                    taken as two standard deviations is
                    about 2,000 mrem. The proposal, which
                    indicated that the variation in external
                    background was about 600 mrem.
                    utilized a geographic weighting of State
                    averages.
                      Radioactivity in food contributes
                    about 20 mrem per year to average
                    population doses and about 17 mrem per
                    year of this dose results from potassium-
                    40 (Ref. 8). Measurements of potassium-
                    40 (and stable potassium) indicate that
                    variability (two standard deviations) of
                    the potassium-40 dose is about 28
                    percent or a lifetime dose of 350 mrem It
                    should be noted that body levels of
                    potassium are regulated by metabolic
                    processes and not dietary selection or
                    residence. The variation of the internal
                    dose is about one-fifth of the variation
                    from external background radiation.
                    FDA has retained the proposed
                    preventive PAG of 500 mrem whole
                    body even though the newer data
                    indicate a greater variation in external
                    background radiation.
                      FDA did not consider perceived risks
                    in deriving the proposed PAG values
                    because perceived risk presents
                    numerous problems  in its
                    appropriateness and application If the
                    factor of perception  is added to the
                    equation, scientific analysis is
                    impossible.
                      10. Two comments questioned the
                    assumptions that the Emergency PAG
                    might apply to 15 million people and
                    that the Preventive PAG might apply to
                    the entire United States. One comment
                    noted that 15 million persons are more
                    than that population currently within 25
                    miles of any United  States reactor sites:
                    thus, using this figure results in guides
                    more restrictive than necessary. The
                    other comment noted that, by reducing
                    the population involved, and
                    unacceptably high value could result.
                      The ratio of total United States
                    population to the maximum number of
                    people in the vicinity of an operating
                    reactor could be erroneously interpreted
                    so that progressively smaller
                    populations would be subject to
                    progressively larger individual risks.
                    This is not the intent of the
                    recommendations. Hence, the risk from
natural disasters, the variation in the
population-weighted natural background
r.iji.ilion dose to the total population.
anu !he variation in dose due to
ingnstion of food, have been used to
provide the basis for the Preventive
PAG The basis for the Emergency PAG
involves considerations of (1) The ratio
between average and maximum
individual radiation doses (taken as 1 to
10). (2) the cost of low and high impact
protective actions. (3) the  relative risks
from natural disasters, (4) health impact,
(5) the upper range  of the PAG's
proposed by EPA (5 rem projected
radiation dose to the whole body and 25
rem projected dose to the  thyroid),  and
(6) radiation doses  from multiple
pathways.
  11. A comment, citing experience with
other contaminants, suggested that
further consideration should be given to
the problem of marketability of foods
containing low levels of radioactivity.
  Marketability is not a concern for
PAG development.  However, the
publication of the PAG's should enhance
marketability of foods because it will
enhance public confidence in food
safety. Also, FEMA has been
specifically directed to undertake a
public information  program related to
radiation emergencies to allay public
fears and perceptions.
  12. A comment noted the difficulty in
assessing the impacts of and the
benefits to be gained from protective
actions. Another comment suggested
that there were lower impact actions
which could be implemented to keep
food off the market until radiation levels
in the food approach normal
background.
  The recommendation that planning
officials consider the impacts of
protective actions in implementing
action does not imply that a
mathematical analysis is required.
Rather, FDA intends that  the local
situation, resources, and impacts that
are important in assuring  effective
protective actions be considered in
selecting any actions to be implemented.
As discussed in paragraph 8. if the local
constraints permit a low impact action,
this can be appropriate at lower
projected doses. Because  it is not
possible in general guidance to consider
fully all local constraints, the PAG's
represent FDA's judgment as to when
protective actions are appropriate.
Agricultural and Dose Models
  13 Several comments noted errors
either in approach or calculations
regarding the proposed agricultural and
dose models, while others specifically
noted that there are newer and better

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                    Federal Register  /  Vol. 47.  No. 205  /  Friday. October 22, 1962  /  Notices
                                                                      47079
models for use in computation of the
derived response levels.
  FDA appreciates the careful review
and the suggestions as to better data
and models. The references suggested.
as well as other current reports, have
been carefully reviewed and appropriate
ones are being used as the basis for
computation of the derived response
levels for the final PAG's. The specific
models and data being used are as
follows:
  Agricultural Model—UCRU51939.1977
(Rcf.9).
  Intake per unit deposition—Table B-l.
UCRU51939 (Ref. 9).
  Peak milk activity—Equation 8. UCRL-
51939 (Ref. 9)
  Area grazed by cow—45 square meters/
djy UCRL-51938 (Ref 9).
  Initial retention on forage—0.5 fraction.
UCR1.-51939 (Ref 9)
  Fcirrfgp yield—0 25 kilogram/square meter
(dry weight). UCRL-51939 (Ref. 9).
  Milk consumption—0.7 liter/day in/anl,
ICRP-23.1974 (Ref. 10).—0.55 liter/day adult.
USDA. 1965 (Ref. 11}.
  Dose conversion factors (rem per
microcune ingested).
Imto.
Kxhna-131

CoMim 134 „









Gjsmm-137

Slmn(ium-«fl

S r^-uum-90


16

0118









0071

0194

249


Htut
16

0068









0061

0012

070



Wetman and Anger.
1971 (Ret 12)
Adun— ORNL/NURE6/
TM-1M. 1978 (Rel
13)
from aduft based on
nlatwa body ««ght
70 kilograms (kg) end
7 7 kg and anecttw
tolomwn. 102 day*
and 19 5 days, adult
Wdinlant
respacAMry
NCRP No 52. 1977
(Re* 14)
Adult. ICRP-30. 1979
(Hal 15)
Infant Papwort*) and
Ve-nan 1973 (Rat
16)
  The use of the newer agricultural
mode! (Ref 9) has resulted in a 20
prrcent increase in the iodme-131
derived response levels identified in
paragraph (d)(l) and (d)|2) of the
it'commerulations. Generally, similar
magmhiui- changes arc reflected in the
Jpnveil response levels for the other
radionuclides. Newer data on iodine-131
dose conversion factors (Ref. 17) would
have further increased the derived
response levels for that radionuchde by
about 40 percent but these data have
not been used pending their acceptance
hy United States recommending
•iiithonbes In addition, the proposal
contained a systematic error in that the
pasture derived response levels were
stated to be based on fresh weight but
were in fact based on dry weight. Fresh
weight values (X of dry weight values)
lire identified in the final
recommendations and are listed under
"Forage Concentration".

Other Comments
  14. A comment addressed the
definition of the critical or sensitive
population for the tables in proposed
S 1090.400(d) and observed that there is
a greater risk per rem to the younger age
groups than to adults. Another comment
requested further explanation of the
relative ability to protect children and
adults.
  FDA agrees that, ideally, the critical
segment of the population should be
defined in terms of the greatest risk per
unit intake. However, this would
introduce greater complexity into the
recommendations than is justified,
because the nsk estimates are uncertain.
The final recommendations provide
denved response levels for infants at the
Preventive PAG and infants and adults
for the Emergency PAG."
  FDA has reexammed the available
data and concludes that taking action at
the Preventive PAG (based on the infant
as the critical or sensitive population)
will also provide protection of the fetus
from the mother's ingestion of milk. The
definition,of newborn infant in the
tables in paragraph (d) of the PAG's has
been revised to reflect this conclusion.
  15. EPA commented that its
regulations governing drinking water [40
CFR Subchapler D) permit blending of
water to meet maximum contaminant
levels. EPA suggested that FDA's short-
term recommendations should be
compatible with the long-term EPA
regulations.
  As stated in paragraphs 1 and 2 of this
notice. FDA's recommendations apply to
human food and animal feed, whereas
EPA is responsible for providing
guidance on contaminated water. Also.
as discussed in paragraph 3 of the
proposal, there is  a long-standing FDA
policy that blending of food is unlawful
under the Federal Food, Drug, and
Cosmetic Act. Further, these guides are
intended Tor protective actions under
emergency situations and are not for
continuous exposure dppln.dtions.  For
these reasons, FDA concludes (hdt the
differences between its
recommendations and EPA's regulations
are appropriate.
  16. Two comments were received on
the adequacy or availability of
resources For sampling and analysis of
Stale, local, and Federal agencies and
the adequacy of guidance on sampling
procedures.
  These recommendations are not
designed to provide a compendium of
sampling techniques, methods, or
resources. The Department of Energy
through its Interagency Radiological
Assistance Plan (IRAP) coordinates the
provision of Federal assistance and an
Offsite Instrumentation Task Force of
the Federal Radiological Preparedness
Coordinating Committee administered
by FEMA is developing specific
guidance on instrumentation and
methods for sampling food (Ref. 21).

Cost Analysis
  17. Several comments argued that
FDA's cost/benefit analysis used to
establish the PAG levels was
inadequate. Comments stated that it is
not appropriate to assign a unique fixed
dollar value to the adverse health
effects associated with one person-ram
of dose.
  FDA advises that its cost/benefit
analysis was not conducted to establish
the PAG levels. FDA considers such use
inappropriate in part because of-the
inability to assess definitively the total"
societal impacts (positive and negative)
of such actions. Rather, the cost/benefit
analysis was used to determine whether
protective actions at the recommended
PAG's would provide a net societal
benefit To make such an assessment it
is necessary to place a dollar value on-a
person-rem of dose.
  18. Several comments also questioned
the appropriateness of the assumption in
the cost/benefit analysis of 23 days of
protective action, the need to address
radionuclides other than iodine-131, and
the need to consider the impact of other
protective actions.
  The cost assessments have been
extensively revised to consider all the
radionuclides for which derived
response levels are provided in tfie
recommendations and to incorporate
updated cost data and risk estimates
(Ref. 22). The cost/benefit analysis is
limited to the condemnation of milk and
the use of stored feed because accident
analyses indicate that the milk pathway
is the most likely to require protective
action. Further, these two actions are
the most likely protective actions that
will  be implemented.
  FDA approached the cost/benefit
analysis by calculating the
concentration of radioactivity in milk  at
which the cost of taking action  equals
the risk avoided by the action taken on
a daily milk intake basis. The
assessment was done on a population
basis and considered only the direct
costs of the protective actions. The
analysis indicates that, for restricting
feed to stored feed, the cost-equals-
benefit concentrations are about one-
fiftieth to one-eightieth of the Preventive
PAG level (deri\ed peak milk
conccnlialion) for iodine-131, cesmm-
134.  and cesium-137 and about one-third

-------
47080
Fedeial Register / Vol.  47.  No. 205 / Friday. October  22.  1982  /  Notices
 of the level for strontium-89 and
 strontium-90. For condemnation or milk.
 based on value at the farm, the cosl-
 equals-benefit concentrations are
 similar fractions of the Emergency PAG
 levels (derived peak milk
 concentration). If condemnation of milk
 is based on retail market value, the cost-
 equals-benefit concentrations are
 greater by a factor of two Thus, it
 appears that protective actions at the
 Preventive or Emergency PAC levels
 will yield a net societal benefit
 However, in the case of strontium-89
 and strontium-90, protective action will
 yield a benefit only for concentrations
 greater than about one-third the derived
 peak values. In the case of iodme-131.
 cesium-134. and cesium-137, protective
 actions could be continued to avoid 95
 percent of the projected radiation dose
 for initial peak concentrations at the
 PAC level.
 RolOfBDCM
  The following information has been placed
 on display in the Dockets Management
 Branch (HFA-305), Food and Drug
 Administration. Km. 4-62.5600 Fishers l-ane.
 Rockville. MD 20857. and may be seen
 between 9 a.m. and 4 p.m.. Monday through
 Friday.
  1 Federal Radiation Council. Memorandum
 for the President. "Radiation Protection
 Guidance for Federal Agencies." Federal
 Register. August 22.1964 (29 FR 12056). and
 Report No. 5 (July 1964).
  2 Federal Radiation Council. Memorandum
 for the President. "Radiation Protection
 Guidance for Federal Agencies." Federal
 Register." May 22.1965 (30 FR 6953). and
 Report No. 7 (May 1965).
  3 National Academy of Sciences/National
 Research Council. "The Effects on Population
 of Exposure to Low Levels of Ionizing
 Radiation." Report of the Advisory
 Committee on Biological Effects of Ionizing
 Radiation (BE1R-I11) (1980).
  4 United Slates Nuclear Regulatory
 Commission. Reactor Safety Study. WASH-
 1400. Appendix VI (October 1975).
  5 Ron. E. and B Modan, "Benign and
 Malignant Thyroid Neoplasms After
 Childhood Irradiation for Tinea Capitis."
Journal of the National Cancer Institute. Vol
 66. No. 1 duly 1980),
  6 International Commission on
 Radiological Protection (ICRP).
 Recommendations of the International
 Commission on Radiological Protection. ICRP
 Publication 26. Annals of the ICRP.  Pergamon
 Press (1977).
  7 Environmental Protection Agency.
 "Miinual of Protective Action Guides and
 Protective Actions for Nuclear Incidents."
 EPA 520/1-75-001. revised June 1980
  8 United Nations Scientific Committee on
 the Effects of Atomic Radiation, 1977 Report.
 United Nations. New York (1977)
  9 Ng. Y. C. C S. Colsher. D ] Qumn. and
S E Thompson, 'Transfer Coefficients for
 the Prediction of the Dose to Man Via the
Forage-Cow-Milk Pathway from
Radionuclides Released to the Biosphere."
                     UCRL-51939. Lawrence Livermore
                     Laboratory (July 15.1977)
                       10 International Commission on
                     Radiological Protection. Report of a Task
                     Group of Committee 2 on Reference Mdn,
                     Publication 23, p 360 Pcrgjmon Press.
                     Oxford (1974)
                       11 U T Department of Agriculture.
                     "Household F. id Consumption Survey 1965-
                     1966"
                       12 Wellman. H N  and R T Anger.
                     "Radioiodme Dosimetry and the Use of
                     Rddioiodmes Other 1 han "'I in Thyroid
                     Diagnosis." Si-minart in Nuclear Meriiune.
                     3356(1971)
                       13 Killough. C C . D E Dunning. S R
                     Bernard, and | C  Pleasant. "Estimates of
                     Internal Dose Equivalent to 22 Target Organs
                     for Radionuclidea Occurring in Routine
                     Releases from Nuclear Fuel-Cycle Facilities.
                     Vol 1." ORNL/NUREC/TM-190. Oak Ridge
                     National Laboratory (June 1978)
                       14 National Council on Radiation
                     Protection and Measurements. "Cesium-137
                     From (he Environment to Man Metabolism
                     and Dose." NCRP Report No 52. Washington
                     (January 15.1977).
                       15 International Commission on
                     Radiological Protection. Limits for Intakes of
                     Radionuclides by Workers  ICRP Publication
                     30. Part 1. Annals of the ICRP. Pergamon
                     Press (1979).
                       16 Papworth. D G.. and J Vennart.
                     "Retention of *°Sr in Human Bone at Different
                     Ages and Resulting Radiation Doses."
                     Physics in Medicine and Biology.  18169-186
                     (1973).
                       17 Kereiakes. J  G. P A Feller.  F A.
                     Ascoli. S  R Thomas. M ] Celfand. and E L
                     Saenger. "Pediatric Radiopharmaceutical
                     Dosimetry" in "Radiopharmoceutical
                     Dosimetry Symposium." April 26-29.1976.
                     HEW Publication (FDA) 76-8044 (June 1976)
                       18 National Academy of Sciences/
                     National Research Council,  'The Effects on
                     Populations of Exposure to Low Levels of
                     Ionizing Radiation." Report  of the  Advisory
                     Committee on Biological Effects of Ionizing
                     Radiation (BEIR-I) (1972).
                       19 National Council on Radiation
                     Protection and Measurements (NCRP). "Basic
                     Radiation Protection Criteria," NCRP Report
                     No 39, Washington (1971).
                       20 Bogen. K T. and A. S  Goldm.
                     "Population Exposure to External  Natural
                     Radiation Background in the United Stales.'
                     ORP/SEPD-60-12. Environmental  Protection
                     Agency. Washington, DC (April 1981).
                       21  Federal Interagency Task Force on
                     Offsite Emergency Instrumentation for
                     Nuclear Accidents. "Guidance on  Offsite
                     Emergency Radiation Measurement Systems:
                     Phase 2. Monitoring and Measurement of
                     Radionuclides to Determine Dose
                     Commitment in the Milk Pathway."
                     developed by Exxon Nuclear Idaho Co Inc.
                     Idaho Falls. ID. Draft, July 1981 (to be
                     published by FEMA).
                       22 Shleien, B. G  D  Schmidt, and R  P
                     Chiacchierini. "Background for Protective
                     Action Recommendations. Accidental
                     Radioactive Contamination of Food and
                     Animal Feeds," September 1981. Department
                     of Health and Human Services. Food and
                     Drug Administration. Bureau of Radiological
                     Health. Rockville. MD
   Pertinent background data and
 information on the recommendations are
 on file in the Dockets Management
 Branch, and copies are available from
 that office (address above).
   Based upon review of the comments
 received on the proposal of December
 15 1978 (43 FR 58790). and FDA's further
 consideration of the need to provide
 guidance to State and local agencies for
 use in emergency response planning in
 the event that an incident results in the
 radioactive contamination of human
 food or animal feed, the agency offers
 the following recommendations
 regarding protective action planning for
 human food and animal feeds:

 Accidental Radioactive Contamination
 of Human Food and Animal Feeds:
 Recommendations for State and Local
 Agencies
   (a) Applicability. (1) These
 recommendations are for use by
 appropriate State or local agencies in
 response planning and the conduct of
 radiation protection activities involving
 the production, processing, distribution,
 and use of human food and animal feeds
 in the event of an incident resulting in
 the lease of radioactivity to the
 environment. The Food and Drug
 Administration (FDA) recommends that
 this guidance be used on a case-by-case
 basis to determine the need for taking
 appropriate protective action in the
 event of a diversity of contaminating
 events, such as nuclear facility
 accidents, transportation accidents, and
 fdllout from nuclear devices.
   (2) Protective actions are appropriate
 when the health benefits associated
 with the reduction in exposure to be
 achieved are sufficient to offset the
 undesirable features of the protective
 actions  The Protective Action Guides
 (PAC's)  in paragraph (c) of these
 recommendations represent FDA's
 judgment as to the level of food
 contamination resulting from radiation
 incidents at which protective action
 should be taken to protect the public
 health Further, as provided by Federal
 guidance issued by the Federal
 Radiation Council, if, in a particular
 situation, and effective action with low
 total impact is available, initiation of
 such action at a projected dose lower
 than the PAG may be justifiable. If only
 very high-impact action would be
 effective, initiation of such action at a
 projected dose higher than the PAG may
 be justifiable. (See 29 FR 12056; August
22.1964.) A basic assumption in the
development of protective action
guidance is that a condition requiring
protective action IB unusual and should
not be expected to occur frequently.

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                    Federal  Register / Vol.  47.  No. 205  / Friday. October  22, 1982 / Notices
                                                                       47081
Circumstances that involve repetitive
occurrence, a substantial probability of
recurrence within a period of 1 or 2
years, or exposure from multiple sources
(such as airborne cloud and food
pathway) would require special
consideration. In such a case, the total
projected dose from the several evenls
and the total impact of the protective
actions that might be taken to avoid the
future dose from one or more of these
events may need to be considered. In
any event, the numerical values selected
for the PAG's are not intended to
authorize deliberate releases expected
to result  in absorbed doses of these
magnitudes.
  (3) A protective action is an action or
measure taken to avoid most of the
radiation dose that would occur from
future ingestion of foods contaminated
with radioactive materials. These
recommendations are intended for
implementation within hours or days
from the time an emergency is
recognized. The action recommended to
be taken should be continued for a
sufficient lime to avoid most of the
projected dose. Evaluation of when  to
cease a protective action should be
made on a case-by-case basis
considering the specific incident and the
food supply contaminated. In the case of
the pasture/cow/milk/person pathway.
for which derived "response levels" are
provided in paragraph (d) of these
recommendations, it is expected that
actions would not need to extend
beyond 1 or 2 months due to the
reduction of forage concentrations by
weathering (14-day half-life assumed].
In the case of fresh produce directly
contaminated by deposition from the
cloud, actions would be necessary at the
time of harvest. This guidance is not
intended to apply to the problems of
long-term food pathway contamination
where adequate time after the incident
is available to evaluate the public health
consequences of food contamination
using current recommendations and the
guidance in Federal Radiation Council
(FRC) Report No. 5, July 1964 and Report
No. 7. May 1965.
  (b) Definitions. (1) "Dose" is a general
term denoting the quantity of radiation
or energy absorbed. For special
purposes it must be appropriately
qualified. In these recommendations it
refers specifically to the term "dose
equivalent."
  (2) "Dose commitment" means the
radiation dose equivalent received by
an exposed individual to the organ cited
over a lifetime from a single event.
  (3] "Dose equivalent" is a quantity
that expresses all radiation on a
common scale for calculating the
effective absorbed dose. It is defined as
the product of the absorbed dose in rads
and certain modifying factors. The unit
of dose equivalent is the rem.
  (4) "Projected dose commitment"
means the dose commitment that would
be received in the future by individuals
in the population group from the
contaminating event if no protective
action were taken.
  (5) "Protective action" means an
action taken to avoid most of the
exposure to radiation that would occur
from future ingestion of foods
contaminated with radioactive
materials.
   (6) "Protective action guide  (PAG)"
means the projected dose commitment
values to individuals in the general
population that warrant protective
action following a release of radioactive
material. Protective action would be
warranted if the expected individual
dose reduction is not offset by negative
social, economic, or health effects. The
PAG does not include  the dose that has
unavoidably occurred before the
assessment.
   (7) "Preventive PAG" is the projected
 dose commitment value at which
 responsible officials should take
 protective actions having minimal ipact
 to prevent or reduce the radioactive
 contamination of human food or animal
 feeds.
   (8) "Emergency PAG" is the projected
 dose commitment value at which
 responsible officials should isolate food
 containing radioactivity to prevent its
 introduction into commerce and at
which the responsible officials should
determine whether condemnation or
another disposition is appropriate. At
the Emergency PAG. higher impact
actions are justified because of the
projected health hazards.
  (9) "Rad" means the unit of absorbed
dose equal to 0.01 Joule per kilogram in
any medium.
  (10) "Rem" is a special unit of dose
equivalent. The dose equivalent in rems
is numerically equal to the absorbed
dose in rads multiplied by the quality
factor, the distribution factor, and any
other necessary modifying factors.
  (11) "Response level"  means the
activity of a specific radionuclide (i)
initially deposited on pasture; or (ii) per
unit weight or volume of food or animal
feed; or (iii) in the total dietary intake
which corresponds to a  particular PAG.
   (c) Protective action guides fPAC'sJ.
To permit flexibility of action for the
reduction of radiation exposure to the
public via the food pathway due to the
occurrence of a contaminating event, the
following Preventive and Emergency
PAG's for an exposed individual in the
population are adopted:
   [I] Preventive PAG which is (i) 1.5
rem projected dose commitment to the
thyroid, or (ii) 0.5 rem projected dose
commitment to the whole body, bone
 marrow, or any other organ.
   (2) Emergency PAG which is (i) 15 rem
 projected dose commitment to the
 thyroid, or (ii) 5 rem projected dose
 commitment to the whole body, bone
 marrow, or any other organ.
   (d) Response levels equivalent to
 PAG. Although the basic  PAG
 recommendations are given in terms of
 projected dose equivalent, it is often
 more convenient to utilize specific
 radionuclide concentrations upon which
 to initiate protective action. Denved
 response levels equivalent to the PAG's
 for radionuchdes of interest are:
   (1) Response level for Preventive
 PAG. Infant' as critical segment of
 population.
   'Newborn infant Includes fetus (pregnant
 women) a§ critical icgment of population for lodine-
 131  For other radionuchdcs. "infant" refers to child
 leas than 1 year of age
Response levels tor preventive PAG
Irttal Activity Area Deposition (rnioracunes/square mam) . - ........ . ..
Forage Concentration • (rmorocunea/kitogrim) . . -.--..
Put MA Activity (meraeunas/Har) .... .....
Total intake1 (merocunes) . 	 . . . . . ..... 	

131,"
013
005
0015
009

134n«
2
08
01S
4

137o/
3
13
024
7

80%
05
016
0009
02

89*
8
3
014
2.6

    'From Mom. torJne-131 it me only nojoadme of significance with respect to milk contamination beyond the tost day In case of a reactor accident, me cumulative intake of iorjme-133 via
 mlk is about 2 percent ol iodne-131 assumng equivalent deposition.
    'Fresh mghl
    •Intake ol oasum we the meet/person padiway (or adults mrty eioeed that ol the rralk pathway: therefore, suet) levels in mlk should cause surveillance and protective actions lor meat as
 appropriate If both oa*un>l34 and cesvm-137 ate equally present as rmghl  be mpecled  lor reactor accidents, the response levels should be reduced by a lector ol  two

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47082              Federal Register / Vol. 47, No. 205  / Friday.  October  22.  1982  /  Notices	

    (2] Response level for Emergency PAG. The  response levels equivalent to the Emergency  PAG are presented fur  both
infants and adults to permit use of either level and thus assure a flexible approach to taking action in cases where exposure
of the most critical portion of the population (infants and pregnant women) can  be prevented:
Response levels lor emergency PAG
Initial Activity Area Deposition (mcrocunes/square meter)
Forage Concentration • Imcrocurtes/kilograrn)
Peak Mdk Activity (mcrocunea/Mer)
Total intake (mooounea)
13V
Infant' '\ Adull
13 16
OS 1 7
015 I 2
09 10
134C.'
Intern'
ZO
a
IS
40
Adult
40
17
3
70
•^n?
»
Adult
30 SO
13
24
70
19
4
80
90,
rntarrl'
5
ia
009
2
Adult
20
e
04
7
a*.
Infant'
ao
30
14
26
ArM
IBM
700
30
400
   •Newborn intent nekioes Mus (pregnant women) as cntieil segment of pepulatnn tor ndme-131
   '"Infant" mien to cMd less than 1 year of age
   'Rom fallout. oAna-131 • ine only radundine ol signihcince with respect to nrik conliimnauon beyond the Im day In ease ol a reactor accident the cumulative mlake ol oome-133 vii
mlk n about 2 percent ol iodne-131 assuming equrvalenl deposition
   •Fresh wagrn.
   •Make ol cesun «e the meat/person pathway lor adults may eiceed mat ol me mdk pathway rhoretoie such levels n milk should cause surveillance and protective arsons lor meat as
aperopfiaia. H both eesum 134 and eesum-137 an equally present, as might be enpected tor reactor  acoeena the response levels should be reduced by a  lacier ol 2
  (e) Implementation. When using the
PAC's and associated response levels
for response planning or protective
actions, the following conditions should
be followed:
  (1} Specific food items. To obtain the
response level (microcurie/kilogram)
equivalent to the PAG for other specific
foods, it is necessary to weigh the
contribution of the individual food to the
total dietary intake; thus.

Rpsrmnw. Level - Total intake (microcunes)
Response Level - eonsumpt,on (1.'
Where: Total intake (microcunes) for the
    appropriate PAG end radionuclide n
    given in paragraph (d) of these
    recommends tioni
      and
Consumption is the product of the average
    daily consumption specified in paragraph
    (<*)(1)(>) of these recommendations and
    the days of intake of the contaminated
    food as specified in paragraph (e)(1)(u) of
    these recommendations.

  (i) The daily consumption of specific
foods in kilograms per day for the
general population is given in the
following table:
              Food
Flour, canal  ....   .  -
Bakery products  __ - —  _—  -
Meet _ _ _	
Poultry	
Cish and shetHsn. .	
Eggs  .	 . _.	
Sugar, arupe. honey, molasses. Me .
VorjstabkM, fioeh (artrsmano potatoes)
Vegetables, earned, trcaen. dried	
Vegetables, sjoe 'angle strength)... .
FnA fresh.	-_.___	
Frutl canned, frozen, dried	. .
FruH, |uce (angle strength)	
                                  Average
                                   con-
                                  sumption
                                  for ins
                                   tioo
                                   (•*>
                                   day)
570
OSS
091
ISO
220
OSS
023
055
073
105
145
jon
008
165
035
04S
                    Food
      Other beverages (soft drinks cottee. alcoholic)
      Soup and gravies (mostly condensed)  .
      Nuls and peanut butter

            Total
                                       Average
                                         con-
                                       sumption
                                        for the
                                       general
                                         non
                                         (kilo-
                                        gram/
                                         day)
                                     180
                                     036
                                     009
                                         2099
  'Eiprassad as cataum equivalent, thai ox the quantity ot
•Kola llud mtk to when dairy products are equivalent si
calcium content.

  (ii) Assessment of the effective days
of intake should consider the specific
food, the population involved,  the food
distribution system, and the
radionuclide. Whether the food is
distributed to the retail market or
produced for home use will significantly
affect the intake in most instances.
Thus, while assessment of intake should
be on a case-by-case basis, some
general comments may be useful  in
specific circumstances.
  (a) For short half-life rudionuclides.
radioactive decay will limit the
ingestion of radioactive materials and
the effective "days of intake". The
effective "days of intake" in this case is
1.44 times the radiological half-life. For
iodine-131 (half-life—8 05 days), the
effective "days of intake" is, thus, 11
days.
  (b) Where  the food product is being
harvested on a daily basis, it may be
reasonable to assume reduction of
contamination due to weathering. As an
initial assessment, it may be appropriate
to assume a 14-day weathering half-life
(used for forage in pasture/cow/milk
pathway) pending further evaluation. In
this case, the effective "days of intake"
is 20 days. A combination of radioactive
decay and weathering would result in
an effective half-life for iodine-131 of 5
days and reduce the "days of intake" to
7 days.
  (c) In the case of a food which is sold
in the retail market, the effective "days
 of intake" would probably be limited by
 the quantity purchased at a given time.
 For most food, especially fresh produce.
 this would probably be about a 1 week
 supply. In some cases, however, larger
 quantities would be purchased for home
 canning or freezing. For most foods and
 members of the public, an effective
 "days of intake" 30 days is probably
 conservative.
   (ni) For population groups having
 significantly different dietary intakes, an
 appropriate adjustment of dietary
 factors should be made.
   (2) Radionuclide mixtures. If a
 mixture of radionuchdes is present, the
 sum of all the ratios of the concentration
 of each specific radionulide to its
 specific response level equivalent to the
 PAG should be less than one.
   (3) Other radionuclides. The response
 level for the Preventive and Emergency
 PAG for other radionuclides should be
 calculated from dose commitment
 factors available in the literature
 (Killough. G. G, et al., ORNL/NUREG/
-TM-190 (1078) [adult only), and U.S.
 Nuclear Regulatory Commission Reg.
 Guide 1.109 (1077)).
   (4) Other critical organs. Dose
 commitment factors in U.S. Nuclear
 Regulatory Commission Reg. Guide 1.169
 (1977) refer to bone rather than bone
 marrow dose commitments. For the
 purpose of these recommendations, dose
 commitment to the bone marrow is
 considered to be 0.3 of the bone dose
 commitment. This is based on the ratio
 of dose rate per unit activity in the bone
 marrow to dose rale per unit activity  in
 a small tissue-filled cavity in bone and
 assumes that strontium-90 is distributed
 only in the mineral bone (Spiers. F. W.,
 et al.. in "Biomedical Implications of
 Radiostrontium Exposure," AEC
 Symposium 25 (1972). The ratio for
 strontium-69 is the same because the
 mean particle energies are similar (0.56
 MeV (megaelectronvolts)). Situations
 could arise in which an organ other than
 those discussed in this paragraph could

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                   Federal Register / Vol.  47. No. 205 / Friday.  October 22. 1982 / Notices
                                                                      47083
be considered to be the organ receiving
the highest dose per unit intake. In the
case of exposure via the food chain.
depending on the radionuclide under
consideration, the gastrointestinal tract
could be the primary organ exposed.
The references cited in paragraph (e)(3)
of these recommendations contain dose
commitment factors for the following
organs: bone, kidneys, liver, ovaries.
spleen, whole body, and gastrointestinal
tract.
  (5) Prompt notification of State and
local agencies regarding the occurrence
of an incident having potential public
health consequences is of significant
value in the implementation of effective
protective actions. Such notification is
particularly important for protective
actions to prevent exposures from the
airborne cloud but is also of value for
food pathway contamination.
Accordingly, this protective action
guidance should be incorporated in
State/local emergency plans which
provide for coordination with nuclear
facility operators including prompt
notification of accidents and technical
communication regarding public health
consequences and protective action.
   (f) Sampling parameter. Generally.
sites for sample collection should be the
retail market, the processing plant and
the farm. Sample collection at the milk
processing plant may be more effcient in
determining the extent of the food
pathway contamination. The geographic
area where protective actions are
implemented should be based on
considerations  of the wind direction and
atmospheric transport, measurements by
airborne and ground survey teams of the
radioactive cloud and surface
deposition, and measurements in the
food pathway.
   (g) Recommended methods of
analysis. Techniques for measurement
of radionuclide concentrations should
have detection limits equal to or less
than the response levels equivalent to
 specific PAG. Some useful methods of
 radionuclide analysis can be found in:
   (1) Laboratory Methods—"HASL
 Procedure Manual." edited by John H.
 Harley. HASL  300 ERDA. Health and
 Safety Laboratory, New York. NY. 1973:
 "Rapid Methods for Estimating Fission
 Product Concentrations in Milk." U.S.
 Department of Health. Education, and
 Welfare. Public Health Service
 Publication No. 999-R-2. May 1963;
 "Evaluation of Ion Exchange Cartridges
 for Field Sampling of lodine-131 in
 Milk." Johnson. R. H. and T. C. Reavy.
 Nature. 208. (5012): 750-752. November
 20.1965; and
   (2) Field Methods—Kearny. C. H..
 ORNL 4900, November 1973; Distenfeld,
 C. and J. Klemish. Brookhaven National
  Laboratory. NUREG/CR-0315.
December 1978; and International
Atomic Energy Agency, "Environmental
Monitoring in Emergency Situations."
1966. Analysis need not be limited to
these methodologies but should provide
comparable results. Action should not
be taken without verification of the
analysis. Such verification might include
the analysis of duplicate samples.
laboratory measurements, sample
analysis by other agencies, sample
analysis of various environmental
media, and descriptive data on
radioactive release.
  (h) Protective actions. Actions are
appropriate when the health benefit
associated with the reduction in dose
that can be achieved is considered to
offset the undesirable  health, economic.
and social factors. It is the intent of
these recommendations that, not only
the protective actions  cited for the
Emergency PAG be initiated when the
equivalent response levels are reached,
but also that actions appropriate at the
Preventive PAG be considered. This has
the effect of reducing the period of time
required dunng which the protective
action with the greater economic and
social  impact needs to be taken. FDA
recommends that once one or more
protective actions are initiated, the
action or actions continue for a
sufficient time to avoid most of the
projected dose. There is a longstanding
FDA policy that the purposeful blending
of adulterated food with unadulterated
food is a violation of the Federal Food.
Drug, and Cosmetic Act. The following
protective actions should be considered
for implementation when the projected
dose equals or  exceeds the appropriate
PAG:
   (1) Preventive PAG. (i) For pasture: (a)
Removal of lactating dairy cows from
contaminated pasturage and
substitution of  uncontaminated stored
feed.
   (£>) Substitute source of
uncontaminated water.
   (ii) For milk:  (a) Withholding of
contaminated milk from the market to
allow  radioactive decay of short-lived
radionuclides. This may be achieved by
 storage of frozen fresh milk, frozen
concentrated milk, or frozen
concentrated milk products.
   (b) Storage for prolonged times at
reduced temperatures also is feasible
 provided ultrahigh temperature
 pasteurization  techniques are employed
 for processing  (Finley. R. D.. H. B.
 Warren, and R. E. Hargrove. "Storage
 Stability of Commercial Milk." Journal
 of Milk and Food Technology.
 3l(12):382-387. December 1968).
    (c)  Diversion of fluid milk for
 production of dry whole milk, nonfat dry
milk, butter, cheese, or evaporated milk.
  [iii] For fruits and vegetables: (a)
Washing, brushing, scrubbing, or peeling
to remove surface contamination.
  [b) Preservation by canning, freezing,
and dehydration or storage to permit
radioactive decay of short-lived
radionuclides.
  (iv) For grains: (a Milling and (6)
polishing.
  (v) For other food products, processing
to remove surface contamination.
  (vi) For meat and  meat products,
intake of cesium-134 and cesium-137 by
an adult via the meat pathway may
exceed that of the milk pathway;
therefore, levels of cesium in milk
approaching the "response level" should
cause surveillance and protective
actions for meat as appropriate.
  (vii) For animal feeds other than
pasture, action should be on a case-by-
case basis taking into consideration the
relationship between the radionuclide
concentration in the animal feed and the
concentration of the radionuclide in
human food. For hay and silage fed to
lactating cows, the concentration should
not exceed that equivalent to the
recommendations for pasture.
  (2) Emergency PAG. Responsible
officials should isolate food containing
radioactivity to prevent its introduction
into commerce and  determine whether
condemnation or another disposition is
appropriate. Before taking this action,
the following factors should be
considered:
  (i) The availability of other possible
protective actions discussed in
paragraph (h)(l) of these
recommendations.
  (ii) Relative proportion of the total
diet by weight represented by  the item
in question.
  (iii) The importance of the particular
food in nutrition and the availability of
uncontaminated food or substitutes
having the same nutntional properties.
  (iv) The relative contribution of other
foods and other radionuclides  to the
total projected dose.
  (v) The time and effort required to
effect corrective action.
  This notice is issued under the Public
Health Service Act (sees. 301.310.311.
58 Stat. 691-693 as amended. 88 Slat.  371
(42 U.S.C. 241,242o. 243]) and under
 authority delegated to the Commissioner
 of Food and Drugs (21CFR 5.10).

   Dated. October 11.1982.
  Arthur Hull Hayes. Jr.,
  Commissioner of Food and Drugs
  |FR Doe B2-2B5U Filed 10-21-82 845am|
  BILLING CODE 4160-01-H

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                                                               Draft

                                  CHAPTER 4

             Protective Action Guides for the Intermediate Phase
                      (Deposited Radioactive Materials)
4.1  Introduction

     Following a nuclear incident it may be necessary to  temporarily
relocate the public from areas where extensive deposition of  radioactive
materials has occurred until decontamination has taken place.  This chapter
identifies the levels of radiation exposure which  indicate when  relocation
from contaminated property  is warranted.

     The period addressed by this chapter is denoted the  "intermediate
phase."  This is arbitrarily defined as the period beginning  after the
source and releases have been brought under control and environmental
measurements are available  for use as a basis for  decisions on protective
actions and extending until these protective actions are  terminated.  This
phase may overlap the early and late phases and may last  from weeks to  many
months.  For the purpose of dose projection, it is assumed to last for  one
year.  Prior to this period protective actions will nave  been taken based
upon the PAGs for the early phase.  It is assumed  that decisions will be
made during the intermediate phase concerning whether particular areas  or
properties from which persons have been relocated  will be decontaminated and
reoccupied, or condemned and the occupants permanently relocated.  These
actions will be carried out during the late or "recovery" phase.

     Although these Protective Action Guides (PAGs) were  developed based on
expected releases of radioactive materials characteristic of  reactor
incidents, they may be applied to any type of incident that can  result  in
long-term exposure of the public to deposited radioactivity.
                                     4-1

-------
     PAGs are expressed in terms of the projected doses  above which  specified
protective actions are warranted.  In the case of deposited  radioactivity,  the
major relevant protective action is relocation.  Persons  not relocated  (i.e.,
those in less contaminated areas) may reduce their dose  through  the  applica-
tion of simple decontamination techniques and by spending more time  than  usual
in low exposure rate areas (e.g., indoors).

     The PAGs should be considered mandatory only for  use in planning,  e.g.,
in developing radiological emergency response plans.   During an  incident,
because of unanticipated local conditions and constraints, professional
judgment by responsible officials will be required in  their  application.
Situations can be envisaged, where contamination from  a  nuclear  incident
occurs at a site or time in which relocation of the public,  based  on  the
recommended PAGs, would be impracticable.  Conversely, under some  conditions,
relocation may be quite practicable at projected doses below the PAGs.  These
situations require judgments by those responsible for  protective action
decisions at the time of the incident.  A discussion of  the  implementation  of
these PAGs is provided in Chapter 7.

     The PAGs for relocation specified in this chapter refer only  to  estimates
of doses due to exposure during the first year after the  incident.   Exposure
pathways include external exposure to radiation from deposited radioactivity
and inhalation of resuspended radioactive materials.   Protective Action Guides
for ingestion exposure pathways, which also apply during  the intermediate
phase, are discussed separately in Chapter 3.

     Individuals who live in areas contaminated by long-lived radionuclides
may be exposed to radiation from these materials, at a decreasing  rate, over
the entire time that they live in the area.  This would  be the case  for those
who are not relocated as well as for persons who return  following  relocation.
Because it is usually not practicable, at the time of  a  decision to  relocate,
to calculate the doses that might be incurred from exposure  beyond one year,
and because different protective actions may be appropriate  over such longer
periods of time, these doses are not included in the dose specified  in  the
PAGs for relocation.
                                     4-2

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4.1.1  Exposure Pathways

     The principal pathways for exposure of the public occupying  locations
contaminated by deposited radioactivity are expected to be exposure  of  the
whole body to external gamma radiation from deposited radioactive materials
(groundshine) and internal exposure from the inhalation of resuspended
materials.  For reactor incidents, external gamma radiation  is  expected  to be
the dominant source.

     Almost invariably relocation decisions will be based on  doses from the
above pathways.  (However, in rare cases where food or drinking water is
contaminated to levels above the PAG for ingestion, and its  withdrawal  from
use will create a risk from starvation greater than that from the radiation
dose, the dose from ingestion should be added to the dose from  the above
pathways.)  PAGs related specifically to the withdrawal of contaminated  food
and water from use are discussed in Chapter 3.

     Other potentially significant exposure pathways include  exposure to  beta
radiation from surface contamination and direct ingestion of  contaminated
soil.  These pathways are not expected to be controlling for  reactor incidents
(AR-89).

4.1.2  The Population Affected

     The PAGs for relocation are intended for use in establishing the boundary
of a restricted zone within an area that has been subjected  to  deposition of
radioactive materials.  During their development, consideration was  given to
the higher risk of effects on health to children and fetuses  from radiation
dose and the higher risk to some other population groups from relocation. To
avoid the complexity of implementing separate PAGs for individual members of
the population, the relocation PAG is established at a level  that will  provide
adequate protection for the general population.

     Persons residing in contaminated areas outside the restricted zone will
be at some risk from radiation dose.  Therefore, guidance on  the  reduction of
                                     4-3

-------
dose during the first year to  residents  outside  this  zone  is  also  provided.
Due to the high cost of relocation,  it  is  more practical  to  reduce dose in
this population group by the early  application of  simple,  low-impact,
protective actions other than  by  relocation.

4.2  The Protective Action Guides for Deposited  Radioactivity

     PAGs for protection from  deposited  radioactivity during  the
intermediate phase are summarized in Table 4-1.  The  basis for  these  values
is presented in detail in Appendix  E.   In  summary,  relocation is warranted
when the projected sum of the  dose  equivalent from  external gamma  radiation
and the committed effective dose  equivalent from inhalation of  resuspended
radionuclides exceeds 2 rem in the  first year.   Relocation to avoid exposure
of the skin to beta radiation  is  warranted at 50 times  the numerical  value
of the relocation PAG for effective dose equivalent.

     Persons who are not relocated,  i.e.,  those  in  areas  that receive
relatively small amounts of deposited radioactive material, should reduce
their exposure by the application of other measures.   Possible  dose
reduction techniques range from the simple processes  of scrubbing  and/or
flushing surfaces, soaking or  plowing of soil, removal  and disposal of  small
spots of soil found to be highly  contaminated (e.g.,  from  settlement  of
water), and spending more time than usual  in lower  exposure rate areas
(e.g., indoors), to the difficult and time-consuming  processes  of  removal,
disposal, and replacement of contaminated  surfaces.   It is anticipated  that
simple processes will be most  appropriate  for early application.   Many  can
be carried out by residents themselves with support from  response  officials
for assessment of the levels of contamination, guidance on appropriate
actions, and disposal of contaminated materials.   Due to  the  relatively low
cost and risk associated with  these protective actions, they  may be
justified as ALARA measures at low  dose  levels.  It is, however, recommended
that response officials concentrate their  initial efforts  in  areas where the
projected dose from the first  year  of exposure exceeds 0.5 rem.  In
addition, first priority should be  given to cleanup of  residences  of
pregnant women who may exceed  this  criterion.
                                     4-4

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Table 4-1  Protective Action Guides for Exposure to Deposited Radioactivity
           During the Intermediate Phase of a Nuclear  Incident
Protective
Action
PAG (projected
dose)3
Comments
Relocate the general       >2 rem     Beta dose to skin may be up to
population.&                          50 times higher.

Apply simple dose          <2 rem     These protective actions
reduction techniques.0                should be taken to  reduce doses
                                      to as low as practicable levels.
a The projected sum of effective dose equivalent from external  gamma
  radiation and committed effective dose equivalent from  inhalation of
  resuspended materials, from exposure or  intake during the  first
  year.  Projected dose refers to the dose that would be  received  in
  the absence of shielding from structures or the  application  of dose
  reduction techniques.  These PAGs may not provide adequate protection
  from some long-lived radionuclides (see  Section  4.2.1).

b Persons previously evacuated from areas  outside  the relocation zone
  defined by this PAG may return to occupy their residences.   Cases
  involving relocation of persons at high  risk from such  action (e.g.,
  patients under intensive care) should be evaluated individually.

c Simple dose reduction techniques include scrubbing and/or  flushing
  hard surfaces, soaking or plowing soil,  minor removal of soil from
  spots where radioactive materials have concentrated, and spending
  more time than usual indoors or in other low exposure rate areas.
4.2.1  Longer Term Objectives of the Protective Action Guides


     It is an objective of these PAGs to assure that 1) doses  in  any  single
year after the first will not exceed 0.5 rem,  and 2) the  cumulative dose

over 50 years (including the first and second  years) will  not  exceed  5  rem.

For source terms from reactor incidents, the above PAG of  2  rem projected

dose in the first year is expected to meet both of those  objectives through
                                     4-5

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radioactive decay, weathering, and normal part time occupancy  in structures.
Decontamination of areas outside the restricted area may be  required  during
the first year to meet these objectives for releases consisting primarily of
long-lived radionuclides.  For situations where it is  impractical to  meet
these objectives though decontamination, consideration should  be given  to
relocation at a lower projected first year dose than that specified by  the
relocation PAG.

     After the population has been protected in accordance with the PAGs for
relocation, return for occupancy of previously restricted areas should  be
governed on the basis of Recovery Criteria as presented in Chapter 8.

     Projected dose considers exposure rate reduction from radioactive  decay
and, generally, weathering.  When one also considers the anticipated  effects
of shielding from partial occupancy in homes and other structures, persons
who are not relocated should receive a dose substantially less than the
projected dose.  For commonly assumed reactor source terms,  we estimate that
2 rem projected dose in the first year will be reduced to about 1.2 rem by
this factor.  The application of simple decontamination techniques shortly
after the incident can be assumed to provide a further 30 percent or  more
reduction, so that the maximum first year dose to persons who  are not
relocated is expected to be less than one rem.  Taking account of decay
rates assumed to be associated with releases from nuclear power plant
incidents (SN-82) and shielding from partial occupancy and weathering,  a
projected dose of 2 rem in the first year is likely to amount  to an actual
dose of 0.5 rem or less in the second year and 5 rem or less  in 50 years.
The application of simple dose reduction techniques would reduce these  doses
further.  Results of calculations supporting these projections are
summarized in Table E-6 of Appendix E.

4.2.2  Applying the Protective Action Guides for Relocation

     Establishing the boundary of a restricted zone may result in three
different types of actions:
                                     4-6

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     I. Persons who, based on the PAGs for the early phase of a  nuclear
        incident (Chapter 2), have already been evacuated from  an  area which
        is now designated as a restricted zone must be converted to
        relocation status.

     2. Persons not previously evacuated who  reside inside the  restricted
        zone should relocate.

     3. Persons who normally reside outside the restricted zone, but  were
        previously evacuated, may return.  A  gradual return  is  recommended,
        as discussed in Chapter 7.

     Small adjustments to the boundary of the restricted zone from that
given by the PAG may be justified on the basis of difficulty or  ease  of
implementation.  For example, the use of a convenient natural boundary could
be cause for adjustment of the restricted zone.  However, such  decisions
should be supported by demonstration that exposure rates to  persons not
relocated can be promptly reduced by methods  other than relocation to meet
the PAG, as well as the longer term dose objectives addressed in Section
4.2.1.

     Reactor incidents involving releases of  major portions  of  the core
inventory under adverse atmospheric conditions can be postulated for  which
large areas would have to be restricted under these PAGs.  As the  affected
land area increases, they will become more difficult and costly  to
implement, especially in densely populated areas.  For situations  where
implementation becomes impracticable or impossible (e.g., a  large  city),
informed judgment must be exercised to assure priority of protection  for
individuals in areas having the highest exposure rates.  In  such situations,
the first priority for any area should be to  reduce dose to  pregnant  women.

4.3  Exposure Limits for Persons Reentering the Restricted Zone

     Individuals who are permitted to reenter a restricted zone  to work, or
for other justified reasons, will require protection from radiation.  Such
                                     4-7

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individuals should enter the restricted zone under controlled conditions in
accordance with dose limitations and other procedures for control of
occupationally-exposed workers (EP-87).  Ongoing doses received by these
individuals from living in a contaminated area outside the restricted zone
need not be included as part of this dose limitation applicable to workers.
In addition, dose received previously from the plume and associated
groundshine, during the early phase of the nuclear incident, need not be
considered.
                                 References


AR-89    AABERG, ROSANNE, Battelle Northwest Laboratories. Evaluation of
         Skin and Ingestion Exposure Pathways. U.S. Environmental Protection
         Agency/Office of Radiation Programs, Washington, D.C.  20460 (1988
         Draft).

EP-87    U.S. ENVIRONMENTAL PROTECTION AGENCY.  Radiation Protection
         Guidance to Federal Agencies for Occupational Exposure.  Federal
         Register.  Vol. 52, No. 17, Page 2822, U.S. Government Printing
         Office, Washington, DC  20402, January 1987.

SN-82    SANDIA NATIONAL LABORATORY.  Technical Guidance for Siting Criteria
         Development.  NUREG/CR-2239.  U.S. Nuclear Regulatory Commission,
         Washington, DC  20555, 1982.
                                     4-8

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                       CHAPTER  5
       Implementing the Protective Action Guides
                 for  the  Early Phase*
       (Application of  Protective Action  Guides
    for Exposure to Airborne Radioactive  Materials
    from  an  Accident at  a  Nuclear Power Facility)
5.0  Introduction
     This chapter deals with methods for estimating population dose
from plume exposure baaed on release rates and meteorological
conditions or based on offsite radiological measurements.   It  also
provides guidance for comparison of projected dose with PAGs for
decisions on protective actions.  These dose projection methods are
recommended for use by State and local officials for development  of
operational plans for responding to incidents at nuclear power
facilities.
     Following a radiological incident involving an atmospheric
release that may require protection of the public, State authorities
will need information to make decisions on what protective  actions
to implement and where they should be implemented.  The information
needed includes (1) Protective Action Guides adjusted for  local
situations and (2) projected doses in specific areas for comparison
to the Guides.  Protective Action Guides were provided  in
Chapter 2.  Projected doses must be determined on the basis of data
available following the incident.  These data may come  from
(1) plant conditions, (2) release rates and meteorological
conditions, or (3) offsite radiological measurements, or
combinations thereof.
 This Chapter  appears here  in  the form it was published in 1980;
 a revised  version is currently  under review.
                                                         Revised 6/79
                           5.1

-------
     The methods presented in  tola  Chapter  for  relating data at the



time of the incident to projected dose are  recommended  for  use  in



development of operational response plans for atmospheric  releases



at nuclear power facilities.



     Planners are encouraged to improve on  the  methods  where



possible and to alter them as  necessary to  respond  to special



circumstances.  State planners should specifically  consider the use



of any improved dose projection methods developed by the nuclear



facility operator.



5.1  Release Assumptions



     The guidance in this Chapter is directly related to releases to



the atmosphere that have been  postulated for nuclear power



facilities.  WASH-1UOO m indicates that should there  be an



accident at a nuclear power station, there  is an extremely  wide



spectrum of different kinds of possible releases to the atmosphere



and different time frames for  releases depending on the severity and



the exact sequence of the failure modes.



     A nuclear power reactor may suffer a loss  of coolant  but



without a meltdown of the reactor core.  For this class of  accident,



the release to the atmosphere  should be mostly  radioactive  noble



gases and iodines.  Accidents  of increasingly larger environmental



impact would occur in association with a meltdown of the reactor



core and eventual loss of containment integrity.  This  class of
                                                          Revised 6/79



                                5.2

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accident could release quantities of radioactive  participate



material aa well as the radioactive noble gases and  iodines.



However, for planning purposes, it La reoonmended  that  radioiodines



be assumed to represent the principal contributor  to inhalation



dose, and for situations where whole body dose from  the  plume would



be the controlling exposure pathway, it should be  assumed that noble



gases would be the principal contributors.



     Guidance on time frames for releases cannot be  very specific



because of the wide range of time frames that could  be  associated



with the potential spectrum of accidents that could  occur.



Therefore, it will be necessary for planners to consider the



possible different tlae periods between the initiating  event and



arrival of the plume and possible tine periods of  releases  in



relationship to time needed to implement protective  actions.  The



Reactor Safety Study indicates, for example, that  major  releases may



begin in the range of one-half hour to as ouch as  30 hours  after an



initiating event and that the duration of the releases  may  range



from one-half hour to several days with the major  portion of the



release occurring within the first day.  In addition, significant



plume travel times are associated with the moat adverse



meteorological conditions that might result in Large potential



exposures far from the site.  For example, under poor dispersion



conditions associated with low windspeeds, two hours or  more might
                                                          Revised 6/79




                                 5.3

-------
be required for the plume to travel a distance  of five  nilea.
Higher wlndspeeds would result in shorter  travel  times  but  would
provide more dispersion, Baking high exposures  at long  distances
much less likely.  Additional Information  on tloe frames  for
releases may be found in Reference (T).
5.1.1  Radioactive Noble Gas and Radioiodine Releases
     For an atmospheric release at a nuclear power  facility that
involved only noble gases and radioiodines, it  would usually be
conservative to assume that 100 percent of the  equilibrium  noble  gas
inventory and 25 percent of the equilibrium radioiodine inventory
would be available for release from containment.   In the  absence  of
more accurate information from the facility operator regarding the
release composition, it should be assumed  that  this composition is
released to the environment.  The relative abundance of radioiodines
and noble gases in an actual release from  containment would be a
function of the effectiveness of engineered safeguards  (e.g.,
filters, spray systems, and scrubbing systems)  in removing  each
component.
    1Thla assumption is in agreement with NRC guidance  (2,5,6)  on
assumptions that may be used in evaluating the  radiological ~
consequences of a loss of coolant accident at a light water cooled
nuclear power facility.
                                                          Revised  6/79
                                5.4

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     Table 3.1 of Appendix D summarizes the total quantities of
radiologies11y significant gaseous radionuclides that would be in
inventory under equilibrium conditions for a  1000 Mie plant.
Calculations of the projected population dose based on a release
mixture consisting of 1001 of the noble gases and 25% of the
radioiodines indicate that the thyroid dose from inhalation of
radioiodine ranges up to UOO times greater than the whole body gamma
dose from noble gaaea and radioiodines.  However, if the engineered
safeguards function as designed, they should reduce the iodine
concentration such that the whole body gamma radiation exposure from
noble gases would be the controlling pathway.
5.1.2  Radioactive Particulate Material Releases
     Except for the most severe and improbable accidents postulated
by VA5H-1400, protective actions (prophylaxis iodine excepted)
chosen on the basis of assuming the iodine exposure pathway is
critical (figure 5.2) should be sufficient to provide protection
from radioactive particular material.  This partlculate material
will deliver an additional dose to the lung and to the whole body
from material located in the lung.  However, it is not anticipated
that lung exposure would represent the controlling exposure pathway
for accidents at nuclear power facilities.
5.2  Sequence of Events
     Following an incident at a nuclear power facility involving a
release to the atmoaphere, the most urgent protective actions in
terms of response time will be those needed to protect the

                                                         Revised 6/79
                                5.5

-------
population from inhalation of radioactive  materials  in the  plume and
from direct whole body exposure  to gaooa radiation from the plume.
The time of exposure to the plume can be divided  into  two periods;
(1) the period immediately following the incident when  little  or  no
environmental data are available to confirm the seriousness  of
population exposures, and (2) a period when environmental levels
and/or concentrations are known.  During the first period,  speed  for
completing such actions as evacuation, seeking shelter,  and  access
control may be critical to minimize exposure in areas where  PAGs  are
postulated to be exceeded.  Furthermore, environmental  measurements
made during this period may have little meaning because of
uncertainty concerning plume location when measurements were made or
uncertainty concerning changes in release  rate due to changes  in
pressure and radionuclide concentrations within containment.
Therefore, it would generally be advisable to initiate  early
predetermined protective actions on the basis of dose projections
provided by the facility operator.  During the second period when
environmental levels are known, these actions can be adjusted  as
appropriate.
     For accidents involving a release to  the atmosphere at  a
nuclear power facility, the following sequence of events is
suggested to minimize population exposure.
                                                          Revised  6/79
                                5.6

-------
     (1)  Notification by the facility operators that an incident



          has occurred with potential to cause offsita projected



          doses that exceed the PAGa.  This notification should be



          provided as soon as possible following the incident and



          prior to the release if possible.



     (2)  Immediate evacuation or shelter of populations in



          pradesignated areas without waiting for confirming release



          rate measurements or environmental radiation measurements.



     (3)  Monitor gamna exposure rates (and iodine concentrations if



          possible) in the environment.  The facility operator



          should monitor release rates and plant conditions.



     (1)  Calculate plume centerline exposure rate at various



          distances downwind from the release point, or use prepared



          isopleths to estimate exposure rates in downwind areas.



     (5)  Use exposure rates, airborne concentrations, and estimated



          exposure duration to convert to projected dose.



     (6)  Compare projected dose to PAGa and adjust areas for



          protective actions as Indicated.



     (7)  Continue to make adjustments as more data become available.



5.2.1  Accident Notification



     The first Indication that a nuclear accident has occurred



should come to State authorities from the facility operator.  The



notification from a nuclear power facility to the State and local
                                                          Revised  6/79



                                5.7

-------
response organizations  should  include  an  estimate of the projected



dose  to the population  at  the  site  boundary and at oore distant



locations along with estimated time frames.   The State emergency



response planners should make  arrangements  with the facility



operator to assure  this information will  be made available on a



timely basis  (within 1/2 hour  or  less  following the incident and



prior to the  start  of the  release)  and  that it  will be provided in



units that can be compared  to  PAGs  (i.e., projected dose in rem to



the whole body or thyroid).



5.2.2  Immediate Actions



     The Planning Basis (T) recommends  that States designate an



Emergency Planning  Zone (EPZ)  for protective actions for plume



exposure out  to about 10 miles from a  nuclear power facility.



Within this distance it may also be practical to plan an area for



immediate response  prior to the availability of information for



making dose projections.  This could be a circular area described by



a designated  radial distance from the  facility.   Actions would be



taken •within  approximately a 90 degree  sector downwind out to the



designated distance based on notification from  the facility operator



that plant conditions exist which present a  potential for offsite



doses in excess of  the PAGs.   The remaining  area out to the EPZ



would be placed on alert pending more  information.   When additional



information or forecasts on wind direction  and  meteorology became



available, decisions could be  made  on  additional areas for










                                                          Revised 6/79



                                5.8

-------
protective actions.  With good meteorological and  wind  direction
information, it might be possible  to reduce the width of  the  sector
for protective actions.  However,  if wind direction  is  variable or
if the start of the release Is delayed, or if the  release  duration
is long, the width of the sector may increase or possibly  extend  to
a complete circle.  The importance of good information  and forecasts
on wind direction cannot be overemphasized.
     The designated distance for immediate actions would be used
only in situations where the facility operator could not estimate
offsite projected doses.  If the facility operator provides
projections of population dose, then these should  be used  by  the
State to determine the downwind distance for immediate  action in
lieu of the predesignated distance.  The outer edge  of  the low
population zone is a suggested radial distance for immediate  actions
in the absence of reasons for other distances.
5.3  Establishment of Exposure Rate Patterns
     During or following initial actions to protect  the close-in
population, environmental exposure rate measurements should be made
to provide a data base for projecting dose and for Devaluating the
need for additional protective actions or termination of  those
actions already taken.  Planning guidance for the  collection  of
these data is provided in Appendix A.  (Note:  Appendix A  is  still
under development.  Reference (£)  will form the basis for  Appendix  A
and is recommended as an alternate source of information.)
                                                          Revised  6/79
                                 5.9

-------
     After obtaining exposure rates or concentrations at selected
locations in the environment, these must be translated to additional
locations to identify the pattern of the exposed area.  Exposure
rate patterns based on a few downwind measurements can be estimated
in a variety of ways.  One simple way is to measure plume centerline
exposure rate  at ground level at some known distance from the
release point and use these data to calculate exposure rates at
other designated distances downwind by assuming that the cloud
centerline exposure rate is inversely proportional to the distance
from the release point.
     The following relationship can be used for this calculation:
             -.ft!
Where:  D  = exposure rate measured at distance R.
        D. = exposure rate at distance R.
         x : rate of diffusion as a function of distance.
This relationship can be used to develop a crude pattern of
estimated exposure rates by assuming that x = 1.5 and that the
    2The centerline exposure rate can be determined by traversing
the plume at a point sufficiently far downwind (usually greater than
one mile from the site) while taking continuous exposure rate
measurements.  The highest reading should be at the center line of
the plume.
                                                         Revised 6/79
                               5.10

-------
exposure rate calculated for  the  plume  centerline would also exist

at points equidistant from the  source in  the general downwind

direction.   To use this method,  one must  be sure that the

exposure rate measurement is  taken at or  near  the plume centerline.

     A second and easier method for estimating exposure rate

patterns is to use a series of  prepared exposure  rate isopleths

(maps with lines connecting points of equal exposure rates)  plotted

on transparencies.  These isopleth plots  are frequently available

from the licensee, thus eliminating the need for  the State  to

develop them.  Since both the meteorological stability class and the

windspeed existing at the time  of the release  affect the shape of

the exposure rate isopleth curves, several sets of curves would  be

needed to represent the variety of stability conditions and

windspeeds likely to exist at that site.   The  appropriate

transparency can be selected  on the basis  of windspeed and

meteorological conditions at  the  time of  the incident.  The

transparency can then be placed over a  map of  the area that has  the

same scale as the isopleth curves sucn  that the curves are  properly

oriented with regard to wind  direction.   The  isopleth curves are
    3The value of  1.5  for  x  is  for  average  meteorological
conditions.  If  the meteorological  stability  condition is known, it
would be more accurate  to  use x =  2 for  stability classes A and B;
x = 1.5 for classes C  and  D; and x  = 1  for  classes E and F.
                                                          Revised 6/79

                                5.11

-------
used to estimate exposure rate  by  plotting  the  exposure  rates known
at specific locations on the curves.  Exposure  rates  at  other
locations are simple multiples  of  the known exposure  rates  as
indicated by the multipliers associated with each  curve.
     A third alternative for determining exposure  rate patterns  is
to obtain gamma exposure rate measurements  at a large number  of
locations and plot these data on a map of the area.   This method
would provide the most accurate data but would  require a large
number of radiation instruments and trained persons to make the
measurements as well as a method for communicating the data to the
control center on a continuing  basis.  This method is primarily
recommended for developing information for  determining the  need  to
revise previous protective action  recommendations.  Protective
actions for plume exposure should  be taken  prior to plume arrival,
if possible.
5.H  Dose Projection
     The projected dose (or dose commitment in  the case  of  inhaled
radionuclides) should be calculated only for the early phase  of  an
emergency.  Early phase includes the duration of the  plume  exposure
for Inhalation PAG3 and up to 2 to U days following the  accident for
whole body exposure.  Exposures that may have occurred before the
dose projection is made are not normally to be  used for  evaluating
the need for protective actions.   Radiation doses  that might  be
                                                          Revised 6/79
                               5.12

-------
received at later times following an accident  alao  should not  be



included within the projected dose for  this  guidance.   These  latter



doses, which nay be from reentry operations, food pathways, or long



tern groundshine are committed over a longer tiae period  and will



require different kinds of protective actions.  Therefore,  they will



require separate guidance recommendations  to be addressed in



subsequent chapters.



     The best method for early determination of the  need  for



protective actions immediately following an  incident and  prior to



the start of the release is for the facility operator to  estimate



potential offsite dose based on information  in the  control  room



using relationships developed during the planning stage that  relate



abnormal plant conditions and meteorological conditions to  potential



offsite doses.  After the release starts and the release  rate  is



measurable and when plant conditions or instrumentation can be used



to estimate the characteristics of the  release and  release  rate as a



function of time, then these factors, along with meteorological



conditions and windspeed and direction, can  be used  with  techniques



presented here to estimate projected dose.   Projected dose  can also



be determined on the basis of environmental measurements  when  these



are available.  Procedures are provided herein to use either  release



rates or environmental measurements to  project dose.   Supporting



documentation for the procedures is provided in Appendix  D.
                                                          Revised  6/79



                               5.13

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5.U.1  Duration of Exposure
     Dose projection is a  function  of the  time  integrated  exposure
rate or of the tiae integrated concentration.   Although  exposure
rate would most likely vary with  time,  this  relationship cannot be
predicted.  For purposes of these calculations, exposure rate  is
assumed to be constant over the exposure period.  Therefore,
projected dose becomes a product of exposure rate,  duration  of
exposure, and a dose conversion factor.
     The time period of exposure may  be difficult to predict.
Exposure would start at a  particular  site  when  the  plume arrived  and
would be ended by a change in wind  direction or by  an  end  to the
release.  It is very important that arrangements be made for the
State or local weather forecast center  to  provide information  on
current meteorological and wind conditions and  predicted wind
direction persistence during the  incidents in addition to
information received from  the facility  operator.  If neither wind
change nor the tlae until  the end of  the release can be  predicted,
the period of exposure could be conservatively  assumed to  be equal
to the 99t probable maximum duration  of wind direction persistence
for that site and for existing meteorological stability  conditions.
Historical data on wind direction persistence as a  function  of
atmospheric stability class for a particular site are  available in
the Final Safety Analysis  Report  prepared  by the facility  operator.
                                                          Revised 6/79
                               5.14

-------
5.1.2  Whole Body Doae Projection
     Having established exposure rate patterns in the environment
and having determined (or estimated) the time period of exposure,
the next task is to estimate the projected whole body and thyroid
doae to members of the population so that the projected dose can be
compared with appropriate PAGs.
     An airborne release from a light water reactor would be
expected to consist primarily of radioactive noble gases and
iodines.  If engineered safeguards operate as designed, they may
reduce iodine concentrations to levels such that the whole body
gamma radiation dose from noble gases will be the controlling
pathway.  Otherwise, the controlling pathway will be inhalation of
radioiodines resulting in committed thyroid dose ranging up to
hundreds of times the whole body gaoma dose depending on the
effectiveness of the engineered safeguards.
     To avoid the necessity for calculating projected doae at the
time of the incident, it is recommended  that dose projection
nomograms be developed.  Figures 5.1 and 5.2 (pages 5.17 and 5.19)
are examples of such nomograms.  Appendix D provides details
regarding their development.  Other shortcut dose projection methods
may have been developed by the facility operators that are fully as
accurate as these methods and should be used if appropriate.
                                                          Revised  6/79
                               5.15

-------
     The projected whole body gamma dose  can  be  estimated  by  simply
multiplying the gaooa exposure rate at a  particular  location  by  the
tlae period of exposure.  (The doae conversion factor  is assumed to
be 1).  Figure 5.1 provides this multiplication.  This  figure  also
provides a relationship between exposure  rate in mR/hr  and  the noble
gas concentration based on the mixture of radioactive noble gases
that would be expected  to exist at about  1.5  hours after shutdown.
Zf the noble gases have decayed for a longer  time, these curves
would significantly overestimate the projected dose  as  determined
from concentrations and exposure time.  If the gamma exposure  rate
from a semi-infinite cloud of airborne noble  gases is  to be
determined from known mixtures other than those  assumed, the
following relationship may be used:
               5  n
     R s 9 x 103  Z  C E
                  .   n n
where:  R = exposure rate (mR/hr)
        C  s concentration in air  (Ci/m  )  for  radionucU.de  "n"
         n
        E  s average gamma energy  per disintegration  (MeV)  for
             radlonuclide "n".  See  table  3*1  of  Appendix D for
             values of E for specific radionuclides.
        9 x 10  s a dimensionless  constant.
                                                          Revised 6/79
                               5.16

-------
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Figure 5.1 Projected whole body gamma don as a function of gamma
exposure rate and projected duration of exposure .
-1.0
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                                                            Revised 6/79

-------
This equation is the familiar expression for gamma exposure  rate
from a semi-infinite cloud, R = .25CE, with the units for R  changed
from R/sec to mR/hr.
5.U.3  Thyroid Dose Projection
     Thyroid dose commitment from inhalation is primarily a  function
of the concentrations of radioactive iodines in the air integrated
over the duration of exposure.  This section provides techniques  for
projecting the thyroid dose using a variety of types of data that
may be available.  The bases for these techniques are provided  in
Appendix D.
     The basic data, concentration of iodines in the air and
duration of exposure, may be obtained from a variety of sources.
The concentration may be measured either as gross iodines or as
specific isotopes.  The concentration may also be calculated based
on release rates and characteristics and meteorological conditions
or based on measured gamma exposure rates.  The duration of  exposure
may be predicted as discussed in section 5.1.1.
     Figure 5.2 provides a family of curves for projected thyroid
dose as a function of airborne concentration (right ordinate) and
duration of exposure (abscissa).
     To estimate projected thyroid dose for a particular site,  plot
the point on figure 5.2 corresponding to the radioiodine
concentrations in Ci/m  and the expected time period of exposure
for persons at that location.  Using a logarithmic interpolation,
                                                          Revised 6/79
                                 5.18

-------
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             Projected  Exposure Time (Hours)
   Figure 5.2 Projected thyroid dose at a function of either
             gamma exposure rate, or radioiodine concentration
             in air and the projected exposure time.
                              5.19
Revised 6/80

-------
estimate the projected  thyroid  doae  from the dose values on the
curves below and above  the point.  For  example,  if the  iodine
concentration is 10   Cl/m  and  is expected  to  last two hours,
then the projected adult thyroid dose would  be  approximately 6  rem,
and the child thyroid dose would be  approximately 12  rem.   Note that
the child thyroid dose  is two times  the  adult thyroid dose.   The
child dose would apply  to general populations while the adult dose
would apply to emergency teams  or to other adults.
     Dose conversion factors to  convert  from time integrated
airborne concentrations to projected dose would vary  as a  function
of the time after reactor shutdown that  concentrations  were
determined.  The dose conversion factors for iodine concentrations
used in figure 5.2 are  based on a mix of radiolodlnes that would be
expected to exist at about 4 hours after reactor shutdown.   If  the
concentration were determined at some other  time,  the dose
conversion factor (and  thus the projected doae)  would be in error.
This error would be less than 30J for measurements  made in the  range
of 1-to 12 hours as shown in figure  4.4  of Appendix D.   This error
is considered too small to Justify the  use of a correction factor,
but figure 4.4 from Appendix D  could be  used for this purpose,  if
desired.
     Air samples would  provide  the best  source  of concentration data
for use in figure 5.2.  However, with present day equipment, field
measurements of environmental radioiodine concentrations may be
                                                          Revised 6/79 (
                               5.20

-------
difficult and too time consuming for quick  decisions  on
implementation of protective actions.   In the  absence of measured
iodine concentrations in air, one may  calculate  the concentrations
based on release rates and meteorological conditions  or based  on
gamma exposure rate measurements in the environment.
5.1.3.1  Concentrations Based on Release Rates
     If information is available on the total  curies  released  or  on
the release rate and duration of release, one  can use these  data
with meteorological information to calculate concentrations  at
specific locations downwind.  Similarly, this  information can  be
used to determine the downwind distance at  which a particular
concentration would occur.  These methods are  discussed below.
     Figure 5.3 provides the atmospheric dilution  factor,  xO/Q,  as
a function of downwind distance and for different  atmospheric
stability classes.  This factor is the concentration  (x>  In  Ci/m3
that would exist for an average windspeed  (0) of  1 m/sec  and for a
release rate (Q) of 1 curie/sec.  To  find  the downwind  concentration
(X) f.or a specific windspeed and release rate, divide  the  value  of
xO/Q by the windspeed in m/sec and multiply by the release rate  in
Cl/sec.
     To find the projected thyroid dose associated with a  particular
concentration, find the point corresponding to the concentration and
the estimated duration of exposure on the  nomogram in  figure 5.2.
Interpolate logarithmically between the dose lines as  necessary.


                                                          Revised 6/79
                               5.21

-------
10
  -3
                                  These values assume
                                  an Inversion lid at
                                  1000 meters altitude
                                  and a ground level
                                  release.
   0.5
        0.5     1      2       5     10     20
                  Distance Downwind  (Miles)
62
    Figure 5.3  Typical  values  for  XU/Q  as a  function of
      atmospheric  stability  class and downwind  distance
                         5.22

-------
     If the release is expressed  in  total  curies  as  opposed to



Ci/sec, any release period can be assumed  for  purposes  of using



figure 5.2 to estimate the projected  dose.   Assuming a  release



period of one hour, the total release  in curies can  be  converted to



release rate in Ci/sec by dividing by  3600 sec/hr.



     A more common problem may be to  determine the downwind distance



at which a particular dose would  occur.  The following  steps would



be appropriate for solving this problem.



     1.  From figure 5.2 (page 5.19)  determine the iodine



concentration in Ci/m  that would cause the  thyroid  dose of



concern for the estimated duration of  the exposure.



     2.  Multiply this concentration  "\" by  the windspeed "0" in



m/sec and divide by the release rate  "Q" in  Ci/sec.   This provides a



dilution factor, x^/Q (m~ ), which can be applied in figure 5.3



(page 5.22).



     3.  Using figure 5.3( follow the  value  for x^/Q across to the



existing stability class and follow  this point down  to  find the



corresponding distance.  This is  the  downwind  distance  where Che



dose of concern should occur at the  plume  center-line.



     Example Problem



     Assume an accident involves  a puff release of 20,000 curies of



iodines.  The release occurs at two  hours after reactor shutdown,



the windspeed is 8 mph = 4 m/sec, and  the atmospheric stability



class is D.  Determine the downwind  distance at which the projected



dose would be 5 rem to the child  thyroid.





                                                          Revised 6/79



                               5.23

-------
     Solution


     Since no duration of exposure was given, one  can  assume  one


hour = 3600 seconds for purposes of calculations.


     From figure 5.2  (page 5.19) note that the concentration, x»

corresponding to a 5  rem dose to the child thyroid from a one hour


exposure would be about 8 x  10"  Ci/m .

     The release rate, Q, can be assumed  to be
          20.000 curies _ ,   C1/Ma
          3,oOO seconds ' 5>5 C1/9ec
     Therefore:
          xO   8 x 10"6 Ci/m3 x Urn/sec   , „    ,_-6  -2
          Q  = 	5.5 Ci/sec	 = 5.8x10   m
From figure 5.3 (page 5.22) the distance corresponding to a dilution


factor of 5.8 x 10~  m"  under stability class D is about 8 Km


or 5-miles.


S.^.3.2  Concentrations Based on Gamma Exposure Rate Measurements


     If environmental concentrations of radioiodines are determined


from air samples at selected locations, it would be useful to obtain


simultaneous average gamma exposure rate measurements at the same


locations in accordance with recommendations of the Task Force on


Instrumentation (£).  The ratio of gamma exposure rate to iodine





                                                         Revised 6/79


                               5.24

-------
concentration should be approximately constant for different



locations if the measurements are not spread out over more  than



about 2 hours.  The process of collecting and analyzing a few air



samples and estimating concentrations based on gamma exposure rate



measurements at other locations could save considerable monitoring



time.



     If no air sample measurements are available, it is possible to



obtain a crude estimate of radloiodine air concentrations from gamma



exposure rate measurements.  Because of the large potential for



errors, this would be the last choice of methods for estimating



airborne iodine concentrations.



     The left ordinate in figure 5.2 (page 5.19) provides a



relationship between the ganna exposure rate from airborne



radioactive noble gases plus iodines and the radioiodine



concentration (right ordinate) that would contribute to this dose.



This relationship changes with the ratio of iodines to noble gases



in the release, the atmospheric stability class, time after



shutdown, the gaona exposure coming from material already deposited



on surfaces, and the gamma exposure from airborne particulate



material.



     Because of the assumptions that were made in the development of



figure 5.2, its use to estimate thyroid inhalation dose solely on



the basis of gamma exposure rates without confirmatory concentration
                                                          Revised  6/79



                               5.25

-------
measurements or without correction  factors would  generally result in



projected thyroid doses higher than those that  would  actually



occur.  The relationships in figure 5.2 between gamma exposure  rate



and iodine concentration are based on the following assumptions:



      1.  The ratio of concentrations of iodines to noble gases  would



be about 0.3 which is the ratio that corresponds  to a  mixture



consisting of 251 of the iodines and 100? of the  noble gases  in a



nuclear power reactor at full power equilibrium conditions.   Figure



5.K provides correction factors that can be multiplied times  the



gamma exposure rate before its use in figure 5.2  in situations  where



actual values are provided for iodine to noble  gas activity ratio.



      2.  The atmospheric stability class would  be "A".  Figure  5.5



provides correction factors as a function of downwind  distance  and



atmospheric stability class for use in situations where these data



are known.



      3.  Measurements would be made within the  range  of 1  to  12



hours after reactor shutdown.  Concentrations based on measurements



made  during the first 4 hours after shutdown would be slightly  lower



than  estimated, thus causing a conservative dose  estimate.



Concentrations based on measurements made 6 or  more hours  after the



reactor shutdown would produce low  dose estimates.  However,  this



nonconservatlve error would be somewhat compensated by the



conservative error introduced by the assumption that  there would  be
                                                          Revised 6/79




                               5.26

-------
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                                                                                                         7  10"

-------
I
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                        TO USE THIS CHART. FIND
                        THE CORRECTION FACTOR
                        CORRESPONDING TO THE
                        DISTANCE AND ATMOSPHERIC
                        STABILITY CLASS AT WHICH
                        THE EXPOSURE MEASUREMENT
                        •AS MADE. AND MULTIPLY IT
                        BY THE MEASURED GAMMA
                        EXPOSURE RATE BEFORE ITS
                        USE IN FIGURE  5.2
      1    U  2    3   4  I  671118   IS  20    30  40 SO   70  100
                          DISTANCE  (KILOMETERS)
     0.6
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  DISTANCE (MILES)
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       Figure 5.5 Gamma exposure rett finite cloud correction factor.
                                 5.28
                                                     Revised  6/80

-------
no contribution to gaona exposure rate from  radioiodinaa  deposited
on the ground.  Both of these errors would increase  in  intensity
with time after the start of the release.
     Caution should be exercised in this method of estimating
thyroid dose to avoid projecting thyroid inhalation  doses on the
basis of gamna exposure coining entirely from deposited  material
after the plume has passed.  For this situation the  gamma exposure
rate would increase as the detector approached the ground.
     Example Problem
     No iodine concentration measurements have been  made, but  gamma
exposure rate measurements indicate maximum  levels of 10  mR/hour at
2 miles downwind.  The stability class is D, and  the nuclear utility
reports the iodine to noble gas ratio in the release is 0.1.   What
is the projected child thyroid dose for a 2  hour  exposure?
     Solution
     Referring to figure 5.2 (page 5.19) the projected  dose without
correction factors for 10 mR/hr and 2 hours  is about 8  rem to  the
child thyroid.  From figure 5.5 (page 5.28)  the correction factor
for D stability and 2 miles = 1.6.  From Figure 5.1  (page 5.27)  the
correction factor for iodine to noble gas ratio of 0.1  =  0.45.
     10 mR/hr x 1.6 x .45 3 7.2 mR/hr.  Referring to figure 5.2, the
corrected thyroid dose is projected to be slightly acre than 5 rem
for a 2 hour exposure.
                                                          Revised 6/79
                                 5.29

-------
5.5  Protective Action Decisions
     The noat effective protective actions for  the  plume  exposure
pathway are evacuation and shelter.  Access control  is also
effective and appropriate but generally would be taken in
conjunction with one of the other two actions.  When contamination
of the skin is suspected, protective actions such as washing and
changes of clothing are justified without the need for planned
procedures because these actions are easy to take and involve little
or no risk.  Chapter 1 provides a general discussion of protective
actions, and Appendix B will provide planning guidance with regard
to evacuation and shelter.  (Appendix B has not been published as of
this revision).
     After dose projections are made and constraints are  identified,
responsible officials oust decide what protective actions should be
implemented and in what areas.  They must also decide which of the
emergency actions that were taken prior to having release
information from the facility or environmental measurements should
be expanded, maintained, or canceled.
     Table 5.1 provides broad guidance for these decisions on the
basis of comparing projected doses to PAGs.  This guidance is
primarily for planning purposes.  Acceptable values  for emergency
doses to the public under actual conditions of a nuclear  accident
cannot be predetermined.  Protective action recommendations in any
individual ease mus* be based on the actual conditions that exist
and are projected at the time of the accident.

                                                          Revised 6/79
                                5.30

-------
              Table 5.1  Recommended protective actions to raduoa whole  body  and  thyroid doaa fro* exposure to a gaaeoua plu
Projaoted Doaa (Ram) to
tha Population
Who la body <1
Thyroid <5
Whola body 1 to <5
Thyroid 5 to <25
Whola body 5 and above
Thyroid 25 and above
Projected Doaa (Bern) to
Emergency Team Workera
Whole body 25
Thyroid 125
Whola body 75
Recommended actions^*)
No planned protective aatlona.(°)
State nay Issue an advisory to aeek shelter and await
further Instructions.
Monitor environmental radiation levels.
Seek shelter aa a minimum.
Consider evacuation. Evacuate unless constraints sake
It lapractlcal.
Monitor environmental radiation levels.
Control access.
Conduct mandatory evacuation.
Monitor environmental radiation levels and adjust area
for mandatory evacuation baaod on these levels.
Control access.

Control exposure of emergency team members to these
levels except for llfesavlng missions. (Appropriate
controls Tor emergency workers, Include time
limitations, respirators, and atabla Iodine.)
Control exposure of emergency team members performing
lifesavlng missions to thla level. (Control of time
of exposure will be moat effective.)
Comments
Previously recommended
protective actions may
be reconsidered or
terminated.
If constraints exist,
special consideration
should be given for
evacuation of children
and pregnant women.
Seeking ahelter would be
an alternative If
evacuation were not
Immediately possible.

although respirators and
stable Iodine ahould be
used where effective to
control doae to
emergency team workers,
thyroid doae may not be
a limiting factor for
lifesavlng missions.
»»
'•'These actions are recoonended for planning purposes.
   must take existing conditions Into consideration.
                                                                    Protective action decisions at the time of the Incident
                 tha time of the Incident, officials may Implement low-Impact protective aotlons In keeping with  the
              principle of maintaining radiation exposures aa low aa reasonably achievable .

-------
     PAGs cannot be used- to assure that a given level of exposure  to
individuals in the population is prevented.  In any particular
response situation, a range of doses may be experienced, depending
mostly on the distance from the point of release.  Some of these
doses nay be in excess of the PAG levels and clearly warrant the
initiation of any feasible protective actions.  This does not mean,
however, that all doses above PAG levels can be prevented.
Furthermore, PAGs represent only trigger levels and are not intended
to represent acceptable dose levels.  PAGs are tools to be used in
planning and as decision aids in the actual response situation for
purposes of dose savings.
     Under emergency conditions all reasonable measures should be
taken to minimize radation exposures to the general public and to
emergency workers.  In the absence of significant constraints and  in
consideration of the generally accepted public health practice of
limiting radiation exposures to as low as reasonably achievable
levels, responsible authorities may want to Implement low impact
protective actions at projected doses below the PAGs.
     The recommendations provide a range of PAG values because
implementation of the guidance will always require the use of good
Judgment and a consideration of local constraints.  The lowest value
should be used if there are no major local constraints in providing
protection at that level, especially to sensitive populations.
                                                          Revised 6/79
                               5.32

-------
Local constraints may make lower values  Impractical  to use,  but in
no case should the higher value be exceeded in determining the need
for protective action.  The question inevitably arises, then, at
uhat projected dose below the minimum PAG values should protective
actions no longer be considered.  This is a value judgment on the
part of the emergency coordinator but should be based on the
following considerations:
     a.  Are the risks associated with taking protective action at
low projected doses greater than the risks associated with the low
projected radiation doses?
     b.  Is there a reasonable probability that the  protective
action being considered can be successfully Implemented without
unreasonable coat or hardship on the participants?
     c.  At very low projected doses, efforts to protect the
population nay do more harm than good.
     The intent is to anew for flexibility in the Implementation of
the guidance because local conditions will vary and  because  special
information may be available.  But above the upper PAG range, there
is significant risk to the exposed populations, and  responsible
agencies should consider it mandatory to plan to implement effective
protective actions, recognizing that when an accident actually
occurs, unforeseen conditions or constraints may prevail such that
professional Judgment will be required with regard to priorities for
protecting the public.

                                                         Revised 6/79
                               5.33

-------
     Guidance for emergency workers  13 given  aa dose  limits  becauae
It la recognized that critical civil functions oust continue while
protective actiona are taken for the general  population, and this
nay require emergency workers to receive  radiation exposures during
emergencies that otherwise would not be permitted.  Exposure of
emergency workers to any dose level  is not Justified  unless  it  is
determined that benefits to society  are being achieved and efforts
are being made to limit their doses  to levels as  low  as  reasonably
achievable.  Emergency workers should consist of  healthy adults and
should not include women that could  potentially be pregnant.
     Emergency response planning should provide for specialized
protection for emergency workers during emergency activities.   This
would include respiratory protection, if  needed,  to reduce internal
organ and thyroid doses from inhalation and perhaps prophylactic
drugs that prevent thyroid exposures from inhaled radioiodine.
There should be appropriate instrumentation to verify exposures and
communication techniques to prevent  overexposures by  warning
emergency workers when to withdraw from radiation fields.
     The health risk associated with dose limits  recommended for
lifesavlng missions are extremely high, and such  high doses  should
be received only on a voluntary basis by  individuals  aware of the
risks involved.  Lifesaving actions  should be performed  by persons
in good health whose normal duties have trained them  for such
missions.
                                                          Revised 6/79
                                 5.34

-------
                              REFERENCES
(1)  U.S.  NUCLEAR REGULATORY COMMISSION.  An Assessment of Accident
     Risks in U.S. Commercial Nuclear Power Plants. (WASH-1UOO),
     U.S.  Nuclear Regulatory Commission, Washington, D.C.,
     October 1975.

(2)  U.S.  NUCLEAR REGULATORY COMMISSION.  Guide and Checklist for
     the Development and Evaluation of State and Local Government
     Radiological Emergency Response Plans in Support of Fixed
     Nuclear Facilities (WASH-1293).  U.S. Nuclear Regulatory
     Commission, Washington, D.C.  December 1971.

(3)  HANS, JOSEPH M.,  JR., AND THOMAS C. SELL.  Evacuation Risks -
     an Evaluation (EPA-520/6-7U-002).   U.S. Environmental
     Protection Agency, Washington, D.C.  June 1971.

(JO  NELSON, N. S.  Approaches to Population Protection in Case of
     Nuclear Accidents.  U.S. Environmental Protection Agency,
     Office of Radiation Programs, Washington, D.C.  (Draft,
     December 197
-------
                          CHAPTER 6
      Implementing the PAGs for the Intermediate Phase
                      (Food and Mater)
   See Chapter  3 and Appendix  D for Current Implementation
        Recommendations for Food.  Also refer to the
                    following documents:
             Federal  Emergency Management Agency
      Guidance Memorandum IN-1, The Ingestion Exposure
       Pathway.   February 26,  1988  Federal  Emergency
          Management  Agency.   Washington, DC  20472
 Guidance  on  Offsite  Emergency Radiation Measurement Systems
   Phase  2, The  Milk  Pathway,  FEMA REP-12,  September 1987.
Guidance on Offsite Emergency Radiation Measurement Systems.
 Phase 3, Mater and Non-Dairy Food Pathway, September 1989.
                             6-1

-------
                                                       Draft

                                 CHAPTER 7

              Implementing the Protective Action Guides for
                          the Intermediate Phase
                     (Exposure to Deposited  Materials)

7.1  Introduction

     This chapter provides guidance for implementing  the PAGs  set  forth  in
Chapter 4.  It is for use by State and  local officials in developing their
radiological emergency response plans to protect the  public from exposure
to radiation from deposited radioactive materials.  Due to the wide variety
in types of nuclear incidents and radionuclide releases that could  occur,
it is not practical to provide implementing guidance  for all situations.
The guidance in this chapter applies primarily to  radionuclides that would
be involved in incidents at nuclear power plants.   It may be useful for
radionuclides from incidents at other types of nuclear facilities  or from
incidents not involving fixed facilities (e.g., transportation accidents).
However, specific implementation procedures for incidents other than those
at nuclear power plants should be developed by planners on a case-by-case
basis.

     Contrary to the situation during the early phase of a nuclear
incident, when decisions usually must be made and  implemented  quickly  by
State and local officials before Federal assistance is available,  many
decisions and actions during the intermediate phase can be delayed  until
Federal resources are present, as described in the Federal Radiological
Monitoring and Assessment Plan (FE-85).  Because of the reduced level  of
urgency for immediate implementation of these protective actions,  somewhat
less detail may be needed in State radiological emergency response  plans
than is required for the early phase.
                                    7-1

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     At the time of decisions on relocation and early  decontamination,
sheltering and evacuation should have already been  completed  to  protect
the public from exposure to the airborne plume and  from  high  exposure
rates from deposited materials.  These protective actions may have  been
implemented prior to verification of the path of the plume  and therefore
some persons may have been unnecessarily evacuated  from  areas where actual
doses are much lower than were projected.  Others who  were  in the path of
the plume may have been sheltered or not protected  at  all.  During  the
intermediate phase of the response, persons must be relocated from  areas
where the projected dose exceeds the PAG for relocation, and  other  actions
taken to reduce doses to persons who are not relocated from contaminated
areas.  Persons evacuated from areas outside the relocation zone may
return.

7.1.1  Protective Actions

     The main protective actions for reducing exposure of the public to
deposited radioactivity are relocation, decontamination, shielding,  time
limits on exposure, and control of the spread of surface contamination.
Relocation is the most effective, and, usually, the most costly  and
disruptive.  It is therefore only applied when the  dose  is  sufficiently
high to warrant it.  The others are generally applied  to reduce  exposure
of persons who are not relocated, or who return from evacuation  status to
areas that received lower levels of deposited radioactivity.   This  chapter
provides guidance for translating radiological conditions in  the
environment to projected dose, to provide the basis for  decisions on the
appropriate protective actions.

7.1.2  Areas Involved

     Figure 7-1 provides a generalized example of the  different  areas and
population groups to be dealt with.  The path of the plume  is assumed to
be represented by area 1.  In reality, variations in meteorological
conditions would almost certainly produce a more complicated  shape,  but
the same principles would apply.
                                    7-2

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I
U)
                ARBITRARY SCALE
                                                                        PLUME TRAVEL

                                                                          DIRECTION
              LEGEND
|   |  1.
                           PLUME DEPOSITION AREA.
                       2.  AREA FROM WHICH POPULATION  IS EVACUATED.
                       3.  AREA  IN WHICH POPULATION IS SHELTERED.
                       4.  AREA FROM WHICH POPULATION IS RELOCATED (RESTRICTED ZONE).
                                      FIGURE 7-1.  RESPONSE AREAS.

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     Because of plant conditions and other considerations prior to or
after the release, persons will already have been evacuated from  area  2
and sheltered in area 3.  Persons who have been evacuated from or
sheltered in areas 2 and 3, respectively, as precautionary actions for
protection from the plume, but whose homes are outside the plume
deposition area (area 1), may return to their homes as soon as
environmental monitoring verifies the boundary of the area that received
deposition (area 1).

     Area 4 is designated a restricted zone and is defined as the area
where projected doses are equal to or greater than the relocation PAG.
Persons residing just outside the boundary of the restricted zone may
receive a dose near the PAG for relocation if decontamination or other
dose reduction efforts are not implemented.

     Area 1, with the exception of the restricted zone, represents the
area of contamination that may continue to be occupied by the general
public.  Nevertheless, there will be contamination levels in this area
that will require continued monitoring and dose reduction efforts other
than relocation.

     The relative positions of the boundaries shown in Figure 7-1 depend
on areas evacuated and sheltered, and the radiological characteristics of
the release.  For example, area 4 (the restricted zone) could fall
entirely inside area 2 (area evacuated), so that the only persons to be
relocated would be those residing in area 4 who were either missed in  the
evacuation process or who, because of the high risk for their evacuation,
had remained sheltered during plume passage.

     At the time the restricted zone is established, a temporary buffer
zone (not shown in Figure 7-1) may be needed outside portions of the
restricted zone in which occupants will not be allowed to return until
monitoring confirms the stability of deposited contamination.  Such zones
would be near highly contaminated areas in the restricted zone where
deposited radionuclides might be resuspended and then redeposited outside
                                    7-4

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the restricted zone.  This could be especially important at  locations
close to the incident site where the radioactivity  levels  are high  and  the
restricted zone may be narrow.  The extent of the buffer zone will  depend
on local conditions.  Similarly, a buffer zone encompassing  the most
highly contaminated areas in which persons are allowed to  reside may be
needed.  This area should be monitored routinely to assure acceptability
for continued occupancy.

7.1.3  Sequence of Events

     Following passage of the airborne plume, several tasks, as shown  in
Figure 7-2, must be accomplished simultaneously to provide for timely
protection of the public.  The decisions on the early task of relocating
persons from high exposure rate areas must be based on exposure rate
measurements and dose analyses.  It is expected that monitoring and dose
assessment will be an on-going process, with priority given  to the  areas
with the highest exposure rate.  The general sequence of events is
itemized below, but the time frames will overlap, as demonstrated  in
Figure 7-2.

     1. Based on environmental data, determine the areas where the
     projected one-year dose will exceed 2 rem and relocate  persons from
     those areas, with priority given persons in the highest exposure  rate
     areas.

     2. Allow persons who were evacuated to return  immediately to  their
     residences if they are in areas where field gamma measurements
     indicate that exposure rates are near normal background levels (not
     in excess of twice the normal background in the area  before the
     incident).  If, however, areas of high deposition are found to be
     near areas with low deposition such that resuspended  activity  could
     drift into the occupied areas, a buffer zone should be  established to
     restrict occupancy until the situation is analyzed and  dose
     projections are confirmed.
                                    7-5

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                        I   I I  III
                                                             I   I  I 11
(A
DC


§
111
Q
O
O
  PERIOD OF

  RELEASE,

  DISPERSION,

  DEPOSITION,

  SHELTERING,

  EVACUATION,

  AND ACCESS

   CONTROL



(NO  TIME SCALE)
o
Ul
fci
                   o
                   o
CO
o
a
                   0.1
                                     CONDUCT AERIAL AND GROUND SURVEYS.  DRAW ISODOSE RATE LINES.
                                       IDENTIFY HIGH DOSE RATE AREAS.  CHARACTERIZE CONTAMINATION.
                                         RELOCATE POPULATION FROM HIGH  DOSE RATE AREAS.
                                          ALLOW  IMMEDIATE RETURN OF EVACUEES TO NONCONTAMINATED  AREAS.
                                              ESTABLISH RESTRICTED ZONE  BOUNDARY AND CONTROLS.
                                              RELOCATE REMAINING POPULATION FROM WITHIN RESTRICTED ZONE.
                                              GRADUALLY RETURN EVACUEES UP TO RESTRICTED ZONE BOUNDARY.
                            CONDUCT D-CON AND SHIELDING  EVALUATIONS AND ESTABLISH PROCEDURES
                                FOR REDUCING EXPOSURE OF PERSONS WHO ARE NOT RELOCATED.
                                                                          PERFORM  DETAILED ENVIRONMENTAL  MONITORING.
                                                                          PROJECT DOSE BASED ON DATA.
DECONTAMINATE ESSENTIAL  FACILITIES AND THEIR  ACCESS ROUTES.
RETRIEVE VALUABLE AND ESSENTIAL RECORDS  AND POSSESSIONS.
                                                                       REESTABLISH OPERATION OF VITAL  SERVICES.
                                                             BEGIN RECOVERY ACTIVITIES.
                                         CONTINUE RECOVERY.
                                 MONITOR AND APPLY
                                 ALARA IN OCCUPIED
                                 CONTAMINATED  AREAS.
                                                    I  I  I
                                                             I   	H
                             1.0            10           100
                               TIME AFTER  DEPOSITION (DAYS)
                                                                          1,000
              FIGURE  7-2.    POTENTIAL TIME FRAME OF RESPONSE  TO  A NUCLEAR INCIDENT.

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3. Determine the location of the isodose line corresponding  to  the
relocation PAG, establish the boundary of the restricted  zone,  and
relocate any persons who still reside within the zone.  Also,
convert any evacuees who reside within the restricted zone to
relocation status.  Evacuated persons whose residence is  in  the area
between the boundary of the plume deposition and the boundary to  the
restricted zone may return gradually as confidence  is gained
regarding the projected dose in the area.

4. Evaluate the dose reduction effectiveness of simple
decontamination techniques and of sheltering due to partial
occupancy of residences and workplaces.  Results of these
evaluations may influence recommendations for reducing exposure
rates for persons who are not relocated from areas  near,  but
outside, the restricted zone.

5. Establish a mechanism for controlling access to  and egress from
the restricted zone.  Typically this would be accomplished through
control points at roadway accesses to the restricted zone.

6. Establish monitoring and decontamination stations to support
control of the restricted zone.

7. Implement simple decontamination techniques in contaminated  areas
outside the restricted zone, with priorities for areas with  higher
exposure rates and for residences of pregnant women.

8. Collect data needed to establish long-term radiation protection
criteria for recovery and data to determine the effectiveness of
various decontamination or other recovery techniques.

9. Begin operations to recover contaminated property in the
restricted zone.
                               7-7

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7.2  Establishment of Isodose-rate Lines

     As soon as Federal or other assistance  is available for aerial  and
ground monitoring, a concentrated effort should begin to establish
isodose-rate lines on maps and the identification of boundaries  to  the
restricted zone.  Planning for this effort should include the development
of standard maps that can be used by all of  the involved monitoring  and
dose assessment organizations to record monitoring data.

     Aerial monitoring (e.g., the Department of Energy Aerial Monitoring
Service) can be used to collect data for establishing general patterns of
radiation exposure rates from deposited radioactive material.  These
data, after translation to readings at 1 meter above ground, may form the
primary basis for the development of isodose lines out to a distance
where aerial monitoring shows no radiation above twice natural background
levels.  Air sample measurements will also be needed to verify the
contribution to dose from inhalation of resuspended materials.

     Gamma exposure rates measured at 1 meter will no doubt vary as  a
function of the location of the measurement  within a very small  area.
This could be caused by different deposition rates for different types of
surfaces (e.g., smooth surfaces versus heavy vegetation).  Rinsing  or
precipitation could also reduce levels in some areas and raise levels in
others where runoff settles.  In general, where exposure rates vary
within designated areas, the higher values should be used for dose
projection for persons within these areas unless judgment can be used to
estimate an appropriate average exposure rate.

     Measurements made at 1 meter to project whole body dose from gamma
radiation should be made with instruments of the "closed window" type so
as to avoid the detection of beta radiation.  Although beta exposure will
contribute to skin dose, its contribution to the overall risk of health
effects from the radionuclides expected to be associated with reactor
incidents should not be controlling in comparison to the whole body  gamma
dose (AR-89).  Special beta dose analyses may be appropriate when time
                                    7-8

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permits to determine its contribution to skin dose.  Since beta dose  rate
measurements require sophisticated equipment that  is generally not
available for field use, beta dose to the skin should be limited based on
measured concentrations of radionuclides per unit  area.

7.3  Dose Projection

     The primary dose of interest for reactor incidents is the sum of the
effective gamma dose equivalent from external exposure and the committed
effective dose equivalent from inhalation.  The exposure periods of
interest are first year, second year, and up to 50 years after the
incident.

     Calculation of the projected gamma dose from  measurements will
require knowledge of the principal radionuclides contributing to exposure
and their relative abundances.  Information on these radiological
characteristics can be compiled either through the use of portable gamma
spectrometers or by radionuclide analysis of environmental samples.
Several measurement locations may be required to determine whether any
selective radionuclide deposition occurred as a function of weather,
surface type, distance from the point of release,  or other factors.  As
part of the Federal Radiological Monitoring and Assessment Plan (FE-85),
the U. S. Department of Energy and the U. S. Environmental Protection
Agency have equipment and procedures to assist State officials in
performing environmental measurements, including determination of the
radiological characteristics of deposited materials.

     The gamma exposure rate may decrease rapidly  if deposited material
includes a significant fraction of short-lived radionuclides.  Therefore,
the relationship between instantaneous exposure rate and projected first-
and second-year annual or the 50-year doses will change as a function of
time, and these relationships must be established  for the particular mix
of deposited radioactive materials present at the  time of the gamma
exposure rate measurement.
                                    7-9

-------
     For incidents involving releases from nuclear power plants, gamma
radiation from deposited radioactive materials  is expected to  be the
principal exposure pathway, as noted above.  Other pathways should  also
be evaluated, and their contributions considered, if significant.   These
may include inhalation of resuspended material  and beta dose to the
skin.  Exposure from ingestion of food and water is normally limited
independently of decisions for relocation and decontamination  (see
Chapters 3 and 6).  In rare instances, however, where withdrawal of food
and/or water from use would, in itself, create  a health risk,  relocation
may be an appropriate protective action for protection from exposure via
ingestion.  In this case, the committed effective dose equivalent from
ingestion should be added to the projected dose from other exposure
pathways for decisions on relocation.

     The following sections provide methods for evaluating the projected
dose from whole body external exposure and from inhalation of  resuspended
particulate material, based on environmental information.

7.3.1  Projected External Gamma Dose

     Projected whole body external gamma doses  at 1 meter height at
particular locations during the first year, second year, and over the
50-year period after the incident are the parameters of interest.   The
environmental information available for calculating these doses is
expected to be the current gamma exposure rate  at 1 meter height and the
relative abundance of each radionuclide contributing significantly  to
that exposure rate.  Calculational models are available for predicting
future exposure rates as a function of time due to radioactive decay and
weathering.  Weathering is discussed in WASH-1400, Appendix VI (NR-75),
and information on the relationship between surface concentrations  and
gamma exposure rate at 1 meter is addressed in  reference (DO-88).

     Following the incident, experiments should be conducted to determine
the dose reduction factors associated with part-time occupancy of
dwellings and workplaces, and with simple, rapid, decontamination
                                   7-10

-------
techniques, so that these factors can also be applied to the calculation
of dose to persons who are not relocated.  However, these  factors  should
not be included in the calculation of projected dose for decisions on
relocation.

     Relocation decisions can generally be made on the basis of  the  first
year projected dose.  However, projected doses during the  second year  and
over 50 years are needed for decisions on the need for other protective
actions for persons who are not relocated.  Dose conversion factors  are
therefore needed for converting environmental measurements to  projected
dose during the first year, second year, and over 50 years following the
incident.  Of the two types of environmental measurements  that can be
made to project whole body external gamma dose, gamma exposure rate  in
air is the easiest to make and is the most directly linked to  gamma  dose
rate.  However, a few measurements of the second type (radionuclide
concentrations on surfaces) will also be needed to properly project
decreasing dose rates.

     Tables 7-1 and 7-2 provide information to simplify the development
of dose conversion factors through the use of data on the  radionuclide
mix, as determined from environmental measurements.  These tables  list
the deposited radionuclides most likely to be the major contributors to
dose from incidents at nuclear power facilities.  In addition  to
providing integrated, effective doses per unit of surface  concentration,
they provide, in column three, the exposure rate (mR/h) in air per unit
of surface contamination.  All exposure rate values are based  on those
given in reference (DO-88).  They were estimated from the  total  body
photon dose rate conversion factors for exposure at 1 m above  the  ground
surface.  Since the ratio of effective dose to air exposure is about 0.7,
dividing the effective dose rate by 0.7 results in an estimate of  the
exposure rate in air.  The integrated effective doses are  based  on dose
conversion factors also listed in reference (00-88).  Table 7-1  takes
into account both radioactive decay and weathering, whereas the  values in
Table 7-2 include only radioactive decay.  The effect of weathering  is
uncertain and will vary depending on the type of weather,  type of
                                   7-11

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Table 7-1  Gamma Exposure Rate and Effective Dose  Equivalent (Corrected for Radioactive Decay and

Radionucl
Zr-95
Nb-95
Ru-103
Ru-106
Te-132
V 1-131
ls>
1-132
1-133
1-135
Cs-134
Cs-137
Ba-140
La-140
Weathering) due to an

Half-life
ide hours
1.54E+03
8.41E+02
9.44E+02
8.84E+03
7.82E+01
1.93E+02
2.30E+00
2.08E+01
6.61E+00
1.81E+04
2.65E+05
3.07E+02
4.02E+01
Initial Uniform Concentration
Initial exposure3
rate at 1 m
(mR/h
per pCi/m2)
1.2E-08
1.3E-08
8.2E-09
3.4E-09
4.0E-09
6.6E-09
3.7E-08
l.OE-08
2.4E-08
2.6E-08
l.OE-08
3.2E-09
3.5E-08
of 1 pCi/

year 1
(mrem per
pCi/m2)
3.3E-05
(b)
7.1E-06
1.2E-05
3.2E-06
1.3E-06
(b)
2.1E-07
1.6E-07
l.OE-04
4.5E-05
1.1E-05
(b)
m^ on Ground Surface
Integrated dose
(weathering factor included)15
year 2
(mrem per
pCi/m2)
4.0E-07
(b)
0
3.7E-06
0
0
(b)
0
0
4.7E-05
2.9E-05
0
(b)


0-50 year
(mrem per
pCi/m2)
3.4E-05
(b)
7.1E-06
1.8E-05
3.2E-06
1.3E-06
(b)
2.1E-07
1.6E-07
2.4E-04
6.1E-04
1.1E-05
(b)
Estimated exposure rate at 1 meter above contaminated ground surface.   Based on data from reference (00-88).
bRadionuclides that
 assumed to quickly
 the parent and the
have short-lived daughters (Zr/Nb-95, Te/I-132, Ru/Rh-106, Cs-137/Ba-137m, Ba/La-140)  are
reach equilibrium.  The integrated dose factors listed are the effective gamma dose due to
daughter.  Based on data from reference (DO-88).

-------
    Table 7-2  Exposure Rate and Effective Dose Equivalent (Corrected for Radioactive Decay) due to an  Initial
                                       2
               Concentration of 1 pCi/m  on Ground Surface
OJ
Integrated dose
Initial exposure3 (weathering factor not included)^
Radionuclide
Zr-95
Nb-95
Ru-103
Ru-106
Te-132
1-131
1-132
1-133
1-135
Cs-134
Cs-137
Ba-140
La-140
aEsti mated exposure
bRadionuclides that
assumed to quickly
Half-life
hours
1.54E+03
8.41E+02
9.44E+02
8.84E+03
7.82E+01
1.93E+02
2.30E+00
2.08E+01
6.61E+00
1.81E+04
2.65E+05
3.07E+02
4.02E+01
rate at 1 meter
rate at 1 m
(mR/h
per pCi/m^)
1.2E-08
1.3E-08
8.2E-09
3.4E-09
4.0E-09
6.6E-09
3.7E-08
l.OE-08
2.4E-08
2.6E-08
l.OE-08
3.2E-09
3.5E-08
above contaminated
year 1
(mrem per
pCi/m?)
3.8E-05
(b)
7.8E-06
1.5E-05
3.3E-06
1.3E-06
(b)
2.1E-07
1.6E-07
1.3E-04
6.0E-05
1.2E-05
(b)
ground surface. Based
have short-lived daughters (Zr/Nb-95, Ru/Rh-106, Te/I-132,
reach equilibrium. The integrated dose factors listed are
year 2
(mrem per
pCi/m2)
8.0E-07
(b)
0
7.6E-06
0
0
(b)
0
0
9.6E-05
5.9E-05
0
(b)
0-50 year
(mrem per
pCi/m2)
3.9E-05
(b)
7.8E-06
3.0E-05
3.3E-06
1.3E-06
(b)
2.1E-07
1.6E-07
4.7E-04
1.8E-03
1.2E-05
(b)
on data from reference (DO-88).
Cs-137/Ba-137m
the effective
, Ba/La-140) are
gamma dose due to
     the parent  and  the daughter.   Based  on  data  from reference  (00-88).

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surface, and the chemical form of the radionuclides.  The user may choose
either table depending on the confidence accorded the assumed weathering
factors.

  The following steps can be used to develop dose conversion factors to
calculate projected future doses from gamma exposure rate measurements for
specific mixes of radionuclides:

     1. Using spectral analysis of gamma emissions from an environmental
        sample of deposited radioactivity, determine the relative abundance
        of the principal gamma emitting radionuclides.  Analyses of uniform
        samples from several different locations may be necessary to
        determine whether the relative concentrations of radionuclides are
        constant.  The results may be expressed as the activity (pCi) of
        each radionuclide in the sample.

     2. Multiply each activity from step 1 by the corresponding values in
        column 3 of Table 7-1 or Table 7-2 (depending on whether or not
        weathering is to be considered) to determine the relative
        contribution to the gamma exposure rate (mR/h) at 1-meter height for
        each radionuclide.  Sum the results for each sample.

     3. Similarly, multiply each activity from step 1 by the corresponding
        values in columns 4, 5, and 6 to determine the Ist-year, 2nd-year,
        and 50-year relative integrated doses contributed by each
        radionuclide.  Sum these results for each sample.  Radionuclides
        listed in Tables 7-1 and 7-2 that have short-lived daughters
        (Zr/Nb-95, Te/I-132, Ru/Rh-106, Cs-137/Ba-137m, Ba/La-140) were
        assumed to be in equilibrium with their daughters when the tabulated
        values for integrated dose were calculated.  Since the values for
        the parents include the total dose from the parent and the daughter,
        do not double count these daughters in the sum.  (In the cases of
        Cs-137/Ba-137m, and Ru-106/Rh-106, the parents are not gamma
        emitters, so the listed exposure rates and doses are actually
        those from the daughters alone.)
                                   7-14

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     4. Using the results from steps 2 and 3, the relevant dose conversion
        factors for each sample are then given by:
               nrc
               DCF
                                    H^mrem)
                                   n
                                   XX.(mR/h)
                                     n
        where i indexes each of the n radionucTides present in the sample.
        (Since the samples represented in the numerator and denominator are
        identical, the effect of the size of the sample cancels.)

     These dose conversion factors may be applied to any measured gamma
exposure rate for which the relative concentrations of radionuclides are the
same as those in the sample that was analyzed.

     The following example demonstrates the use of the above procedures for
calculating a DCF.  For purposes of the example it is assumed that
environmental measurements revealed a mix of radionuclides as shown in column
3 of Table 7-3.  The (relative) exposure rate conversion factors in column 4
of Table 7-3 are taken from column 3 of Table 7-1.  The (relative) exposure
rates in column 5 are the products of columns 3 and 4.  The (relative) doses
for individual radionuclides in columns 6, 7, and 8 were calculated by
multiplying the concentrations in column 3 by the dose conversion factors in
columns 4, 5, and 6 of Table 7-1, respectively.  (Columns 4, 5, and 6 of Table
7-2, which do not include weathering, could have been used instead of those in
Table 7-1.)

     For this example, the conversion factor for dose in the first year was
obtained for the assumed radionuclide mix from the totals of columns 5 and 6
of Table 7-3, which indicate that a calculated dose of 0.023 mrem in the first
year corresponds to an initial exposure rate of 1.5E-4 mR/h.  Therefore, the
first year dose conversion factor (DCF.) for this example is 150 mrem for
each mR/h measured at the beginning of the period.
                                   7-15

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Table 7-3   Example  Calculation of Dose Conversion  Factors  for Gamma Exposure Rate Measurements Based on

            Measured Isotopic Concentrations
Radionuclide
Iodine-131
Tellurium-132
1-132
Ruthenium-103
Rhodium-106f
Cesium-134
Barium-137m^
Totals
Half-life
(hours)
193
78
2.3
944
8,840
18,100
265,000

Measured
concentration
(pCi/sampled)
2.6E+2
3.6E+3
3.6E+3
2.2E+2
5.0EH
6.8E+1
4.2E+1

mR/hC
2
pCi/m
6.6E-9
4.0E-9
3.7E-8
8.2E-9
3.4E-9
2.6E-8
l.OE-8

Calculated
Exposure rate
at 1 m (mR/hr)
1.7E-6
1.4E-5
1.3E-4
1.8E-6
1.7E-7
1.8E-6
4.2E-7
1.5E-4
Calculated
year 1
(mrem)
3.3E-4
1.2E-2
(e)
1.6E-3
5.8E-4
6.9E-3
1.9E-3
2.3E-2
effective dose
year 2
(mrem)
0
0
(e)
0
1.9E-4
3.2E-3
1.2E-3
4.6E-3
at 1 meter
50 year
(mrem)
3.3E-4
1.2E-2
(e)
1.6E-3
9.2E-4
1.6E-2
2.6E-2
5.6E-2
aThe data in this table are only examples to demonstrate a calculational  process.  The results should not be
 used in the prediction of relationships that would exist following a nuclear incident.

''Calculations are based on data in Table 7-1, which includes consideration of both radioactive decay and
 weathering.

cExternal exposure rate factors at 1 meter above ground for a person standing on contaminated ground, based
 on data in Table 7-1.

dThe size of the sample is not important for this analysis because only the relative concentrations are needed
 to calculate the ratio of integrated dose to exposure rate.

eThe integrated dose from 1-132 is not calculated separately because it is the short-lived daughter of Te-132,
 and is assumed to be in equilibrium with it.  The assumed quantity present is that for a daughter in
 equilibrium with the parent.

fThis is a short lived daughter of a parent that has no gamma emissions and the halflife given is that of the
 parent.

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     This DCF may be multiplied by any gamma exposure rate measurement  to
estimate the dose in the first year for locations where the exposure  rate
is produced by a radionuclide mix the same as assumed for calculating the
DCF, and where weathering affects the exposure rate in the same manner  as
assumed.  For example, if a gamma exposure rate measurement were  taken  at
the location where the contamination sample in Table 7-3 was taken, this
exposure rate could be multiplied by the DCF calculated in the above
example to obtain the projected first year dose at that point.  Based on
the example analysis and a relocation PAG of 2 rem, for this case  the
exposure rate at the boundary of the restricted zone should be no  greater
than
                           2000 mrem
                         150 mrem/mR/h  ~  *'

if the contribution to effective dose from inhalation of  resuspended
radioactive materials is zero  (See Section 7.3.2).  The example  DCF for  the
second year and 50 years are obtained by a similar process, yielding  DCFs
of 31 and 370 mrem per mR/h, respectively.

     The ratio of the second year to first year dose  is 31/150 = 0.21.   If
this is the case, persons not  relocated on the basis  of a 2 rem  PAG should,
for this example, receive no more than 0.21  x 2 = 0.4 rem in year 2.
Similarly, the dose in fifty years should be no more  than 4.9 rem.  Actual
doses should be less than these values to the extent  that exposure rates
are reduced by shielding from  structures and by decontamination.

     Prior to reaching conclusions regarding the gamma exposure  rate  that
would correspond to the relocation PAG, one  would need to verify by
multiple sampling the consistency of the relative abundance of specific
radionuclides as well as the relative importance of the inhalation pathway.

     Dose conversion factors will change as  a function of the radiological
makeup of the deposited material.  Therefore, dose conversion factors must
be calculated based on the best current information following the incident.
Since the relative concentrations will change as a function of time due  to
different decay rates, dose conversion factors must be calculated for
                                   7-17

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specific measurement times of interest.  By calculating  the  decay  of  the
original sample(s), a plot of dose conversion factors  (mrem  per mR/h)  as  a
function of time after the incident can be developed.  As weathering
changes the radionuclide mix, and as more is learned about other dose
reduction mechanisms, such predictions of dose conversion factors  may
require adjustment.

7.3.2   Inhalation Dose Projection

     It can be shown, for the mixture of radionuclides assumed to  be
deposited from postulated reactor incidents, and an assumed  average
resuspension factor of 10"  m~ , that the effective dose from
inhalation is small compared to the corresponding effective  dose from
external exposure to gamma radiation.  However, air sample analyses should
be performed for specific situations (e.g., areas of average and high
dynamic activity) to determine the magnitude of possible inhalation
exposure.  The 50-year committed effective dose equivalent (H5Q)
resulting from the inhalation of resuspended airborne radioactive  materials
is calculated as follows:
                             H5Q = I x DCF                     (1)
where
     I   = total intake (uCi), and
     DCF = committed effective dose equivalent per unit  intake (rem/yCi).

     It is assumed that the intake rate will decrease with time due to
radioactive decay and weathering.  No model is available to  calculate  the
effect of weathering on resuspension of deposited materials, so the model
developed for calculating its effect on gamma exposure rate  (NR-75) is
assumed to be valid.  This should provide conservative results.  The total
intake (I) from inhalation over time t may be calculated for each
radionuclide, using the following equation:
            . BC  [i    (i-e-l) +       (l-e-        )]        (2)
                o  x  \                   A  \
                                   7-18

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where
       B  =   average breathing rate for adults
          =   1.05E+4 m3/a (EP-88),
       C  =   initial measured concentration of the resuspended
        0                               3
              radionuclide in air (pCi/m ),
       t  =   time during which radionuclides are  inhaled  (a),

       x, =   radioactive decay constant  (a~  ),
              assumed weathering decay constant for  63 percent  of  the
                                                 _i
              deposited activity, taken as 1.13 a    (NR-75), and
       \3 =   assumed weathering decay constant for  37 percent  of  the
              deposited activity, taken as 7.48 E-3  a'1  (NR-75).
     Table 7-4 tabulates results calculated using the  above  assumptions
for weathering.  The table contains factors relating the committed
effective dose from exposure during the first and second years  after  the
incident to an initial air concentration of 1 pCi/m  for each of  the
principal radionuclides expected to be of concern from reactor
incidents.  The dose conversion factors are taken from FGR-11 (EP-88).
Parent radionuclides and their short  lived daughters are grouped  together
because these dose conversion factors are based on the assumption that
both parents and daughters will occur in equal concentrations and will
decay with the half life of the parent.  Therefore, measured
concentrations of the short lived daughters should be  ignored and only
the parent concentrations should be used in calculating  long term
projected doses.

     Table 7-4 lists factors which include the effects of  both  weathering
and radioactive decay, as well as those that include only  the effects of
radioactive decay.  Users of these data should decide  which  factors to
use based on their confidence on the  applicability of  the  weathering
models used (NR-75) to their environment.
                                   7-19

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      Table 7-4  Dose Conversion Factors  for Inhalation  of  Resuspended  Material
N>
O
                                           Committed effective  dose equivalent  from specified exposure periods
                                           based  on  an  initial  concentration of one pCi/m^ in air (with
                                           and without  weathering)
                                             Committed  dose3
                                             considering radioactive
                                             decay and  weathering
                                             (mrem per
Committed dose3
considering radioactive
decay only
(mrem per pCi/m3)
Radionuclide^
Sr-90/Y-90
Zr-95/Nb-95
Ru-103
Ru-106/Rh-106
Te-132/I-132
1-131
Cs-134
Cs-137/Ba-137m
Ba-140/La-140
Ce-144/Pr-144
Lung class0
Y/Y
Y/Y
Y
Y/D
W/D
0
0
D/0
D/W
Y/Y
year 1
9.3E 0
6.8E-2
1.3E-2
2.8E 0
1.3E-3
1.1E-2
3.2E-1
2.4E-1
4.5E-3
2.0E 0
year 2
5.5E 0
0
0
l.OE 0
1.9E-5
0
1.5E-1
1.4E-1
0
4.2E-1
year 1
1.4E+1
7.9E-2
1.5E-2
3.7E 0
1.3E-3
1.1E-2
4.1E-1
3.3E-1
4.7E-3
2.7E 0
year 2
1.3E+1
0
0
1.9E 0
1.9E-5
0
3.0E-1
3.2E-1
0
9.8E-1
      Calculated using dose factors from Table 2.1.  Reference EP-88

      bShort lived daughters are not listed separately because the entries include the dose from both the
       daughter and the parent.  These factors are based on the concentration of the parent only, at the
       beginning of the exposure period.
      cThe lung clearance class chosen was the one which results in the highest dose conversion factor.

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     The committed effective dose equivalent is calculated by multiplying
the measured initial air concentration (pCi/m ) for each radionuclide
of concern by the appropriate factor from the table and summing the
results.  This sum may then be added to the corresponding external whole
body gamma dose to yield the total committed effective dose equivalent
from these two pathways.

     The PAGs include a guide for dose to skin which  is 50 times the
magnitude of the PAG for effective dose.  Analysis (AR-89) indicates that
this guide is not likely to be controlling for radionuclide mixes expected
to be associated with nuclear power plant incidents.  Dose conversion
factors are provided in Table 7-5 for use in case of  incidents where the
source term consists primarily of pure beta emitters.  The skin dose from
each radionuclide may be calculated by multiplying the measured concen-
              2
tration (pCi/m ) by the corresponding dose conversion factor  in the
table.  This will yield the first year beta dose to the skin  at one meter
height from exposure to deposited materials plus the  estimated dose to
the skin from materials deposited on the skin as a result of  being in the
contaminated area.  These factors are calculated based on information in
Reference AR-89, which used weathering factors that apply for gamma
radiation and would, therefore, be conservative for application to beta
radiation.  Calculated doses based on these factors should be higher than
the doses that would be received.

7.4 Priorities

     In most cases protective actions during the intermediate phase will
be carried out over a period of many days.  It is therefore useful to
consider what priorities are appropriate.  Further, for situations where
the affected area is so large that it is impractical  to relocate all of
the public, especially from areas exceeding the PAGs  by only  a small
amount, priorities are needed for protective actions.  The following
priorities are appropriate:

     1.    As a first priority, assure that all persons are protected
           from doses that could cause acute health effects from all
           exposure pathways, including previous exposure to  the plume.
                                   7-21

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Table 7-5  Skin Beta Dose Conversion Factors for Deposited Radionuclides3
Radionuclides
Co-58
Co-60
Rb-86
Sr-89
Sr-90
Y-90
Y-91
Zr-95
Nb-95
Mo-99
Tc-99m
Ru-103
Ru-106c
Rh-105
Sb-127
Te-127
Te-127m
Te-129
Te-129m
Te-131m
Te-132
1-131
1-132
Cs-134
CS-136C
Cs-137C
Ba-140
La-140
Ce-141
Ce-143
Ce-144C
Pr-143
Nd-147
Np-239
Am-241
Dose conversion
(mrem per
factors'5
pCi/m2)
Radioactive decay Radioactive
plus weathering decay only
1.2E-7
4.2E-7
6.3E-5
1.5E-4
1.2E-5
2.2E-4
1.6E-4
7.2E-7
6.1E-7
4.4E-6
7.7E-9
6.8E-7
6.4E-7
6.5E-8
3.4E-6
l.OE-6
7.8E-7
5.0E-7
3.4E-5
2.9E-7
5.4E-9
8.5E-7
5.0E-5
2.6E-5
1.4E-7
2.1E-5
9.1E-6
1.2E-5
6.6E-7
2.3E-6
8.7E-7
1.3E-5
4.3E-6
3.4E-8
4.6E-8
1.4E-7
5.6E-7
6.7E-5
1.6E-4
1.7E-5
2.9E-4
1.9E-4
8.3E-7
7.4E-7
4.6E-6
7.7E-9
7.8E-7
8.7E-7
6.6E-8
3.4E-6
l.OE-6
9.5E-7
5.0E-7
3.6E-5
2.9E-7
5.4E-9
8.7E-7
5.0E-5
3.3E-5
3.7E-7
2.9E-5
9.6E-6
1.3E-5
7.1E-7
2.3E-6
1.1E-6
1.4E-5
4.5E-6
3.4E-8
6.4E-8
aBased on data from reference AR-89.
^Dose equivalent integrated for a one-year exposure at one meter height plus
 the estimated dose to the skin from materials deposited on the skin as a
 result of being in the contaminated area.

contributions from short-lived (one hour or less) decay products are
 included in dose factors for the parent radionuclides "(i.e.,  Rh-106, Ba-136,
 Ba-137, and Pr-144).


                                   7-22

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      2.  Recommend the application of simple decontamination techniques
          and that persons remain indoors as much as possible to reduce
          exposure rates.

      3.  Establish priorities for relocation with emphasis on high
          exposure rate areas and pregnant women (especially those in the
          8th to 15th week of pregnancy).

7.5   Reentry

      After the restricted zone is established, persons will need to
reenter for a variety of reasons, including recovery activities, retrieval
of property, security patrol, operation of vital services, and, in some
cases, care and feeding of farm and other animals.  It may be possible to
quickly decontaminate access ways to vital institutions and businesses in
certain areas so that they can be occupied by adults either for living
(e.g., institutions such as nursing homes, and hospitals) or for
employment.  Clearance of these areas for such occupancy will require dose
reduction to comply with occupational exposure limits (EP-87).  Dose
projections for individuals should take into account the maximum expected
duration of exposure.

      Persons working in areas inside the restricted zone should operate
under the controlled conditions normally established for occupational
exposure (EP-87).

7.6   Surface Contamination Control

      Areas under the plume can be expected to contain deposited
radioactive materials if aerosols or particulate materials were released
during the  incident.  In extreme cases, individuals and equipment may be
highly contaminated, and screening stations will be required for emergency
monitoring  and decontamination of individuals and to evaluate the need for
medical evaluation.  Equipment should be checked at this point and
decontaminated as necessary to avoid the spread of contamination to other
                                   7-23

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locations.  This screening service would be required  for only  a  few  days
following plume passage until all such persons have been evacuated or
relocated.

      After the restricted zone  is established, based on the PAGs for
relocation, adults may reenter the restricted zone under controlled
conditions in accordance with occupational exposure standards.   Monitoring
stations will be required along  roadways to control surface contamination
at exits from the restricted zone.  Because of the possibly high
background radiation levels at control points near exits, significant
levels of surface contamination  on persons and equipment may be
undetectable at these locations.  Therefore, additional monitoring and
decontamination stations may be  needed at nearby  low  background
locations.  Decontamination and  other measures should be implemented to
maintain low exposure rates at monitoring stations.

7.6.1  Considerations and Constraints

      Surface contamination limits to control routine operations at
nuclear facilities and to transport radioactive material are generally set
at levels lower than are practical for situations  involving high-level,
widespread contamination of the  environment.

      The principal exposure pathways for loose surface contamination on
persons, clothing, and equipment are (a) internal doses from ingestion by
direct transfer, (b) internal doses from inhalation of resuspended
materials, (c) beta dose to skin from contaminated skin or clothing  or
from nearby surfaces, and (d) dose to the whole body  from external gamma
radiation.

      Because of the difficulties in predicting the destiny of
uncontrolled surface contamination, a contaminated individual  or item
should not be released to an unrestricted area unless contamination  levels
are low enough that they produce only a small increment of risk  to health
(e.g., less than 20 percent), compared to the risk to health from the
principle exposure pathway (e.g., whole body gamma dose) in areas
                                   7-24

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immediately outside the restricted zone.  On the other hand, a level of
contamination comparable to that existing on surfaces immediately outside
the restricted zone may be acceptable on materials leaving the restricted
zone.  Otherwise, persons and equipment occupying areas immediately
outside the restricted zone would not meet the surface contamination
limits.  These two constraints are used to set permissible surface
contamination limits.

      The contamination limit should also be influenced by the potential
for the contamination to be ingested, inhaled, or transferred to other
locations.  Therefore, it is reasonable to establish lower limits for
surfaces where contamination is loose than for surfaces where the
contamination is fixed.

      For routine (nonincident) situations, measurement of gross
beta-gamma surface contamination levels is commonly performed with a
thin-window geiger counter (such as a CDV-700).  Since beta-gamma
measurements made with such field instruments cannot be interpreted in
terms of dose or exposure rate, the guidance set forth below is related to
the background radiation level in the area where the measurement is being
made.  Supplementary levels are provided for gamma exposure rates measured
with the beta shield closed.  Guidance levels expressed in this form will
be easily detectable and should satisfy the above considerations.
Corresponding or lower levels expressed in units related to instrument
designations may be adopted for convenience or for ALARA determinations.
Smears may also be used to detect loose surface contamination at very low
levels.  However, they are not considered necessary for emergency response
and, therefore, such guidance is not provided.

7.6.2  Numerical Relationships

      As discussed in Section 7.3.1, a relationship can be established
between projected first year doses and instantaneous gamma exposure rates
from properly characterized surface contamination.  Based on assumed
radiological characteristics of releases from fuel melt accidents, gamma
exposure rates in areas where the projected dose is equal to the
                                   7-25

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relocation PAG of 2 rem in the first year may be in the range of 2 to 5
uiR/h during the first few days following the deposition from a type SST-2
accident (See Section E.I.2).  (This relationship must be determined for
each specific release mixture.)  Based on relationships in reference
(DO-88) and a mixture of radionuclides expected to be typical of an SST-2
                                                   8      2
type accident, surface contamination levels of 2x10  pCi/m  would
correspond approximately to a gamma exposure rate of 1 mR/h at 1 meter
height.

7.6.3  Recommended Surface Contamination Limits

      Surface contamination must be controlled both before and after
relocation PAGs are implemented.  Therefore, this section deals with the
control of surface contamination on persons and equipment being protected
during both the early and intermediate phases of a nuclear incident.

      For emergency situations, the following general guidance regarding
surface contamination is recommended:

      1.  Do not delay urgent medical care for decontamination efforts or
          for time-consuming protection of attendants.

      2.  Do not waste effort trying to contain contaminated wash water.

      3.  Do not allow monitoring and decontamination to delay evacuation
          from high or potentially high exposure rate areas.

      4.  (Optional provision, for use only if a major contaminating event
          occurs, and rapid early screening is needed.)  After plume
          passage, it may be necessary to establish emergency
          contamination screening stations in areas not qualifying as low
          background areas.  Such areas should be less than 5 mR/h gamma
          exposure rate.  These screening stations should be used only
          during the early phase and for major releases of particulate
          materials to the atmosphere to monitor persons emerging from
          possible high exposure areas, provide simple (rapid)
          decontamination if needed, and make decisions on whether to send
                                   7-26

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    them for special care or to a monitoring and decontamination
    station in a lower background area.  Table 7-6 provides guidance
    on surface contamination levels for use if such centers are needed.

5.  Establish monitoring and personnel decontamination (bathing)
    facilities at evacuation centers or other locations in low
    background areas (less than 0.1 mR/h).  Encourage evacuated
    persons who were exposed in areas where inhalation of particulate
    materials would have warranted evacuation to bathe, change
    clothes, wash clothes, and wash other exposed surfaces such as
    cars and trucks and their contents and then report to these
    centers for monitoring.  Table 7-7 provides recommended surface
    contamination guidance for use at these centers.

6.  After the restricted zone is established, set up monitoring and
    decontamination stations at exits from the restricted zone.
    Because of the probably high background radiation levels at these
    locations, low levels of contamination may be undetectable.  If
    contamination levels are undetectable, then they probably do not
    exceed those in some unrestricted areas occupied by the exposed
    population and no decontamination is required.  Nevertheless,
    these individuals should be advised to bathe and change clothes at
    their first opportunity and certainly within the next 24 hours.
    If, after decontamination at the boundary of the restricted zone
    station, persons still exceed the limits for this station, they
    should be sent for further decontamination or for medical or other
    special attention.  As an alternative to decontamination,
    contaminated items other than persons or animals may be retained
    in the restricted zone for radioactive decay.

7.  Establish auxiliary monitoring and decontamination stations in low
    background areas (background less than 0.1 mR/h).  These stations
    should be used to achieve ALARA surface contamination levels.
    Table 7-7 provides surface contamination screening levels for use
    at those stations.
                             7-27

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Table 7-6  Recommended Surface Contamination Screening Levels for

           Emergency Screening of Persons and Other Surfaces at Screening

           or Monitoring Stations in High Background Radiation Areas

           (0.1 mR/h to 5 mR/h Gamma Exposure)3
Condition
Geiger-counter shielded-

window reading
Recommended action
Before decontamination
<2X bkgd and <0.5 mR/h
above background

>2X bkgd or >0.5 mR/h
above background
Unconditional
release

Decontaminate.
Equipment may be
stored or disposed
of as appropriate.
After decontamination
<2X bkgd and <0.5 mR/h
above background

>2X bkgd or >0.5 mR/h
above background
Unconditional
release

Continue to
decontaminate or
refer to low back-
ground monitoring
and d-con station.
Equipment may also
be stored for
decay or disposed
of as appropriate.
a Monitoring stations in these high exposure rate areas are for use
  only during the early phase of an incident involving major atmos-
  pheric releases of particulates.  Otherwise use Table 7-7.
                                   7-28

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Table 7-7 Recommended Surface Contamination Screening Levels for Persons

          and Other Surfaces at Monitoring Stations in Low Background
           Radiation Areas (<0.1 mR/h Gamma Exposure Rate)
Condition

Before decontamination

After simple
decontamination effort

After fullc
decontamination
effort



After additional
full decontamination
effort


Geiger counter
thin window3 reading
<2X bkgd
>2X bkgd
<2X bkgd
>2X bkgd
<2X bkgd

>2X bkgd

<0.5 mR/hd
<2X bkgd
>2X bkgd
<0.5 mR/hd
>0.5 mR/hd
Recommended action

Unconditional release
Decontaminate
Unconditional release
Full
decontamination
Unconditional release

Continue to d-con
persons
Release animals
and equipment
Unconditional release
Send persons for
special evaluation
Release animals
and equipment
Refer, or. use
                                                     informed judgment on
                                                     further control of
                                                     animals and equipment
a Window thickness of approximately 30mg/cm2 is acceptable.  Recommended
  limits for open window readings are expressed as twice the existing
  background (including background) in the area where measurements are being
  made.  Corresponding levels, expressed in units related to instrument
  designations, may be adopted for convenience.  Levels higher than twice
  background (not to exceed the meter reading corresponding to 0.1 mR/h) may
  be used to speed the monitoring of evacuees in very low background areas.

b Flushing with water and wiping is an example of a simple
  decontamination effort.

c Washing or scrubbing with soap or solvent followed by flushing is an
  example of a full decontamination effort.

d Closed shield reading including background.
                                   7-29

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                                References

AR-89 AABERG, ROSANNE, Battelle Northwest Laboratories. Evaluation of Skin
      and Ingestion Exposure Pathways. U.S. Environmental Protection
      Agency/Office of Radiation Programs, Washington, D.C.  20460, June
      1989.

DO-88 U.S. DEPARTMENT OF ENERGY.  External Dose-Rate Conversion Factors
      for Calculation of Dose to the Public.  DOE/EH-0070  U.S. Department
      of Energy, Washington, D.C.  20545, July 1988.

EP-87 U.S. ENVIRONMENTAL PROTECTION AGENCY.  Radiation Protection Guidance
      to Federal Agencies for Occupational Exposure.  Federal Register.
      Vol. 52, No. 17, Page 2822, U.S. Government Printing Office,
      Washington, DC  20402, January 1987.

EP-88 U.S. ENVIRONMENTAL PROTECTION AGENCY.  Limiting Values of
      Radionuclide Intake and Air Concentration and Dose Conversion
      Factors for Inhalation, Submersion, and Ingestion.  EPA
      520/1-88-020.  U.S. Environmental Protection Agency, Washington,
      D.C.  20460, September 1988.

FE-85 FEDERAL EMERGENCY MANAGEMENT AGENCY.  Federal Radiological Emergency
      Response Plan (FRERP).  Federal Register Vol. 50, No. 217, U.S.
      Government Printing Office, Washington, DC  20402, November 5, 1985.

NR-75 U. S. NUCLEAR REGULATORY COMMISSION.  Reactor Safety Study.  An
      Assessment of Accident Risks in U. S. Commercial Nuclear Power
      Plants. WASH-1400.  NUREG-75/014.  U.S. Nuclear Regulatory
      Commission, Washington, DC  20555, October 1975.
                                   7-30

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           Chapter 8
Radiation Protection Guides for
   The Late Phase (Recovery)
           (Reserved)

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APPENDIX A





 Glossary

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                                APPENDIX A

                                 Glossary


The following definitions apply specifically to terms used  in this manual.

Acute health effects:  Prompt radiation effects (those that would be
observable within a short period of time) for which the severity of the
effect varies with the dose, and for which a practical threshold exist.

Ablation;  The functional destruction of an organ through surgery or
exposure to large doses of radiation.

Buffer zone:  An expanded portion of the restricted zone selected for
temporary radiation protection controls until the stability of
radioactivity levels in the area is confirmed.

Cloudshine:  Gamma radiation from radioactive materials in an airborne
plume.

Committed dose:  The radiation dose due to radionuclides in the body over
a 50 year period following their inhalation or ingestion.

Delayed health effects:  Radiation effects which are manifested long after
the relevant exposure.  The vast majority are stochastic, that is, the
severity is independent of dose and the probability is assumed to be
proportional to the dose, without threshold.

Derived response level (DRL):  A level of radioactivity in  an
environmental medium that would be expected to produce a dose equal to  its
corresponding Protective Action Guide.

Dose conversion factor:  Any factor that is used to change  an
environmental measurement to dose in the units of concern.
                                    A-l

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Dose equivalent:  The product of the absorbed dose  in rad,  a quality
factor related to the biological effectiveness of the radiation  involved
and any other modifying factors.

Effective dose equivalent:  The sum of the products of the  dose  equivalent
to each organ and a weighting factor, where the weighting factor is the
ratio of the risk of mortality from delayed health  effects  arising from
irradiation of a particular organ or tissue to the  total risk of mortality
from delayed health effects when the whole body is  irradiated uniformly to
the same dose.

Evacuation:  The urgent removal of people from an area to avoid  or reduce
high-level, short-term exposure, usually from the plume or  from  deposited
activity.  Evacuation may be a preemptive action taken in response to a
facility condition rather than an actual release.

Genetic effect:  An effect in a descendant resulting from the modification
of genetic material in a parent.

Groundshine:  Gamma radiation from radioactive materials deposited on the
ground.

Incident phase:  This guidance distinguishes three  phases of an  incident
(or accident): (a) early phase, (b) intermediate phase, and (c)  late phase.

     (a)  Early phase:  The period at the beginning of a nuclear incident
          when immediate decisions for effective use of protective actions
          are required, and must be based primarily on predictions of
          radiological conditions in the environment.  This phase may last
          from hours to days.  For the purpose of dose projection, it is
          assumed to last for four days.

     (b)  Intermediate phase:  The period beginning after the incident
          source and releases have been brought under control and reliable
          environmental measurements are available  for use  as a  basis for
          decisions on additional protective actions and extending until
                                    A-2

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          these protective actions are terminated.  This phase may overlap
          the early and late phases and may last from weeks to many
          months.  For the purpose of dose projection,  it  is assumed  to
          last for one year.

     (c)  Late phase:  The period beginning when recovery  action  designed
          to reduce radiation levels in the environment to permanently
          acceptable levels are commenced, and ending when all recovery
          actions have been completed.  This period may extend from months
          to years (also referred to as the recovery phase).

Linear Energy Transfer (LET):  A measure of the ability of biological
material to absorb ionizing radiation; specifically, for charged  particles
traversing a medium, the energy lost per unit  length of path as a result
of those collisions with elections in which the energy  loss is less than  a
specified maximum value.  A similar quantity may be defined for photons.

Nuclear incident:  An event or series of events, either deliberate or
accidental, leading to the release, or potential release,  into the
environment of radioactive materials in sufficient quantity to warrant
consideration of protective actions.

Prodromal effects:  The forewarning symptoms of more serious health effects.

Projected dose:  Future dose calculated for a  specified time period on the
basis of estimated or measured initial concentrations of radionuclides or
exposure rates and in the absence of protective actions.

Protective action:  An activity conducted  in response to an incident  or
potential incident to avoid or reduce radiation dose to members of the
public (sometimes called a protective measure).

Protective Action Guide (PAG):  The projected  dose to standard man, or other
defined individual, from an accidental release of radioactive material at
which a specific protective action to reduce or avoid that dose is warranted.
                                    A-3

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Recovery:  The process of reducing radiation exposure rates and
concentrations of radioactive material in the environment to  levels
acceptable for unconditional occupancy or use.

Reentry:  Temporary entry into a restricted zone under controlled
conditions.

Relocation:  The removal or continued exclusion of people (households)
from contaminated areas to avoid chronic radiation exposure.

Restricted zone:  An area with controlled access from which the  population
has been relocated.

Return:  The reoccupation of areas cleared for unrestricted residence or
use.

Sheltering:  The use of a structure for radiation protection  from  an
airborne plume and/or deposited radioactive materials.

Short-lived daughters:  Radioactive progeny of radioactive isotopes that
have half-lives on the order of a few hours or less.

Weathering factor:  The fraction of radioactivity remaining after  being
affected by average weather conditions for a specified period of time.

Weighting factor:  A factor chosen to approximate the ratio of the risk of
fatal cancer from the irradiation of a specific tissue to the risk when
the whole body is irradiated uniformly to the same dose.

Whole body dose:  Dose resulting from uniform exposure of the entire body
to either internal or external sources of radiation.
                                    A-4

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             APPENDIX B
Risks To Health From Radiation Doses
        That May Result From
          Nuclear  Incidents

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                                 Contents

                                                                     Page


B.I   Introduction	B-l

      B.I.I  Units of Dose	B-l
      B.I.2  Principles for Establishing Protective Action Guides.   B-3

B.2   Acute Effects	B-4

      B.2.1  Review of Acute Effects	B-4

             8.2.1.1  The Median Dose for Lethality	B-6
             B.2.1.2  Variation of Response for Lethality  ....   B-7
             B.2.1.3  Estimated Lethality vs Dose for Man  ....   B-10
             B.2.1.4  Threshold Dose Levels for Acute Effects   .  .   8-14
             B.2.1.5  Acute Effects in the Thyroid 	   B-16
             B.2.1.6  Acute Effects in the Skin	B-17
             B.2.1.7  Clinical Pathophysiological Effects  ....   B-17

      B.2.2  Summary and Conclusions Regarding Acute Effects  .  .  .   B-22

B.3   Mental Retardation 	   B-22

B.4   Delayed Health Effects 	   B-24

      B.4.1  Cancer	B-24

             B.4.1.1  Thyroid  	   B-27
             B.4.1.2  Skin	B-28
             B.4.1.3  Fetus  	   B-28
             B.4.1.4  Age Dependence of Doses  	   B-29

      B.4.2  Genetic Risk	B-30

      B.4.3  Summary of Risks of Delayed Effects 	   B-31

      B.4.4  Risks Associated with Other Radiation Standards  .  .  .   B-31

      References	B-33


                                  Figures

B-l  Acute Health Effects as a Function of Whole Body Dose ....   B-12

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                           Contents (continued)


                                                                    Page
                                  Tables


B-l  Radiation Doses Causing Acute Injury to Organs  	  B-18

B-2  Acute Radiation Exposure as a Function of Rad
     Equivalent Therapy Units (rets) 	  B-19

B-3  Radiation Exposure to Organs Estimated to Cause Clinical
     Pathophysiological Effects Within 5 Years to 0.1 Percent
     of the Exposed Population	B-20

B-4  Average Risk of Delayed Health Effects in a Population  . .  .  B-31

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                                APPENDIX B

                   Risks To Health From Radiation Doses
                            That May Result From
                             Nuclear Incidents
B.I  Introduction
      This appendix reviews the risks from radiation that form  the  basis
for the choice of Protective Action Guides (PAGs) for the response  to  a
nuclear incident, as well as the choice of limits for occupational
exposure during a nuclear incident.

B.I.I  Units of Dose

      The objective of protective action is to reduce the risk  to health
from exposure to radiation.  Ideally, one would  like to  assure  the  same
level of protection for each member of the population.   However,
protective actions cannot take into account individual variations in
radiosensitivity, since these are not known.  Therefore, these  PAGs are
based on assumed average values of risk.  We further assume that these
risks are proportional to the dose, for any level of dose below the
threshold for acute effects (see Section B.2.).

      The dose from exposure to radioactive materials may be delivered
during the period of environmental exposure only (e.g.,  external gamma
radiation), or over a longer period (e.g., inhaled radionuclides which
deposit in body organs).  In the latter case, dose is delivered not only
at the time of intake from the environment, but continues until all of
the radioactive material has decayed or is eliminated from the  body.
Because of the variable time over which such doses may be delivered, the
PAGs are expressed in terms of a quantity called the "committed dose."
Conceptually, committed dose is the dose delivered over  an individual's
remaining lifetime following an intake of radioactive material.  However,
due to differences in physiology and remaining years of  life, the
                                    B-l

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committed dose to a child from internal radioactivity may differ from  that
to an adult.  For simplicity, adult physiology and a remaining  lifetime of
50 years are assumed for the purpose of calculating committed doses.

      Another important consideration is that different parts of the body
are at different risk from the same dose.  Since the objective  of
protective actions is the reduction of health risk, it is appropriate  to
use a quantity called "effective dose."  Effective dose is the  sum of  the
products of the dose to each organ or tissue of the body and a  weighting
factor representing the relative risk.  These weighting factors (IC-77)
are chosen as the ratio of mortality (from delayed health effects) from
irradiation of particular organs or tissues to the total risk of such
mortality when the whole body is irradiated uniformly at the same dose.

      Finally, doses from different types of radiation (e.g. alpha, beta,
gamma, and neutron radiation) have different biological effectiveness.
These differences are customarily accounted for, for purposes of radiation
protection, by multiplicative modifying factors.  A dose modified by these
factors is designated the "dose equivalent."  The PAGs are therefore
expressed in terms of committed effective dose equivalent.  The PAGs are
augmented by limits for a few specific organs (skin and thyroid) which
exhibit special sensitivity.  These are expressed in terms of committed
dose equivalent (rem).  In the process of developing PAG values, it is
necessary to evaluate the threshold dose levels for acute health effects.
These levels are generally expressed in terms of absorbed dose  (rad) to
the whole body from short term (one month or less) exposure.  Other units
(Roentgens, rem, and rets) are also used in information cited from various
references.  They are all approximately numerically equivalent  to rads in
terms of the risk of acute health effects from beta and gamma radiation.

      PAGs are intended to apply to all individuals in a population other
than workers performing emergency services.  However, there may be
identifiable groups that have different average sensitivity to  radiation
or, because of their living  situation, will receive higher or lower
                                    B-2

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doses.  In addition, some groups may be at greater risk from taking  a
given protective action.  These factors are separately considered, when  it
is appropriate, in establishing values for the PAGs.

B.I.2  Principles for Establishing Protective Action Guides

      The following four principles provide the basis for establishing
values for Protective Action Guides:

      1.   Acute effects on health (those that would be observable within
           a short period of time and which have a dose threshold below
           which they are not likely to occur) should be avoided.

      2.   The risk of delayed effects on health (primarily cancer and
           genetic effects, for which linear nonthreshold relationships  to
           dose are assumed) should not exceed upper bounds that are
           judged to be adequately protective of public health, under
           emergency conditions, and are reasonably achievable.

      3.   PAGs should not be higher than justified on the basis of
           optimization of cost and the collective risk of effects on
           health.  That is, any reduction of risk to public health
           achievable at acceptable cost should be carried out.

      4.   Regardless of the above principles, the risk to health from a
           protective action should not itself exceed the risk to health
           from the dose that would be avoided.

      With the exception of the second, these principles are similar to
those set forth by the International Commission on Radiological Protection
(IC-84b) as the basis for establishing intervention levels for nuclear
accidents.  We examine, below, the basis for estimating effects on health
for use in applying the first two of these principles.
                                    B-3

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8.2  Acute Effects

      This section provides  information relevant  to  the  first  principle:
avoidance of acute effects on health from radiation.

      Acute radiation health effects are those clinically  observable
effects on health which are manifested within two or  three months  after
exposure.  Their severity depends on the amount of radiation dose  that  is
received.  Acute effects do not occur unless the  dose  is relatively large,
and there is generally a level of dose (i.e., threshold) below which  an
effect is not expected to occur.  Acute effects may be classified  as
severe or nonsevere clinical pathophysiological effects.   Severe
pathophysiological effects are those which have clinically observable
symptoms and may lead to serious disease and death.   Other patho-
physiological effects, such as hematologic deficiencies, temporary
infertility, and chromosome changes, are not considered  to be  severe, but
may be detrimental in varying degrees.  Some pathophysiological effects,
such as erythema, nonmalignant skin damage, loss  of  appetite,  nausea,
fatigue, and diarrhea, when associated with whole body gamma or neutron
exposure, are prodromal (forewarning of more serious  pathophysiological
effects, including death).

B.2.1  Review of Acute Effects

      This section summarizes the results of a literature  survey of
reports of acute effects from short-term (arbitrarily  taken as received  in
one month or less) radiation exposure in some detail.  Many reports of
observed effects at lower doses differ, and some  are  contradictory;
however, most have been included for the sake of  completeness.  The
results of the detailed review described in this  Section are summarized  in
Section B.2.2.

      The biological response to the rapid delivery of large radiation
doses to man has been studied since the end of World  Mar II.   Dose-
response relationships for prodromal (forewarning) symptoms (ED )  and
                                    B-4

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for death within 60 days (LD  ,gQ), where x is the probability  (in
percent) of response, have been developed from data on the Japanese A-bomb
survivors, Marshall Island natives exposed to fallout, and patients
undergoing radiotherapy.  This work has been supplemented by a number of
animal studies under controlled conditions.

      The animal studies, usually using lethality as the end point, show
that many factors can influence the degree of response.  The rate at which
the dose is delivered can affect the median lethal dose (LD50) in many
species, particularly at dose rates less than 5 R/min (PA-68a; BA-68).
However, in primates there is less than a 50 percent increase  in the
LDgQ as dose rates are decreased from 50 R/min to about 0.01 R/min
(PA-68a).  There is good evidence of species specificity (PA-68a; BO-69).
The LDr0 ranges from about 100 rad for burros to over 1000 rad for
lagomorphs (e.g., rabbits).  Response is modulated by: age (CA-68), extent
of shielding (partial body irradiation) (BO-65), radiation quality
(PA-68a; BO-69), diet, and state of health (CA-68).

      While animal studies provide support and supplemental information,
they cannot be used to infer the response for man.  This lack  of
comparability of man and animals had already been noted by a review
committee for the National Academy of Sciences as early as 1956, in
considering the length of time over which acute effects might  be
expressed (NA-56):  "Tnus, an LD    30-day consideration is inadequate
to characterize the acute lethal dose response of man, and an  LDKn,
                             i                                  w
60 days would be preferable."

      Several estimates of the levels at which acute effects of radiation
occur in man have been published.  For example, an early estimate of the
     committee (known as the BEAR Committee) also noted  "The reservation
must be made here that the exposed Japanese population was heterogeneous
with respect to age, sex, physical condition and degree  of added trauma
from burns or blast.  The extent to which these factors  affected the
survival time has not been determined.  In studies on laboratory animals
the converse is true—homogeneous populations are studied" (NA-56, p.1-6),
                                    B-5

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dose-response curves for prodromal (forewarning) symptoms and for
lethality was made in the first edition of "The Effects of Nuclear
Weapons" (1957) (GL-57), and a more recent and well documented estimate  is
given in a NASA publication, "Radiobiological Factors  in Manned Space
Flight" (LA-67).

B.2.1.1  The Median Dose for Lethality

     The radiation dose that would cause 50 percent mortality in 60 days
was estimated as 450 Roentgens in early reports (NA-56; GL-57; RD-51). The
National Commission on Radiation Protection and Measurements (NCRP)
calculated that this would correspond to a midline absorbed dose of 315
rad (NC-74).  The ratio of 315 rad to 450 Roentgens is 0.70, which is
about the estimated ratio of the active marrow dose, in rads, to the
tissue kerma in air, in rads (KE-80).  The BEAR Committee noted that the
customary reference to LD5Q in animal studies, as if it were a specific
property, independent of age, was not justifiable (NA-56):    "...it is
evident, now, that the susceptibility of a whole population is not
describable by a single LD,.-.  The published values are usually obtained
for young adults and are therefore maximal or nearly maximal for the
strain.  In attempts to estimate LD5Q in man, this age dependence should
be taken into consideration" (NA-56, pp.4-5).  They observed that the
LDrQ approximately doubled as rats went from neonates  to young adults
and then decreased as the animals aged further.  Finally, the BEAR
Committee concluded: "The situation is complex, and it became evident that
it is not possible to extrapolate with confidence from one condition of
radiation exposure to another, or from animal data to man"
(NA-56, p.1-8).  Nevertheless, results from animal studies can aid in
interpreting the human data that are available.

     The NCRP suggested the LD™,™ might be 10 to 20 percent lower for
the old, very young, or sick, and somewhat greater for healthy adults of
intermediate age (RD-51).  Other estimates of adult LD,-0,gn have ranged
from about 300 rad to 243 ^ 22 rad.  These lower estimates are apparently
based on a ratio of air to tissue dose similar to those calculated for
midline organs in the body; 0.54 to 0.66 (KE-80; OB-76; KO-81).

                                    B-6

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     A NASA panel examined all patient and accident studies, tried to
remove confounding factors, and concluded, "On this basis,  it may be
assumed that the LD5Q value of 286 rad obtained by a normal fit to the
patient data is the preferred value for healthy man" (LA-67).

     An LDcn.,n of 286 + 25 rad (standard deviation) midline absorbed
          oU/oU        —
dose and an absorbed dose/air dose ratio of 0.66, suggested by the
National Academy of Science (LA-67), is probably a reasonable value for
healthy males.  In the absence of more complete information, we assume
that a value of 300 rad + 30 rad is a reasonable reflection of current
uncertainties for average members of the population.

8.2.1.2  Variation of Response for Lethality

     Uncertainty in the dose-response function for acute effects has been
expressed in various ways.  The slope of the estimated dose-response
function has most commonly been estimated on the basis of  the percent
difference in the LD5Q and the LD,,- g or LDg4 , (one standard
deviation from the LDVnK as was done by NASA (GL-57).  These and other
parameters derived in a similar manner describe the uncertainty in the
central risk estimate for the dose-response function.

     Another means is to use an estimate of upper and lower bounds for the
central risk estimate, e.g., the 95 percent fiducial limits.  At any given
response point on the dose-response function, for example,  the LD,-, the
dose causing that response has a 95 percent probability of  lying between
the lower and upper bounds of the 95 percent fiducial limit for that
point.  To estimate this value, probit analyses were run for each species
using data in published reports (KO-81; TA-71).  This provided estimates
for each species for comparability analyses.  The 95 percent fiducial
limits at the LD5Q response for LDcn/oQ studies averaged ^9 percent
(range -9 to +26 percent) and for LD5Q,60 studies ^17 percent  (range -20
                                    B-7

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to +45 percent).  At the LD,5 response, values were +_16 percent  (range
-12 to +50 percent) for LD15/-0 data and +26 percent  (range -20  to  +65
percent) for LD,,-,g0 data.  For the LDg5 response, values were +_17
percent (range -36 to +36 percent) for the LD85/30 data and +24  percent
(range -46  to +31 percent) for LD85,go data.

     The differences in the magnitude of the fiducial limits are a
function of the differences in age, sex, radiation quality, degree  of
homogeneity of the experimental animals, husbandry, and other factors.
The estimates show that the fiducial limits, expressed as a percent of the
dose at any response, get greater the farther from the LD™ the  estimate
is made.  For the purpose of estimating fiducial limits for humans, the 95
percent fiducial limits will be considered to be LD,,. +15 percent,
LDcQ +10 percent, and LDgr +JL5 percent.  Beyond these response levels,
the fiducial limits are too uncertain and should not  be used.

     If the median lethal dose, LDcn,,nt is taken as  300 +30 rad midline
                                  DU/oU                  —
absorbed dose, the response to higher and lower doses depends on the
degree of biological variation in the exposed population.  The NASA panel
decided the wide variation in the sensitivity of patients was a  reflection
of the heterogeneity of the sample; and that the variation in sensitivity,
the slope of the central estimate of the response function, would be
stated in the form of one standard deviation calculated as 58 percent of
the LOcn-  They further decided the deviation in the  patients (58
percent) was too great, and the standard deviation for "normal"  man should
be closer to that of dogs and monkeys (18 percent) (LA-67).  (The
rationale for selecting these species was not given.)

     Jones attempted to evaluate the hematologic syndrome from mammalian
lethality studies using the ratio of dose to LD5Q dose as an indicator
of the steepness of the slope of the dose-response function (JO-81).
However, he evaluated LD™ studies only of species having a rather  steep
slope, i.e., dogs, monkeys, mice, and swine.  He also looked at  several
different statistical models for dose-response functions and pointed out
the problems caused by different models and assumptions, particularly in
                                    B-8

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evaluating the tails of the dose-response function  (less than LD1Q and
greater than LDgo).  Jones recommended using a log-log model, which he
felt provided a better fit at low doses (JO-81).

     Scott and Hahn also evaluated acute effects from mammalian  lethality,
but suggested using a Weibull model (SC-80).  One of the advantages of the
Weibull model is that in addition to developing the dose-response function,
it can also be used to develop hazard functions.  These hazard functions,
if developed using the same model, can be summed to find the joint hazard
of several different types of exposure (SC-83).  This would allow esti-
mation of the total hazard from multiple organ exposures to different
types of radiation.

     As mentioned earlier, the human median lethal  dose is commonly
reported in terms of the LDcn/Kn'  Most laboratory  animal median lethal
doses are reported in terms of the LD50,-0.  In those cases where
estimates of both Lticn,->n and LD™,,.,. are available, i.e., the burro
                    oU/JU       bU/ou
(ST-69), the variation (that is, the slope of the dose-response  curve) is
greater in the LD5(,,60 study than in the LDcQ/3Q study.  Both the dog
and the monkey data are for LD™,™, and so are not appropriate  for
direct comparison to man.

     If an estimate of the deviation is made for data from other studies
and species, those where most of the fatalities occur within 30  days (like
dogs and monkeys) have standard deviations of from  around 20 percent
[swine (x-ray) (ST-69), dogs (NA-66), hamsters (AI-65), primates (Macaca)
(DA-65)] to 30 percent [swine (60Co) (HO-68)].  Those in which most
deaths occur in 60 days, like man, have deviations  from around 20 percent
[sheep (CH-64)] to 40 percent [goats (PA-68b), burros (TA-71)].  Nachtwey,
ejt a_L (NA-66) suggested the steepness of the slope of the exposure
response curve depends on the inherent variability  of the subjects exposed
and any variation induced by uncontrolled factors,  e.g., temperature,
diurnal rhythm, and state of stimulation or arousal.  So, while  the slope
of the response curve for the patients studied by the NASA panel may be
unrealistically shallow for normal human populations, there is no reason
to think it should be as steep as those for dogs and monkeys.

                                    B-9

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     The average deviation for those species (burros, sheep,  and  goats)

for which the standard deviation of the lDcnicn is available  has  been
                                          bU/bU
used as an estimator for man.  The mean value is 34 ^ 13 percent.  This  is

only slightly greater than the average value for all physically large

animals (swine, burros, sheep, and goats), 32 + 12 percent.


B.2.1.3  Estimated Lethality vs Dose for Man


     As noted in Section B.2.1.1, dose-response estimates vary for a

number of reasons.  Some factors affecting estimates for humans are:

     1. Age:

        Studies on rats indicate the 1050 is minimal for perinatal
        exposure, rises to maximum around puberty, and then decreases
        again with increasing age (CA-68).  The perinatal 1059 is about
        one-third of that for the healthy young adult rats; that  for the
        geriatric rat is about one-half of that for the young adult rat.

     2. Sex:

        Females are slightly more sensitive than males in most species
        (CA-68).

     3. Health:

        Animals in poor health are usually more sensitive than healthy
        animals (CA-68), unless elevated hematopoietic activity is
        occurring in healthy animals (SU-69).
     While these and other factors will affect the LD5Q/60 and the
response curve for man, there are no numerical data available.
     The variation in response at a given dose level  increases  as  the
population at risk becomes more heterogeneous and as  the length of time

over which mortality is expressed increases.  In general,  larger species
show greater variance and longer periods of expression than do  small

mammals, e.g., rodents.  It is likely that the human  population would  show
at least the same amount of variation as do the larger animals, i.e.,  a
coefficient of variation of about one-third.
                                   B-10

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     The degree of variation exhibited in animal studies follows  a
Gaussian distribution as well as or better than a log normal distribution
over that range of mortality where there are reasonable statistics.  We
have assumed here that the functional form of human response is
Gaussian.   Generally, sample sizes for extreme values (the upper and
lower tails of the distribution) are too small to give meaningful
results.  Therefore, we have not projected risks for doses more than two
standard deviations from the LD50,6Q.  Ue recognize that estimates of
acute effects may not be reliable even beyond one standard deviation for a
population containing persons of all ages and states of health.   However,
in spite of these uncertainties, previous estimates have been made of  the
acute effects caused by total body exposure to ionizing radiation as a
function of the magnitude of the exposure (NC-71; LU-68; FA-73; NA-73).

     Given the large uncertainties in the available data, a median lethal
dose value of about 300 rad  at  the midline, with a standard deviation  of
100 rad, may be assumed for  planning purposes.  Such risk estimates  should
be assumed to apply only in  the interval from 5 percent to 95 percent
fatality, as shown in Figure B-l.  (See also section B.2.1.4.)

     Figure B-l is based on  the following values:

               Dose (rad)         Percent fatalities
                  <140                  none^
                   140                     5
                   200                    15
                   300                    50
                   400                    85
                   460                    95

     For moderately severe prodromal (forewarning) effects, we
believe the dose at which the same percentage of exposed would  show
effects would be approximately  half of that causing fatality.   This
yields the following results (see also Figure B-l):
2The risk of fatality below 140 rad  is not necessarily  zero;  rather,  it
 is indeterminate and likely to remain so.  This also applies  to  prodromal
 effects below 50 rad.
                                   B-ll

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100
 10
          100     200     300     400     500
              WHOLE BODY ABSORBED DOSE (rad)
600
   FIGURE  B-1.  ACUTE HEALTH EFFECTS AS A FUNCTION
                OF WHOLE  BODY DOSE.
                          B-12

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               Dose (rad)             Percent affected
                   50                         <2
                  100                         15
                  150                         50
                  200                         85
                  250                         98
     Although some incidence of prodromal effects has been observed  at
doses in the range of 15 to 20 rads in patients  (LU-68) and  in  the 0 to
10 rads range of dose in Japanese A-bomb survivors  (SU-80a;  GI-84),  there
is great uncertainty in interpreting the data.   Patients may be  abnormally
sensitive, so that the dose-response function in patients may represent
the lower bound of doses that would show a response  in a healthy
population (LU-67).  The response of Japanese survivors in the  low dose
ranges is complicated by the blast and thermal exposure that occurred at
the same time (SU-80b).  For these reasons, care should be taken in
applying estimates of prodromal effects.  The prodomal dose-response
function listed above is more likely to overestimate the proportion  of
persons affected than to underestimate it.

     These estimated ranges and effects are in agreement with estimates
made for manned space flights (LA-67; LU-67), which  included consideration
of the effect of abnormal physiology or sickness in  the patients to  which
the data apply.  Uncertainty in estimates of the biological  effects  of
radiation exposure is great.  It is probably due in  part to  variation in
the health of individuals in exposed populations.   These estimates assume
a healthy young adult population and may not be  a conservative  estimate of
risk for other population groups, such as children  or the elderly.
Lushbaugh, et a]_.  (LU-68) found that prodromal effects probably  occur in
both healthy and ill persons in about the same dose  range.   However,
Lushbaugh, et a\_.  (LU-68) and NATO (NA-73) suggest  that acute mortality in
a population which is ill, injured, or in other  ways debilitated will
occur in 50 percent of that population at doses  of  200-250 rad  in about 60
days (LDcn,cn), in contrast to an LD,.-.,. from doses of 220-310  rad
        bU/bU                       bU/bU
for a healthy young adult population.  Thus, the ill or injured  are
assumed to have an increased risk of acute mortality at high doses.
                                   B-13

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     The above estimates for LD50/fin are  also based on  the  assumption  of
minimal medical care following exposure.   UNSCEAR  (UN-88) estimates  that
the threshold for mortality would be about 50 percent higher  in  the
presence of more intense medical care.

B.2.1.4  Threshold Dose Levels for Acute  Effects
     This section summarizes  information available  in  the  literature
regarding thresholds for health effects.   It also reviews  actions  that
have been taken as a result of radiation exposure to provide  insight  on
dose levels at which actions  to avoid dose may be appropriate.

     Some acute effects, such as cellular  changes,  may occur  at  low doses
with no dose threshold.  Most such effects have a minimum  threshold of
detectability; for example, five rad  is about the lower  limit  of whole
body dose which causes a cellular effect detectable by chromosome  or  other
special analyses (NC-71; FA-73).  This value is recommended by UNSCEAR as
the starting point for biological dosimetry (UN-69).   Purrott, et  a\_. have
reported a lower limit of detection of chromosome aberrations  of 4 rad for
x-rays and 10 rad for gamma rays (PU-75).

     More recent advanced chromosome  banding techniques  permit detection
of increased incidence of chromosome  abnormalities  from  continuous
exposure to systematically deposited  radioisotopes  or  radioisotopes
deposited in the lung at very low levels,  e.g., body burdens  of  100 to
1200 pCi of plutonium-239 (BR-77).  While  the exact dose associated with
such burdens is not known, it is probably  on the order of  10  to  100
millirem per year.  Lymphocytes exposed to 5 rem in vitro  show severe
metabolic dysfunction and interphase  cell  death (ST-64).   The  extent  to
which similar effects occur after in  vivo  exposure  is  unknown.   While
chromosome abnormalities in circulating lymphocytes are  reported to
persist for long periods (UN-69), the significance  of  such abnormalities
is not known (BR-77).

     Hug has suggested 5 rem  as the lower  limit of  exposure which  might
produce acute effects (WH-65).  Five  rad is also in the  low dose,  short-

                                   B-14

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term exposure range defined by Cronkite and Haley, and is below the 10 rad
which they thought would cause only a slight detectable physiological
effect of unknown clinical significance (CR-71).

     Although the ICRP has suggested that annual doses of 15 rad would not
impair the fertility of normal fertile men (IC-69), an acute dose of 15
rad causes "moderate" oligospermia (approximately 70 percent reduction in
sperm count) which lasts for some months (LA-67).  Popescu and Lancranjan
reported alterations of spermatogenesis and impaired fertility in men
exposed to from 500 millirad to 3 rad per year for periods varying from  2
to 22 years (PO-75).  The shortest exposure period in which abnormal
spermatogenesis was reported was 31 to 41 months (PO-75); at the highest
dose rate reported (3 rad/a), this is a cumulative dose of 8 to 10 rem.
While more study is required, these results suggest the need to restrict
acute doses to below 10 rem to avoid this effect, because a given acute
dose is anticipated to be more effective than the same cumulative dose
given over a longer period of time (NA-56; UN-58).

     Many observations have indicated that doses of 10 rem or more to the
pregnant woman are hazardous to the fetus.  Mental retardation due to
exposure of the fetus is discussed in Section B.3; this discussion is
restricted to acute effects.  The World Health Organization (WHO)
indicates that there is no evidence of teratogenic effects from short term
exposure of the fetus to a dose less than 10 rad during the early phase  of
gestation, the period when the fetus is most sensitive to these
effects (WH-84).

     A number of authorities have recommended that exposures of 10
roentgens or higher be considered as an indication for carrying out
induced abortion (HA-59, DE-70, BR-72, NE-76).  Brent and Gorson also
suggest that 10 rad is a "practical" threshold for induction of fetal
abnormalities (BR-72).  The Swedish Government Committee on Urban Siting
of Nuclear Power Stations stated the situation as follows:  "What we have
called unconditional indication of abortion involves the exposure of
pregnant women where radiation dose to the fetus is higher than 10 rad.
                                   B-15

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When such doses are received In connection with medical  treatment,  it  has
hitherto been assumed that the probability of damage  to  the  fetus  is so
high that an abortion is recommended.  The probability for such  injury is
still moderate compared with the normal frequency of  similar fetal
injuries, and the probability is particularly reduced when the dose  is
received late in the pregnancy" (NA-74).

B.2.1.5  Acute Effects in the Thyroid

     Acute effects are produced in the thyroid by doses  from radioiodine
on the order of 3,000 to 100,000 rad.  Ablation of the thyroid requires
doses of 100,000 rad (BE-68).  The thyroid can be rendered hypothyroid by
doses of about 3,000 to 10,000 rad (IC-71).  A thyroid dose  from
radioiodines of 1000 rad in adults and 400 rad in children implies  an
associated whole body dose of about 1 rad due to radioiodines circulating
                                       131
in the blood.  Following inhalation of    I, the committed thyroid  dose
                               131
is about one rad/yCi intake of    I in adults.  In the developing  fetus,
                                                       131
the thyroid dose ranges from one to six rad per yCi of    I  entering the
mother's body (IL-74).

     Although acute clinical effects are only observed at high doses,
subclinical acute thyroid radiation effects may occur at  lower doses
(DO-72).  Impaired thyroid capability may occur above a  threshold  of about
200 rad (DO-72).

     Effects of radiation exposure of the thyroid have been  shown  in
animal experiments.  Walinder and Sjoden found that doses in excess  of
3,000 rad from    I caused noticeable depression of fetal and juvenile
mouse thyroid development (WA-69).  Moore and Calvin, working with  the
Chinese hamster, showed that an exposure as low as 10 roentgens  (x-rays)
would give rise to 3 percent aberrant cells when the thyroid was cultured
(MO-68).  While the direct relationship of these results  to  human  effects
is not certain, mammalian thyroid cells can be injured at exposures  as low
as 10 roentgens.
                                   B-16

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B.2.1.6  Acute Effects in the Skin

     The first stage of skin reaction to radiation exposure  is erythema
(reddening) with a threshold of from 300 to 800 rad.  Acute  exudative
radiodermatitis results from doses of 1,200 to 2,000 rad  (WH-84).

B.2.1.7  Clinical Pathophysiological Effects

     A large amount of anecdotal information  is available on  the  injury  of
organ tissues by high doses of radiation.  Acute  injury to tissue  includes
swelling and vacuolation of the cells which make  up the blood vessels,
increased permeability of vessels to fluids so that exudates  form,
formation of fibrin clots and thrombi, fibrinoid  thickening  in the walls
of blood vessels, and swelling and vacuolization  of parenchymal cells.
In summary, there is an initial exudative reaction followed  in time  by
fibrosis and sclerosis (WH-76, CA-76).

     Estimates of radiation doses necessary to cause severe  tissue
response in various organs are given in Table B-l.  These tissue  dose
estimates are based on response to radiotherapy treatment, which  is
normally given on a fractionated dose basis,  but  also may be  given as a
continuous exposure.  Therefore, these estimates  must be  adjusted  to the
equivalent single radiation dose for use in the present analysis.  The
formalism of Kirk, et ajk (KI-71) is used to  estimate the equivalent dose
for a single acute exposure in rad-equivalent therapy units  (rets: the
dose calculated from the fractionated exposure which is equivalent to a
single acute exposure for a specific biological endpoint.)   Table  B-2
lists acute exposure equivalents in rets for  various organs.

     With the exception of bone marrow, the exposures required to  cause
5 percent injury within 5 years (TD 5/5) in internal organs  are in the
range of 1,000 to 5,000 rad.  Since, with this type of injury, the dose
response is nonlinear and has a threshold (i.e.,  is nonstochastic),  there
is an exposure below which injury is not expected.  If the shape  of  the
injury dose-response curve is the same for all internal organs as  it is
                                   B-17

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Table B-l  Radiation Doses Causing Acute Injury to Organs (RU-72, RU-73)
Organ
Bone marrow
Liver
Stomach
Intestine
Lung
Kidney
Brain
Spinal cord
Heart
Skin
Fetus
Lens of eye
Ovary
Testes
Volume or
area of
exposure3
whole
segment
whole
100 cm2
400 cm2
100 cm2
whole
100 cm2
whole
whole
10 cm
60 percent
—
whole
whole
whole
whole
Risk of injury
5 percent
(rad)
250
3000
2500
4500
4500
5000
1500
3000
2000
6000
4500
4500
5500
200
500
200-300
500-1500
in five years
50 percent
(rad)
450
4000
4000
5500
5500
6500
2500
3500
2500
7000
5500
5500
7000
400
1200
625-1200
2000
Type of injury
aplasia and
pancytopenia
acute and chronic
hepatitis
ulcer, perforation,
hemorrhage
ulcer, perforation,
hemorrhage
acute and chronic
pneumonitis
acute and chronic
nephrosclerosis
infarction,
necrosis
infarction,
necrosis
pericarditis and
pancarditis
ulcers, fibrosis
death
cataracts
permanent
sterilization
permanent
sterilization
aDose delivered in 200-rad fractions, 5 fractions/week.
 — Unspecified.
                                   B-18

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Table B-2  Acute Radiation Exposure as a Function of Rad Equivalent
           Therapy Units (rets)
Organ
Bone marrow
Liver
Stomach
Intestine
Lung
Kidney
Brain
Spinal cord
Heart
Skin
Fetus
Lens of eye
Ovary
Testes
Volume or
area of
exposure
whole
segment
whole
100 cm2
400 cm2
100 cm2
whole
100 cm2
75 percent
whole
whole
10 cm
60 percent
—
whole
whole
whole
whole
(sterilization)
Risk of injury
5 percent
(rets)
230
1135
1000
1465
1465
1570
720
1135
770b
875
1770
1465
1465
1665
200
355
200-430a
340-7203
in five years
50 percent
(rets)
340
1360
1360
1665
1665
1855
1000
1245
1000
1950
1665
1665
1950
315
620
410-875*
410-875*
      aFor a 200-rad/treatment, 5 treatments/week schedule (LU-76),
      Reference WA-73.
       — Unspecified.
                                   B-19

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for the lung, plotting the two acute exposure equivalents  (TD 50/5  and
5/5) for each organ on log probability paper allows a crude estimation  of
the number of clinical pathophysiological effects per 1000 persons  exposed
as a function of dose level.  If one acute effect per 1000 persons  within
5 years (TD 0.1/5) is taken as the threshold for the initiation of
clinical pathophysiological effects in organs other than thyroid, the
equivalent dose level for most organs is 550 rets or more; testes 440 ^
150 rets, ovary 170 + 70 rets, and bone marrow 165 rets.

     The radiation exposure to organs in rad units that will cause
clinical pathophysiological effects within 5 years to 0.1 percent of the
exposed population as a function of the duration of a continuous level  of
exposure can then be estimated by using Goitein's modification of the Kirk
methodology (60-76).  This relationship is shown in Table B-3.
Table B-3  Radiation Exposure to Organs Estimated to Cause Clinical
           Pathophysiological Effects within 5 Years to 0.1 Percent
           of the Exposed Population  (GO-76)
Duration of
exposure
(days)
(acute)
1
2
4
7
30
365b

Ovary
(rad)
(170 rets)*
315
390
470
550
840
1740

Bone marrow
(rad)
(165 rets)
300
380
450
540
820
1690

Testes
(rad)
(440 rets)
810
1010
1210
1430
2190
4510

Other organs
(rad)
(550 rets)
1020
1260
1510
1790
2740
5640
aThe dose in rets is numerically equal to the dose in rads.
^Assuming tissue recovery can continue at the same rate as observed
 during 30- to 60-day therapeutic exposure courses.
     Bone marrow is an organ of particular concern because radionuclides
known to concentrate in this organ system occur in nuclear incidents.  The
acute lethality due to the hematologic syndrome (LA-67) is estimated to
                                   B-20

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occur in the range of 200 to 1,000 rad, so that the difference  is  small
between exposure levels that might cause acute lethality and exposure
levels that might cause only "severe clinical pathophysiology,"  as  derived
from radiotherapy data.

     In summary, organ systems are not expected to show symptoms of severe
clinical pathophysiology for projected short-term exposure doses less  than
a few hundred rad.  Projected doses to bone marrow at  this high  level  are
relatively more serious and more likely to result in injury than doses to
other organ systems.

     Even if severe clinical pathophysiological effects can be  avoided,
there is still a possibility of clinical pathophysiological effects of a
less severe or transitory nature.  The 1982 UNSCEAR report (UN-82)
reviewed much of the data on animals and man.  In the  animal studies,
there were reports of:  changes in stomach acid secretion and stomach
emptying at 50 to 130 rad; stunting in growing animals at the rate  of  3 to
5 percent per 100 rad; degeneration of some cells or functions  in
the brain at 100 rad, particularly in growing animals; temporary changes
in weight of hematopoietic tissues at 40 rad; and more damage in ovaries
and testes caused by fractionated doses rather than acute doses.   Some of
the effects are transitory, others are long-lasting, but with only  minor
reductions in functional capacity.

     Human data are limited and are reported primarily in the radiotherapy
literature.  The data suggest most tissues in man are more radiation
resistant than those in animals.  However, the human hematopoietic  system
shows a transient response, reflected by decreased circulating white cells
and platelets, at about 50 rad.  Temporary sterility has been observed
after doses of 150 rad to the ovaries and 10 rad to the testes,  when given
as fractionated doses.

     There is not sufficient data to determine dose-response functions
nor to describe the duration and severity 'of dysfunction expected.
                                   B-21

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8.2.2  Summary and Conclusions Regarding Acute Effects

     Based on the foregoing review of acute health effects  and  other
biological effects from large doses delivered over short periods of time,
the following whole body doses from acute exposure provide  useful
reference levels for decisionmaking for PAGs:

     50 rad  -  Less than 2 percent of the exposed population would be
                expected to exhibit prodromal (forewarning) symptoms.

     25 rad  -  Below the dose where prodromal symptoms have been  observed.

     10 rad  -  The dose level below which a fetus would not be expected
                to suffer teratogenesis (but see Section B.3, Mental
                Retardation.).

     5 rad  -   The approximate minimum level of detectability  for acute
                cellular effects using the most sensitive methods.
                Although these are not severe pathophysiological effects,
                they may be detrimental.

     Based on the first principle to be satisfied by PAGs (paragraph
B.I.6), which calls for avoiding acute health effects, values of 50 rem
for adults and 10 rem for fetuses appear to represent upper bounds.

B.3  Mental Retardation

     Brain damage to the unborn is a class of injury reported in atomic
bomb survivors which does not fall into either an acute or delayed effect
category, but exhibits elements of both.  What has been observed is a
significant, dose-related increase in the incidence and severity of mental
retardation, microencephaly (small head size), and microcephaly (small
brain size) in Japanese exposed to radiation in utero during the 8th to
15th week after conception (BL-73; MI-76).  While the actual injury may be
acute, it is not identified until some time after birth.
                                   B-22

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     In an early study Mole (MO-82) suggested that, although radiation
may not be the sole cause of these conditions,  it  is prudent to  treat the
phenomenon as radiation-related.  More recently, Otake and Schull  (OT-83)
have concluded:  (1) there is no risk to  live-born due to doses  delivered
up to 8 weeks after conception, (2) most  damage occurs at the time when
rapid proliferation of neuronal elements  occurs, i.e., 8 to 15 weeks of
gestational age, (3) the dose-response function for incidence during this
period appears to fit a linear model, (4) the risk of occurrence is about
five times greater during the period 8-15 weeks of gestation than  in
subsequent weeks, and (5) in later stages of gestation, e.g., after the
15th week, a threshold for damage may exist.

     In their published reports, Otake and Schull  (OT-83) evaluated the
incidence of severe mental retardation using the T-65 dosimetry  and the
dosimetry estimates developed in the ongoing dose  reassessment program for
the atomic bomb survivors, and using two  tissue dose models.  Their
estimated ranges of risk were:

          8 to 15 weeks after gestation:  3-4xlO~3  cases/rad;
          16 or more weeks after gestation: 5-7xlO~4 cases/rad.

The higher values are based on the T-65 dosimetry  and the Oak Ridge National
Laboratory estimate of tissue dose.  The  lower  values are based  on Oak Ridge
National Laboratory dosimetry and the Japanese  National Institute  of
Radiological Sciences estimates of tissue dose.  Later estimates based on  the
dose reassessment completed in 1986 are consistent with these published
results (SC-87).

     In view of the foregoing, the risk of mental  retardation from exposure
of a fetus in the 8th to 15th week of pregnancy is taken to be about 4xlO~
per rad.  Because of this relatively high risk, special consideration should
be given to protection of the fetus during this period.  The risk  to a fetus
                                            _4
exposed after the 15th week is taken as 6x10    per rad.  For the cases
studied (OT-84), no increased incidence of mental  retardation was  observed
for exposure during the 1st to the 7th week of  pregnancy.
                                   B-23

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     Federal Radiation Protection Guidance, adopted  in  1987, recommends  that
dose to occupationally exposed pregnant women be controlled to keep  the  fetal
dose below 0.5 rem over the entire term of pregnancy, and  that no  dose be
delivered at more than the uniform monthly rate that would satisfy this  limit
(i.e., approximately 50-60 mrem/month)(EP-87).  The  NCRP has, for  many years,
recommended a limit of 0.5 rem (NC-71).  ICRP recommends controlling exposure
of the fetus to less than 0.5 rem in the first 2 months to provide
appropriate protection during the essential period of organogenesis  (IC-77).

B.4  Delayed Health Effects

     This section addresses information relevant to  the second principle
(paragraph B.I.5) for establishing PAGs, the risk of delayed health  effects
in exposed individuals.  The following subsections summarize the estimated
risks of cancer and genetic effects, the two types of delayed effects caused
by exposure to radiation.

B.4.1  Cancer

     Because the effects of radiation on human health have been more
extensively studied than the effects of many other environmental pollutants,
it is possible to make numerical estimates of the risk  as  a result of a
particular dose of radiation.  Such estimates, may,  however, give  an
unwarranted aura of certainty to estimated radiation risks.  Compared to the
baseline incidence of cancer and genetic defects, radiogenic cancer  and
genetic defects do not occur very frequently.  Even  in  heavily irradiated
populations, the number of cancers and genetic defects  resulting from
radiation is known with only limited accuracy.  In addition, all members of
existing exposed populations have not been followed  for their full lifetimes,
so data on the ultimate numbers of effects is not yet available.   Moreover,
when considered in light of information gained from  experiments with animals
and from various theories of carcinogenesis and mutagenesis, the observed
data on the effects of human exposure are subject to a  number of
interpretations.  This, in turn, leads to differing  estimates of radiation
risks by individual scientists and expert groups.  In summary, the estimation
                                   B-24

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of radiation risks is not a fully mature science and the evaluation of
radiation hazards will continue to change as additional information
becomes available.

     Most of the observations of radiation-induced carcinogenesis  in
humans are on groups exposed to low-LET radiations.  These groups  include
the Japanese A-bomb survivors and medical patients treated with x-rays  for
ankylosing spondylitis in England from 1935 to 1954 (SM-78).  The  National
Academy of Science Committee on the Biological Effects of Ionizing
Radiations (6EIR) (NA-80) and UNSCEAR (UN-77) have provided knowledgeable
and exhaustive reviews of these and other data on the carcinogenic effects
of human exposures.  The most recent of the BEIR studies was published  in
1980 and is here designated BEIR-3 to distinguish it from previous reports
of the BEIR committee.

     The most important epidemiological data on radiogenic cancer  is  that
from the A-bomb survivors.  The Japanese A-bomb survivors have been
studied for more than 40 years, and most of them have been followed  in  a
major, carefully planned and monitored epidemiological survey, the Life
Span Study Sample, since 1950 (KA-82, WA-83).  They were exposed to a wide
range of doses and are the largest group that has been studied.  They are
virtually the only group providing extensive information on the response
pattern at various levels of exposure to low-LET radiation.

     The estimated cancer risk from low-LET, whole body, lifetime  exposure
presented here is based on a life table analysis using a linear response
model.  We use the arithmetic average of relative and absolute risk
projections (the BEIR-3 L-L model) for solid cancers, and an absolute
risk projection for leukemia and bone cancer (the BEIR-3 L-L model).  For
whole body dose, this yields an estimated 280 (with a possible range  of
120 to 1200) fatalities per million person-rem for a population cohort
representative of the 1970 U.S. population.  We assume this estimate  also
applies to high-LET radiation (e.g. alpha emitters); no reduction  has been
                                   B-25

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                                                -4            3
applied for dose rate.  (The rounded value, 3x10   fatalities   per
person-rein, has been selected for this analysis.)
     Whole body dose means a uniform dose to every organ  in the  body.   In
practice, such exposure situations seldom occur, particularly  for  ingested  or
inhaled radioactivity.  Inhaled radioactive particulate materials  may  be
either soluble or insoluble.  Soluble particulate materials deposited  in the
lung will be rapidly absorbed, and the radionuclides associated  with them
distributed throughout the body by the bloodstream.  As these  radionuclides
are transported in the blood, they irradiate the entire body.  Usually, they
then redeposit in one or more organs, causing  increased irradiation of that
organ.  Insoluble particulate materials, on the other hand, are  only
partially absorbed into body fluids.  (This fraction is typically  assumed to
be about 8 percent.)  This absorption occurs over a period of  years, with a
portion entering the bloodstream and another retained in  the pulmonary lymph
nodes.  The balance (92 percent) of inhaled insoluble particulate  materials
are removed from the lung within a few days by passing up the  air  passages  to
the pharynx where they are swallowed.  Inhaled insoluble  particulate materials
thus irradiate both the lung and the gastrointestinal tract, with  a small
fraction being eventually absorbed into the bloodstream (TG-66).   These
nonuniform distributions of dose (and therefore risk) are taken  into account
through use of the weighting factors for calculating effective dose.

     There is a latent period associated with  the onset of radiation-induced
cancers, so the increased risk is not immediately apparent.  The increased
risk is assumed to commence 2 to 10 years after the time  of exposure and
continue the remainder of the exposed individual's lifespan (NA-80).
^Preliminary reviews of new results from studies of populations exposed
 at Hiroshima and Nagasaki indicate that these risk estimates may be
 revised upwards significantly in the near future, particularly for acute
 exposure situations.  EPA has recently used a slightly higher value,
 4 x 10~4 fatalities in standards for air emissions under the Clean Air
 Act.  We will revise these risk estimates to reflect new results following
 appropriate review.
                                   B-26

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     For uniform exposure of the whole body, about 50 percent of  radiation-
induced cancers in women and about 65 percent in men are fatal  (NA-80).
Therefore, 1 rem of low-LET radiation would be expected to cause  a  total
of about 500 cancer cases if delivered to a population of one million.
(In the case of thyroid and skin, the ratio of nonfatal to fatal  cancers
are much higher.  These are addressed separately below.)  This  corresponds
to an average annual individual probability of developing cancer  of about
7x10"  per year.  For perspective, the average annual risk of dying of
cancer from all causes in the United States, in 1982, was 1.9x10" .

B.4.1.1  Cancer Risk Due to Radiation Exposure of the Thyroid

     Exposure of the thyroid to extremely high levels of radiation  may
cause it to degenerate.  At moderate levels of exposure some  loss of
thyroid function will occur.  At lower levels of exposure, there  are
delayed health effects, which take the form of both thyroid nodules and
thyroid malignancies (NA-72; NA-80).  Doses as low as 14 rad  to the
thyroid have been associated with thyroid malignancy in the Marshall
Islanders (CO-70).  The increased risk of radiation-induced cancer  is
assumed to commence about 10 years after initial exposure and to  continue
for the remaining lifespan of an exposed individual.

     The true nature of thyroid nodules cannot be established until  they
are surgically removed and examined histologically, and those that  are
malignant can lead to death if not surgically removed (SA-68; DE-73;
PA-74).  Although thyroid malignancies are not necessarily fatal,  effects
requiring surgical removal of the thyroid cannot be considered  benign.   In
this analysis, all thyroid cancers, both fatal and nonfatal,  are  counted
for the purpose of estimating the severity of thyroid exposures.

     Based on findings in BEIR-3, we estimate that 1 rem of thyroid
                                                                _4
exposure carries a risk of producing a thyroid cancer of 3.6x10  ,  of
which a small fraction (on the order of 1 in 10) will be fatal  (NA-80).
Since the calculation of effective dose equivalent does not include
consideration of nonfatal thyroid cancers and the severity of the medical
procedures for their cure, it is appropriate to limit the dose  to the

                                   B-27

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thyroid by an additional factor beyond that provided by the PAG expressed
in terms of effective dose equivalent.  Protective action to  limit  dose  to
thyroid is therefore recommended at a thyroid dose 5 times the numerical
value of the PAG for effective dose.

B.4.1.2  Cancer Risk Due to Radiation Exposure of the Skin

     The risk of fatal skin cancer is estimated to be on the  order  of  one
percent of the total risk of fatal cancer for uniform irradiation of the
entire body (IC-78).  However, since the weighting scheme for calculating
effective dose equivalent does not include skin, the PAG expressed  in
terms of effective dose does not provide protection against radionuclides
which primarily expose skin.  As in the case of the thyroid,  the ratio of
nonfatal to fatal cancers from irradiation of the skin is high (on  the
order of 100 to 1).  It would not be appropriate to ignore this high
incidence of nonfatal skin cancers by allowing 100 times as much dose  to
the skin as to the whole body.  For this reason, evacuation is recommended
at a skin dose 50 times the numerical value of the PAG for effective dose.

B.4.1.3  Cancer Risk Due to Radiation Exposure of the Fetus

     The fetus is estimated to be 5 to 10 times as sensitive  to radio-
genic cancer as an adult (FA-73; WH-65).  Stewart reports increased
relative incidence of childhood cancers following prenatal x-ray doses as
low as 0.20 to 0.25 rem and doubling of childhood cancers between 1-4  rem
(ST-73).  She concluded that the fetus is about equally sensitive to
cancer induction in each trimester.  Her findings are supported by  similar
results reported by MacMahon and Hutchinson (MA-64), Kaplan (KA-58),
Polhemus and Kock (PO-59), MacMahon (MA-63), Ford, et ah (FO-59),  Stewart
and Kneale (ST-70b), and an AEC report (AE-61).  MacMahon reported  that
although there were both positive and negative findings, the  combination
of weighted data indicates a 40 percent increase in childhood cancer
mortality after in vivo exposure to diagnostic x rays (1.0 to 5.0 rad):
about 1 cancer per 2,000 exposed children in the first 10 years after
birth (MA-63).  He concluded that although the range of dose  within which
                                   B-28

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these effects are observed is wide, effects will be fewer at 1 rad  than  at
5 rad.

     Graham, et al., investigating diagnostic x-ray exposure, found a
significantly increased relative risk of leukemia  in children:   by  a
factor of 1.6 following preconception irradiation  of mothers or  in  utero
exposure of the fetus; by a factor of 2 following  postnatal irradiation  of
the children; and by a factor of 2 following preconception  irradiation of
the mother and in utero exposure of the child (GR-66).

B.4.1.4  Age Dependence of Doses

     Almost all dose models are based on ICRP "Reference Man," which
adopts the characteristics of male and female adults of working  age.
ICRP-30 dosimetric models, which use "Reference Man" as a basis,  are
therefore appropriate for only adult workers and do not take into account
differences in dose resulting from the differences in physiological
parameters between children and adults, e.g., intake rates, metabolism,
and organ size.  Although it is difficult  to generalize for all
radionuclides, in some cases these differences tend to counterbalance
each other.  For example, the ratio of volume of air breathed per unit
time to lung mass is relatively constant with age, so that the ICRP adult
model for inhaled materials provides a reasonably  good estimate  of  the
dose from a given air concentration of radioactive material throughout
life.

     The thyroid is an exception because the very  young have a relatively
high uptake of radioiodine into a gland that is much smaller than the
adult thyroid (see Section B.4.2.2.).  This results in a larger  childhood
dose and an increased risk which persists  throughout life.  Me have
examined this worst case situation.  Age-specific  risk coefficients for
fatal thyroid cancer (See Table 6-8 of "Risk Assessment Methodology"
(EP-89)) are about 1.9 higher per unit dose for persons exposed  at  ages  0
to 9 years than for the general population.  Age-dependent dose  factors
(see NRPB-R162 (GR-85)) for inhalation of  1-131, are a factor of  about 1.7
higher for 10 year olds than for adults.   Therefore, the net risk of fatal

                                   B-29

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thyroid cancer from a given air concentration of 1-131 is estimated to be
a factor of about 3 higher for young children than for the remainder of
the population.  This difference is not considered large enough, given the
uncertainties of exposure estimation for implementing protective actions,
to warrant establishing age-dependent PAGs.

B.4.2  Genetic Risk

     An average parental dose of 1 rem before conception has been
estimated to produce 5 to 75 significant genetically-related disorders
per million liveborn offspring (NA-80).  For this analysis we use  the
geometric mean of this range, i.e. 1.9x10" .  This estimate applies to
effects in the first generation only, as a result of dose to parents of
liveborn offspring.  The sum of effects over all generations is estimated
                                                         -4
to be approximately twelve times greater; that is, 2.3x10  .  In
addition, since any radiation dose delivered after a parent's last
conception has no genetic effect, and not all members of the population
become parents, less than half of the entire dose in an average population
is of genetic significance.  Taking the above factors into account, we
estimate that the risk of genetically-related disorders in all generations
       -4
is 1x10   per person-rem to a typical population.

     Although the overall severity of the genetic effects included as
"significant" in the above estimates is not well known, rough judgements
can be made.  The 1980 BEIR report referred to "	disorders and  traits
that cause a serious handicap at some time during lifetime" (NA-80).  From
the types of defects reported by Stevenson (ST-59), it can be estimated
that, of all radiation-induced genetic effects, 50 percent lead to minor
to moderate medical problems (i.e., hair or ear anomalies, polydactyl,
strabismus, etc.), 25 percent lead to severe medical problems (i.e.,
congenital cataracts, diabetes insipidus, deaf mutism, etc.), 23 percent
would require extended hospitalization (i.e., mongolism, pernicious
anemia, manic-depressive psychoses, etc.), and 2 percent would die before
age 20 (i.e., anencephalus, hydrocephalus, pancreatic fibrocytic disease,
etc.).
                                   B-30

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B.4.3  Summary of Risks of Delayed Effects

     Table B-4 summarizes average lifetime risks of delayed  health  effects
based on results from the above discussion.  Because of the  nature  of  the
dose-effect relationships assumed for delayed health effects  from
radiation (linear, nonthreshold), there is no dose value below which no
risk can be assumed to exist.

Table B-4  Average Risk of Delayed Health Effects in a Population3

Fatal cancers
Nonfatal cancers
Genetic disorders
(all generations)
Effects
Whole Body
2.8E-4&
2.4E-4b
l.OE-4
per person-rem
Thyroid0
3.6E-5
3.2E-4


Skin
3.0E-6
3.0E-4

3 Me assume a population with the same age distribution  as  that  of  the
  U.S. population in 1970.
0 Risk to the fetus is estimated to be 5 to  10 times higher.
c Risk to young children is estimated to be  about  two  to three  times
  as high.
B.4.4  Risks Associated with Other Radiation Standards

     A review of radiation standards for protection of members of  the
general population from radiation shows a range of values spanning several
orders of magnitude.  This occurs because of the variety of bases  (risk,
cost, practicability of implementation, and the situations to which  they
apply) that influenced the choice of these standards.  Some source-
specific standards are relatively protective, e.g., the EPA standard
limiting exposure of the public from nuclear power operations (25  mrem/y)
from all pathways combined corresponds to a risk (for cancer death)  of
     A
5x10   for lifetime exposure.  Similarly, regulations under the Clean

                                   B-31

-------
Air Act limit the dose due to emissions of radionuclides  to  air  alone  from
all DOE and NRC facilities to 0.01 rem per year, which corresponds  to  a
                   _4
cancer risk of 2x10   for lifetime exposure.  Other guides permit much
higher risks.  For example, the level at which the EPA recommends action
to reduce exposure to indoor radon (0.02 working levels)  corresponds to a
risk of about 2x10"  (for fatal lung cancer) for lifetime exposure.  All
of these standards and guides apply to nonemergency situations and  were
based on considerations beyond a simple judgement of  acceptable  risk.

     Federal Radiation Protection Guidance for nonemergency  situations
recommends that the dose from all sources combined (except from  exposure
to medical and natural background radiation) to individuals  in the
population not exceed 0.5 rem in a single year (FR-60) and that  the dose
to the fetus of occupationally-exposed mothers not exceed 0.5 rem during
the 9-month gestation period (EP-87).  This dose corresponds to  an  annual
incremental risk of fatal cancer to members of the general population  of
            _4
about 1.4x10  .  If exposure of the fetus is limited  to one  ninth of 0.5
rem per month over a 9-month gestation period, as recommended, the  risk of
severe mental retardation in liveborn is limited to about 7x10"  .

     The International Commission on Radiation Protection recommends that
the dose to members of the public not exceed 0.5 rem  per  year due to
nonrecurring exposure to all sources of radiation combined,  other than
natural sources or beneficial medical uses of radiation  (IC-77).  They
also recommend a limiting dose to members of the public of 0.1 rem  per
year from all such sources combined for chronic (i.e., planned)  exposure
(IC-84a).  These upper bounds may be taken as representative of  acceptable
values for the situations to which they apply.  That  is,  these are  upper
bounds of individual risk that are acceptable for the sum of all  sources
and exposure pathways under international recommendations, for
circumstances that are justified on the basis of public benefit,  and when
actual doses from individual sources are "as low as reasonably achievable"
(ALARA) within these upper bounds.
                                    B-32

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                                   B-36

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         in Late Radiation Injury in Diverse Organs.  Cancer Research 37
         (Suppl.)1976:2046-2055.

WH-84    WORLD HEALTH ORGANIZATION. Nuclear power: Accidental releases
         -principles of public health action.  WHO Regional Publications,
         European Series No. 16. 1984.
                                   B-40

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       APPENDIX C
Protective Action Guides
  for the Early  Phase:

 Supporting  Information
        (Reserved)
           C-l

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                                  APPENDIX D*
               Background  for Protective Action Recommendations:
                    Accidental  Radioactive Contamination of

                            Food  and Animal  Feeds**
*This is a new Appendix and is not the one referred to in Chapter 5.  The
 original Appendix D "Technical Bases for Dose Projection Methods" published
 in this manual in 1980 has been deleted and the material incorporated  into
 the "Accident Assessment" training program conducted by the Federal
 Emergency Management Agency.

**This background document concerning food and animal feeds was published by
 the Food and Drug Administration in 1982.

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                                              HHS Publication FDA 82-8196
 Background for Protective Action
   Recommendations: Accidental
    Radioactive Contamination  of
       Food  and Animal Feeds
               B. Shleien, Pharm.D.
                 G.D. Schmidt
            Office of the Bureau Director

                     and

             R. P. Chiacchierini, Ph.D.
            Division of Biological Effects
              WHO Collaborating Centers for
              • Standardization of Protection
                Against Nomonizmg Radiations
              • Training and General Tasks in
                Radiation Medicine
              • Nuclear Medicine
                 August 1982
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
               Public Health Service
           Food and Drug Administration
             Bureau of Radiological Health
               Rockville. Maryland 20857

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                                    FOREWORD


   The Bureau of Radiological Health develops and  carries out a  national program to
control unnecessary human exposure  to  potentially hazardous ionizing and nonionizing
radiations and to ensure the safe, efficacious use of such radiations.  The Bureau publishes
the results of its work in scientific journals and in its own technical reports.

   These  reports provide a mechanism for disseminating results of Bureau and contractor
projects.  They  are  distributed to Federal, State, and local  governments; industry; hos-
pitals; the medical  profession; educators; researchers; libraries; professional  and trade
organizations; the press; and  others.  The reports are sold by the Government Printing
Office and/or the National Technical Information Service.

   The Bureau also makes its technical reports available to the World  Health Organization.
Under a  memorandum of agreement between WHO  and the Department of Health  and
Human Services, three WHO Collaborating Centers have been established within the Bureau
of Radiological Health, FDA:

      WHO Collaborating  Center for Standardization  of  Protection  Against Nonionizing
      Radiations;

      WHO Collaborating Center for Training and General Tasks in Radiation Medicine; and

      WHO Collaborating Center for Nuclear Medicine.

   Please report errors or  omissions  to  the  Bureau.   Your  comments and requests for
further information are also encouraged.
                                               John C. Villforth
                                              'Director
                                               Bureau of Radiological Health
                                          11

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                                    PREFACE
   By FEDERAL  REGISTER action of March 11,  1982 (*7 FR 10758),  the Federal Emer-
gency Management Agency (FEMA) outlined the responsibilities of several Federal agencies
concerning emergency response planning guidance that the agencies should provide to State
and local authorities.  This updated a prior notice published in the FEDERAL REGISTER by
the General Services Administration (GSA) on December  2
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                                     ABSTRACT
Shleien, B., G.D.  Schmidc,  and R.P. Chiacchierini.  Background for  Protecrive Action
Recommendations: Accidental Radioactive Contamination of Food and Animal Feeds.  HHS
Publication FDA 82-8196 (August 1982) (pp. 44).

        This report provides background material for the development of FDA's
     Protective Action Recommendations:  Accidental Radioactive Contamination
     of Food and Animal Feeds. The rationale, dosimetric  and agricultural transport
     models for the Protective Action Guides are presented, along with information
     on dietary intake.  In  addition, the document contains  a discussion of fie!4
     methods of analysis of radionudides  deposited on  the  ground or  contained
     in milk  and herbage.  Various protective actions are described and evaluated,
     and a cost-effectiveness analysis for the recommendations performed.
             The opinions and statements contained in this report may not
          necessarily represent  the 'views  or  the  stated policy  of  the  World
          Health Organization (WHO).  The mention of commercial products,
          their  sources, or their  use in connection with material reported
          herein is  not  to  be construed  as either  an  actual or  implied
          endorsement  of  such  products by  the Department of Health  and
          Human Services (HHS) or the World Health Organization.
                                        IV

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                                    CONTENTS

                                                                          Page

Foreword	ii

Preface	iii

Abstract	  iv

Chapter 1. Rationale for Determination of the Protective Action Guides  ....   1

   1.1 Introduction	   1
   1.2 Models for Evaluation of Risk	   1

       1.2.1 Somatic Risk Evaluation	   1
       1.2.2 Genetic Risk Evaluation	   2

   1.3 Assessment of Common Societal and Natural Background
       Radiation Risks	   3

       1.3.1 Common Societal Risks	   3
       1.3.2 Risks from Natural Radiation	   4

   1.4 Preventive and Emergency PAG's	   5

       1.4.1 Preventive PAG	   6
       1.4.2 Emergency PAG	   7

   1.5 Evaluation of PAG Risks	   7

Chapter 2. Oosimetric Models,  Agricultural Transport Models,
           Dietary Intake, and Calculations  . ,	   8

   2.1 Dosimetrie Models	   8

       2.1.1 Introduction	   8
       2.1.2 Iodine-131: Dose to Thyroid	   8
       2.1.3 Cesium-137 and-134: Dose to  Whole Body	   9
       2.1.4 Strontium: Dose to Bone  Marrow	10
       2.1.5 Other Radionuclides	  11

   2.2 Agriculture Transport Models ,	  12

       2.2.1 Transport Models	  12
       2.2.2 Total Intake	  13
       2.2.3 Peak Concentration	  14

   2.3 Dietary Intake	14

   2.4 Calculations	15

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                                                                            Page

Chapter 3. Methods of Analyses for Radionuclide Determination	18

   3.1 Introduction	18

   3.2 Determinations of Radionuclide Concentrations by
       Sensitive Laboratory Methods	     18

   3.3 Determinations of Radionuclide Concentrations by Field Methods  ....   19

       3.3.1  Ground Contamination (Beta Radiation)	19
       3.3.2  Herbage	20
       3.3.3  Milk	21

Chapter 4. Protective Actions	26

Chapter 5. Cost Considerations	31

   5.1 Cost/Benefit Analysis	31

       5.1.1  Introduction	31
       5.1.2  Benefit of Avoided Dose	32
       5.1.3  Protective Action Costs	32
       5.1.4  Population Milk Intake and Dose	33
       5.1.5  Milk Concentration for Cost = Benefit	33

   5.2 Economic Impact	35

   5.3 Cost-Effectiveness Analysis	37

   5.4 Summary and Conclusion	38

References	39
                                         VI

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               CHAPTER 1. RATIONALE FOR DETERMINATION OF THE
                            PROTECTIVE ACTION GUIDES
1.1 INTRODUCTION

   The process of determining  numerical limits for radiation  standards  is one  of  risk
assessment.  This process, in which risk considerations are an important factor in decision-
making, consists of two elements: determination of the probability that an event will occur,
and determination of "acceptable risk." A recent discussion of acceptable risk defines risk
as a measure of  the  probability  and severity of adverse  effects. Safety is the degree  to
which risks are judged acceptable (1).

   Since  initiation  of protective action assumes   that  an  accident  has occurred, no
attention will be given to the estimation of  probabilities for accident occurrence in the
present analysis.

   One process of determining "acceptable risk" is to compare estimates of  risk associated
with an  action with already prevalent or "natural" risks that  are accepted by society.
This method of evaluation  is employed in the present discussion by comparing the  risk
from  natural disasters and from the  variation in "natural radiation background"  to the
radiation risk associated with the numerical limits for the  Protective Action  Guides  (PAG).

   "Protective action  guide"  (PAG)  means  the  projected  dose commitment  values  to
individuals in the general population that warrant protective action following a release of
radioactive material. Protective action would be warranted if the expected  individual dose
reduction is not offset by negative social, economic, or health effects. The PAG does not
include the  dose  that has unavoidably occurred prior to  the assessment. "Projected dose
commitment" means  the dose commitment that would be received in the  future by indi-
viduals in the population  group from the contaminating event if no  protective  action
were taken.  The projected dose commitment  is expressed in the  unit of dose equivalent or
the rem.

   The "natural  radiation  background" consists of  contributions from external  radiation
and internal  deposited radioactivity from  ingestion and inhalation. For the  most part, the
variation  in  the  internal natural radiation dose is  due  to the  variability  of whole-body
potassium-40.  Since  these PAG's are limited to ingestion, a parameter that describes the
variability of the internal natural radiation dose might appear more appropriate  than using
the variability of  the external or total natural radiation dose in evaluating the acceptability
of a given level of risk. However, the  potassium level in the body (and hence internal dose)
is controlled  by metabolic processes and dietary intake has little  effect.  Hence the risk of
natural disasters, which is dependent on geographical  location  of  residence,  is  in  this
agency's opinion a better measure of acceptable risk.


1.2 MODELS FOR EVALUATION OF RISK

   Models for the somatic and genetic effects of radiation are required for  comparisons of
radiation risks from the PAG's relative  to other naturally occurring risks.

1.2.1  Somatic Risk Evaluation

   A review  of the current literature  indicates that the  risk estimates developed in the
National Academy of Science Committee  on the Biological Effects of Ionizing Radiation or
the BEIR-I report (2) and  the BEIR-HI report (3) are appropriate for use  in analysis of

                                         1

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somatic risk.  Mortality rather than incidence estimates are employed in the comparisons.
In the case  of  comparisons  to  natural  background radiation,  use  of mortality data or
incidence estimates would yield  the same numerical PAG limits, because these limits are
based on a comparison between risks rather than an evaluation of absolute risk.

   The radiation doses in the event of a contaminating accident will most likely result from
ingestion of the  fission products cesium-134 and -137; strontium-89 and -90; and iodine-131.
For  the  purpose of this analysis it  is assumed that all  projected extra cancers  can be
attributed to internal  radiation via  the food pathway  (i.e.,   the  risks from ingested
radioactive material is the same as that fro n external radiation).

   The BEIR-III (3) best estimate of lifetime cancer  risk (linear quadratic model) for a
single exposure to low-dose, low LET radiation is from 0.77 to 2.26 x 10~* deaths per person-
rem, depending on whether the absolute or relative-risk projection model is used (calculated
from Table  1).  The equivalent risk estimate from BEIR-I (2) is  1.17 to 6.21 x  10~* deaths
per person-rem.

                      Table 1.  Risk estimates for single dose

                                       Deaths per million persons per 10
                                   rads single  dose whole-body BEIR-III
Dose response model
Linear quadratic
Linear
Quadratic
Absolute risk
766
1671
95
Relative risk
2255
5014
276
   These risk estimates are for a single dose of 10 rem, because limitations of the scientific
information do not justify estimates at  lower doses according to the BEIR Committee.
Because of the uncertainty of risk estimates at low doses, BEIR-III provided risk estimates
based on a linear model and a pure quadratic dose response model as well as estimates based
on the preferred linear quadratic model.  The risk estimates for the linear model are about
a factor of 2 higher and those of the quadratic model^and  about a factor of S lower than
those of the linear quadratic  model.   It should further be noted,  that BEIR-III does not
recommend that  their risk  estimates be  extrapolated  to lower  doses  because  of the
inadequacies of the scientific basis.  BEIR-III does  recognize however that Federal agencies
have a need to estimate impacts at lower doses. While BEIR-III prefers  the linear-quadratic
dose response model as the best estimate, regulatory agencies have continued to favor the
linear  model as  the basis for making risk estimates.   While the BEIR-III estimates will be
used here  to estimate  the impact (health  effects) at lower doses,  it is  fully recognized
that current scientific opinion leaves alternatives  as  to which dose response and risk model
to use.

   As previously stated, for  the purpose of  setting PAG's, comparison of radiation risks to
those from natural disasters is considered  the approach of choice in this document.

1.2.2 Genetic Risk Evaluation

   The model for genetic risks from radiation exposure is described in the BEIR-III report
(3).  In  the first generation, it is estimated  that 1  rem of parental  exposure throughout the
general population will  result in an increase of 5 to 75 additional serious genetic disorders
per million liveborn offspring. The precision for estimating genetic risks is less precise than
those for somatic risks.  Given the broad range,  genetic  risks are evaluated,  but are not
precise enough to be a basis for setting the PAG's.

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1.3   ASSESSMENT  OF COMMON SOCIETAL AND  NATURAL BACKGROUND RADIA-
      TION RISKS

1.3.1  Common Societal Risks

   As previously  stated,  one  m-thod  of determining the acceptability  of  a risk  is by
comparing prevalent or normal risks from hazards common to society. A list of the annual
risks  from common societal hazards is given in Table 2. Comparision of radiation  risks to
commonly accepted societal risks Assumes that the age dependencies are similar and  that all
individuals are equally exposed tr the  hazard.   This latter assumption  is, of course, not
entirely valid in that persons nearer a nuclear power plant or a dam, or in an earthquake or
tornado area might be  expected to be at greater  risk than persons living at a distance from
the particular hazard.

             Table 2.  Annual risk of death from  hazards common to society

                                                            Risk of death
                  Category                Reference   (per  person per  year)
All disease
Leukemia and all other cancer
Motor vehicle accidents
Accidental poisoning
Air travel
Tornadoes (Midwest)
Earthquakes (Calif.)
Floods (46 million at risk)
Catastrophic accidents
(tornadoes, floods,
hurricanes, etc.)
Natural disasters

Tornadoes

Hurricanes

Floods

Lightning
Winter storms
(<0
(5)
(6)
(6)
(7)
(8)
(8)
(9)


(10)
(11)
(6)
(7)
(9)
(7)
(9)
(8)
(9)
(7)
(9)
8 x 10-3
1.5 x 10-J
3 x 10-"
1 x 10'5
9 x 10"'
2 x 10-6
2 x 10-'
2.2 x 10-6


1.2 x 10~'
9 x lO'7
8 x Iff1
0.4 x ID'6
0.6 x 10-'
0.* x ID'6
0.3 x 10-'
2 x 10"s
0.5 x 10"'
0.5 x 10-'
0.* x ID'6
         Natural  disasters (sum  of  above)	2.1  to  3.9 x 10~6

   Table 2 indicates that the annual individual risk from natural disasters is approximately
1 to  k x  10"6.  This risk represents a common risk level, which is generally not considered
in selecting place of residence.  At this level of risk, some action to prevent further loss of
life could be expected  by society following  the occurrence of a natural disaster.  It  thus
appears prudent to evaluate the somatic risks from radiation in relation to the risk of death
from  a natural  disaster.  For comparison purposes, a value of 1 in a million (1 x 10'6) annu-
al risk of death,  which is often quoted as an acceptable risk, will be used as the risk of
natural disasters.  Actual data indicate that the risk of  natural disasters may be a  2  or 3
times greater risk than this value.   For a risk of death of 1 x 10"' per year, the lifetime
accepted societal risk would be about 70 x  10"6.  This is equivalent to a single radiation
dose of  1*0 to  420 mrem, using  the linear model, or 310 to 910 mrem using the BEIR-III
linear  quadratic model (see  Table 1). The upper and lower ranges are those obtained from
employment  of relative and absolute risk  models and  the  dose response extrapolations
mentioned  above (from calculations based on  data in Table  1).  Genetic effects are not
considered  m evaluating common societal hazards because of  the difficulty in  assessing

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deaths occurring from genetic consequences, either natural or radiation induced.  If sponta-
neous abortions  are  deleted from mis  category,  then  fatal genetic effects  are a small
portion of the overall genetic  impact on health.   However, it is difficult to accurately
evaluate genetic effects, and even more difficult to compare its impact to the impact of
somatic effects in an effective manner.


1.3.2 Risks From Natural Radiation

    Further perspective i»n acceptable risk can be obtained by examining the risks of natural
background radiation.  In risk assessments where a radiation risk is compared co that from
the  natural radiation background,  the question is which variable associated with natural
background should be used to determine  "acceptable risk?"  Since background radiation has
always  been  a part of the natural  environment,  a plausible argument might be  to assume
that the risks associated with the average natural radiation dose represent an  "acceptable
risk."

    It has also been argued that because of the ever present risk from natural  radiation, a
level of manmade radiation ought to be acceptable if  it is "small" compared to natural
background (12).  It has been suggested  that "small" be  taken as the  standard deviation of
the  population-weigh ted natural background (13).  In previous evaluations  that led to the
FDA's  proposed  PAG  recommendations  (1*) the  geographic variable  (two  standard
deviations) in the natural  radiation dose was used as  a point  of comparison for judging
acceptable radiation risk (15).  This value, calculated on a State-by-State basis assuming a
log-normal distribution  and  not weighted  for population,  is 8.5  mrem  per  year.  The
cumulative lifetime dose equivalent would thus be about  500 mrem, which was the basis for
the  proposed PAG recommendation for the whole body at the Preventive PAG level.  The
Environmental Protection Agency (EPA), in a further analysis of previously published data
(16), has calculated the  cumulative distribution of dose equivalent in the U.S.  population.
These data show that 95 percent of the population receives between  28 and 84 mrem/year
from cosmic and  terrestrial   background radiation  (17).   The  actual  distribution  is
asymmetric and not log-normal. Thus, one-half of this 95-percent increment range, or  28
mrem/year, will be taken as the  value for judging acceptable risk. Adler (13) notes that one
standard deviation of  the natural external and internal radiation background derived from
earlier  sources  (18)  is 20  mrem.  Personal conversations  with Adler revealed that  this
estimate is based on air exposures  rather than dose equivalent (mean  whole body) and
involved a broad rounding off of values.  At the 95-percent increment value (latest EPA
data) of 28 mrem/year (19), the  additional lifetime dose over 70 years is about 2000 mrem.
About 6 million persons (2-1/2 percent of the population) receive lifetime doses  that exceed
the mean background  radiation dose by this amount or more.

   Another possibility, especially applicable to setting limits for internal emitters, is using
che variation in internal natural  radiation dose as a reference for establishing an acceptable
standard for PAG's.   For PAG limits  for radionuclides via the ingestion pathway, doses to
organs other  than the lungs are most pertinent.   Using this suggestion still  requires  a
judgmental decision as to whether the variation in internal natural radiation dose is "small."
A summary of  internal natural  radiation doses is given in Table 3.   It  is apparent  that
natural  radiation doses to human tissues and organs is determined mainly by potassium-40
concentration.   The  average annual  internal  whole-body radiation dose  per person from
ingested natural radioactivity is  19.6 mrem, of which 17 mrem is due to potassium-40.

   In potassium-40 whole-body  measurements of  10,000 persons, a standard deviation  of
about 12 percent (95-percent  confidence level of 23.52 percent) was observed (20).  The
study further concluded  that the standard deviation is also the same for different groups of
age and sex, and therefore, it may be concluded [hat the same biological variation exists for
all the different age-sex groups.  In another study based on che chemical determinations of
total body  potassium  the average amount in a 70-kg man was estimated co be 136 g with a
standard deviation of ± 28  g or ±20 percent (95-percent  confidence increment  of  ± f0
percent) (21).

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                  Table 3. Annual internal radiation dose per person
                         for non-inhaled natural radioactivity2

                     Annual dose (mrads/year) whole-body average
                              (unless  otherwise noted)
H-3
Be-7
C-l*
Na-22
K-*0
Rb-87
U-238-U-23* series
Ra-222
Po-210
Ra-226
Th-230
Th-232
0.001
0.008
1.3
0.02
17
0.4
0.0*3°
0.060°
0.7
0.031°
0.0*°
0.0*°
                             Total                19.65
                DBased on soft tissue dose (lung, testes, and ovaries)

    An indirect  means of  determining  the variability of whole-body  potassium  values  is
based on  the  constant ratio of mean potassium values to cotal body  water up to age 50
(20).  The 95-percent confidence increment for the variability of total body water in males,
ages 16 co 90 is 16 percent, while for females it is 13 percent for ages  16 to 30 and  21
percent for ages 31 to 90 (22).

    From  the  above data,  it  appears  that the increment for the 95-percent confidence
level for whole-body potassium, and hence potassium-*0, is between ± 15  percent and ± 40
percent. Note that this variability may be due to differences in body water or body weight^
Only in the case of one study (21) is it dear the total body weight is considered a constant.
It is apparent that a range of values between approximately 3 to  7 mrad per year may be
used to describe the variability in natural potassium-40 dose to the population on a whole-
body dosimetric basis. The mid-point  of this range  is 5 mrad per year or a lifetime dose
commitment (70 years) of 350 mrem.

    Thus, the lifetime radiation dose associated with the variability in natural  radiation is
about 350 mrem (internal) and 2000 mrem (external).
l.t PREVENTIVE AND EMERGENCY PAG'S

   PAG's have been proposed for two levels of response:

      1.   Preventive PAG  -  applicable to situations  where protective actions causing
minimal impact on che food supply are appropriate. A preventive PAG establishes a level ac
which  responsible  officials  should  take protective  action  to prevent  or reduce  the
concentration of radioactivity in food or animal feed.

     2. Emergency PAG - applicable to incidents where protective actions of great impact
on the food supply  are justified because of  the projected health hazards.  An Emergency
PAG  establishes  a  level at  which  responsible  officials should isolate food containing
radioactivity co prevent its introduction into commerce, and at which the responsible offi-
cials must determine whether condemnation or another disposition is appropriate.

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1.4.1  Preventive PAG

   During  recent years numerous reports  on risks  and risk/benefit assessments for the
evaluation  of technological insults have been published.  A number of these have concluded
that an annual risk of death of 1 in a million is acceptable to the public (8).  The total aver-
age annual risk  to the  U.S. population from natural disasters appears to be about 2 or 3
times  greater than the 1 in a million annual risk.  Those individuals living in certain flood
plains, tornado, or earthquake areas accept risks that may be greater than the average by a
f act&i  of 2 or more (See data for tornadoes and earthquakes in Table 2).

   As previously mentioned, based on BE1R-III (3) upper risk estimates, a 1 in a million annu-
al risk of death corresponds to a single radiation dose of 140 co 910 mrem.

   It is our conclusion that an annual risk of 1 in a million provides a proper perspective for
setting food protective actions guides (PAG's) for radiation  contamination accidents of low
probability. It appears chat most individuals in the United States will never be exposed to
such a radiation  contamination accident and  that any  one individual is not  likely to be
potentially exposed more than once in his lifetime.

   Based on the above considerations, the uncertainty in radiation risk estimates and the
uncertainty in the average natural disaster risks, a value of 0.5 rem whole body is selected
for the Preventive PAG.  Thus, at projected doses of 0.5 rem from contaminated food, it is
recommended  that protective actions having low impacts be taken for protection of the
public.  The specific value of 0.5 rem represents a judgment decision rather than a specifi-
cally derived value from specific models  and assumptions.

   Further perspective on acceptable risks for setting the PAG's is the risks associated with
natural background radiation.  The discussion above indicates that lifetime dose associated
with  the 95-percent increment  of  the variability in natural radiation is about 350 mrem
internal and 2000 mrem external (that is, 2-1/2 percent of the  population receives doses
greater than the average by this amount or more).

   This Preventive  PAG is  applicable  to  whole-body  radiation exposure  and to major
portions of the body  including active  marrow  (ingestion of strontium) in conformity with
current U.S. radiation protection practice.  Coincidently, 0.5 rem is the Federal Radiation
Council's (FRC) annual limit for individuals of the general population (23).

   Present convention, recommended by  the Federal Radiation Council (23) based  on prior
estimates of relative radiation risks for various organs indicates chat radiation limits for the
thyroid gland be set. at 3 times  those for the whole body.  More recent scientific information
indicates that  the risks from organ doses relative  co whole body differ from those assumed
when the current  U.S. regulations and FRC guidance were established.  The  International
Commission on Radiological Protection (ICRP) in  revising its recommendations on internal
exposure derived weighting factors  that  represent the ratio of risk from irradiation to a
given tissue (organ) to the total cancer  risk  due to uniform irradiation to the whole body.
The ICRP weighting factors are 0.12 for red bone marrow and 0.03 for  thyroid,  indicating
that the cancer risk is 8 times less for red bone marrow and 33 times less for  thyroid than
for whole body exposure (24).  Further considerations of  effects other than cancer  resulted
in che limitation of organ doses to  50 rems per year for occupational workers. Thus the
ICRP recommendations in effect provide for or allow single organ doses that are 8 times
greater for red bone marrow and 10 times greater for thyroid than for whole body.  The EPA
has recently proposed Federal guidance for occupational radiation protection  that incorpo-
rates che basic ICRP  recommendations (46 FR 7836, 3an. 23, 1980).  Setting the Preventive
PAG  at 0.5 rem for  whole body  and red bone marrow and 1.5 rem for  thyroid provides
significantly more protection  from  the  actual risks of organ doses than from whole-body
risks. To che extent that the whole-body  risk is considered acceptable, che red bone marrow
and thyroid limits are conservative by factors of S and 3.3, respectively.

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1.*.2  Emergency PAG

   The philosophy of the protective action guidance of FDA is that low impact protective
actions should be initiated when contamination of food exceeds the Preventive PAG. The
intent is  that  such  protective actions  be implemented  to  prevent  che appearance  of
radioactivity in food at levels that would require the condemnation of food. If such actions
are ineffective, or high levels appear in food, then the  Emergency PAG is  that level at
which higher impact (cost) protective actions are  warranted.  At the Emergency  PAG
radiation level, action should be taken to isolate and prevent  the introduction of such food
into commerce and to determine whether condemnation or other disposition is appropriate.

   With regard  to  the numerical relationship between the Preventive PAG  level and the
Emergency  PAG level, prior  conventions  may be considered. For example, the Federal
Radiation Council  (23) assumed that the dose to the most  highly exposed individual does not
vary from the average dose to the whole population by a factor greater than three; Hence, a
factor of  3 was used to define the difference between  maximum and average population
limits.  Traditionally, it has been more common  to use a factor of 10 as a  safety factor,
such as between occupational and general public limits.   A factor of 10 difference between
the Emergency and Preventive PAG levels, based on these traditional radiation protection
approaches has in the past been thought to introduce a sufficient level of conservatism. The
proposed PAG's (14) adopted this rationale in setting the Emergency PAG's. The analyses of
costs, to  follow,  also  indicate that a factor of  10  between the  Preventive PAG  and
Emergency PAG is appropriate. As calculated in the last chapter of this  report the cost of
condemnation of milk (high impact protective action) is  about a factor of 10 greater than
the  cost  of using uncontaminated stored  feed  (low  impact  protective action).   Since
contamination of  the milk pathway is considered to be  the most probable and significant
food problem, this is the only pathway that  is cost analyzed.

   The use of a factor of  10  adopted here  results in an  Emergency PAG of  5 rem for the
whole body which  numerically  is equivalent to the current occupational annual limit.  This
limit permitted each year over a working lifetime is associated with the expectation of
minimal increased radiation risks.
 1.5 EVALUATION OF PAG RISKS

    The risks associated with a radiation dose equal to the PAG's can be readily calculated
 from  the BEIR-UI risk estimates in Table 1.  For the Preventive PAG of 0.5 rem, the deaths
 per million persons exposed are one-twentieth of those given for the 10-rad single dose (or
 about 38  to  250 deaths for  the linear  quadratic and linear models respectively).  On an
 individual basis,  this is  a  risk of death of  0.38 to 2.50 x  10"1 (0.0038  to 0.025 percent)
 over  a lifetime.   BEIR-OI gives  the expectation of cancer deaths in  the U.S. population
 as 167,000 per million or an individual expectation of cancer death of 16.7 percent.

    As noted above, the BEIR-UI estimate of serious first generation genetic disorders is 5 to
 75 per million live offspring per rem of  parental exposure.  Thus, for a dose of 0.5 rem, the
 expectation is  2.5  to 38 disorders  per  million live offspring.  BEIR-II1 notes  the current
 estimate of the incidence of serious human disorders of genetic origin as roughly 10 percent
 of liveborn offspring.

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     CHAPTER 2.  DOSIMETRIC MODELS, AGRICULTURAL TRANSPORT MODELS,
                      DIETARY INTAKE, AND CALCULATIONS


2.1  DOSIMETRIC MODELS

2.1.1 Introduction

   The dosimetric models and metabolic parameters for estimating the dose from internally
deposited radionudides are in  a state  of flux.  The recent reports and  current activity
represent the first major revision since  the adoption  of ICRP Publication 2 (25) and NCRP
Report 22 (26) in 1959. ICRP Publication 30 (27) superseded ICRP Publication 2 and revised
the basic approach in setting limits for intake of radionudides by workers. The ICRP recom-
mendations  are intended  to avoid nonstochastic effects and to limit the occurrence of
stochastic effects to an acceptable level.  This approach indudes  the use of weighting
factors to sum the risk from organ  doses in setting the limits for intakes.  This system
contrasts with the earlier approach  where limits were based on the dose to the  "critical
organ."

   The ICRP Publication 30 approach has considerable merit, but is not yet  widely accepted
in the United States.  Its use in calculating the derived response levels would represent a
major change.  Accordingly, the approach is to use the organ to whole-body dose relation-
ship of current U.S. regulations and to select critical organ dose conversion factors that are
based  on current dosimetric models and metabolic parameters.   Where apropriate, the
recent ICRP and NCRP organ dose models will be accepted as representing current scientif-
ic opinion.   It should be noted that future reports  and revisions by NCRP, MIRD (Medical
Internal Radiation Dose Committee of The Sodety of Nuclear Medidne) and other Federal
agencies may necessitate a revision of the dose conversion values selected here.

   The PAG's are applicable to the most critical or sensitive segment of the population. In
most cases this means that  the infant or child is the critical segment.  In  the  case of the
Emergency PAG, derived response levels are also  presented for  the  adults.  This permits
greater flexibility in the choice of protective actions in cases where infants are not present
or can be excluded from use of the spedfic food item  being considered.


2.1.2 Iodine-131: Dose To Thyroid

   Fetal uptake of iodine begins at about the 9th week of gestation and reaches a maximum
in the newborn infant (2S,29) before  returning to adult levels.  Kereiakes et al. (30) report
that thyroid uptake during the  first  2 weeks of life is very high and report a  value of 70
percent of that administered for the newborn.  The radioiodine uptake expressed  per unit
thyroid weight remains high for the newborn and  infant and only  gradually decreases
throughout childhood and adolescence to adult levels. The newborn infant  will  be  taken as
the most critical segment of the population because factors concerning intake,  uptake, and
radiosensitivity indicate that the thyroid gland of an infant receives a higher radiation dose
per unit 1-131 ingested than any other  age group (30). However, it is interesting to note that
data indicate that only about 3 percent of infants are given whole cow's milk at 1 month of
age and about  1 percent at 10 days (31). Hence, assuming that all infants  are given whole
milk provides a conservative estimate of infant thyroid doses.

   Data on the dose to the fetal thyroid from 1-131 ingested by che mother is rather limit-
ed. The study of Dyer and Brill (29) reports an increase in the fetal  thyroid dose from 0.7 to
5.9 rads per  uCi administered  to the mother for  fetal ages of 13  to 22  weeks.   It thus

-------
appears that the fetal thyroid dose is less than that of the newborn infant ingesting 1-131
contaminated milk.

   The current literature on normal thyroid uptake in U.S. adults shows 24-hour jptake has
decreased from  about 30 percent reported in the 1960's to about 20 percent or less in cur-
rent comparable studies.  Kereiakes et al. (32) use a 20-percent uptake for all ages.  This
reduced uptake apparently results from changes in the U.S. diet, whereas [CRP 30 (27) has
continued to use an uptake of 30 percent to reflect world averages.

   The Medical Internal Radiation Dose (MIRD) Committee schema (33) has be *n used by
Wellman and Anger (3*) to calculate dose factors per uCi ingested for the newb >rn for the
1-, 5-, 10-,  and  15-year-old child, and for the adult.  These factors were then modified by
Kereiakes et al. (32) to reflect a 20-percent uptake for all ages.  A biological half-life of 68
days is used for all ages, which results in an effective half-life of 7.2 days.  Although there
is some evidence that the biological half-life  for the infant is less, the radiation dose is
largely controlled by the radiological half-life and use of a single value appears appropriate
here.  Because of some uncertainty regarding the fetal thyroid dose and lack of acceptance
by national  and international groups, the older data (27-percent uptake) of WelJman and
Anger (34) will be used. This provides some additional conservatism in the derived response
levels for  1-131.    The   cumulative  activity is  2.08  uCi-days  per  uCi ingested
(administered).

                    Table 4. Summary of 1-131 dose conversion factors
Age
Newborn
1 yr.
5 yrs.
10 yrs.
15 yrs.
Adult
Thyroid weight (R)
1.5
2.2
4.7
8.0
11.2
16.0
Dose rad/ uCi
16.0
10.9
5.1
3.0
2.1
1.5.
For the infant and adult, the dose conversion factors to be used are 16.0 and 1.5 rad/ yCi
ingested.


2.1.3  Cesium-137 and-134: Dose To Whole Body

   The NCRP (35) has reviewed the behavior of Cs-137 in the environment and its metabo-
lism  and dose to man.   From studies of Cs-137 in food chains,  the biological half-life is
found to vary from  15  ±5 days in infants to 100 ±5 days in adults.  The biological half-
life in pregnant women  is reported to be  1/2 to  2/3 that in  nonpregnant women and
consequently the dose to the fetus is also reduced.

   Retention of Cs-137 in the adult  is stated to be well  represented by  a  2-exponential
equation with biological half-times of 1.4 days and 135 days applicable to retention in body
fluid and soft tissues, respectively. Integration of this equation yields an accumulated activ-
ity of  170  uCi-days per  uCi of intake.  This accumulated  activity may  be expressed in
terms of a single retention function yielding a value of 118 days.

   The dosimetry of internally deposited Cs-137 in infants and  adults is treated separately
for the beta particle  and photon components. The difference between infants and adults is a
smaller photon contribution to the infant because of the smaller  body size. For a uniform
concentration of 1  uCi/kg of body  weight,  the total  beta and photon  dose rate  is  19
mrad/day to the infant  and 25 mrad/day to the adult. Use of the above accumulated activ-
ity factor of 170  uCi-days per uCi intake yields a dose of  0.061 rad/ uCi intake for the
adult.  Assuming an  effective retention time  of 20 days for  the  infant, the corresponding
factor for  the  infant is 0.071 rad/uCi  intake.  The use of  a smaller effective  retention

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time (15 days as noted in NCRP (26)) or 10 days as used in NUREG-0172 (36) would reduce
the infant dose conversion factor.  The use of 20 days thus  tends to overestimate the infant
dose.

   It  is  also important to  consider the dose from Cs-134 which, depending on operating
history, occurs in nuclear reactor fuel at levels equal to  or greater than  that of Cs-137.
Unfortunately,  published dosimetry data for Cs-134 for the infant  are  rather  limited.
Conversion factors for the  adult that  use current models and metabolic data are found in
ORNL/NUREG/TM-190 (37).  Johnson  et al. (38) have used this same data base to compute
committed effective dose equivalent  conversion factors for both infants and adults.  The
mean absorbed dose per cumulated activity factor for the infant were modified by the ratio
of adult and infant organ mass (with  a further correction co photon component based on
absorbed fraction) to produce the infant factors.  It was  stated that this procedure may
underestimate the infant dose.

   The approach adopted  here  will  be  to  modify the adult dose conversion factor  in
ORNL/NUREG/TM-190 (37) based only on relative body  weight  and cumulated activity
(effective  retention  half-times).   The  dose  conversion  factor  for cesium-134 from
ORNL/NUREG/TM-190 adult whole body is  0.068 rem/uCi  ingested and  the  estimated
factor for the infant is then 0.118 rem/uCi ingested.  This value should overestimate the
infant dose and is conservative.

                Summary of Cs-134 and Cs-137 Dose Conversion Factors

              Table 5. Summary of dose factors for Cs-134 and Cs-137

                                                     Infant        Adult
Body Mass
Uptake to whole body3
T biological (days)
T effective Cs-134 (days)
Cs-137 (days)
7,700g
1.0
20
19.5
20
70,000g
1.0
118
102
118
         Dose conversion (rem/ uCi ingestion)
                   Cs-134                               0.118          0.068
         	Cs-137	0.071	0.061
         dFor cesium-13*, ORNL/NUREG/TM-190 uses uptake of 0.95.

2.1.4  Strontium: Dose To Bone Marrow

   The tissues at greatest risk in the skeleton have been identified as the active red marrow
in trabecular bone and endosteal cells near bone surfaces (generally referred  to  as bone
surface). Spiers and his coworkers (39,40) have developed methods to calculate the absorbed
doses, Dm  and  Ds, received by red marrow and bone surfaces, respectively from  beta-
emitting radionuclides uniformly distributed  throughout the volume of bone.  They consider
the dose, Do, in a small, tissue-filled cavity in an infinite extent of mineral bone uniformly
contaminated with the radionuclide and give dose factors DS/DO and Dm/Do for obtaining
the absorbed doses. For both Sr-89 and Sr-90, the ratio of Ds/Dm is about 1.5.  Therefore,
since  che dose limit  recommendations are 15  rem to  bone and 5  rem to red  marrow
(occupational limits), the dose to red marrow is the limiting criterion and will  be used in this
report (26).

   The work of Spiers and his coworkers has been used by  the ICRP (27) in calculating dose
commitment factors for adults and by Papworth and Vennart (41) for doses as a function of
age at times of ingestion.  The dose commitment values from Papworth and  Vennart in red
marrow  per  uCi of Sr-89 and Sr-90 ingested are as follows (Table 6).
                                         10

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                          Table 6.  Dose commitment values
                                for Sr-89 and Sr-90
Age at Ingestion
/ V
(years)
0
0.5
1
2
3
4
5
6
7
8
9
10
11
Adultsa
rem per uCi
br-S?
0.41
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2.2 AGRICULTURE TRANSPORT MODELS

    A review of  the agricultural transport mechanism for radionuclides,  which employs pa-
rameters  appropriate for the U.S. experience, is contained in the  Reactor Safety Study,
WASH-1400, Appendix VI (7).  An analysis specific for calculating derived response levels
(concentration values) in agricultural media for emergency action that reflects the British
experience is found in a report of the Medical Research Council (*3).

    A more recent and comprehensive assessment of the transport mechanisms for the forage-
cow-milk  pathway is found in UCRL-51939 and will be used here (M)


2.2.1  Transport  Models

    According to Ng et  al., the time dependency of the concentration of a radionuclide in
the milk  of  a cow continuously  grazing pasture contaminated by  a single event can be
described by (W):
      where C^(t) = concentration of radionuclide in milk at time t (yCi/1)

      IQ(O) = initial rate of ingestion of radionuclide by the  cow ( u Ci/d)

      Aj =  coefficient of ith exponential term, which describes the secretion in milk (liter"1)

          i = effective elimination rate of the itn milk component (d~l)
     XR = radiological decay constant (d'1)

     ^MBi = biological elimination rate of ic^ milk component (d" l)

     Xp = effective rate of removal of the nuclide from pasture (d'1), and

     Xp = XR + Xw, where X\y is removal rate for a stable element from  pasture (d'1),
          and

     t = time of milk secretion (d).

The  total activity ingested by a person who drinks  this milk can now  be determined by
integration:

                         ;"idt = /"jcM(t)dt = ;jic(o)

     where  I =  rate of ingestion of the radionuclide by a person (uCi/d) and

     3 = rate of consumption of milk (liter/d).

The solution for the total activity ingested by man is:

                                  r -, dt =
                                  0
                                         12

-------
      where f M = transfer coefficient;  i.e., the fraction of daily intake by cow that is se-
                 creted per liter of milk at equilibrium (d/liter)
Ng et al. have conducted a comprehensive review of the literature relevant to the deter-
mination of transfer coefficients for both stable elements and  radionuclides (44).  These
data are  summarized in UCRL-51939,  which also include values »:'  the  normalized co-
efficients, A-,, the biological half-life TMBi  (related  to  AMB^ for srlected  elements and
values of fM for all stable elements.  This information is then used with the radioactive half-
life to calculate  values of fM for specific radionuclides of interest (Table B-l of Ng et al.
(44)).                      M

  An examination of the logistics of the forage-cow-milk-man pathway shows that there is
generally a delay time between the production of  milk by the cow and its  consumption by
the general public.  Therefore, it is appropriate to introduce a factor,  S, to account for
radioactive decay between production and consumption, where

     S = e ' Xt where X = the decay constant for a given radionuclide (d~ l)
     and t = the delay between production and consumption (d).

   Since the delay time for fresh whole milk is assumed to be 3 days  only 1-131 of the
radionuclides of  interest here has a sufficiently short half-life to  result in a value of S
significantly smaller than one.  Thus, for  1-131:

     S(I-131) = e-°-0865C 3
     5(1-131) = 0.772

   Therefore, the total activity ingested as calculated by the above formula (Jldt) must 6e
multiplied by 0.772 in the case of iodine- 1 31.


2.2.2  Total Intake

   The  calculated values  of integrated activity  ingested per  uCi/m 2 deposition from
Appendix B of UCRL-51939 will  be accepted  as the basis for deriving the  response levels
equivalent  to  the PAG (44) .   The  values in Appendix  B are based  on these values of
parameters:

     (1)    Ic(0)»  initial rate of intake by cow

           UAF = "utilized area factor" (93)

           UAF = 45 m z/d

           Initial Retention on Forage = 0.5 fraction

           Initial Deposition = 1 uCi/m 2

           thus Ic(0) = 22.5 uCi/d,

     (2)  J = 1 liter/day consumption of milk, and

     (3)  Half-residence time on forage is 14 days.
                                          13

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   The UAF of 45 m 2/d assumes a forage consumption by the cow of 11.25 kg/d dry weight
or 56 kg/d wet weight based on a forage yield of 0.25 kg/m2 (dry weight) (45).

   The values of the total intake  per unit deposition (uCi/uCi/m *) for a 1-liter per day
milk intake from Ng et al., are given in Table 7, line 1  (44).
              Table 7. Derivation of raporae levels equivalent to 1 rein dose commit nenl to critical organ
i - 131 cs - is* • • cr-T3»
. o LW1
1. Pathway intake factor* (tf) |.ja J.J2 ).22
(uCl/uCi/m1 per l/d)
Infant Adult Infant Adult Infant Adult
2. Dose conversion factor 16 1.3 .US .068 .071 .061
(rem/uCl ingested)
3. Intake per rem * 1 . .063 .67 S.3 l».7 l».l 16.*
line 2 '
(uCl intake per rem)
». Specif Ic intake factor (line Ix .72* .37* 2.11 1.77 2.23 1.77
0.7 or 0.33) - (uCl per u Cl/m1
3. Initial surface deposition (line 3) .OS6 1.17 3.9 8.6 S.3 9.3
line*
(uCI/m* per rem)
6. Peak concentration factor (see text) 0.116 0.078 0.078
(uCi/l per u Cl/m')
7. Peak milk concentration .0100 .136 .303 .67 .09 .72
( line 3 x line 6)
(uCI/l per rem)
8. Initial grass concentration .03*3 .«7 1.33 3.*3 2.30 3.70
(line 3xO.»)
(uCl/kg per rem)
"Corrected for decay during distribution (3 days 1 act or - .772)
5r - 90 5r - 59
.636 .»6
Infant Adult Infant Adult
2.09 .70 .19* .012
.00 I.O 3.2 S3
.«3 .33 .322 .293
.90 O.I 16 329
0.0196 0.018
.0177 .080 .288 3.9
.361 1.63 6.«0 LJ2

2.2,3 Peak Concentration
   The time dependent equation for the concentration in milk CM(t) given above has been
evaluated for times up to 20 days. From a graph of the results, the peak concentration per
initial unit area deposition have been  determined and are summarized in Table 7, line 6.
The peak concentration occurs at 3 days for 1-131 and at 6-8 days for cesium and strontium.
2.3 DIETARY INTAKE

   Infant less than  1 year old - For the  purposes  of these recommendations, the dietary
intake of milk is estimated to be 0.7 liters per day for a newborn infant.

   Based on  the average intake up to and including 1 year of age, the daily intake of  milk
for an infant less than 1 year of age is 0.7 liters (46). An additional 300 g of food may also
be assumed to be ingested by an infant  less  than  1 year of age (based on intake of 6 month-
old infants - Kahn, B. (47)).

   Adult - Based on U.S. Department of Agriculture Household Food  Consumption Survey
1965-1966, the average consumption for the  general population is  given in Table 8.  The
dietary intake of milk is taken to be 0.55 liters per day for the adult.

   In addition to water ingested in food and drink, an estimated 150 ml of tap water is also
ingested each day (46) for a total daily food  intake of 2.2 kg.
                                          14

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               Table S. Average consumption for the general population

                                                    Average consumption
                                                 for  the  general population
Food
Milk, cream, cheese, ice cream3
Fats, oils
Flour, cereal
Bakery products
Meat
Poultry
Fish and shellfish
Eggs
Sugar, syrups, honey, molasses, etc.
Potatoes, sweet potatoes
Vegetables (excluding potatoes) fresh
Vegetables canned, frozen, dried
Vegetables juice (single strength)
Fruit, fresh
Fruit canned, frozen, dried
Fruit juice (single strength)
Other beverages
(soft drinks, coffee, alcoholic bvgs.)
Soup and gravies (mostly condensed)
Nuts and peanut butter
Total
R/day
567.5
5*. 5
90.8
149.8
217.9
50.5
22.7
50.5
72.6
104.0
105.3
77.2
9.1
163.0
36.3
05.0

177.1
36.3
9.1
2088.1
% of total diet
27.2
2.6
0.3
7.2
10.0
2.6
1.1
2.6
3.5
5.0
7.0
3.7
0.0
7.8
1.7
2.2

8.5
1.7
0.0
99.9
           'Expressed as calcium equivalent; that is, the quantity of whole fluid
           milk to which dairy products are equivalent in calcium content.
          (From the U.S. Department of Agriculture Household Food Consump-
           tion Survey, 1965-1966)


2.0 CALCULATIONS

   The  calculation  of the derived response levels  equivalent to 1 rem dose commitment
to critical organ for the grass-cow-milk-man pathway is summarized in Table 7.  An explana-
tion of Table  7 and the calculations follow:

     Line  1  Pathway Intake Factor is  the total intake (pCi) for a 1 liter per day milk
ingestion per  1  uCi/m2 of initial area deposition (00).

     Line 2  Dose  Conversion Factor  is the dose commitment in rem/uCi ingested.  See
section  1 for summary.

     Line 3 Intake  per rem is intake in uCi to yield a 1 rem organ dose.

     COMPUTATION - The reciprocal of line  2.

     Line 0 Specific Intake Factor is the product of the Pathway Intake Factors (line 1) and
the milk ingestion  rate of  0.7  I/day infant or 0.55 I/day adult.   In the case of  1-131, a
factor of 0.772 is included to adjust for 3 day's decay between production and consumption.

     COMPUTATION - Line 1 x (1 or .772) x (0.7 or 0.55)

     Line 5 Initial Surface Deposition is initial area deposition of a specific radionuclide in
pCi/mz which gives a 1-rem dose commitment.


                                         15

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     COMPUTATION - Line 3 divided by Line 4

     Line 6 Peak Concentration Factor is the peak maximum concentration in milk (uCi/1)
from an initial  area  deposition of 1 uCi/m2.  Summary  in Section 2.2.3  per model of
Ng et al.
     Line 7 Peak Milk Concentration is the maximum milk concentration ( yCi/1) that yields
a dose commitment of 1 rem from continuous ingestion of the contaminated milk supply.

     COMPUTATION - Line 5 x Line 6

     Line 8  Initial Grass Concentration is the activity concentration (uCi/kg) on grass
(edible  forage)  chat results  from  the Initial Surface  Deposition  giving  a 1-rem  dose
commitment.

     Retention fraction on forage - 0.5

     Forage yield - 1.25 kg/m2 (wet weight)

     COMPUTATION - Line 5 x      0.5
                               1.25 k
   The derived response levels that correspond to the Preventive PAG (1.5 rem thyroid:  0.5
rem whole body and bone marrow) and the Emergency PAG (15 rem thyroid; 5 rem whole
body and bone marrow) are given in Tables 9 and 10.

         Table 9.  Derived response levels for grass-cow-milk pathway equivalent
         to Preventive PAG dose commitment of 1.5 rem thyroid, 0.5 whole body
                             or red bone marrow to infant1

   Response levels for    ~~"~~~~~~~"~"~
    Preventive PAG	1-1312   Cs-13»3    Cs-1373    Sr-90      Sr-89

   Initial activity
     area deposition
(uCi/m2)
Forage concentration1*
( viCi/kg)
•v
Peak milk acitivity
( uCi/1)
Total intake ( uCi)
0.13
0.05
0.015
0.09
2
0.8
0.15
4
3
1.3
0.24
7
0.5
0.18
0.009
0.2
8
3
0.14
2.6
   1 New born infant includes  fetus (pregnant women) as critical segment of population
    for iodine-131.  For other radionuclides, "infant" refers to child less than 1 year of
    age.
   2From fallout, iodine-131 is the only radioiodine of significance with respect  to milk
    contamination beyond the first day.  In case of  a reactor accident, the cumulative
    intake of iodine-133 via milk is about 2 percent  of iodine-131, assuming equivalent
    deposition.
   3 In take of cesium via the meat-man pathway for  adult may  exceed that of the milk
    pathway; therefore, such levels in milk should cause surveillance and protective ac-
    tions  for meat, as appropriate.   If both Cs-134 and Cs-137 are equally present, as
    might be expected in reactor accidents, the response  levels should be reduced by a
    factor of 2.
   "Fresh weight.
                                         16

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     Table 10. Derived response levels for grass-cow-milk pathway equivalent to emergency PAG dose commitment
                             of 15 rem thyroid, 5 rem whole body or red bone marrow

Response levels for             I- 131J          Cs - 134'          Cs - 137'          Sr - 90             Sr - 89
emergency PAG	Infant1    Adult   Infant2    Adult   Infant2   Adult    Infant2    Adult   Infant2   Adult

Initial activity
area deposition
  (pCi/m2)               1.3        18      20          40     30          50       5        20       80     1600

Forage concentration
  (uCi/kg)"              0.5         78          17     13          19       1.8       8       30      700

Peak milk activity
                          0.15        2       1.5         3      2.4        4       0.09      0.4       1.4      30
Total intake  (uCi)	0.9	10      40	70     70	80       2	7	26      400
'Newborn infant includes fetus (pregnant women) as critical segment of population for iodine-131.
2"Infant" refers to child less than I year of age.
3From fallout, iodine-131 is the only radioiodine of significance with respect to milk contamination beyond first day. In case
 of a reactor  accident, the cumulative intake of  iodine-133 via milk is about 2 percent of iodine-131 assuming equivalent de-
 position.
"Fresh weight.
5 Intake of cesium via the meat-man pathway for adult may exceed that of the milk pathway:  therefore,  such levels in milk
 should cause surveillance and protective actions for meat, as appropriate. If  both Cs-134 and Cs-137 are equally present as
 might be expected for reactor accidents, the response levels should be reduced by a factor of 2.

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    CHAPTER 3. METHODS OF ANALYSES FOR RADIONUCLIDE DETERMINATION


3.1 INTRODUCTION

   The  measurement  of  radionuclides in food can be accomplished by either laboratory
methods or  field methods using  portable survey  instrumentation.   Unfortunately, neither
method  of  analysis  was developed expressly for the purpose of implementing protective
actions.  In order to provide  instrumentation guidance to the States, the Federal Radiologi-
cal Preparedness Coordinating Committee formed a Task Force on  off site instrumentation.
A draft  report on instrumentation analysis methods for che milk pathway is now undergoing
review by the Task Force and a second report on other food is under development.  This
effort is being fostered by past and current contracts of Nuclear  Regulatory Commission
(NRC) and Federal Emergency Management  Agency (FEMA) with Brookhaven National Lab-
oratory  and Idaho National Engineering Laboratory.

   The  material and  methods  are given as interim guidance until these  more definitive
reports  are  available.  It should  be noted that laboratory methods of Chapter 3.2, below,
were developed for environmental monitoring purposes and are more sensitive than required
for protective actions implementation.  And, conversely, the field  methods of Chapter  3.3
are generally  inadequate for the  purpose of implementing action  at the Preventive PAG
level. Analysis methods should be able to measure radionuclide concentrations in food lower
by a factor of 10 than the derived levels for Preventive PAG. Thus, it may be necessary to
use a combination of laboratory and field methods in implementing and ceasing protective
actions.


3.2  DETERMINATIONS OF RADIONUCLIDE CONCENTRATIONS BY SENSITIVE
     LABORATORY METHODS

   Many compendia of- methods  of analysis of environmental samples are available.  The
EML Procedure  Manual recommended  is noted  for its up-to-date methodologies, which
continuously undergo revision and improvement (48).  Analysis need not be limited to refer-
ence 48 but laboratory analysis of food should provide limits of detection as  listed below,
which are lower than required for protective action:

                                         Limit of detection*
                         Radionuclide	pCi/liter or  kg

                            1-131                  10
                            Cs-137               10
                            Sr-90                  1
                            Sr-89                  5

              •Concentration detectable at the 95-percent confidence level.

   A source of more rapid methods of analysis of radionuclides in milk, applicable to these
recommendations is described by  B. Kahn et al. (49). The methods for gamma radionuclide
analysis (applicable  to 1-131  and  Cs-137 presented in this  reference are also  applicable to
pasture. The gamma scan  determinations of 1-131 and Cs-137  in milk  (or water) can
generally be accomplished within 2 or  3 hours.  For samples measuring in the 0-100 pCi/liter
range,   the  error  at the 95-percent confidence level (2 sigma) is 5 to  10  pCi/liter.  For
samples measuring greater than 100 pCi/liter the error is 5 to 10 percent.
                                         18

-------
   Radiostrontium procedures permit analyses of several samples simultaneously in 5 hours
of laboratory bench time, plus 1-2 weeks for ingrowth of yttrium daughters.  If the laborato-
ry is sec up for routine analysis of these radionudides recovery in tracer studies is 80 ±  5
percent.

   An ion  exchange field method for determination of 1-131 in  milk, whid. uses gamma
spectroscopy after sample collection, has also been described (50).  The main advantage of
this method is  that it permits a  large number of samples to be  processed in the field or
shipped and analyzed in a central laboratory.

   For analysis of samples other  than milk the HASL reference (48) is recomnr ended.


3.3 DETERMINATIONS OF RADIONUCLIDE CONCENTRATIONS BY FIELD METHODS

3.3.1  Ground Contamination (Beta Radiation)

   The  conversion of ground survey readings to contamination levels can be accomplished
by using the following equations and factors (assuming a metal tube wail thickness (sceel) of
30 mg/on2):

      1. Use a G-M survey meter calibrated to yield 3,000 counts/min per 1  mR/h of Ray

      2. Hold the probe not more than 5 cm above the ground with the beta shield open.

      3.  Assure that 100 counts/min can be detected above a normal 50 to  100 counts/min
background.

      4. Take readings in open terrain; that is, not in close proximity to heavy vegetation,
cover, or buildings.

         For determinations of ground deposition:

         D = RxF

         where, D = ground deposition (in yCi/m2),

                R = G-M reading (in units of 102 counts/min) (background
                     corrected), and

                 F = factor given in Table 11.

         For determination of concentrations in vegetation:

         C = (Dx

         where, C = concentration (in yCi/kg),

                 D = ground deposition (in p Ci/m2),

                 f = fraction of  deposited nuclide in the vegetation, and

                 d = density of vegetation cover (in kg/m2).

      Generally, f ranges  from  0.1 to 1 and is  usually  taken to be  0.25 for 1-131 in the
United Kingdom, and 0.5 in the United States.
                                         19

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   Data of a similar nature may also be found in "Emergency Radiological Plans and Proce-
dures," in the Chapter (Item 04.3.4) on "Conversion of Survey Meters to Concentration," (51).

         Table 1 1 . Ground surface contamination levels3 of various nudides
        required to yield 100 counts/min (net) on a G-M meter (open window)
 -                                                            p -

 _____ _ Nuclide _ (uCi/m2  per  100  counts/min)

  Zr-95 + Nb-95                                                 6

  Ce-141                                                        2

  1-131, Ru-103m, mixed Ru-Rh (100-dold)b                      1

  Co-60, Sr-89, Y-90, Y-91, Cs-137, Ba-140, La-
    -        -       -                                          0.3
  Ce-144 + Pr-144, Ru-10^i Rh-106,
  mixed radioiodines (1-h to 1-week old),
  mixed  fission-products  (100-d old)
 *Level varies with background readings, ground roughness, and vegetation cover.
 "Age refers to time since irradiation of the fuel from which the Fission Products were
  released.


3.3.2 Herbage

   A field  method for estimation of radionudide contamination at the response levels
equivalent  to the Emergency  PAG  for pasture  (forage) which has  been suggested by
International A comic Energy Agency (52) is as follows:

     1.  Obtain enough vegetation to fill a 30 cm x 40 cm plastic bag approximately half
full.  This is about one-third of a kilogram (Note: the vegetation cover should be obtained
from at least 1 m2 of  ground.  The vegetation should be cut at approximately 1 to 2 cm
from che ground and should not be contaminated in the process by soil).

     2.  Note the area represented by this quantity of material.

     3.  Compress the air from the bag and seal.

     4.  Transfer  che sample to a low background area.
                 ^
     5.  Flatten bag and lay probe of a portable G-M survey meter on  the center of the bag.

     6.  Wrap bag around probe and note reading (window open and background corrected).

     7.  Calculate the contamination from the following equation:

        C = R/k

        where, C = vegetation concentration (in y Ci/kg),

               R = G-M reading (in units of 102 counts/min)  (background corrected), and

               k = 102 counts/min per u Ci/kg as given in Table 12.

     8.  Convert u Ci/kg to u Ci/m2 on che basis of che area represented by  the sample.
                                        20

-------
     9.   The limiting radionuclide (i.e., having the lowest recommended PAG relative to
          its deposition on pasture) is iodine-131. According to Table 12, this radionuclide
          is detected  with  the lowest efficiency.   Thus,  if the operator assumes this
          radionuclide to be  exclusively  present  in  the pasture the most  conservative
          estimates relative to the Emergency PAG would be reached.

                  Table 12.  Typical G-M survey-meter readings probe
                           inserted in the center of  a large
                                 sample i f vegetation
                                                     k
                    Nuclide	(10* x counts/min per  uCi/kg)

                Sr-89, Sr-90 + Y-90                   20
                Ru-106 + Rh-106                     50
                Ba-140 >La-140                      10
                1-131. Cs-137	4	
3.3.3  Milk
   The experimental data for field determination of radionuclides in milk are limited to
determination of iodine-131, and the details are rather sketchy. What material is available
is abstracted below.

      1.  Although no data are available for field determination of radionuclides other than
iodine-131  in milk, Table 13 presents  experimental information obtained in water (52,53).
To the extent milk is more self-shielding than water, the following data is presented as a
guide rather than a means of analysis.

           Table 13. G-M survey-meter open window readings (counts/min
              per  iiCi/liter) (probe immersed in contaminated water)

                                     Size of sample  container
              Nuclide          1 liter           5 liters        > 10 liters
          	Counts/min  per  uCi/l	

          Sr-89               2000             2000             2000
          Sr-90 + Y-90        2000             2000             2000
          Ru-106
-------
       by the probe shielded within the test hole by 3 cpm. Background, on the aver-
       age, was measured (in "pure" water) to be 12 to 15 cpm (in an uncontaminated
       environment). Thus, total background counts (with sky shine) is on the average
       around 19 cpm.

    e.  From Figure 2, the net counts per minute equivalent to the response level for
       the  Emergency  PAG applicable  for  milk (infant  as critical segment of
       population) is approximately 20.

 3.  Method of C. Distenf eld and J. Klemish (55).

    a.  Instruments:

       i.  CDV 700 instrument turned to 10 X scale and calibration adjustment turned
          to require the meter  to indicate 2 mR/hr.  (NB: Discrepencies were noted
          between data from scale and pulse counting with an oscilloscope).

       ii.  Modified  CDV 700 M with factory calibration. Good agreement between
          scale reading and electronic check.

    b.  Geometry: The basic container was a 5-gallon heavy-wall polyethylene "3erri"
       type measuring  12x9x10 inches.  A 2-inch O.D.  blind tube was installed to
       allow the G-M probe to sample the center of the container.

    c.  Counts were  taken inside and at the top (external) to the container.

    d.  Background was determined in a water filled plastic container (15x25x20 cm)
       about 7 meters from the sample vessel.

    e.  Net counts per minute equivalent to the  response levels for the Emergency
       PAG for milk are summarized in Table 14.

4.  The International Atomic Energy Agency reports on a series of experiments (53).
    The data are duplicated in Table 15.

5.  A  forthcoming  report  of   the  Federal  Interagency Task Force on Offsite
    Emergency Instrumentation  for  Nuclear Incidents to be published by  FEMA is
    "Monitoring and  Measurements of Radionudides to Determine Dose Commitment
    in the Milk Pathway." A  subsequent report by the Task Force will address field
    methods and monitoring strategies for other food pathways.

6. The relative sensitivity of the various techniques is summarized in Table 16.
                                  22

-------
                   Water tight
                 Al or plastic tub*
                  (1"to 1 1/2"
                  dlam.; 3* long)
                                      Plastic lining
                                                  E irth fill - 4
a) 17.5 qts of
   "pure" water
b) Contaminated
  milk.
S gal. container '//.
(small plastic   '/I
 garbage	}   "{.
        'W//////////.
3.3" stick in     7/L
bottom of tube
* CDV-700. Model No. 68 covered with small plastic bag taped to cable
 of probe la further protect against dampness.
                                                           Figure 1.   Geometry for making
                                                             measurements within a volume
                                                             of liquid.
                                             I	1	1	1	1	1	1

                                           (After Keamy ORNL-4900)
                              0   20   40   60   80   100  120  140  160  180  200  220  240

                                                  Net Counts Per Minute*
                               'Net counts per minute determined by ear. Net counts per
                               minute = grosscounts per minute — background in pure water.
                                         Figure 2.  Net counts per minute*

                                             23

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     Table 14. Net counts per minute equivalent to the response
              levels for the Emergency PAG for milk
  Instrument
Probe Position
                                        Approximate
                                  net counts per minute
    CDV-700
Inside
Outside
    CDV-700M
Inside    Outside
Response level for
Emergency PAG
(Milk-Infant)
(Milk- Adult)
20*
260
ga
110
220
2,900
100
1,300
*At or below background cpm - precision not adequate.
        Table 15.  Survey-meter readings versus concentration
                   of 1-131 in a 40-liter milk can
Meter
used
Al-walled
GM probe



Mica-window
GM probe



a,B,Y
scintillation
survey-meter3


Transportable
single-channel
analyzer system


uCi I- 131 /liter
milk
0.9
0.5
0.1
0.05
Background
0.9
0.5
0.1
0.05
Background
0.9
0.5
0.1
0.05
Background
0.10
0.05
0.01
0.005
Background
Net counts
Inside can
1,500
500
100
50
50
600
400
100
50
50
5,500
3,000
600
250
100
1,200
650
140
80
30
per minute
Outside can
300
200
50
50
50
250
100
50
50
50
3,000
1,500
300
150
100
-
-
-
-
-
 ^Crystal is 3-mm thick disc of "Bioplastic" scintillator sprayed with
   10 mg/cm2 of ZnS.  Effective area is 6.4 cm2.
                               24

-------
            Table 16.  Comparison of methodologies
                                         cpm per uCi liter"
                                         Inside      Outside
IAEA - 197* (52)                          1,000
Kearney - ORNL (5»)                        140
Distenfeld and Klemish - Brookhaven (55)
                         CDV-700          13*         56
                         CDV-700M       1,«0        660
IAEA - 1966 (53)
       Al Walled CM Probe                1,100        350
       Mica-Window CM Probe               700        250
       at6iy Scintilla**0"                  6,000      3,300
        Survey Meter
       Transportable Single               12,000
	Channel Analyser	
                             25

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                         CHAPTER k.  PROTECTIVE ACTIONS


   The National Advisory Committee on Radiation (56) (NACOR) made the following recom-
mendation that applies to action taken to reduce potential exposure following the accidental
release of radioactivity:

   "A  countermeasure,  useful to public health, must fulfill  a number  of i-.*q>iirements.
First, it must be effective; that is, it must substantially reduce population exposures below
those which would prevail if the  counter measure were not used.  Second, it must be safe;
i.e.,  the  health risks associated with its use must  be considerably less than those of  the
contaminant at the  level at  which  the countermeasure  is applied.  Third, it  must be
practical.   The logistics of  its  application must be well worked out; its  costs  must be
reasonable;  and ail  legal problems  associated  with its  use  must  be  resolved.  Next,
responsibility and authority  for  its application must be well identified.  There must be no
indecision due  to jurisdictional and misunderstandings between health  and other  agencies
concerned  with radiation control.   Finally,  careful  attention must  be given  to  such
additional  considerations as its  impact on the public, industry, agriculture, and govern-
ment."

   An action, in order to be useful must be effective, safe, and practical. An action may be
applied at the source in an attempt to control the release of radioactivity from the source;
or, the action may be applied at the beginning of the food chain (soil, vegetation, or cattle),
to the immediate vector prior to ingestion by man (milk or food), or to the population itself.
For  the most part  these recommendations suggest protective  actions to milk, human and
animal foods, or soil and this chapter is limited to actions concerning  these media.  Further
recommendations by  NACOR (56) extend the discussion of protective  measures to public
health actions directly affecting  the exposed population. For details of agriculture actions,
several Department of Agriculture reports are  available that deal with specific actions for
crops and soil (57,58,59).

   Potential actions relative to the pasture-milk-man pathway are summarized in Table 17.
For  this pathway, only four countermeasures are rated as effective,  safe, and practical (a
somewhat  arbitrary  scale of  judgment  was  used).   Of   the  four, one has distinctive
disadvantages.  Although removal of radionuclides from milk has been  shown to be practical
no facilities for doing this exist.  Another, diverting fresh milk to processed milk products,
freezing  and/or storage,  is  effective only for short-lived radionuclides.  Thus, changing
dairy cattle to an alternate source  of uncontaminated feed  and condemnation of milk
are the only two protective actions rated good for effectiveness, safety, and practicality.

   Of course the other  countermeasures should  also be considered,  but  they appear less
promising.

   Actions for  fruits and vegetables are presented in Table  18 (60,61,62).  Note chat studies
in which these products were  contaminated  under  actual conditions with fallout (Studies
2 and 3)  yielded a  lower reduction in the radioactivity removed during  preparation than
was  the case in an investigation (Study 1) in which radionuclides were sprayed on the food.
Depending on the food, reductions between 20 and 60 percent in strontium-90 contaminations
are possible by  ordinary home preparation or by food canning processes (60).

   Milled grains contain only  a  small  portion of the  total radioactive contamination of
the whole grain; removal of bran from wheat and polishing of rice are effective methods of
reducing contaminating fallout (58). Todd indicated average concentration of Sr-90 (pCi/kg)
                                          26

-------
in wheat of wheat berry (22  ), wheat bran (68  ), and only <*.&  in flour. In rice the corres-
ponding values are: whole grain U.9  ), and milled rice (0.7  ),(58).
     Although these recommendations are intended for implementation within hours or days
after an emergency, long-term actions applicable to soil are shown for information purposes
only in  Table  19.   Alternatives  to  decontamination and  soil  management  should  be
considered,  especially if the radioactive  material is widespread, because great effort is
required for effective treatment of contaminated land.

   The concept of Protective Action assumes that the actions impien ented will continue
for a sufficient period of time to avoid most of the projected dose.  Tie concentration of
radioactivity in a given food will decrease because of radioactive deoiy and weathering as a
function of time after the incident.  Thus, as discussed in Chapter 5 ol this report, actions
that have a positive cost-benefit ratio at the  time of initial contamination or maximum
concentration may not have a positive cost-benefit ratio at later times. Therefore, depend-
ent on  the particular food and food pathway, it may be appropriate to implement a series of
protective actions until the concentrations in the food have essentially reached background
levels.
  »
   As  an example of the Implementation of  protective actions, consider  the case where an
incident contaminates the pasture-cow-milk-man pathway  with a projected dose of  2-3
times the Emergency PAG due to iodine- 131.  In such a situation  these protective actions
may be considered appropriate:

     1.  Immediately remove cows  from pasture and place them on stored feed in order to
prevent as much iodine-131 as is possible from entering the milk;

     2.  Condemn any milk that exceeds the Emergency PAG response at the farm or milk
plant receiving  station;

     3.  Divert milk contaminated at  levels below the Emergency PAG  to milk products;
and

     *>.  Since  the supply of stored feed  may be limited and the costs of this protective
action  greater  than diversion to milk products, the  use  of stored feed may  be the first
action  to cease; this should  not be done, however, until the concentration of 1-131 has
dropped below the  Emergency PAG and preferably is approaching the Preventive PAG.

     5.  The diversion of  fresh  milk  to  milk  products must continue until most of the
projected dose  has been avoided; this action might be ceased when the cost-effectiveness
point is reached or the concentration of iodine-131 approaches the background levels.

   This discussion assumes that there is an adequate supply of whole milk from  noncon-
taminated sources, that there is an available manufacturing capacity to handle the diverted
milk, and that the iodine-131 is the only radionuclide involved.  In an actual situation these
conditions may not be present and other  factors may affect the practicality of proposed
protective actions.  The agency responsible for emergency action must identify and evaluate
those factors that  affect the practicality of  protective action, and thus develop a response
plan (with tentative protective action) that is responsive to local conditions and capabilities.
                                         27

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                   Table 17. Actions applicable to the pasture-milk-man pathway (compiled from references 57 and 59)
DO
Action
Applicable to cattle
Provide alternate source of
uncontaminated animal feed
Add stable iodine to cattle ration
Add stable calcium to cattle ration
Add binders to cattle ration
Substitute sources of uncontaminated water
Applicable to milk
Condemnation of milk
Divert fresh milk to processed milk products
Process fresh - store
Process fresh - store
Remove radionuclides from milk
Radionuclide(s) for which protective action is applicable
Practicality
Effectiveness Safety (effort required)
!III, "Sr, "Sr, M7Cs (+)a (+) ( + ) Good
I Marginal Some hazard (+)
"Sr, "Sr Marginal Some hazard ( + )
IJ7Cs, "Sr, "Sr Marginal Questionable (+)
117- •»_ 90- , . / . . .c
Cs, Sr, Sr (+) (*) ( + )
111. 89- 90_ 11 V / % i ^ , .d f~ j
1, Sr, Sr, Cs (+) (+) ( + ) Good
Mll, "Sr (+) (+) ( + ) Good
>0Sr, M7Sr Marginal Questionable (+)
>nl (O (+) (t) Good
ml, "Sr, "Sr, J7Cs (*) ( + ) (*)e Good
           : 90%effective
      bMarginal: less than 90% effective
      cDepends on availability
      ^Somewhat dependent on volume
      eNo processing plant presently available

-------
ro
                      Table 18.  Percent reduction in radioactive contamination of fruits and vegetables by processing

Spinach
Snap beans
Carrots
Tomatoes
Broccoli
Peaches
Onions
Potatoes
Cabbage
Green beans
Normal
External
"Sr
92
-
-
-
94
" 100
-
_
-
-
Study 1 (60)
food preparation for freezing, canning or
Contamination3 Internal
U)Cs
95
-
-
.
92
"•100
.
_
-
-
"Sr
64
-
_
65
72
~100
-
_
-
-
dehydration
Contamination3
-A-uu"UJCs
88
_
_
_
89
-100
_
_
-
-
Study 2(61)
Canning
22
62
19
21
„
50
.
_
-
-
Study 3 (62)
Home preparation
90Sr
.
-
19
28
.
_
37
24
•»
36
         Contamination on surface is referred to as external contamination.  Internal contamination is contamination of fleshy portion
          of product from surface deposition of radionuclide.

-------
                    Table 19.  Actions applicable co soil (compiled from references 57 and 59)
            Action
Radionuclide(s) for which protective action is applicable
                                            Practicality
Effectiveness8	Safety	(effort required)"
Applicable to soil

Soil management—minimum tillage:     905,-       poor to fajr
 deep plowing with root inhibition       tosr       Good to fair
 irrigation & leaching                  »o$r       poor
 liming & fertilizing                    »osr       Poor to fair

Removing contaminated surf ace crops   »«Sr       Most poor
                    Not applicable
                          it
aRating for reducing strontium -90
  Good- 95% reduction
  Fair - 75-95% reduction
  Poor - 75% reduction
^Rating for effort required
  Good - not  significantly more than normal field practice
  Fair - extra equipment or labor required
  Poor - very great requirement of equipment, materials, and labor
Good
Poor
Good
Good

Poor to fair
Removal of soil surface contamination:
warm weather with vegetation cover
cold weather no cover
»°Sr
»°Sr
Good to fair "
Good to poor »
Poor
Good to poor

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                        CHAPTER 5. COST CONSIDERATIONS


5.1  COST/BENEFIT ANALYSIS

5.1.1    Introduction

   The general expectation is that protective action  taken in the event of  a nuclear
incident will result in a net societal benefit  considering the cost of the action and the
corresponding avoided dose.  These cost assessments, including cost/benefit analysis, have
not been used to set the numerical value of the PAG's but rather to evaluate the feasibility
of specific protective actions.

   At  least two basically different approaches can be used to assess the cost/benefit ratio
of protective actions for the milk pathway. One approach would be to assume a protective
action scenario (maximum milk concentration and length of time of protective action) and
to calculate the total  cost of the action and the benefit because of the avoided dose.  The
ratio of the cost/benefit can then be used to scale the maximum milk concentration to that
concentration that yields equal costs and benefits.  The problem with this approach is that
positive net benefits when milk concentration of radioactivity is  high are used  to offset
the negative net benefits during the later times of action.

   This deficiency leads to the second approach of calculating the milk concentration  on  a
per liter  basis  where the cost of the protective action equals the benefit because of the
dose avoided.   This  approach  will  be used here since  it gives a clearer picture of the
identified costs and benefits.  The  specific concentration at which costs equals benefits
should not however be viewed as the appropriate level for taking  protective action.   The
philosophy of  protective action is to take action  to avoid  most of the  projected doses.
Further, the simple  analysis considered here treats only  the direct  cost  of  protective
actions and ignores the  administrative costs of starting, monitoring, and ceasing action,
and other related social and economic impacts.

   Although the PAG recommendations provide that protective actions  be taken on the
basis of projected dose to the infant,  cost/benefit  analysis must consider the cost impact
on the milk supply and  the benefit  on a whole population basis. Accordingly the benefit
realized from  avoiding  the  dose associated with a given  level  of milk contamination
C (uCi/1) must be summed  over the age groups having different Intakes (I)  and Dose
Factors (OF) and is:

     Benefit = C (uCi/1) x Value ($/rem) ZIi(l/d).DFi(rem/uCi).

The total cost of the protective actions, which must also be summed over all the age intake
groups is:

         Cost = PA COST x Zli

   Costs are in 1980 - 1981 dollars. These equations can then be solved for the concentration
(C) at which cost = benefit giving:

        C (C=B) =        PA  COST Zli
                  Value ($/rem)
                                          31

-------
 5.1.2 Benefit of Avoided Dose

    In situations in which  chere  has  been an uncontrolled  release of radioactivity ro the
 environment, both the health savings and cost of a protective action can be expressed in
 terms of dollar values. This does not exclude the probability that undesirable features will
 result from an action thm is difficult to evaluate in economic terms.

    A previous cost-benefit analysis described che radioactive concentration of iodine-131 in
 milk at which it would *Te justifiable to initiate condemnation of milk (63).  Following is a
 summary of the moneta-y benefit of radiation dose avoided using the approach suggested,
 with changes because of increased costs over time and new data on the relative incidence of
 various tumors.

    The International Commission on Radiological Protection, (6*) has endorsed the principle
 of  expressing the detriment from  radiation  in monetary terms in order  to  facilitate
 simplified  analysis of costs and  benefits.   This permits a direct comparison between the
 societal advantage gained in a reduction of  the radiation dose and the cost of achieving this
 reduction.   Cost-benefit analysis is the evaluation process by which one can determine the
 level at which, or above which,  it would  be justifiable to initiate the protective action
 because the health savings equaled  or exceeded, the economic coses  of  die protective
 action.  Certain  factors,  such  as loss of public confidence  in a food supply,  are noc
 considered; nor are  economic  factors because of  hoarding and a shortage of  supply
 considered.   A  similar  treatment  of  the problem  with  almost  the  same  result  has
 been published (65).  This  type of exercise is useful prior to taking an action as  one, and
 only one, of a series of inputs into decisionmaking.

    The costs, and hence health savings to society, of 1 person-rem of whole-body dose (the
 product of a dose of  1  rem to the whole body and 1 person) has been estimated by various
 authors to  be between $10 and $250 (66). The Nuclear Regulatory Commission (NRC) value
 for a cost-benefit analysis for augmented equipment for light-water reactors to reduce
 population  dose, sets radiation costs at $1000 per  person-rem (67).

    Based on medical expenses in 1970, the total future cost of  the consequences of all
 genetic damage of 1 person-rem (whole-body) was estimated by the BEIR Committee (2) to
 be  between $12 and  $120.  These costs are in  good agreement with estimates  made by
 Arthur  0.  Little,  Inc., for  the Environmental  Protection Agency, which calculated  that
 in terms of 1973 dollars, 1 person-rem of radiation yielded a tangible cose of between $5 and
 $181 due to excess genetic disorders. A tangible cost of between $7 and $24 per person-rem
 was estimated to  be the result of excess cancer in the same report.  Therefore,  the total
 health cost of a person-rem from  these studies is between $12 and $205 (68).

    Assuming that $200 is a reasonable estimate for the overall somatic health cost  to socie-
 ty per person-rem whole body, the proportionate cost for individual organ doses must  then
 be derived. For the purposes of  assessing health cost, it is  appropriate to use the relative
 incidence of cancer estimated to result from organ doses vs.  whole body doses. From BEIR-
 III (3) (Table V-14 and  V-17, and  using an average of the male and female incidence) the
 thyroid  contributes 20 percent of cancer and leukemia (red bone marrow doses) 11 percent
of the total cancer incidence.  Hence, the monetary costs per rem of radiation dose avoided
are: to thyroid $40; and to red bone marrow $22.


5.1.3  Protective Action Costs

   The  direct cost of protective action will  be assessed for  (1) cost of stored feed, (2)
condemnation at the farm (farm value), and (3) condemnation at the processing plant (retail
value).

     1.  Cost of  stored feed. For the participating herds (May 1, 1978 - April 30, 1979)
 the Dairy Herd Improvement Letter (69) reports  a consumption of 12,600 Ibs. of succulent

                                          32

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forage and 3,000 Ibs. of dry forage, with a corresponding annual milk production of 14,129
Ibs. (6200 liters).   (The cows also consumed 5,800  Ibs. of  concentrates,  which are not of
concern here.)  Taking 3 Ibs. of succulent forage (silage) as equivalent to 1 Ib. of hay, the
annual hay equivalent consumption is 7,200 Ibs  (70).   Thus,  1.16 Ibs. of  hay equivalent is
consumed per liter of milk production.  The 1980 average price received by farmers for all
baled hay was $67.10 per ton or $0.0335 par Ib. (71).  The Protective Action (PA) cost of
buying baled hay to replace pasture as the sole forage source is then $0.039 per liter.

      2.  Milk-farm value.  The average pr'ce received by  farmers for  fluid-eligible milk,
sold to plants and dealers in 1980, was $13.11 per hundred weight (monthly range $12.70 to
$14.20) (71).  The lower prices are received during  the pasture season  of April  through
August. For 44  liters per hundred weight, tlie farmer value of milk is $0.30 per liter.

      3.  Milk-retail value. Since it may be  necessary to take protective action at some
stage in the milk processing and distribution system it is appropriate to consider the retail
value of milk.  If condemnation of milk is taken at the receiving station or processing plant
there will be  additional costs above farm  value associated with disposal.  It  is felt  that
retail price should represent an appropriate value. The average city  retail  price of fortified
fresh whole milk  sold in stores, January through October  1980 was $1.037 per 1/2 gallon
(72).  The monthly price increased from  $1.015 in January to $1.067 in October, apparently
because of inflation.  Based on the average price  the value of $0.56 per liter will be  used.


5.1.4  Population Milk Intake and Dose

   Table 20 summarizes the milk intake by population age groups  and  gives values of the
age group intake  factor Ii(l/d). The total  intake by a population of 1000 is 281 1/d or an
average individual daily intake of  0.28 1.  The intake factor (li) is used with the dose factor
DFi listed in  Table 21 to  calculate the dose factor  summed  over the whole  population
weighted by age per uCi/1 of milk contamination.


5.1.5  Milk Concentration For Cost = Benefit

   The above results  are then used to calcultate the milk concentration at which  the
Protective Action (PA) costs equals the benefit from the  dose avoided.   The results  are
presented in Table 22.  The cost = benefit concentration for use of  stored feed in place of
contaminated  pasture is about 0.2 to 0.3 of the  Preventive PAG for strontium  and 0.01 to
0.02 for iodine and cesium.  For condemnation, the  cost = benefit concentrations based on
farm  value of milk have ratios of the Emergency PAG similar to those above.   The cost =
benefit concentrations  based on retail value of milk are about a factor of 2 greater than
those based on the milk's farm value. The fact that  the cost = benefit concentrations are a
significant percent of the PAG for  strontium results largely because the value of the  person-
rem dose to red bone marrow is one-ninth that of whole-body doses while the PAG's are set
at equal doses consistent with current regulations.  Further the controlling PAG's  are for
the infant, while the cost/benefit reflects population averaged benefits.

                         Table 20.  Population milk  intake lEIi)
ARC group
In utero
0 <1
1 - 10
11 - 20
>20

Persons per
1000 popu-
lation
11
14
146
196
633
El
Milk intake3
(1/d)
.4
.775
.470
.360
.200
i
Intake (li) by
age group
(J/d)
4.4
10.9
68.6
70.6
126.7
281.2
              a!CRP,  1974

                                          33

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                  Table 21.  Population dose factors
5r-89
Age group
In utero
0 < 1
1 - 10
11 - 20
>20
DFi
rem/uCi
.414
.194
.0565
.0175
.012
EHDFi
li x DFi
rem • 1
uCi d
1.22
2.12
3.88
1.24
1.52
10.58
Sr-90
DFi
rem/uCi
4.03
2.49
.929
.82
.70
li x DFi
rem • [_
uCi d
17.7
27.2
63.8
57.9
88.7
255.3
Reference for
DFi values3
0 yr old
0.5 yr-old
Average
Av 11 yr& adult
Adult
 See Chapter 2.
Cs-134


Age group
In utero
0 < 1
1 - 10

11 - 20
> 20


DFi
rem/uCi
.068
.118
.093

.093
.068
ZliDFi
•i x DFi
rem • 1
yCi d
.3
1.29
6.39

6.57
8.51
23.06
Cs-137

DFi
rem/uCi
.061
.071
.066

.066
.061

li x DFi
rem • 1
uCi d
.27
.77
4.53

4.66
7.73
17.966

Reference for
DFi values3
Adultb
Infant
Av. infant
& adult
it
Adult

aSee Chapter 2.
"No credit taken for reduced biological half-life in pregnant women.
                   1-131
Age  group
          li x DFi
  DFi     rem • 1^
rem/uCi  uCi   d
 Reference for
 DFi values3
In utero
0 < 1
1 - 10

11 - 20
>20
               8
              16
               5.7

               2.1
               1.5
             Eli DFi
             35
            174
            391

            148
            190
            938
Max. estimate
Newborn
Average from
 smooth curve
15 yr old
Adult
aSee Chapter 2.
                                34

-------
                  Table 22.  Milk concentration at which cost = benefit
                  (Population basis - value of IlixDFi for 1000 persons)

Zli x DFi
rem 1
uCi'd
5r-89
10.58


5r-90
255


1-131
938


Cs-134
23.1


Cs-137
17.96


               Value ($/rem)     22         22       40      200       200

                       PA cost          CONG. (Cost = Benefit) (uCi/1)

         Stored Feed    $0.039       .047   .002   .0003    .0025    .003
         Farm Milk       0.30         .36    .015   .0023    .018     .025
         Retail Milk      0.56         .68    .028   .0042    .034     .044

                                               Peak CONG.  (uCl/1)
Preventive PAG
Emergency PAG infant
Emergency PAG adulr
.14
1.4
30
.009
.09
.H
.015
.15
2.0
.15
1.5
3.0
.24
2.4
4.0
5.2 ECONOMIC IMPACT

   The Emergency Planning Zone (EPZ) for the ingestion pathway has been set at 50 miles
(73).  The area impacted that requires protective action is the major factor influencing cose.
Assessment of the economic impact will be considered for the case of contamination of the
milk pathway in one 22.5° Sector out to a distance of 50 miles.  Table 23 gives data on the
annual sales of whole milk and total area of  leading dairy States and selected States. The
annual milk sales in Wisconsin of 3.52 x 10s Ibs. per sq. mile exceeds that of any other
State and will be used to assess the economic impact. There may, of course, be individual
counties and areas surrounding nuclear power plants where milk production exceeds the
Wisconsin State average. The Wisconsin average should, however, represent a maximum for
most areas of the United States.

                     Table 23.  Milk production of selected States
                       (Statistical Abstract of the U.S., 1978)
State
WI
VT
NY
PA
IA
CT
MN
OH
MI
CA
MA
N:
Whole milk sold
(109 Ibs/vear)
20.5
2.06
9.92
7.37
4.07
.595
9.27
4.43
4.63
11.53
0.55
0.52
Total area
(mi2)
56,154
9,609
49,576
45,333
56,290
5,009
84,068
41,222
58,216
158,693
8,257
7,836
Milk per unit area
10s lbs/mi2
3.52
2.14
2.00
1.64
1.38
1.19
1.10
1.08
0.80
0.73
0.67
0.66
   Another important factor in assessing the economic impact of protective actions in the
milk pathway is the length of time that such actions will be necessary. During most of the
year in northern parts of the U.S., cattle will already be on stored feed and chere will be no

                                         35

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additional costs for the stored feed protective action.  For other situations and the Emer-
gency PAG, the time over which protective  actions will  be necessary  is a function of  a
number of  parameters unique to each site and the causative  accident.  Thus, what are
intended  as conservative  assumptions  will be  selected.  The  time behavior  of  1-131 on
pasture grass is controlled by the 8-day radioactive half-life and the  U-day weathering half-
life (yielding an effective  half-life of about 5 days).   Milk which contains 1-131  at the
Emergency PAG of 0.15  uCi/1 will be reduced to the cost  = benefit concentration (farm
value) of  0.0023 uCi/1 about  30  days  later.  Obviously in most cases of an atmospheric
release, those areas closer to the release point will have higher levels of contamination and
longer times of protective action. The NRC and EPA in the Planning Basis Report NUREG-
0396 (NRJ, ^1978) assume that radiation doses from the airborne plu ne decrease according
to  the  r  l<   factor.  Use of this factor for  contamination of pasture results in  milk
concentrations at 2 miles that are about 100 times that at 50 miles. For an effective half-
life of 5  days this  would require an additional 30-35 days of protective action at 2 miles
over that at 50 miles to yield the same milk levels  upon  ceasing action.  Although these
models cannot be assumed to be rigorously accurate in a specific accident situation, they do
indicate that action might be required for 1 or 2  months.

    NUREG-0396 notes that the dose from milk pathway is of the  order of 300 times the
thyroid dose from inhalation (7*).  Under this assumption (and above models), the food PAG's
would be  exceeded at hundreds of miles if protective action because of inhalation were
required at 10 miles.  It should be noted that the meteorological models that are empirically
derived are not likely to be valid for such long distances. Further changes in wind direction
and meteorological dispersion conditions may reduce the levels 01 pasture contamination
and the downwind  distance.   For  assessing ecomomic impact,  contamination of a 22.5°
Sector out  to  a distance of  50  miles will be arbitrarily assumed,  even  though  actual
contamination patterns are not likely to be similar.

    Under  these assumptions we then have:

      Area (Circle - 50 mile radius) - 7850 mi2

      Area (22.5° Sector - 50 mile) - Ml mi2

      Milk Production - 3.52 x 10s lbs/mi2 per year - 2.93 x 10" lbs/mi2 per month

      Production (22.5°/50 mi Sector) -  1.** x 10 7 lbs./month

      Cost of Stored Feed - $0.017 per Ib. milk

      Cost Impact (22.5°/50 mile Sector) - $2.*6 x 10s per month

    Thus,  the direct cost of  placing cows  on stored feed within a  22.5° Sector out to 50
miles based on farm value, would be about $0.25  million per month.  The cost would be zero
during that portion of the year and in geographical areas where cattle are already on  stored
feed. While such protective actions might be required for  periods up to 2 months at areas
near the accident site, such would not be the case at the greater distances which involve the
major portion of the area.  Condemnation of milk is the protective action of last resort for
areas of very high contamination. As noted above, the farm value of milk is $0.30 per liter.
Thus, the  condemnation of  milk at the Emergency PAG for a 22.5°/50 mile sector would
have a cost of about  $2 million for a month of protective  action. Where 1-131 is the only
significant contaminant, whole milk can  be diverted to manufactured products,  such as
powdered  milk, which can be stored to allow disappearance of the radioactivity.  We  do not
have cost  figures for this action.

    It is of interest to compare the arbitrary assumptions on land area used above  to the
contamination resulting from the Windscale accident. (NB: This was not a power reactor of
the type presently used in the United States).  According to Booker,  the Windscale accident
resulted  in  milk values exceeding  0.015  uCi/1 at  about 200  kilometers or  125 miles

                                          36

-------
downwind (75).  Milk contamination was estimated as exceeding 0.01  uCi/I over  16,700
km2 or  6*00 mi2.   Thus,  the WindscaJe accident resulted  in  contamination exceeding
the Preventive PAG over an area about 10 times greater than that assumed above.  Protective
actions were taken  at Windscale at  milk  concentrations of  0.1  uCi/1 (approximately
the  Emergency PAG)  and  involved  an area of about 520 km2  or  200 mi2  for  periods
of 3-6 weeks.
5.3 COST-EFFECTIVENESS ANALYSIS

   Cost-effectiveness analysis is defined as the economy with which a particular task may
be carried out.

   The data available for this analysis was obtained with the cooperation of the Nuclear
Regulatory Commission.  Briefly, the NRC employed the models cited in the Reactor Safety
Study (7) to  evaluate the agricultural costs and cumulative dose commitment that could
occur under  two accident conditions - a design basis for siting purposes and a PWR 7
accident (7).   A typical  reactor site in  the  northeastern  United States was envisioned.
Unfortunately, the parameters employed are not directly comparable with the pathways and
dosimetric parameters associated with  the PAG's.  Nevertheless, a good indication of the
effects of  taking a protective action (in  this case the condemnation  of milk) at specific
interdiction levels can be ascertained.

   Figure 5 presents the agricultural costs at  specific interdiction criteria.  The costs are,
for the most part, associated with the market value of milk.  The interdiction criteria are in
terms of rem to an infant thyroid.  From Figure 3, it can be seen that costs drop rapidly
between 0.5 and  10 rem and  more gradually after 20 rem.  The ratio of costs for a design
basis accident (siting) to a PWR 7 remains constant.

                     I0»r-
                   a
                  •a
                   o
                   .•
                  •a
                  tfl
                  o
                  u

                  K
                        \
                     10'
                                                             (ding)
• PWR 7
                     101
                             10     20     30     40     SO

                               INTERDICTION CRITERIA (rem-thyroid)

                     Figure 3. Agricultural cost model accident.


                                         37
             60

-------
    Figure b is a graph of the dose commitment for a design basis accident and a PWR 7
 assuming protective action is initiated at specific interdiction levels.  The dose commit-
 ments are  accrued via external  as  well  as  internal exposure (inhalation and ingestion).
 Therefore,  they do not exactly fit the situation described in the PAG's under consideration.
 The dose commitment rises rapidly when the interdiction criteria are between 0.5 and 20
 rem.  The increase in dose commitment for a design basis accident is less rapid than for a
 PWR 7.  Hence, at or  above an interdiction criteria of 20 rem, savings in radiation dose are
 minimal compared to the savings accrued below 10 rem.
                    10* r-
                  —
                  3


                  UJ
                     10*

                  8
                     10-
                  o
                  a
                    10*
                                           »

                                           •  PWR 7
                              I
I
I
I
                             10     20     30     40     SO
                               INTERDICTION CRITERIA (rwn-thyoid)
                           60
                     Figure 4.  Dose commitment model accident.
5.* SUMMARY AND CONCLUSION

   The milk concentration at which the population benefits (from dose avoided) equals the
direct costs of stored feed is equivalent to about one-third of the Preventive PAG for stron-
tium and to one-fiftieth or less for iodine-131 and  cesium.  If condemnation is based on
retail milk value, then the respective concentrations are about one-half and one-fiftieth of
the Emergency PAG.  Unless the indirect  costs  of implementing protective actions are
significantly greater than the direct costs, it appears feasible to take protective actions at
the respective PAG level and  to  continue  such action to avoid about 90 percent of the
projected dose for iodine and cesium. In the case of strontium contamination of milk, such
action is only cost  beneficial  until the  concentration is about 30  percent  of the PAG
response level.

   Estimated  costs of taking protective action within the Emergency Planning Zone (EPZ)
for a 22.5° Sector to 50 miles  (about 500 mi2) is $2 million per month for condemnation
(farm  milk value) and $0.2f million  per  month for use of  stored feed.   In  the case of
                          •J
                                         38

-------
atmospheric dispersed contamination, protective action may have to continue for 2 months
near the site.

   The  recommended  approach is to  place  all cows  on  stored feed  to prevent  the
contamination  of  milk at  significant  levels, to divert iodine contaminated  milk  to
manufactured products  that have a long shelf life  to allow radioactive  decay, and only
consider condemnation of milk exceeding the Emergency PAG. It appears chat doses co the
public can be limited to less than 10 percent of the Preventive PAG (or less then 0.15 rem
thyroid) by actions having direct costs of a few  milion dollars for  a significant accident.
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      Rapid  Methods for Estimating Fission Product Concentrations  in Milk.  U5DHEW,
      Public Health Service Publication No. 999-R-2 (1963).

50.   Johnson, R.H. and T.C. Reavey.   Evaluation of Ion  Exchange Cartridges  fcr Field
      Sampling of Iodine-131  in Milk. Nature 208:750-752 (1965).

51.   Held, K.R. Emergency Radiological Plans and Procedures. Item 04.3.* on Conversion
      of Survey Meter Readings  co Concentration.  USAEC  Report  HW-70935,  Hanford
      Laboratories (1962).

52.   International  Atomic Energy  Agency.   Evaluation of Radiation Emergencies  and
      Accidents. Technical Report Series No. 152, pp.69-77, Vienna (197*).

53.   International  Atomic Energy Agency. Environmental Monitoring in Emergency Situa-
      tions. Safety Series No. 18, Vienna (1966).

it.   Kearney, C.H.  Trans-Pacific Fallout and Protective Countermeasures.  Oak Ridge
      National Laboratories, ORNL-4900 (1973).

55.   Oistenfeld, C. and J. Klemish.  Environmental Radioiodine  Monitoring to Control,
      Exposure  Expected  from  Containment  Release Accidents.   BNL-NUREG/50882
      Brookhaven National Laboratories  (December 1978).

56.   National Advisory Committee on Radiation. A Report to  the Surgeon General, Radio-
      active  Contamination of  the Environment: Public Health Action.  U.S. Dept.  HEW,
      PHS, Washington, DC (May 1962).

57.   Park, A.B. Statement  before the JCAE.  Hearing on the Federal Radiation Council
      Protective Action Guides, pp. *-83, Washington, DC (June 1965).

58.   Todd, F.A. Protecting  Foods and Water.  In: Protection of the Public in the Event of
      Radiation Accidents. World Health Organization, Geneva (1963).

59.   Menzel, R.G. and P.E. James.  Treatment for Farmland Contaminated with Radio-
      active Material.  Department of Agriculture, Washington, DC (June 1971).

60.   National Canners Association, Final Progress Report. Investigation on the Removal of
      Radioactive Fallout from Vegetables and  Fruits During Processing by Normal and by
      New or Modified Processing Operations.  Agriculture Research Service Contract 12-1*
      100-7187 (7*) (May 1960).

61.   Laug, E.P. Temporal and Geographical Distributions of Strontium-90  and Cesium-137
      in Food.  Radiological Health Data 4(9):*53 (September 1963).

62.   Thompson, J.C., Jr.  90Sr Removal in Vegetables Prepared for Home Consumption.
      Health Phys 11(2): 136 (February 1965).

63.   Shleien, B.   A  risk and  cost  effectiveness analysis of United States guidelines
      relative to radioactivity in foods.  Health Phys 29:307-312 (1975).

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64.   International Commission on Radiological Protection (ICRP). Implications of Commis-
     sion Recommendations That Doses DC Kept as Low as Readily  Achievable.  ICRP
     Publication 22 Washington, DC (April 1973).

65.   Hedgran A. and B. Lindell.  On  the Swedish Policy with Regard to  the Limitation of
     Radioactive Discharges from Nuclear Power Stations.  Annual Report cf the Swedish
     National Institute of Radiation Protection, "Verksamheten  1970." Stockholm, Sweden,
     (1971).

66.   Cohen,  3.  A Suggested Guideline for Low-Dose Radiation Exposure tr Populations
     Based on Benefit-Risk Analysis.  UCRL-72848 (1971).

67.   Code of Federal Regulations, Title 10, Chapter 1,  Part  50.  Licensing of Production
     and Utilization Facilities. Appendix I, FR Vol. *0, No. 87, 19439, (May 5, 1975).

68.   Environmental Protection Agency Contract No. 68-01-0*96.  Development of Common
     Indices of  Radiation Health Effects,  p. E-4.  Arthur D. Little, Inc. (September 197*).

69.   Dairy Herd Improvement Letter,  Vol. 55, No.2.  Science and Education Administration,
     U.S. Department of Agriculture,  Beltsville, MD, 20705 (December  1979).

70.   Hoards  Dairyman. Vol.  125, No. 23,  p. 1596.  W.D. Hoard & Sons Company, Fort
     A tkinson.  Wisconsin (December 1980).

71.   U.S. Department  of Agriculture.  Agricultural  Prices,  Crop Reporting Board.  ESS,
     USDA, Washington, DC 20250 (Jan-Dec 1980).

72.   Bureau of  Labor Statistics, US Department of Labor. Washington,  DC 20212.

73.   U.5. Nuclear Regulatory Commission. Criteriafor Preparation and Evaluation of Radio-
     logical  Emergency Response Plans  and Preparedness in Support of Nuclear Power
     Plants.   NUREG-0654/FEMA-REP-l.  USNRC, Washington, DC 20555 (November
     1980).

74.   U.S. Nuclear  Regulatory Commission.  Planning Basis for  the Development of State
     and  Local Government Radiological Emergency Response  Plans in  Support of Light
     Water Nuclear Power Plants. NUREG-0396/EPA 520/1-78-016. USNRC, Washington,
     DC 20555  (December 1978).

75.   Booker, D.V.  ,Physical Measurements of Activity in Samples from Windscale. AERE
     HP/R2607.   United Kingdom Atomic Energy  Authority,  Atomic  Energy  Research
     Establishment, Harwell, Berkshire (1958).

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                                              Draft
                    APPENDIX E
Protective Action Guides for the Intermediate Phase





                    (Relocation)





              Background Information

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                                   Contents
                                                                          Page

E. 1    Introduction	   E-l

       E.I.I  Response Duration	   E-2
       E.I.2  Source Term	   E-2
       E.I.3  Exposure Pathways	   E-4
       E.I.4  Response Scenario	   E-5

E.2    Considerations for Establishing PAGs for the Intermediate Phase..   E-7

       E.2.1  Principles	   E-9
              E.2.1.1 Cost/Risk Considerations	   E-10
              E.2.1.2 Protection of Special Groups	   E-12
       E.2.2  Federal Radiation Protection Guides	   E-14
E.3    Dose from Reactor Incidents	   E-15
E.4    Alternatives to Relocation	   E-17
E.5    Risk Comparisons	   E-18
E.6    Relocation PAG Recommendations	   E-21
E.7    Criteria for Reentry into the Restricted Zone	   E-23

References	   E-25
                                    Figures


E-l    Response Areas	   E-6

E-2    Time Frame of Response to a Major Nuclear Reactor Accident	   E-8

E-3    Cost of Avoiding Statistical Fatalities and Exposure
       Rates Corresponding to Various Total First Year Doses	   E-13
                                      ii

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                             Contents (continued)
                                                                          Page
                                    Figures

E-4    Average Lifetime Risk of Death from Whole Body Radiation Dose
       Compared to the Average Risk of Accidental Death from Lifetime
       (47 years) Occupation in Various Industries	   E-19
                                    Tables

E-l    Brief Descriptions Characterizing Nuclear Power Plant Accident
       Types (SN-82)	   E-3

E-2    Release Quantities for Postulated Nuclear Reactor Accidents	   E-3

E-3    Annual Doses Corresponding to 5 Rem in 50 Years	    E-16

E-4    Measure of Lifetime Risk of Mortality from a Variety of Causes...   E-20

E-5    Summary of Considerations for Selecting PAGs for Relocation	   E-22

E-6    Estimated Maximum Doses to Nonrelocated Persons	   E-24
                                      iii

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                                Appendix E

           Protective Action Guides for the  Intermediate Phase
                               (Relocation)
                          Background  Information

E.I  Introduction

     This Appendix provides background  information for the choice of
Protective Action Guides  (PAGs) for relocation  and other protective
actions to reduce exposure to deposited radioactive materials during  the
intermediate phase of the response to a nuclear incident.  The resulting
PAGs and associated implementing guidance are provided in Chapters 4  and
7, respectively.

     This analysis is based on  the assumption that an airborne plume  of
radioactive material has  already passed over an area and left a deposit
of radioactive material behind, or that such material exists from some
other source, and that the public has already been either sheltered or
evacuated, as necessary,  on the basis of PAGs for the early phase of  a
nuclear incident, as discussed  in Chapters 2 and 5.  PAGs for subsequent
relocation of the public  and other protective actions, as well as dose
limits for persons reentering the area from which the public is
relocated, are addressed  in this Appendix.

     We first set forth the assumptions used to derive information
pertinent to choosing the dose  level at which relocation of the public is
appropriate.  This is followed  by an examination of information relevant
to this decision, and selection of the PAG for  relocation.  The Appendix
concludes with a brief discussion of the basis  for dose limits for
persons temporarily reentering  areas from which the public has been
relocated.
                                      E-l

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E.I.I  Response Duration

     In order to decide whether to initiate relocation of the public  from
specific areas it is necessary to predict the dose that would be
avoided.  One factor in this prediction is the duration of the exposure
to be avoided.  Relocation can begin as soon as patterns of exposure  from
deposited radioactivity permit restricted areas to be identified.   For
the purpose of this analysis, relocation of persons who have not already
been evacuated from the restricted zone is assumed to take place on the
fourth day after the incident.  Return of evacuated persons to their
residences outside the restricted zone and transition to relocation
status of persons already evacuated is assumed to occur over a period of
a week or more.

     The period of exposure avoided by relocation ends when the relocated
person either returns to his property or is permanently resettled  in  a
new location.  At the time of relocation decisions, it will usually not
be possible to predict when either of these actions will occur.
Therefore, for convenience of dose projection, it is assumed that  the
period of exposure avoided is one year and that any extension beyond  this
period will be determined on the basis of recovery criteria.  This
assumption corresponds to emergency response planning guidance by  ICRP
(IC-84) and IAEA (IA-85).

E.I.2  Source Term

     The "source term" for this analysis is comprised of the quantities
and types of particulate radioactive material found in the environment
following a nuclear incident.  Nuclear incidents can be postulated with a
wide range of release characteristics.  The characteristics of the  source
terms assumed for the development of these PAGs are those postulated  for
releases from various types of fuel-melt accidents at nuclear power
plants (SN-82).  Table E-l provides brief descriptions of these accident
types.  Radionuclide releases have been estimated for the three most
severe accident types (SST-1, SST-2, SST-3) based on postulated core
inventories and release fractions (Table E-2).  The other types (SST-4

                                      E-2

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Table E-l  Brief Descriptions Characterizing Various Nuclear Power Plant
           Accident Types (SN-82)
Type
Description
SST-1    Severe core damage.  Essentially involves loss of all installed
         safety features.  Severe direct breach of containment.

SST-2    Severe core damage.  Containment fails to isolate.  Fission
         product release mitigating systems (e.g., sprays, suppression
         pool, fan coolers) operate to reduce release.

SST-3    Severe core damage.  Containment fails by base-mat melt-
         through.  All other release mitigation systems function as
         designed.

SST-4    Modest core damage.  Containment systems operate  in a degraded
         mode.

SST-5    Limited core damage.  No failures of engineered safety features
         beyond those postulated by the various design basis accidents.
         The most severe accident in this group assumes that the
         containment functions as designed.
Table E-2  Release Quantities for Postulated Nuclear Reactor Accidents
Principal
radionuclides
contributing
to dose from
deposited
materials
Zr-95
Nb-95
Ru-103
Ru-106
Te-132
1-131
CS-134
CS-137
Ba-140
La-140



Half-life
(days)
6.52E+1
3.50E+1
3.95E+1
3.66E+2
3.25
8.05
7.50E+2
1.10E+4
1.28E+1
1.67


Estimated

SST-1
1.4E+6
1.3E+6
6.0E+6
1.5E+6
8.3E+7
3.9E+7
8.7E+6
4.4E+6
1.2E+7
1.5E+6


quantity released3
(Curies)
SST-2
4.5E+4
4.2E+4
2.4E+5
5.8E+4
3.9E+6
2.6E+5
1.2E+5
5.9E+4
1.7E+5
5.1E+4




SST-3
1.5E+2
1.4E+2
2.4E+2
5.8E+1
2.6E+3
1.7E+4
1.3E+2
6.5En
1.7E+2
1.7E+2
a Based on the product of reactor inventories of radionuclides  and
  estimated fractions released for three accident categories  (SN-82).

                                      E-3

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and SST-5) would generally not produce offsite doses from  exposure  to
deposited material sufficient to warrant consideration of  relocation.

     For other types of source terms, additional analysis  may  be
necessary to assure adequate protection.  For example, if  the  release
includes a large proportion of long-lived radionuclides, doses will
continue to be delivered over a long period of time and, if  no remedial
actions are taken, the dose delivered in the first year may  represent
only a small portion of the total dose delivered over a lifetime.   On  the
other hand, if the release consists primarily of short-lived
radionuclides, almost the entire dose may be delivered within  the first
year.

     From the data in Table E-2, it is apparent that, for  the  groups of
accidents listed, both long and short lived radionuclides  would be
released.  Consequently, doses due to deposited materials  from such
accidents would be relatively high during the first year followed by long
term exposures at lower rates.

E.I.3  Exposure Pathways

     The principal exposure pathway to members of the public occupying
land contaminated by deposits of radioactive materials from  reactor
incidents is expected to be exposure of the whole body to  external  gamma
radiation.  Although it is normally expected to be of only minor
importance, the inhalation pathway would contribute additional  doses to
internal organs.  The health risks from other pathways, such as beta dose
to the skin and direct ingestion of dirt, are also expected  to be minor
in comparison to the risks due to external gamma radiation (AR-89).  Skin
and inhalation dose would, however, be important exposure  pathways  for
source terms with significant fractions of pure beta emitters,  and
inhalation dose would be important for source terms with significant
fractions of alpha emitters.

     Since relocation, in most cases, would not be an appropriate action
to prevent radiation exposure from ingestion of food and water, these

                                      E-4

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exposure pathways have not been included in this analysis.  They are
addressed in Chapters 3 and 6.  In some instances, however, where
withdrawal of food and/or water from use would, in itself, create  a
health risk, relocation may be an appropriate alternative protective
action.  In this case, the committed effective dose equivalent from
ingest ion should be added to the projected dose from deposited
radionuclides via other pathways, for decisions on relocation.

E.I.4  Response Scenario

     This section defines the response zones, population groups, and  the
activities assumed for implementation of protective actions during the
intermediate phase.

     After passage of the radioactive plume, the results of environmental
monitoring will become available for use in making decisions to protect
the public.  Sheltering, evacuation, and other actions  taken to protect
the public from the plume will have already been implemented.  The tasks
immediately ahead will be to (1) define the extent and  characteristics of
deposited radioactive material and identify a restricted zone in
accordance with the PAG for relocation, (2) relocate persons from  and
control access to the restricted zone, (3) allow persons to return to
areas outside the restricted zone, (4) control the spread of and exposure
to surface contamination, and (5) apply simple decontamination and other
low-cost, low-risk techniques to reduce the dose to persons who are not
relocated.

     Because of the various source term characteristics and the different
protective actions involved (evacuation, sheltering, relocation,
decontamination, and other actions to reduce doses to "as low as
reasonably achievable" levels), the response areas for  different
protective actions may be complex and may vary in size  with respect to
each other.  Figure E-l shows a generic example of some of the principle
areas involved.  The area covered by the plume is assumed to be
represented by area 1.  In reality, variations in meteorological
conditions would almost certainly produce a more complicated shape.

                                      E-5

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                                                          PLUME  TRAVEL
                                                            DIRECTION
LEGEND
 |    |  1.  PLUME DEPOSITION AREA.
 L-J
         2.  AREA FROM WHICH POPULATION IS EVACUATED.
         3.  AREA IN WHICH POPULATION IS SHELTERED.
         4.  AREA FROM WHICH POPULATION IS RELOCATED  (RESTRICTED ZONE).
                       FIGURE E-1.  RESPONSE AREAS.

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     Based on plant conditions or other considerations prior to or  after
the release, members of the public are assumed to have already been
evacuated from area 2 and sheltered in area 3.  Persons who were
evacuated or sheltered as a precautionary action for protection from  the
plume but whose homes are outside the plume deposition area (area 1)  are
assumed to return to their homes or discontinue sheltering when
environmental monitoring verifies the outer boundary of area 1.

     Area 4 is the restricted zone and is defined as the area where
projected doses are equal to or greater than the relocation PAG.  The
portion of area 1 outside of area 4 is designated as a study zone and is
assumed to be occupied by the public.  However, contamination levels  may
exist here that would be of concern for continued monitoring and
decontamination to maintain radiation doses "as low as reasonably
achievable" (ALARA).

     The relative positions of the boundaries shown in Figure E-l are
dependent on areas evacuated and sheltered.  For example, area 4 could
fall entirely inside area 2 (the area evacuated) so that relocation of
persons from additional areas would not be required.  In this case
relocation PAG would be used only to determine areas to which evacuees
could return.

     Figure E-2 provides, for perspective, a schematic representation of
the response activities expected to be in progress in association with
implementation of the PAGs during the intermediate phase of the response
to a nuclear incident.

E.2  Considerations for Establishing PAGs for the Intermediate Phase

     The major considerations in selecting values for these PAGs for
relocation and other actions during the intermediate phase are the  four
principles that form the basis for selecting all PAGs.  Those are
discussed in Section E.2.1.  Other considerations (Federal radiation
protection guidance and risks commonly confronting the public) are
discussed in Sections E.2.2 and E.5.

                                      E-7

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                         I  I  I  I I I III   I   I I  I 11111   I   I  I I 11 111   I   I  ITTTTTI
w
EC

O
O
O
LJJ
I
o
  PERIOD OF

  RELEASE,

  DISPERSION,

  DEPOSITION,

  SHELTERING,
o
UJ
UJ
_i
o_
5
O
O
 EVACUATION,   55
 AND ACCESS

   CONTROL



(NO TIME SCALE)
                   O
                   g]
                   Q
                                      CONDUCT AERIAL AND GROUND SURVEYS.  DRAW ISODOSE RATE LINES.
                                        IDENTIFY HIGH DOSE RATE AREAS.  CHARACTERIZE CONTAMINATION.
                                          RELOCATE POPULATION FROM HIGH  DOSE RATE AREAS.
                                           ALLOW IMMEDIATE  RETURN OF EVACUEES TO NONCONTAMINATED AREAS.
                                                ESTABLISH RESTRICTED ZONE  BOUNDARY AND  CONTROLS.
                                                RELOCATE REMAINING POPULATION FROM WITHIN  RESTRICTED ZONE.
                                                GRADUALLY RETURN  EVACUEES UP TO RESTRICTED ZONE BOUNDARY.
CONDUCT  D-CON  AND SHIELDING EVALUATIONS AND ESTABLISH PROCEDURES
    FOR  REDUCING EXPOSURE  OF PERSONS WHO  ARE  NOT RELOCATED.
                                                         PERFORM DETAILED ENVIRONMENTAL MONITORING.
                                                         PROJECT DOSE BASED ON DATA.
                                                        DECONTAMINATE ESSENTIAL FACILITIES AND  THEIR ACCESS ROUTES.
                                                        RETRIEVE VALUABLE AND ESSENTIAL  RECORDS AND  POSSESSIONS.
                                                                         REESTABLISH OPERATION OF VITAL SERVICES.
                                                               BEGIN  RECOVERY ACTIVITIES.
                                          CONTINUE  RECOVERY.
                                  MONITOR AND APPLY
                                  ALARA IN OCCUPIED
                                  CONTAMINATED  AREAS.
                         I  I  I  I Mill   I   I I  I INI
                                                 I  I  I  I Mill   I  I  I  I Mill
                    0.1
                              1.0            10            100
                                TIME AFTER DEPOSITION (DAYS)
                                                        1,000
               FIGURE   E-2.    POTENTIAL  TIME  FRAME OF RESPONSE  TO  A NUCLEAR  INCIDENT.

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     In addition, a planning group consisting of State, Federal, and
industry officials provided recommendations in 1982 which EPA considered
in the development of the format, nature, and applicability of PAGs for
relocation.  Abbreviated versions of these recommendations are as follows:

     a.  The PAGs should apply to commercial, light-water power reactors.

     b.  The PAGs should be based primarily on health effects.

     c.  Consideration should be given to establishing a range of PAG
         values.

     d.  The PAGs should be established as high as justifiable because at
         the time of the response, it would be possible to lower them, if
         justified, but it probably would not be possible to increase them.

     e.  Only two zones (restricted and unrestricted) should be
         established to simplify implementation of the PAGs.

     f.  The PAGs should not include past exposures.

     g.  Separate PAGs should be used for ingestion pathways.

     h.  PAGs should apply only to exposure during the first year after an
         incident.

     Although these PAGs apply to any nuclear incident, primary
consideration was given to the case of commercial U.S. reactors.  In
general, we have found it possible to accommodate most of the above
recommendations.

E.2.1  Principles

     In selecting values for these PAGs, EPA has been guided by the
principles that were set forth in Chapter 1.  They are repeated here for
convenience:

                                      E-9

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     1.  Acute effects on health (those that would be observable within  a
         short period of time and which have a dose  threshold  below  which
         they are not likely to occur) should be avoided.

     2.  The risk of delayed effects on health (primarily cancer and
         genetic effects, for which linear nonthreshold relationships  to
         dose are assumed) should not exceed upper bounds that  are judged
         to be adequately protective of public health, under emergency
         conditions, and are reasonably achievable.

     3.  PAGs should not be higher than justified on the basis  of
         optimization of cost and the collective risk of effects on
         health.  That is, any reduction of risk to  public health
         achievable at acceptable cost should be carried out.

     4.  Regardless of the above principles, the risk to health from a
         protective action should not itself exceed  the risk to health
         from the dose that would be avoided.

     Appendix B analyzed the risks of health effects as a function of
dose (Principles 1 and 2).  Considerations for selection of PAGs for the
intermediate phase of a nuclear incident differ from those for  selection
of PAGs for the early phase primarily with regard to implementation
factors (i.e., Principles 3 and 4).  Specifically, they differ  with
regard to cost of avoiding dose, the practicability  of leaving  infirm
persons and prisoners in the restricted zone, and avoiding dose to
fetuses.  Although sheltering is not generally a suitable alternative  to
relocation, other alternatives (e.g., decontamination and shielding) are
suitable.  These considerations are reviewed in the  sections that follow.

E.2.1.1  Cost/Risk Considerations

     The Environmental Protection Agency has issued  guidelines  for
internal use in for performing regulatory impact analyses (EP-83).   These
include consideration of the appropriate range of costs for avoiding a
statistical death.  The values are inferred from the additional

                                     E-10

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compensation associated with employment carrying a higher than normal
risk of mortality, and is expressed as a range of $0.4 to $7 million  per
statistical death avoided.  The following discussion compares these
values to the cost of avoiding radiation-induced fatal cancers through
relocation.

     The basis for estimating the societal costs of relocation are
analyzed in a report by Bunger (BU-89).  Estimated incremental societal
costs per day per person relocated are shown below.  (Moving and  loss of
inventory costs are averaged over one year.)
     Moving                                  J1.70
     Loss of use of residence                 2.96
     Maintain and secure vacated property     0.74
     Extra living costs                       1.28
     Lost business and inventories           14.10
     Extra travel costs                       4.48
     Idle government facilities               1.29
                                      Total
     The quantity of interest is the dose at which the value of  the  risk
avoided is equal to the cost of relocation.  Since the above costs are
expressed in dollars/person-day, it is convenient to calculate the dose
that must be avoided per-person day.  The equation for this is:

                          H  -!-
                           E ~ VR

     where:
          HE = dose (rem/day)
           C = cost of relocation (dollars/day).
           V = value of avoiding a statistical death (dollars/death)
           R = statistical risk of death from radiation dose (deaths/rem)
                                                            _4
     Using the values cited above, and a value for R of 3x10   deaths/rem
(See Appendix B), one obtains a range of doses of about 0.01 to 0.2  rem/day.
Thus, over a period of one year the total dose that should be avoided  to
justify the cost of relocation would be about 5 to 80 rem.
                                     E-ll

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     These doses are based on exposure  accumulated  over  a  period  of one
year.  However, exposure rates decrease with time due  to radioactive decay
and weathering.  Thus, for any given cumulative  dose  in  the  first year, the
daily exposure rate continually decreases,  so  that  a  relocated  person will
avoid dose more rapidly in the first part of the year  than later.  Figure
E-3 shows the effect of changing exposure rate on the  relationship between
the cost of avoiding a statistical death and the time  after  an  SST-2
accident (See Table E-l) for several assumed cumulative  annual  doses.  The
curves represent the cost per day divided by the risk  of fatality avoided  by
relocation per day, at time t, for the  annual  dose  under consideration,
where t is the number of days after the accident.   The right ordinate shows
the gamma exposure rate (mR/h) as a function of  time  for the postulated
radionuclide mix at one meter height.

     The convex downward curvature results  from  the rapid  decay of
short-lived radionuclides during the first  few weeks  following  the
accident.  Since the cost per day for relocation is assumed  to  be constant
and the dose avoided per day decreases, the cost effectiveness  of relocation
decreases with time.  For this reason it is cost effective to quickly
recover areas where the population has  been relocated  at projected doses
only marginally greater than the PAG.

     Only trends and general relationships  can be  inferred from Figure E-3
because it applies to a specific mix of radionuclides.  However,  for this
radionuclide mix, cost analysis supports relocation at doses as low as one
rem for the first week and two rem for  up to 25  days  after an accident.

E.2.1.2  Protection of Special Groups

     Contrary to the situation for evacuation  during  the early  phase of an
incident, it is generally not practical to  leave a  few persons  behind when
most members of the general population  have been relocated from a specified
area for extended periods of time.  Further, no  data  are available on
differing risks of relocation for different population groups.   In the
absence of such data, we have assumed that  these risks will  be  similar to
                                      E-12

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                                                         0.2
                                                         0.3

                                                         0.4

                                                         0.5
                                                         0.6
                                                         0.7
                                                         0.8 uj
                                                            O
             0.9
                                                         1.0
                                                         6
                                                         7
                                                         8
                                                         9
                                                         10
                                                         20



                                                         30


                                                         40
                10       15       20
                TIME AFTER ACCIDENT (days)
25
30
FIGURE E-3. COST OF AVOIDING  STATISTICAL FATALITIES AND
           EXPOSURE RATES CORRESPONDING TO VARIOUS
           TOTAL FIRST YEAR  DOSES (ASSUMES  AN SST-2
           ACCIDENT AND  A $27 PER PFRSON-DAY COST OF
           RELOCATION).
                           E-13

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those from evacuation.  Those risks were taken as equivalent  to  the  health
risk from doses of 30 mrem for members of  the general  population and of  150
mrem for persons at high risk from evacuation (see Appendix C).   Therefore,
to satisfy Principle 4 for population groups at high risk, the PAG for
relocation should not be lower than 150 millirem.  Given the  arbitrary nature
of this derivation, it is fortunate that this value  is much lower than the
PAG selected, and is therefore not an important factor in  its choice.

     Fetuses are a special group at greater risk of  health effects from
radiation dose than is the general population, but not at  significantly
greater risk from relocation itself.  The  risk of mental retardation from
fetal exposure (see Appendix 8) is significant.  It  is affected  by the stage
of pregnancy relative to the assumed one-year exposure, because  the  8th  to
15th week critical period during which the risk is greatest,  must be
considered in relation to the rapidly changing dose  rate.  Taking these
factors into account, it can be postulated that the  risk of mental
retardation due to exposure of the fetus during the  intermediate phase will
range from one to five times the cancer risk of an average member of the
public, depending upon when conception occurs relative to  the time of the
incident.  The elevated risk of radiation-induced cancer from exposure of
fetuses is less significant, as discussed  in Appendix  B.

     It will usually be practicable to reduce these  risks  by  establishing a
high priority for efforts other than relocation to reduce  the dose in cases
where pregnant women reside near the boundary of the restricted  zone.
However, women who are less than seven months pregnant may wish  to relocate
for the balance of their pregnancy if the  projected  dose during  pregnancy
cannot be reduced below 0.5 rem.

E.2.2  Federal Radiation Protection Guides

     The choice of a PAG at which relocation should  be implemented does  not
mean that persons outside the boundary of  the restricted zone should not be
the subject of other protective actions to reduce dose.  Such actions are
justified on the basis of existing Federal radiation protection  guidance
                                     E-14

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(FR-65) for protecting the public, including implementation of the
principle of maintaining doses "as low as reasonably achievable"
(ALARA).

     The intended actions to protect the public from radiation doses
on the basis of Radiation Protection Guides (RPGs) are those related to
source control.  Although it is reasonable for members of the public to
receive higher exposure rates prior to the source term being brought under
control, the establishment of acceptable values for relocation PAGs must
include consideration of the total dose over the average remaining
lifetime of exposed individuals (usually taken as 50 years).

     The nationally and internationally recommended upper bound for
dose in a single year from man-made sources, excluding medical radiation,
is 500 mrem per year to the whole body of individuals in the general
population (IC-77, FR-65).  These recommendations were not developed for
nuclear incidents.  They are also not appropriate for chronic exposure.
The ICRP recommends an upper bound of 100 mrem per year, from all sources
combined, for chronic exposure (IC-77).  The corresponding 50-year dose at
100 mrem/yr is 5 rem.   We have chosen to limit a) the projected first
year dose to individuals from an incident to the Relocation PAG, b) the
projected second year dose to 500 mrem, and c) the dose projected over a
fifty-year period to 5 rem.  Due to the extended duration of exposures and
the short half-life of important radioiodines, no special limits for
thyroid dose are needed.

E.3. Dose from Reactor Incidents

     Doses from an environmental source will be reduced through the
natural processes of weathering and radioactive decay, and from the
shielding associated with part time occupancy in homes and other
structures.  Results of dose calculations based on the radiological
characteristics of releases from three categories of postulated,
fuel-melt, reactor accidents (SST-1, SST-2, and SST-3) (SN-82) and
a weathering model from WASH-1400 (NR-75) are shown in Table E-3.
                                     E-15

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This table shows the relationship between annual doses for the case
where the sum, over fifty years, of the effective dose equivalent
from gamma radiation and the committed effective dose equivalent from
inhalation of resuspended materials, is 5 rem.  Radioactive decay  and

weathering reduces the second year dose from reactor incidents to  20 to 40
percent of the first year dose, depending on the radionuclide mix  in the

release.
Table E-3  Annual Doses Corresponding to 5 Rem in 50 Years3
 Year
     c
     Dose According to Accident Category

SST-l(rem)        SST-2(rem)          SST-3(rem)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1.25
0.52
0.33
0.24
0.18
0.14
0.12
0.10
0.085
0.080
0.070
0.060
0.060
0.055
0.055
0.050
1.60
0.44
0.28
0.20
0.16
0.12
0.11
0.085
0.075
0.070
0.060
0.055
0.055
0.050
0.045
0.045
1.91
0.38
0.24
0.17
0.13
0.11
0.090
0.070
0.065
0.060
0.050
0.050
0.045
0.040
0.040
0.040
aWhole body dose equivalent from gamma radiation plus committed
 effective dose equivalent from inhalation assuming a resuspension factor
 of 10~6 nr1.  Weathering according to the WASH-1400 model  (NR-75)
 and radioactive decay are assumed.

bRadionuclide abundance ratios are based on reactor inventories from
 WASH-1400 (NR-75).  Release quantities for accident categories SST-1,
 SST-2 and SST-3 are shown in Table E-2.  Initial concentrations are
 assumed to have decayed for 4 days after reactor shutdown.

cAnnual doses after 16 years would be less than 0.05 rem.
                                     E-16

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     Based on studies reported in WASH-1400  (NR-75), the most conservative
dose reduction factor for structures (frame  structures) is about 0.4  (dose
inside divided by dose outside) and the average fraction of  time spent  in  a
home is about 0.7.  Combining these factors  yields a net dose reduction
factor of about 0.6.  In most cases, therefore, structural shielding  would
be expected to reduce the dose to persons who are not relocated to  60
percent (or less) of the values shown  in Table E-3 before the application
of decontamination.

E.4  Alternatives to Relocation

     Persons who are not relocated, in addition to dose reduction provided
by partial occupancy in homes and other structures, can reduce their  dose
by the application of various techniques.  Dose reduction efforts can range
from the simple processes of scrubbing and/or flushing surfaces, soaking or
plowing of soil, removal and disposal  of small spots of soil found  to be
highly contaminated (e.g., from settlement of water), and spending  more
time than usual in lower exposure rate areas (e.g., indoors), to the
difficult and time consuming processes of removal, disposal, and
replacement of contaminated surfaces.  It is anticipated that simple
processes would be most appropriate to reduce exposure rates for persons
living in contaminated areas outside the restricted zone.  Many of  these
can be carried out by the residents with support from officials for
monitoring, guidance on appropriate actions, and disposal.   The more
difficult processes will usually be appropriate for recovery of areas from
which the population is relocated.

     Decontamination experiments involving radioactive fallout from nuclear
weapons tests have shown reduction factors for simple decontamination
methods in the vicinity of 0.1 (i.e.,  exposure rate reduced  to 10 percent
of original values).  However, recent  experiments at the Riso National
Laboratory in Denmark (WA-82, WA-84),  using  firehoses to flush asphalt  and
concrete surfaces contaminated with radioactive material of  the type  that
might be deposited from reactor accidents, show decontamination factors for
radionuclides chemically similar to cesium that are in the range of 0.5 to
0.95, depending on the delay time after deposition before flushing  is

                                     E-17

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applied.  The factor for ruthenium on asphalt was  about 0.7  and  was
Independent of the delay of flushing.  The results  of  these  experiments
indicate that decontamination of the important reactor fission products
from asphalt or concrete surfaces may be much more  difficult  than
decontamination of nuclear weapons fallout.  Other  simple dose reduction
methods listed above would be effective to varying  degrees.   The average
dose reduction factor for gamma radiation from combinations  of simple
decontamination methods is estimated to be at least 0.7.  Combining  this
with the 40 percent reduction estimated above for  structural  shielding
indicates that the doses listed in Table E-3 may be more than twice  as high
as those which would actually be received by persons who are  not relocated.

E.5  Risk Comparisons

     Many hazardous conditions and their associated risks are routinely
faced by the public.  A lingering radiation dose will  add to  those risks,
as opposed to substituting one risk for another, and,  therefore, radiation
protection criteria cannot be justified on the basis of the  existence of
other risks.  It is, however, useful to review those risks to provide
perspective.  This section compares the risks associated with radiation
doses to those associated with several other risks  to  which  the  public is
commonly exposed.

     Figure E-4 compares recent statistics for the  average lifetime  risk of
accidental death in various occupations to the estimated lifetime risk of
fatal cancer for members of the general population  exposed to radiation
doses ranging up to 25 rem. Non-radiation risk values  are derived from
information in reference (EP-81) and radiation risk values are from
Appendix 6.  These comparisons show, for example,  that the lifetime  cancer
risk associated with a dose of 5 rem is comparable  to  the lifetime risk of
accidental death in some of the safest occupations, and is well  below the
average lifetime risk of accidental death for all  industry.

     Risks of health effects associated with radiation dose  can  also be
compared to other risks facing individuals in the  general population.  The
risks listed in Table E-4 are expressed as the number  of premature deaths

                                     E-18

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   10
     -2
UJ
0
UJ
oc
3

5
UJ
OC
0.
u.
o
 tn
 E
 UJ
 UJ
 o
 <
 oc
 UJ
   ID'3
   10-4
            •CONSTRUCTION  & MINING

             AGRICULTURE


            -TRANSPORTATION & PUBLIC UTILITIES
 AVERAGE FOR ALL UTILITIES
•GOVERNMENT


.SERVICE
 MANUFACTURING
• RETAIL &
 WHOLESALE.
 TRADE
                                                                25 rem
          •5 rem
•1 rem
           •0.5  rem
I	I
I
I
                                         I
I
I
                           8   10   12  14   16   18
                           rem  (effective dose equivalent)
                                          20   22   24   26
FIGURE E-4.  AVERAGE LIFETIME  RISK OF DEATH  FROM WHOLE BODY  RADIATION DOSE
            COMPARED  TO THE AVERAGE  RISK  OF ACCIDENTAL DEATH FROM LIFETIME
            (47 YEARS) OCCUPATION IN VARIOUS INDUSTRIES.
                                     E-19

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Table E-4  Measure of Lifetime Risk of Mortality from  a  Variety  of  Causes3
           (Cohort Size = 100,000)
                        Aggregate years   Reduction of        Average  years
 Nature of  Premature    of  life lost     life expectancy     of  life  lost  to
 accident    deaths       to cohort       at birth  (years)    premature deaths
Falls
Fires
Drowning
Poisoning
by drugs and
medicaments
1,000
300
190
69
12,000
7,600
8,700
2,500
0.12
0.076
0.087
0.025
11
26
45
37
Cataclysm13

Bites and
stings0

Electric
current
in homes^
17

 8
490

220


290
0.005

0.002


0.003
30

27


37
aAll mortality effects shown are calculated as changes from  the U.S.  Life
 Tables for 1970 to life tables with the cause of death under  investigation
 removed.  These effects also can be interpreted as changes  in the  opposite
 direction, from life tables with the cause of death removed to the 1970
 Life Table.  Therefore, the premature deaths and years of life lost  are
 those that would be experienced in changing from an environment where  the
 indicated cause of death is not present to one where it  is  present.  All
 values are rounded to no more than two significant figures.

^Cataclysm is defined to include cloudburst, cyclone, earthquake, flood,
 hurricane, tidal waves, tornado, torrential rain, and volcanic eruption.

cAccidents by bite and sting of venomous animals and insects include  bites
 by centipedes, venomous sea animals, snakes, and spiders; stings of  bees,
 insects, scorpions, and wasps; and other venomous bites  and stings.  Other
 accidents caused by animals include bites by any animal  and nonvenomous
 insect; fallen on by horse or other animal; gored; kicked or  stepped on by
 animal; ant bites; and run over by horse or other animal.   It excludes
 transport accidents involving ridden animals; and tripping, falling  over an
 animal.  Rabies is also excluded.

^Accidents caused by electric current from home wiring and appliances
 include burn by electric current, electric shock or electrocution  from
 exposed wires, faulty appliances, high voltage cable, live  rail, and open
 socket.  It excludes burn by heat from electrical appliances  and lighting.
                                     E-20

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and the average reduction of life-span due to these deaths within a group
of 100,000 persons.  For purposes of comparison, a dose of 5 rem to each
member of a population group of 100,000 persons representative of the
average U.S. population carries an estimated lifetime risk of about 150
fatal cancers (see Appendix 8).  The number of deaths resulting from the
various causes listed in Table E-4 is based on data from mortality
records.

     In summary, the risk of premature death normally confronting the
public from specific types of accidents ranges from about 2 to 1000 per
100,000 population.  The estimated radiation doses required to produce a
similar risk of death from radiation-induced cancer range from about 0.07
to 33 rem.

E.6  Relocation PAG Recommendations

     Previous sections have reviewed data, standards, and other
information relevant to establishing PAGs for relocation.  The results are
summarized in Table E-5, in relation to the principles set forth in
Section E.2.1.

     Based on the avoidance of acute effects alone (Principle 1) 50 rem
and 10 rem are upper bounds on the dose at which relocation of the general
population and fetuses, respectively, is justified.  However, on the basis
of control of chronic risks (Principle 2) a lower upper bound is
appropriate.  Five rem is taken as an upper bound on acceptable risk for
controllable lifetime exposure to radiation, including avoidable exposure
to accidentally deposited radioactive materials.  This corresponds to an
average of 100 mrem per year for fifty years, a value commonly accepted as
an upper bound for chronic annual exposure of members of the public from
all sources of exposure combined, other than natural background and
medical radiation (IC-77).  In the case of projected doses from nuclear
reactor accidents, a five rem lifetime dose corresponds to about 1.25 to
2 rem from exposure during the first year and 0.4 to 0.5 rem from exposure
during the second year.
                                     E-21

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Table E.5  Summary of Considerations for Selecting PAGs for Relocation
Dose
(rem)                      Consideration                      Principle

50     Assumed threshold for acute health effects  in adults.       1

10     Assumed threshold for acute health effects  in the
       fetus.                                                      1

 6     Maximum projected dose in first year to meet 0.5 rem        2
       in the second year3.

 5     Maximum acceptable annual dose for normal
       occupational exposure of adults.                            2

 5     Minimum dose that must be avoided by
       one year relocation based on cost.                          3

 3     Minimum projected first-year dose corresponding
       to 5 rem in 50 years3.                                      2

 3     Minimum projected first-year dose corresponding
       to 0.5 rem in the second year3.                             2

 2     Maximum dose in first year corresponding to
       5 rem in 50 years from a reactor incident,
       based on radioactive decay and weathering only.             2

1.25   Minimum dose in first year corresponding to 5 rem
       in 50 years from a reactor incident based on
       radioactive decay and weathering only.                      2

0.5    Maximum acceptable single-year dose to the
       general population from all sources from
       non-recurring, non-incident exposure.                       2

0.5    Maximum acceptable dose to the fetus from
       occupational exposure of the mother.                        2

0.1    Maximum acceptable annual dose to the general
       population from all sources due to routine  (chronic),
       non-incident, exposure.                                     2

0.03   Dose that carries a risk assumed to be equal to
       or less than that from relocation.                          4

aAssumes the source term is from a reactor incident and that  simple
 dose reduction methods are applied during the first month after  the
 incident to reduce the dose to persons not relocated from contaminated
 areas.
                                     E-22

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    Analyses based on Principle 3 (cost/risk) indicate that considering  cost
alone would not drive the PAG to values less than 5 rem.  Analyses  in
support of Principle 4 (risk of the protective action itself) provide  a
lower bound for relocation PAGs of 0.15 rem.

    Based on the above, 2 rem projected committed effective dose equivalent
from exposure in the first year is selected as the PAG for relocation.
Implementation of relocation at this value will provide reasonable  assurance
that, for a reactor accident, a person relocated from the outer margin of
the relocation zone will, by such action, avoid an exposure rate which,  if
continued over a period of one year, would result in a dose of about 1.2 rem.
This assumes that 0.8 rem would be avoided without relocation through  normal
partial occupancy of homes and other structures.  This PAG will provide
reasonable assurance that persons outside the relocation zone, following a
reactor accident, will not exceed 1.2 rem in the first year, 0.5 rem in  the
second year, and 5 rem in 50 years.  The implementation of simple dose
reduction techniques, as discussed in section E-4, will further reduce dose
to persons who are not relocated from contaminated areas.  Table E-6
summarizes the estimated maximum dose that would be received by these
persons for various reactor accident categories with and without the
application of simple dose reduction techniques.  In the case of non-reactor
accidents these doses will, in general, differ, and it may be necessary  to
apply more restrictive PAGs to the first year in order to assure conformance
to the second year and lifetime objectives noted above.

    Since effective dose does not include dose to the skin (and for other
reasons discussed in Appendix B) protective action to limit dose to skin is
recommended at a skin dose 50 times the numerical value of the PAG  for
effective dose.  This includes consideration of the risk of both curable and
fatal cancers.

E.7  Criteria for Reentry into the Restricted Zone

    Persons may need to reenter the restricted zone for a variety of
reasons, including radiation monitoring, recovery work, animal care,
property maintenance, and factory or utility operation.  Some persons

                                     E-23

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outside the restricted zone, by nature of their employment or habits, may
also receive higher than average radiation doses.  Tasks that could  cause

such exposures include, 1) changing of filters on air handling equipment
(including vehicles), 2) handling and disposal of contaminated vegetation
(e.g., grass and leaves) and, 3) operation of control points for the
restricted zone.


    Individuals who reenter the restricted zone or who perform tasks
involving exposure rates that would cause their radiation dose to exceed
that permitted by the PAGs should do so in accordance with existing  Federal
radiation protection guidance for occupationally exposed workers (EP-87).
The basis for that guidance has been provided elsewhere (EP-87)
Table E-6  Estimated Maximum Doses to Nonrelocated Persons From Areas Where

the Projected Dose is 2 REMa
                                    Dose (rem)
Accident
Category
SST-1
SST-2
SST-3
No
addi
Year 1
1
1
1
.2
.2
.2
tional dose
Year 2
0.5
0.34
0.20
reduction
50
5
3
3
years
.0
.9
.3
Early
Year 1
0.9
0.9
0.9
simple dose
Year 2
0.35
0.24
0.14
reduction^
50
3
2
2
years
.5
.7
.3
aBased on relocation at a projected dose of 2 rem  in the first
 year and 40 percent dose reduction to nonrelocated persons from normal,
 partial occupancy in structures.  No dose reduction is assumed from
 decontamination, shielding, or special limitations on time spent  in high
 exposure rate areas.

bThe projected dose is assumed to be reduced 30 percent by the
 application of simple dose reduction techniques during the first  month.
 If these techniques are completed later in the first year, the first year
 dose will be greater.
                                     E-24

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                                 REFERENCES
AR-89       AABERG, ROSANNE, Battelle Northwest Laboratories. Evaluation of
            Skin and Ingestion Exposure Pathways. U.S. Environmental
            Protection Agency/Office of Radiation Programs, Washington,
            D.C.  20460 (1989 in press).

BU-89       8UNGER, BYRON M., Cost of Relocation.  U.S. Environmental
            Protection Agency/Office of Radiation Programs.  Washington,
            D.C. 20460.  1989 (draft).

EP-81       U.S. ENVIRONMENTAL PROTECTION AGENCY. Background Report.
            Proposed Federal Radiation Protection Guidance for Occupational
            Exposure. EPA 520/4-81-003. U.S. Environmental Protection
            Agency/Office of Radiation Programs. Washington, D.C. 20460.
            January, 1981.

EP-83       U.S. ENVIRONMENTAL PROTECTION AGENCY, Office of Policy
            Analysis.  Guidelines for Performing Regulatory Impact Analysis,
            EPA-23-01-84-003. U.S. Environmental Protection Agency,
            Washington, DC 20460. December 1983.

EP-87       U.S. ENVIRONMENTAL PROTECTION AGENCY.  Radiation Protection
            Guidance to Federal Agencies for Occupational Exposure.  Federal
            Register.  Vol. 52, No. 17, p. 2822, U.S. Government Printing
            Office, Washington, DC 20402..January 27, 1987.

FR-65       FEDERAL RADIATION COUNCIL.  Radiation Protection Guidance for
            Federal Agencies.  Federal Register, Volume 30, pp. 6953-6955,
            U.S. Government Printing Office, Washington, DC 20402, May 22,
            1965.

IA-85       INTERNATIONAL ATOMIC ENERGY AGENCY.  Principles for Establishing
            Intervention Levels for Protection of the Public in the Event of
            a Nuclear Accident or Radiological Emergency, Safety Series
            No.72, International Atomic Energy Agency, Vienna, 1985.

IC-77       INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION.
             Radiological Protection.  ICRP Publication 26, Pergamon Press,
            Oxford, England, January 1977.

IC-84       INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION.  Protection
            of the Public in the Event of Major Radiation Accidents:
            Principles for Planning, ICRP Publication 40, Pergamon Press,
            New York, 1984.

NR-75       U.S. NUCLEAR REGULATORY COMMISSION.  Calculations of Reactor
            Accident Consequences, WASH-1400, U.S. Nuclear Regulatory
            Commission, Washington, DC 20555, October 1975.
                                     E-25

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SN-82       SANDIA NATIONAL LABORATORIES.  Technical Guidance for Siting
            Criteria Development, NUREG/CR-2239, U.S. Nuclear Regulatory
            Commission, Washington, DC 20555, December 1982.

WA-82       WARMING, L.  Weathering and Decontamination of Radioactivity
            Deposited on Asphalt Surfaces, Riso-M-2273, Riso National
            Laboratory, DK 4000 Roskilde, Denmark, December 1982.

WA-84       WARMING, L. Weathering and Decontamination of Radioactivity
            Deposited on Concrete Surfaces. RISO-M-2473. Riso National
            Laboratory, DK-4000 Roskilde, Denmark. December 1984.
                                      E-26

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         APPENDIX F
Radiation Protection Criteria
     for the Late Phase
   Background  Information
          (Reserved)

-------