Manual

            of

Protective Action Guides

           and

   Protective Actions

           for

    Nuclear  Incidents
      September  1975
Environmental Protection Agency
 Office of Radiation Programs
Environmental Analysis Division
   Washington,  D. C.  20460
                                        14322

-------
                               Preface







      This manual has been prepared to provide practical guidance




to State, local, and other officials on criteria to use in planning




protective actions for radiological emergencies that could present




a hazard to the public.  The guidance presented here is not intended




as a substitute for, or an addemdum to, a State radiological emergency




response plan.  It is intended only to provide information for use




in the development of such a plan.




      In conformance with a Federal Register Notice of interagency




responsibilities for nuclear incident response planning dated




January 17, 1973, EPA is responsible for (1) establishment of pro-




tective action guidelines, (2) recommendations as to appropriate




protective actions,  (3) assistance to State agencies in the develop-




ment of emergency response plans, and (4) establishment of radiation




detection and measurement systems.  This document is intended to be




responsive to these  assigned responsibilities.




      The manual is  organized to provide first, a general discussion




of Protective Action Guides and their use in planning  for the implemen-




tation of protective actions to protect the public.  This is followed




by chapters dealing  with Protective Action Guides for  specific exposure




pathways and  time periods.  The application of Protective Action Guides




and protective actions  is discussed separately for various categories




of source terms.  Support information  that has not been previously




published is  provided as appendices.
                                 11

-------
      The loose, leaf format was chosen for flexibility.   Copies of




additional or revised sections will be forwarded routinely to manual




recipients designated as having responsibilities for developing or




updating State radiological emergency response plans.




      Users of this manual are encouraged to provide comments and




suggestions for improving the content.  Comments should be sent to




the EPA Office of Radiation Programs, Environmental Analysis Division,




Washington, D. C.  20460.
                                  iii

-------
                             Contents
Chapter 1 - Perspectives for  Protective Action	  1.1

     1.0  Introduction	  1.1
     1.1  The Need for Planning	  1.2
     1.2  Nature of Protective Action Guides, Protective Action,
          and Restorative Action	  1.3
     1.3  Protective Action Decision Making	  1.7

          1.3.1  Action Factors	  1.8
          1.3.2  Incident Determinations	  1.8
          1.3.3  Exposure Pathways	  1.11
          1.3.4  Populations at Risk	  1.13
          1.3.5  Radiation Effects	  1.14

     1.4  Response Plan Action Times	  1.17

          1.^.1  Preparation of Plans	  1.17
          1.4.2  Implementation of Plans	  1.19

     1.5  TypeF of Action	  1.22
     1.6  Goals of Protective Action	  1.24

          1.6.1  Balancing Factors to Achieve Protection Goals..  1.25
          1,6.2  Constraints on Goal Attainment	  1.26
          1.6,3  Evaluation of Constraints	  1.28

                 1.6.3.1  Constraints on Evacuation	  1.28
                 1.6.3.2  Seeking Shelter	  1.38
                 1.6.3.3  Access Control	  1.40
                 1.6.3.4  Respiratory Protection	  1.40
                 1.6.3.5  Prophylaxis (Thyroid Protection)	  1.41
                 1.6.3.6  Milk Control	  1.42
                 1.6.3.7  Food Control	  1.46
                 1.6.3.8  Water Control	  1.47
                 1.6.3.9  Restorative Actions	  1.48

Chapter 2 - Protective Action Guides for Exposure to Airborne
            Radioactive Materials	  2.1

     2.0  Introduction	  2.1
     2.1  Whole Body External Exposure	  2.2
     2.2  Inhalation Dose	  2.4
                                IV

-------
          2.2.1  Exposure to Radio iodines in a Plume ............  2.4
          2.2.2  Exposure to Particulate Material in a Plume ----  2.6

     2 . 3  Interpretation of PAGs ................................  2.6

Chapter 3 - Protective Action Guides for Exposure from
            Foodstuffs or Water .................................  3.1

Chapter 4 - Protective Action Guides for Exposure from Material
            Deposited on Property or Equipment ..................  4.1
Chapter 5 - Application of Protective Action Guides for Exposure
            to Airborne Radioactive Materials ................... 5.1

     5.0  Introduction .......................................... 5.1
     5 . 1  Release Assumptions ................................... 5.2

          5.1.1  Noble Gas and Radioiodine Releases ............. 5.3
          5.1.2  Radioactive Particulate Material Releases ...... 5.5

     5.2  Application of Protective Actions ..................... 5.5

          5.2.1  Actions Based on Licensee Notification ......... 5.7
          5.2.2  Actions Based on Environmental Measurements.... 5.10

                 5.2.2.1  Dose Projection for Noble Gas and
                          Iodine Releases ....................... 5.10
                 5.2.2.2  Dose Projection for Particulate
                          Material Releases ..................... 5.25

Chapter 6 - Application of PAGs for Foodstuffs and Water
            Contamination ....................................... 6.1

Chapter 7 - Application of PAGs for Contaminated Property or
            Equipment ........................................... ' • ^

Chapter 8 - Application of PAGs for Transportation Incidents ---- 8.1

References [[[ R~l

Appendix A - Summary  of Interim Guidance on  Offsite Emergency
             Radiation Measurement Systems ...................... A.-1
Appendix B - Planner's Evaluation Guide for  Protective Actions.. B-l
Appendix C - Summary  of Technical Bases for  Protective Action
             Guides ............................................. c-1

-------
                              Tables


                                                                 Page

 Table  1.1   Exposure Pathways  and  Appropriate Responses	 1.5

 Table  1.2   Action and Health  Effects  Versus Exposure Pathways... 1.16

 Table  1.3   Protective and  Restorative Actions  for Nuclear
            Incidents Resulting  in Airborne Releases	 1.29

 Table  1.4   Initiation Times for Protective Actions	 1.30

 Table  1.5   Approximate Range  of Time  Segments  Making Up  the
            Evaucation Time	 1.36

 Table  1.6   Parameters Affecting the Cost of Evacuation	 1.39

 Table  2.1   Protective Action  Guides for Whole  Body  Exposure  to
            Airborne Radioactive Materials	 2.3

 Table  2.2   Protective Action  Guides for Thyroid Dose Due to
            Inhalation from a  Passing  Plume	 2.5

 Table  5.1   Initial Inventory  of the Radiologically  Significant
            Noble Gases and Iodines	 5.4

 Table  5.2   Recommended Protective Actions to  Avoid  Whole Body
            and Thyroid Dose from Exposure to  a Gaseous Plume.... 5.8


                              Figures

Figure  1.1   Sequence of Events for Response  Planning and
            Responding to Nuclear  Incidents	 1.18

Figure  5.1   Projected Whole Body Gamma Dose  as a Function of
            Ganmia Radiation Exposure Rate and  Projected Time
            Period of Exposure	 5.15

Figure  5.2   Projected Thyroid Dose as a Function of  Gamma
            Radiation Exposure Rate and Projected Time  Period
            of Exposure	  5.16

Figure  5.3   Gamma Radiation Exposure Rate Correction Factor	 5.18

Figure  5.4   Typical Values for XU/Q as a Function of Atmospheric
            Stability and Downwind Distance	 5. 22
                                 VI

-------
                                 CHAPTER 1




                     Perspectives for Protective Action









1.0  Introduction




          In emergency preparedness planning for a nuclear incident with




     potential for exposing the general public' to li.-innlul rad f .il Ion,




     public health officials require criteria to determine the need for




     protective actions and for choosing appropriate protective actions.




     EPA is respcnslble for providing these criteria and for assisting




     the States in preparing emergency response plans to implement these




     criteria.




          After a nuclear incident occurs, an estimate is made of the




     radiation dose which affected population groups may potentially receive.




     This dose estimate is called the projected dose.  A protective action




     is an action taken to avoid or reduce this projected dose when the




     benefits derived from such action are sufficient to offset any




     undesirable features of the protective action.  The Protective Action




     Guide  (PAG) is the projected dose to individuals in the population




     which warrants taking protective action.




          A Protective Action Guide under no circumstances  implies an




     acceptable dose.  Since the PAG is based on  a  projected dose, it  is




     used only in an ex post facto effort to minimize the risk from an




     event which is occurring or has already occurred.
                                      1.1

-------
          Exposures to populations  from an  incident  may well be above




     acceptable levels,  in an absolute sense.   However, since  the  event




     has  occurred,  PAGs should be implemented  to  ameliorate the impact




     on already exposed or yet-to-be exposed populations.




          On this basis there is no direct  relationship between acceptable




     levels of  societal risk and Protective Action Guides.  PAGs balance




     risks and  costs against the benefits obtained from protective action,




     assuming that the projected threat will transpire.   The responses




     made in a  given situation should be based on PAGs and  the spectrum




     of possible protective actions available  at  that time.




1.1  The  Need for Planning




          Within the general framework of providing  maximum health protec-




     tion for an endangered public, the public official  charged with re-




     sponse to  a hazardous situation may be faced with a  number  of decisions




     which must be made in a short time.  A number of possible alternatives




     for  action may be available, but the information needed  to  select  the




     optimum alternative may not be available.  In those  situations where




     a public official must rapidly select  the best of several alternatives,




     it is helpful if the number of decision points can be  reduced during




     the  accident response planning phase.




          The efforts of planning activities can usually  be based  on the




     need for immediate response.  Therefore,  the objective is to  minimize




     the  number of possible responses so that resources  are expended only




     on viable alternatives in emergency situations.  During planning it




     is possible to assess value judgments and determine  which steps in
                                     1.2

-------
     response are not required, which steps can be answered on the  basis

     of prior judgments, and which remain to be decided in an actual

     emergency.  From this exercise, it is then possible to devise  a

     set or several sets of operational plans which can be called out  to

     answer the spectrum of hazardous situations which may develop.

          In the case of an accident at a nuclear reactor, a hazardous

     situation could develop which may have public health implications

     over a large area with diverse populations and population densities.

     Probably little time will be available to make decisions.  The

     availability of "action guides" based on advance planning will facili-

     tate rational decisions in emergency situations.  During the planning

     stage, the responsible public official must consider the total range

     of possible release scenarios and consider in each what goals  are

     achievable keeping in mind both fiscal and societal costs.  Because

     of this knowledge of local conditions, he will be aware of any con-

     straints which may restrict his scope of response, such as specific

     industries, institutions, traffic patterns, etc.  He will then be able

     to select the optimum response for each situation.

1.2  Nature of Protective Action Guides, Protective Action, and Restorative
     Action

          Protective Action Guides are the numerical projected doses which

     act as trigger points to initiate protective action.

          PAGs must be provided for three broad pathways of radiation

     exposure:

          (1)  Exposure from airborne radioactive releases.  This type of

               exposure could occur within a short period following an
                                     1.3

-------
          incident  as  a result  of  inhalation  of  radioactive materials




          or from external  whole body  exposure.




     (2)   Exposure  through  the  food  chain.  This exposure will be




          from ingestion of contaminated foodstuff  and water.  It




          may commence shortly  after the passage of airborne  radio-




          active materials  and  may continue for a long  or  short




          time depending on the radionuclides involved.




     (3)   Exposure  from radioactive  materials deposited  on  the ground.




          Heie we are  dealing with a change in background  radiation




          levels, and  exposure  pathways may include inhalation,




          ingestion, and external  whole body exposures.




     Different PAGs must be developed for each pathway  of  exposure




since different criteria of risk,  cost, and benefit are involved.




Each exposure pathway would involve different sets of protective or




restorative actions as indicated in table 1.1.  Each action listed




applies to the general population except for prophylaxis,  respiratory




protection, and protective clothing.  These actions would primarily




apply to emergency workers.




     Exposure ro the airborne plume is related to the duration of a




release into the atmosphere.  While release durations as long as




30 days or more are theoretically possible, for emergency purposes,




release durations of a few hours up to a few days are more realistic.




Protective action to be taken  for this pathway may  include any or all




of the following:
                                1.4

-------
                              Table 1.1  Exposure Pathways  and Appropriate Responses
Exposure from Airborne Materials
                    Exposure from Foodstuffs and Water
   Protective
    Actions
Restorative
  Actions
Protective
 Actions
                                       Exposure from Contaminated
                                                   or Equipment
Restorative
  Actions
Protective
 Actions
Restoriv
  Actiou




C
o
•rl
4-1
CQ
3

•H
4J
U
CU
o
to CO
P« C
o
a -H
O 4J
4J U
W  O
                                               co 
-------
     (1)   evacuation,




     (2)   respiratory  protection,




     (3)   shelter,




     (A)   prophylaxis  (thyroid protection),  and




     (5)   controlled access.




     Restorative actions would then include:




     (1)   reentry first by survey and decontamination teams,




     (2)   removal of respiratory protection,




     (3)   exit from shelters,




     (4)   stepping prophylactic measures,  and




     (5)   allowing free access by the population.




     Exposure through  the food chain may be either short term or




chronic depending on the characteristics and half-lives of the




radionuclides involved.  Control of this pathway of exposure would




be by:




     (1)   control of access to contaminated animal feeds,




     (2)   decontamination of certain foodstuffs,




     (3)   diversion and storage to allow decay of short half-life




          radionuclides, and




     (4)   destruction of contaminated foods.




     Exposure from materials deposited on the ground might also be




either short term or chronic depending on the radionuclides involved,




Protective actions would include:
                                1.6

-------
          (1)   evacuation,  and




          (2)   controlled access.




     Since  the  problem for ground  contamination involves  an  increase




     in background levels,  denial  of access  might  continue for  extended




     periods of time.   Decontamination may then be the  only  action which




     will allow free  access to and utilization of  contaminated  areas within




     a  short time.  Restorative actions would be reentry, decontamination,




     and lifting of controls.




         The PAGs are to provide  standardized criteria for  selecting




     predetermined actions  at  the  sacrifice  of some flexibility in




     balancing  the risk of  health  effects  versus the effects of protective




     actions during an emergency.   The loss  of flexibility in response is




     expected to be within the limits of accuracy  of determining the




     factors involved.  The loss of flexibility is also offset  by the




     advantage  of being able to respond to the immediacy of  the risks in




     the case of an emergency.




         The range of PAG values  allows consideration  for local constraints




     during planning  for implementation.  PAGs should be assigned for each




     site to assure that local constraints are properly introduced.




1.3  Protective Action Decision Making




         A nuclear incident as defined herein refers to  a series of events




     leading to the release of radioactive materials into the environment of




     sufficient magnitude to warrant consideration of protective actions.




     Protective actions are those  actions  taken following a  nuclear incident
                                     1.7

-------
       that are intendad to minimize the radiation exposure of the general




       public resulting from incidents.




            The decision to initiate a protective action may be a complex




       process with the benefits of taking the action being weighed against




       the risks and constraints involved in taking the action.  In addition,




       the decision will likely be made under difficult emergency conditions,




       probably with .little detailed information available.  Therefore,




       considerable planning is necessary to reduce to manageable levels  the




       types of decisions leading to effective responses to protect the




       public in the event of a nuclear incident.




1.3.1  Action Factors




            Within the context of nuclear incidents,  a wide variety of




       possible situations may develop.  Some perspective of the needs of the




       responsible planning officer can be shown in a brief description of




       the factors involved.   Basically, the officer  must balance problems




       involving identification of the magnitude of the release, possible




       pathways to the population at risk, how much time is available to  take




       action,  what action to take, and what the effects might be.




1.3.2  Incident Determinations




            The first problem to arise will be that of identifying the type of




       incident and the magnitude of the release.  Nuclear incidents  may  be




       extremely variable and may range from very small releases having no




       measurable consequences offsite to large scale releases possibly




       involving lar^e populations and areas.   Responses must  be appropriate




       to  the incident reported.
                                       l.i

-------
     One of the variables will be the source term, which refers to




the characteristics and release rate of the radioactive material.




The amounts and types of radionuclides available for release should




be immediately calculable by site personnel.  What is actually being




released to the environment can be estimated but may not be confirmed




for some time after the incident.




     The magnitude and duration of the release may be estimated by




site personnel from plant conditions or from knowledge of the type




of incident that has occurred.  However, the estimate may be highly




uncertain and must be updated on the basis  of onsite and offsite




monitoring observations and operational status of  engineered safeguards,




     If source term information is not available  immediately, default




values should be available from planning efforts.  These values could




be based on accident scenarios from WASH-1400  (1), design basis acci-




dents evaluated in the NRC safety evaluation report  for  individual




facilities, or other scenarios appropriate  for  a  specific  facility.




     The second major variable will be where the  released material  is




expected to go.  Meteorology  and geography  will affect  this variable.




Current meteorological conditions can  be observed directly  at  the  site




and  relevant  locations.   However, complete  meteorological  data will




never be available, and  extension of  observed  data must  be  made to




predict  the course of  released material.




     Current  weather  conditions  may  restrict  the  options for  response,




e.g., evacuation  in a  blizzard may be reduced  or  impossible.   Weather
                                  1.9

-------
forecasts have all of the inherent uncertainty of the current condition




estimates since they are derived from these.




     Geography is important both in its influence on meteorology and




on demography and in its influence on value judgments to be made.




The planning for a coastal site or a river valley site may be different




due to road patterns and methods for communicating or applying protec-




tive actions.




     Demography is a variable to be considered during the planning




stage.  Demography is of most importance in helping to assess the




possible impact of an incident.  Population numbers, age distribution,




distribution within an area, etc., will have some influence on responses




available in any situation.




     Providing for the ability to detect and measure a release are




important factors for planning.  Although it may be possible to detect




releases and measure release rates at the site, information from environ-




mental measurements will be needed to confirm any estimates made on the




basis of onslte measurements.  Detection and measurement at locations




offsite are necessary to update and/or confirm predictions about the




movement of the release in the environment.  Locations for installed




equipment must be planned, probably on the basis of average area




meteorology.  Instrumentation needs are discussed in more detail in




Appendix A.




     The source term, meteorology, and geography parameters are




utilized in making a prediction of the path and time profile for the
                               1.10

-------
       release.   This  prediction,  in combination  with  demography data, will




       be  used  to select the best responses for  the situation.  The most




       reasonable approach is to plan path and time profiles  (isopleths)




       for unit  release situations and then to modify  them as real  data




       are obtained.




1.3.3  Exposure  Pathways




            The  next  decision after the determination  of an accident situa-




       tion will probably concern identification  of important pathways of




       radionuclides  to the population.  Exposure pathways of immediate




       importance and the time available to interrupt  them can be  decided




       to a large extent on the basis of planning judgments.




            The single most important pathway during the emergency phase




       is probably by air.  The air pathway will be via inhalation of




       either gases or particulates and whole body exposure to the plume.




       Released gases will be either radioactive noble gases, organic




       iodides,  inorganic iodides, or volatile inorganic materials.  Par-




       ticles will probably form by the condensation of vaporized material.




            Water is a pathway for exposure by ingestion or immersion.  Re-




       leased material may enter the water directly or in the form of  fallout




       or rainout followed by surface runoff.  The immersion pathway of




       exposure is unlikely to have significance except in very specialized




       circumstances.  Ingestion of water  is  probably only a minor pathway
                                       1.11

-------
of exposure in the short run.  However, the gastrointestinal system




must be considered for longer term ingestion of contaminated drinking




water.




     Ingesticn of food is an important exposure pathway.  However,




with the possible exception of drinking water, milk, and contaminated




leafy vegetables, entry of released materials into food and passage




along this pathway is delayed.  Identification of sensitive points




for control should be made during planning.




     Characterization of release materials involved in air, water,




and food pathways will not be done for some time after an accident.




The initial decisions will have to be made on the basis of  estimates




developed in. planning and modified as real information becomes




available.




     Direct external whole body radiation exposure may be a hazard.




Released material deposited  in soil or water or suspended in air  and




material still at the site serve as sources of direct radiation,  mostly




by gamma and beta radiations.  Although  exposure rate may be measured




directly at specific locations, the distribution must be estimated and




the estimates updated on the basis of monitoring data.  Fairly  complete-




monitoring will  be needed during implementation of  restorative  actions.




      Soil contamination, in  addition  to  providing part  of the direct




whol* body exposure, also provides a  contribution to  the air pathway.




Released material deposited  on soil can  be  resuspended, thus possibly
                                1.12

-------
       entering  the air,  water,  and food pathways.   Evaluation of  these




       hazards will be  particularly important  in  deciding  appropriate




       actions during the restoration phase, e.g.,  level of  decontamination




       needed.




1.3.4  Populations  at Risk




            The  next consideration of importance  to the responsible official




       is  what population is to  be protected.   Prior judgment and  planning




       based on  the geography and demography of the area around  the site




       and on critical  pathways  are essential  to  identifying populations




       at  greatest  risk.




            The  avtrage population is made up  of  persons with varying




       sensitivities to radiation exposure, and responses  may be keyed  to




       the most  sensitive, or responses may be restricted, depending on




       characteristics  of the local population.




            (1)   For purposes of response planning, the  general  population




                 will be evaluated on the basis of risk  to individuals  within




                 the population, usually on  the basis of  avoiding  clinical




                 effects.  However, the population as a whole will also be




                 considered in planning some  responses on  the basis of




                 statistical risk of somatic and/or genetic effects.




            (2)   Sensitive populations may be  considered  on a special basis.




                 Children, including the fetus and unborn  children, are




                 generally more  sensitive than healthy adults.   For this




                 reapon,  such members of the population may be  selected
                                      1.13

-------
                 either as the most sensitive receptors or as a special




                 group for protection.




            (3)  Selected populations will also be present.  These




                 populations may be selected on voluntary or involuntary




                 bases.  Workers at a nuclear facility are classified




                 as radiation workers and fall under different criteria  for




                 protection than the general population.   Those persons  who




                 are engaged in public service activities during or after




                 the accident are voluntarily placing themselves under




                 different criteria for protection than the general popula-




                 tion.  Finally, some persons are involuntarily included




                 under different criteria because the risk of taking action




                 is different than for the general population.  This




                 involuntarily selected population may include bedridden




                 and critically ill patients, patients in intensive care




                 units, prisoners,  etc.




1.3.5  Radiation  Effects




            A  final parameter which must be considered is radiation effects.




       These may  fall into two categories,  early or delayed,  but are not




       mutually exclusive.




            (1)   Early (acute)  effects,  occurring within  90 days,  may include




                 fatalities,  symptoms  of radiation sickness,  or clinically




                 detectable changes.   Efforts to protect  selected  populations




                 will extend  to  prevention  of fatalities,  minimization of
                                     1.14

-------
          symptoms of radiation sickness in radiation workers and




          public service personnel, and prevention of clinically




          detectable changes of uncertain significance in the rest




          of rhe population.  The basis for decisions regarding early




          effects is not hard to justify because of the imminence




          of such effects.  However, they must be made rapidly under




          conditions of competing needs to protect the public.




     (2)  Delayad statistical effects (i.e., biological effects which




          can only be observed on a statistical basis) will occur




          at random in a population after exposure to released




          materials.  These effects may be fatalities or disabilities




          of somatic or genetic origin.  The incidence of these




          effects is estimated on the basis of statistical evaluation




          of epidemiological studies in groups of people who had been




          exposed to radiation.  Decisions concerning statistical




          effects ori populations will be more difficult because




          of the lack of immediacy of the effects.  But in the long




          run, these effects might cause the greatest impact on the




          general population.




     The response times, actions to consider, and possible health




effects for each pathway are shown in table 1.2 for a typical population.




     Effects on animals, vegetation, or real estate are also possible




but may be controlled or alleviated to the extent that decontamination




Is employed or that destruction of the affected items is employed.
                               1.15

-------
           Table  1.2   Action  and Health Effects
                      Versus Exposure Pathways
Exposure                Response
Pathway                 Time
Air - Particulate       Min - Hr
      Gas               Min - Hr

Water - Particulate
            Rainout     Hr - Da
            Fallout     Min - Hr
        Immersion       Day

Food - Milk             Da
       Drinking Water   Hr
       Beverages        Da
       Foodstuffs       Da
Mo
Mo
Mo
Mo
Soil - Resuspension     Da
       Direct           Min - Da

Direct - Facility       Min
         Air            Min - Hr
         Water          Hr
          Action
          Available
            P
            P
 P
 P
PSR

PSR
PiiR
P&R
P&R

 R
P&F

P&R
 P
P&R
              Public
              Health
              Effects

                D
              F,E,D
  D
  D
D,F,E

  D
  D
  D
  D

  D
E,D,F

F,S,D
F,E5D
D,F,E
Actions: ? - Protective      R - Restorative
Effects: F - Rapid Fatality  E - Early      D - Delayed
                           1.16

-------
\.'t   KiMyviiiiHr  I'bin  Arl Ion  Times




         A  typical  sequence  of  events  tor  developing  emergency plans nnd




     responding  to  nuclear incidents  is  shown  in  figure  1.1.  This figure




     illustrates the general  order of events but  not relative lengths of




     time for  each  event.   These will vary  according to  individual circum-




     stances.




 .1   Preparation of Plans




         Considerable preparation will be  required to ensure the adequacy




     of emergency response plans.  This preparatory time includes the




     following elements:




         (1)  The decision must be made to prepare emergency response plans




              according to the legislative mandates or needs within a




              given State.




         (2)  Then basic plans should be developed using appropriate




              guidance from this manual and the AEG "Guide and Checklist" (2)




              These plans should include emergency response actions  for




              coping with nuclear incidents and directions on the use of




              EPA  Protective  Action  Guides for these situations.




         (3)   These plans  should be  approved by responsible persons  or




              agencies.




         (4)   Scenarios  must  be  developed  from the basic plans  to cover




              major contingencies which can be identified.




        Methods of  implementation must  be  prepared and  tested  so that




    nonviable  responses  and contingency  plans  may be identified and  dis-




    carded.  This discarding  of  nonviable responses may  be  based  in  part
                                  1.17

-------

RESPONSE
PLANNING










Oe
pr
ge


NUCLEAR

INCIC


Develop emergency response
plan





i

Prepare equipment,
train personnel
and test plan


Review of
plan
1



)ENT











R ESPONSE
EMERGENCY
Preliminary evalu-
ation of inc
idcnt
and projected doses




\

f
cision to Acceptance
epare emer- Of
ncy response pian
plan


Cl) Notification tiroe
fO\ Daennnfa +"ima






Activate
emerge



Notify
author

(




i

PROTECTION



RESTORATION



Field monitoring and continuing evaluation
of exposure pathways, population at risk, dose
projections, PAGs, and protective actions
State
ncy plan


i


DrTttfl r* +• i \l& a/* ¥ -i r\r\ Aafi e- -J rvw


Protective Action Restorative
Initiated Implemented Action

'
ities

4)










—
(11



CD


._
(Z) _

Radiation
returns tc
guide leve
—

' Projected Dose time
^^










>
Is




Implementation time
Time before  population exposure
(Ideally protective actions would be  implemented during this  time.)
Possible accumulation of projected dose before initiation of  protective action
Partial  accumulation and partial  avoidance of projected dose
Time in  which projected dose is avoided by protective action
Partial  accumul-ation of projected dose during restoration
                    FIGURE 1,1  SEQUENCE OF  EVENTS  FOR  RESPONSE PLANNING
                                  AND  RESPONDING TO  NUCLEAR INCIDENTS

-------
      on evaluation of local constraints.  For example, evacuation of




      prisoners or critically ill persons might not be considered viable




      while alternative protective actions may be at least partially




      effective.




           Development of the basic emergency response plan may run a course




      of several months or longer.  However, planning should be a continuing




      activity after the basic plans are developed.  Advances in meteorology,




      development of new protective actions, changing demography, etc.,




      should be used in reevaluation of the original scenarios.  And of




      course, recurrent testing of implementation methods should be carried




      out.




1.4.2  Implementation of Plans




           A sequence of steps to implement a response plan following a




      nuclear incident is also shown in figure 1.1.  The time after an in-




      cident may be divided  into three phases which are called emergency,




      protection, and restoration.  These phases are not necessarily distinct




      consecutive time periods, but they do serve to indicate the general




      nature of activities in a typical response sequence.




           The emergency phase includes all those activities leading to




      initiation of protective actions.  This phase involves assessment of




      the situations and is  characterized by urgency in determining the need




      for protective action  and getting the action initiated.  In general,




      this may be considered to be the first few hours following notification




      of an  incident and deals primarily with protection of the population
                                      1.19

-------
from exposure to the airborne plume.

     The most important step in emergency response is the prompt

notification that an incident has occurred that could result in an

offsite exposure such that there is a need for initiating protective

action.  It is the facility operator's responsibility to notify State

or local authorities that such an incident has occurred.  It is

important that agreements be reached during the planning phase on

who is to be notified, data to be provided, offsite measurements that

will be made, and actions to be initiated at the site so that there

will be a minimum time loss in starting implementation of protective

action in the offsite area.  Proper planning must include incentives

to prevent delays in notification.  Nuclear facility operators have

the initial responsibility for accident assessment.  This includes

prompt action necessary to evaluate public health and safety both

onslte and offsite (2).  Ideally, this notification should occur as

soon as conditions in the facility are such that an impending accidental

release potential exists.  While such notification could lead to false

alarms on rare occasions, they could also permit more timely protective

actions than postponing the notification until a release has occurred.

     The sequence of events during the emergency phase includes the

notification of responsible authorities, evaluation and recommendations

for action, and warning of the public.  In this early phase of response,

the time available for effective action will probably be quite limited.
      As part of  their plans,  the  State  should establish with the facility
operator a strict protocol  for notification of the State such that early
responding of possible impending releases would not involve disincentives
to  the facility operator.
                                1.20

-------
     Immediately upon becoming aware that an incident has occurred




that may result in exposure of the offsite population, a preliminary




evaluation should be made by the facility operator to determine




the nature and potential magnitude of the incident.  This evaluation,




if possible, should determine potential exposure pathways, population




at risk, and projected doses.  At this time, projected doses may be




estimated froir. monitoring data at the point of radionuclide release




or from releases anticipated for particular types of nuclear incidents.




The incident evaluation information should then be presented to the




proper authorities.  If authorities were notified earlier and have




mobilized resources, protective actions can be started immediately in




predesignated areas or in the areas indicated by projected dose based




on facility operator information.  In the absence of detailed informa-




tion from the facility operator as indicated above, the emergency plans




should provide for action in the immediate downwind area of the facility




based on notification that a substantial release has occurred or that




plant conditions are such that a substantial release potential exists.




     The next step is to gather additional information on radiation




levels in the environment, meteorology, and environmental conditions.




Further actions or modifications to actions already taken should be




based on these data and Protective Action Guides considering constraints




discussed in section 1.6 of this chapter.




     The State should continue to seek information on radionuclide




releases and environmental monitoring data.  In fact, an evaluation of
                               1.21

-------
     such information, as well as exposure pathways,  population  at  risk,




     dose projections, and PAGs should be a continuing activity  in




     both the emergency and protection phases in order to  modify pro-




     tective actions as needed.




          The protection phase begins with the initiation  of  protective




     action and continues until that action is terminated.  Figure  1.1




     indicates that ideally the protective action such as  evacuation would




     be implemented before any population exposure.   However,  the action




     may not be initiated in time to avoid all of the projected  dose,




     and some dose may be received during implementation of the  action.




          The restoration phase includes those actions taken  to  restore




     conditions to "normal".  Restorative actions include  the halting of




     protective actions, the lifting of restrictions,  and  possible  decon-




     tamination procedures.




1.5  Types of Action




          The action taken may be, as previously indicated, either  protec-




     tive or restorative.  It may also be voluntary or involuntary, or no




     action at all may be taken.




          (1)  No action would usually be taken by State authorities if




               the risk of undesirable radiation effects is anticipated to




               be much less than the risk of taking action.




          (2)  Voluntary action may be suggested for  the population at




               risk, or it may be taken by them anyway on  the basis of




               public information provided during an  accident situation.




               Voluntary action may be valid in the gray area where the
                                    1.22

-------
          risk of exposure to released material and the risk of taking




          action are not too different.  It may also be taken at




          lower levels of exposure by individuals to alleviate their




          fears.  The negative aspects of possible confusion and




          possible panic where incomplete knowledge exists must be




          considered during decisions to implement protective actions.




     (3)   Involuntary (mandatory) action by State authorities should




          be implemented when the risk of undesirable effects exceeds




          the risk of taking action to such an extent that public




          well-being can be adversely affected.  This is when action




          must be taken in the public interest.




     The  types of action which can be taken include:




     (1)   Protective actions, such as evacuation, taking shelter in




          homes or civil defense shelters, controlling food and water




          distribution, prophylaxis (e.g., thyroid protection), or




          individual protective actions (e.g., gas masks, protective




          clothing, etc.); and




     (2)   Restorative action where everything is returned to "normal".




          This action includes lifting restrictions or halting




          activities initiated as protective actions.  It also




          includes decontamination where necessary.




     The  actions to be taken should be evaluated and set in priority or




sequence  with identification of ranges for appropriate action and of




decision  points during planning.  Based on prior judgment of which
                               1.23

-------
     actions  may be effective in any given situation,  scenarios  can  be




     prepared which will indicate which actions or mix of actions  are




     appropriate for various situations.




1.6  Goals of Protective Action




          The ideal goal of protective action in an emergency is complete




     protection of the endangered population.  However, various  constraints




     may prevent attaining this ideal, so a more realistic goal  is minimi-




     zation of harmful effects.




          In  the case of an emergency involving a radiological hazard,




     efforts  are directed towards minimizing:




          (1)  early somatic effects such as death within days or develop-




               ment of extensive symptoms of radiation sickness;




          (2)  delayed somatic effects, such as increased probability




               of death due to radiation related cancer; and




          (3)  genetic effects such as increased prenatal mortality  or




               increased probability of hereditary defects in future




               generations.




     The minimization of effects implies that  the radiation exposure under




     consideration is an avoidable exposure.   However, for purposes  of




     determining whether to take a protective  action on  the basis of




     projected dose from an airborne plume,  the projected dose  should not




     include unavoidable dose  that has been  received prior to the time the




     dose projection is done.  If a situation  should occur where the unavoidable




     dose would bo very large  as compared  to the  avoidable dose, different




     protective actions might  be warranted.
                                     1.24

-------
1.6.1  Balancing Factors to Achieve Protection Goals




           The ideal goal is maximum protection of the public with the




      least cost and disruption.  Within the need to protect the public




      several constraints, including physical, social, and fiscal, will




      be operating.




           The planner should balance the cost of not taking action (risk




      of radiation exposure) against the cost of taking action from both




      fiscal and societal aspects.  In particular, the fiscal costs of




      preparing for action, as well as the costs of all actions to be taken,




      should be balanced against the need for response to protect the public,




      Also, the societal costs such as panic and disruption of life style




      should be balanced against the risk to society of not taking action.




           This balancing of costs and risks will place constraints on the




      options available for action.  This balancing also implies that in




      planning, certain cut-off points can be identified, e.g., a marginal




      increase ip protection probably may not justify the required expendi-




      tures or extensive disruption of families or daily activities.




      These costs and constraints should be evaluated in planning by the




      responsible public officials in determining the responses to be made




      in a given situation.




           Even if the balance of costs indicates that a response or set




      of actions is reasonable, other constraints may preclude their use.




      These additional constraints on action are primarily physical in




      nature (e.g., in the case of a puff release, exposure time may be




      too short to allow effective protective action).
                                       1 .25

-------
1.6.2  Constraints on  Goal  Attainment




            The  constraints which  operate  to  prevent  attaining  the ideal




      goal  include  those of  environmental, demographic,  temporal, resource




      availability, and exposure  duration.




            Environmental constraints will include meteorologic and




      geographic considerations.   Protective action  options ir.ay be restric-




      ted by  severe weather  conditions, windstorms,  blizzards, tornadoes,




      large accumulations  of snow,  etc.   Options are also  restricted by




      numbers,  types  and directions of  roads,  and obstruction  of easy




      egress  from a site by  rivers, mountains,  or other  geologic formations.




            Options  are further  constrained by the density  and  distribution




      of population,  the total  size of  the population  involved, the age




      and health status of segments of  the population, and other demographic




      considerations.




            Temporal constraints will be present during all phases of




      protective action and  some  situations  during restorative action.  Time




      available for action may  be a real  constraint  for  evacuation of




      close-in  populations,  particularly  in  the case of  short  term (puff)




      releases.  After an  incident, exposures of the population close  to  the




      site  may  occur  before  control of  the situation is  established.   Even




      after a decision for action has been made, notification  of the population




      and implementation of  the action  may require enough  time such that  sub-




      stantial  exposures occur.  The constraint of time  in restorative action




      will  probably be more  related to  reduction of  costs  rather than  to




      direct  protection of the  population.  Rapid decontamination to allow
                                      1.26

-------
access to utilities, food stores, crops, etc., will reduce the total




cost due t" the accident.




     Resources will be one of the largest constraints on viable




options fo . action.  The best planning will fail if the resources




to implement actions are not available.  Resources needed are




fiscal, manpower, and property, although fiscal will probably be




the limiting factor.  Given sufficient fiscal investment, then




manpower, equipment, and training, all will be available in adequate




quantities.  However, since only limited amounts of fiscal support




may be available, the lack of equipment and manpower with sufficient




training ana practice in implementation of protective actions will




limit the numbsr of viable options for protecting the public.




     In general, as the population to be protected increases, less




protection is available for the same total cost (equal levels of




protection require greater fiscal investment in large populations




than in small populations).  Likewise, as the level of preparedness




increases, the cost of obtaining and maintaining this preparedness




increases.  The cost of protective action, however, will probably be




a step function.  Each decision to take an action or extend an action




will cause an incremental step increase in the cost.  All of these




constraints Jiust be considered in planning operations so that the




optimum projection of the public can be obtained with the least




expenditure, both social and fiscal, commensurate with the goal of




protective action.
                               1.27

-------
1.6.3  Evaluation of ^Constraints




            Local officials involved in developing emergency response  plans




       must be thoroughly informed on what protective actions are  available




       for limiting the radiation exposure of the general  public during  a




       nuclear incident.   These actions are a vital part of  the emergency




       response plan and  should be specified during the planning phase




       rather than at the time of the incident.   There are,  however, local




       constraints associated with each protective action  which will influence




       the decision to implement a given protective action.   The local planner




       must also be familiar with and apply these constraints to any emergency




       situation.  Ideally, it should be possible to balance these constraints




       in some analytical fashion which would place each constraint in its




       proper perspective on a common scale.  Since many of  the constraints




       cannot be quantified, local planners must use rational, subjective




       judgment in evaluating them.




            Tables 1.3 and .1.4 list protective actions that  are available




       for various types  of reactor incidents as a function  of approximate




       time periods following the incident, and the following discussion




       attempts to evaluate constraints such as costs, time, societal  con-




       siderations, etc., that relate to each protective action.   This infor-




       mation should be valuable to the local planner in making the value




       judgments that are necessary to plan actions during an emergency-




1.6.3.1  Constraints on Evacua* ion




            While evacuation may seem to be the protective action  of choice




       following a nuclear incident at a fixed nuclear facility,  constraints
                                      1.28

-------
      Table  1.3  Protective and Restorative Actions  for Nuclear-
                     Incidents Resulting  in Airborne  Releases
Nuclear Incident
(a)
Puff Release -Gaseous
or Gaseous and
Particulate
Continuous Release
Gaseous or Gaseous
and Particulate
Protection Phase
Approximate Time of Initation
0-4 hr.
1,2,3,4,5
1,2,3,4,5
4-8 hr.
3,4,5
1,2,3,4,5
> 8 hr.
3,4,5,6,
7,8
1,2,3,4,
5,6,7,8
Restoration
9,10,11
9,10,11
 1  Evacuation

 2  Shelter

 3  Access  control

 4  Respiratory protection for
    emergency workers

 5  Thyroid protection for emergency
    workers

 6  Pasture control

 7  Milk control

 8  Food and water control

 9  Lift protection controls

10  Reentry

11  Decontamination
(a)
(b)
(c)
Puff release - less than
  2 hours


Continuous release -
  2 hours or more

Restoration phase may begin
  at any time as appropriate
                                 1.29

-------
                                 Table 1.4  Initiation Times for Protective Actions
Approximate
Initiation Time
0-4 hours
4-48 hours
2-14 days
Exposure Pathway
inhalation of gases or
parti culates
direct radiation
milk
harvested fruits and
vegetable
drinking water
unharvested produce
harvested produce
milk
drinking water
Action to be Initiated
evacuation, shelter, access control, respiratory
prctcct.icn, [.vcphylc :',<, (thyroid proftction)
evacuation, shelter, access control
take cows off pasture, prevent cows from drinkin
surface water, quarantine contaminated milk
wash all produce, or impound produce
cut off contaminated supplies, substitute from
other sources
delay harvest until approved
substitute uncontaminated produce
discard or divert to stored products, such as
cheese
filter, demineralize
LO
O

-------
associated with a specific site could render the evacuation ineffective




or undesirable.  Other optional protective actions such as taking




shelter should be considered.  The planner must take into consideration




all local constraints to determine whether or not evacuation is a




viable protective action for the given situation.  Examples of the




effects of constraints could be provided on a general basis.  However,




it remains the responsibility of the planner to determine the most




reasonable protective actions for each site.




     A.  Effectiveness of Evacuation




     The effectiveness of evacuation in limiting radiation dose is




a function of the- time required to evacuate.  If a radioactive cloud




is present, the dose will increase with the time of exposure; if the




evacuation is completed before the cloud arrives, then evacuation




is obviously 100 percent effective.  Anything that delays an evacuation




is therefore a constraint, and such constraints are likely to be very




much a function of local site conditions and planning.  The planner




should be aware of these constraints in order to minimize their




impact, thus maximizing the effectiveness of the evacuation.




     The evacuation time, T(EV), at a particular site is defined as




the time from the start of the nuclear incident to the time when evacuees




have cleared the affected areas.  It may be expressed as:




               T(EV) = T  + T  + T  + T
-/here:
     T  = time delay after occurrence of the incident associated with
                               1.31

-------
notification of. responsible officials, interpretation of data> am!



the decision to evacuate as a protective action.



     T  = time required by officials to notify people to evacuate,



     T  = time required for people to mobilize and get underway.



     T  = travel time required to leave the affected areas.



     T  includes several separate time elements as defined above,



and all of them can be reduced by effective planning.  Nominal values



for T  may range from 0.5 hours up to 1.5 hours and possibly longer



depending on the adequacy of planning and whether the decision is to



be based on onsite information or offsite environmental measurements.



     The least well defined time constraint is T , which is strongly



influenced by local population, geographic conditions, and planning.



T  has been postulated to be inversely proportional to population



density; the closer people are together, the quicker it is to notify



them to evacuate.  For fast developing incidents, news media warnings



must be augmented by telephone, pulic address, and door knocking, the



effectiveness of which is a function of local planning and resources,



There are new innovations such as computer telephoning, planes with



loud speakers, etc., which the local planner may find worthwhile



to explore.   Tru value of T  under the best conditions of local, planning



is estimated to range from 15 minutes to 1 hour or more.



     T._, the time required for people tc prepare to leave, depends on
      M


such parameters a;>:
                               1.32

-------
     (1)   Is tne family together?



     (2)   Rural or urban community?  Some farms or industries require



          nore shutdown time than others.



     (3)   Special evacuations - special planning effort is required



          to evacuate schools, hospitals, nursing homes, penal



          institutions, and the like.



     (4)   Tnere will be some people who will refuse to evacuate.



     The bee; time for T._ for an urban family together might be 0.2 to
                        M


0.5 hours, whi^.e to shut down a farm or factory might take hours.



     The evacuation travel time, T , is related to:



     (1)   Tota1 number of people to be evacuated.



     (2)   Tae capacity of a lane of traffic.



     (3)   The number of lanes of highway available.



     (4)   Distance of travel.


     (5)   Roadway obstructions such as uncontrolled merging of traffic



          or accidents.


     The totil number of people to be evacuated depends on the popula-



tion density and affected area.  It is an advantage if  good planning



can keep the area and thus the number of people to as small a value



as possible, or possibly to evacuate one area at a time so that the



number of people on  the move  at one  time is within the  capacity of the



roads.


     The capacity of a lane of  traffic depends on  the number of vehicles



per hour and the capacity of  each.   Surveys during evacuations found
                                1.33

-------
4 persons/car on the average indicating that at 2,500 cars/hr at




35 mph, the capacity of a lane is 10,000 persons/hr.  Commuter traffic,




however, contains about 1.2 persons/car, lowering the capacity to




about 3,000 persons/hr-lane.  Use of buses exclusively, if this is




practical, increases the lane capacity by a factor of about 10 such




that 100,000 persons/hr-lane could be moved.  However, if buses are




used, the increase in time caused by getting the buses to the evacua-




tion area and oy return trips must be considered.   If the average




speed of traffic is less than 35 mph, capacity/lane-hr is lowered in




proportion.



     The number of lanes of  traffic  is  ordinarily  sufficient  for evacu-




ation  from  the  low population zone around  fixed  nuclear  facilities.




Lanes  may be  increased  by  using lanes  that ordinarily  carry  traffic




 into the  area.  All  these  lanes cannot  be  used,  however,  since  some,




 at the option of  the  planner, must be  held open  for emergency vehicles




 coming into thr* area.



     Traffic  control will  be effective in reducing the evacuation




 travel time.   Tf  lanes ordinarily inbound are used for outbound traffic,




 traffic officers will be required to direct vehicles to them; otherwise




 they will not be used.  Traffic barriers,  signs, traffic light over-




 rides, disabled vehicle removals, etc., will be required to keep




 traffic speeds high.  Traffic control at bottlenecks will be of par-




 ticular importance.  Allowing single lanes to run alternately rather




 than having r.ars dovetail through an intersection will significantly
                                 1.34

-------
increase traffic flow.  Access controls to keep unauthorized vehicles




and persons out of the evacuated areas will be needed also.




     Examination of specific sectors around four different light-




water powei reactors indicates that T  may range from 0.2 to as much




as 1.5 hours under exceptional conditions where the road system is




inadequate compared to the population to be evacuated.  An average




traffic speed of 35 mph was assumed if road capacity was great enough




to preclude traffic jams.




     Table ?..5 summarizes the various time segments that act as




constraints on evacuation.  These values are rough estimates that




should be improved upon by the local planner for each site.  An




example of  . one-hour evacuation might be the evacuation late in the




evening of a rural area including a small town (250 persons).  In




such a case the population is small, concentrated, and at that time




the families would be united.  An example of an evacuation  in the




longer time range might be evacuation during the daytime of a rural, low




population zone containing farms.  Warning would be time consuming,




and the preparation for farm shutdown might be lengthy.  The road




system is adequate, but families may be separated during the day,




requiring Icnger evacuation travel distances.  Emergency plans for




areas located near State boundaries would require interstate cooperation




and planning.  .ligh population, high density areas such as  those  around




Indian Point present a different situation, and evacuation  times  are




more complex, probably longer, and must be analyzed on a case by  case




basis.  In these areas, notification time may be  short but  access
                                1.35

-------
Table 1.5  Approximate Range of Time Segments
            Making Up the Evacuation
                                 Approximate
Time Segment                        Range
                                    Hours
     TD                          0.5 - 1.5


     T                           0.2 - 1.0(C)
      N

     T                           0.2 - 2.0(d)
      M

     T                           0.2 - 1.5(S)
      T                          1.1 - 6.0
       population, high density areas such as
  those around Indian Point, present a different
  situation,  and evacuation times are more complex,
  probably  longer, and must be analyzed on a case
  by case basis.

  Maximum time may occur when offsite radiation
  measurements and dose projections are required
  before protective action is taken.

  Maximum time may occur when population density is
  low and evacuation area is large.

  Maximum time may occur when families are separated,
  a large number of farms or industries must be shut down,
  and special evacuations are required.

  Maximum time may occur when road system is inadequate
  for the large population to be  evacuated and  there are
  bottlenecks.
                     1.36

-------
limited.  Appendix B provides techniques for evaluating the various




time periods involved in evacuation.




     B.  Risk ?f Death or Injury




     If evacuation were likely to greatly increase an individual's




risk of deatn or injury, this would act as a significant constraint




on the use of evacuation as a protective action for a nuclear incident.




Fortunately, examination of numerous evacuations indicate that risk




of death or injury is not likely to be increased when evacuation is made




by motor vehicle (_3) .  Premature childbirth is routinely encountered




in emergencies and subsequent evacuations, and in at least one State




emergency pj.an, prior arrangements are made for this problem.




     C.  Evacuation  Costs




     For evacuations caused by storms or floods, cost is not usually




a constraint bacause hazard to life and limb is obvious and because




the evacuation cost  is judged to be small compared to the damage




caused by the disaster.  However, in the event of a nuclear incident




where there may be the strong inclination to evacuate even though  the




radiation dose t.o be saved is vanishingly small, the economic cost of




the evacuat:on may act as a constraint.  Therefore, the planner may




wish to estimate this cost for various kinds of evacuation.




     Evacuation costs may be broken into four categories:




     (1)  costs involving evacuees,




     (2)  costs involving evacuators,




     (3)  financial  losses of farm  areas, and




     (4)  financial  losses of urban and  industrial areas.
                                  1.37

-------
              Limited information on estimated  costs  is  given  in reference  (_3) .




         For a specific site,  the various  costs probably can be ascertained




         with more accuracy.   Parameters  that would affect  the costs of an




         evacuation around a  specific site are  listed in table 1.6.  Considera-




         tion of these parameters and how  they  affect cost  should  allow the




         planner to calculate the approximate monetary cost of an  evacuation




         and thus estimate and evaluate this constraint.




1.6.3.2   Seeking Shelter




              The local constraints on seeking  shelter as a protective action,




         such as time ti take action, cost of taking  the action, and societal




         considerations , intuitively tend  to support  taking such action since




         the cost in each case is relatively small.   However,  if one compares




         the effect oJ seeking shelter with some other action  such as evacuation




         on the basis of dose savings, it  may be concluded  that evacuation  will




         save a far greater dose than seeking shelter.  Generally, shelter




         provided by dwellings with windows and doors closed and ventilation




         turned off "ould provide good protection from inhalation  of gases  and




         vapors for & short period (i.e.,  one hour or less) but would be  generally




         ineffective after about two hours due  to natural ventilation of  the




         shelter.




              Not every constraint can be  evaluated using established techniques;




         therefore, a certain amount of subjective judgment must be made  on the




         part of the xocal planner.  The important thing is that the local




         planner be aware of  the constraints associated  with each  action  and




         that these constraints be balanced on  whatever  basis  possible  in order
                                        1.38

-------
Table 1.6  Parameters Affecting the Cost of Evacuation
             Area
                  Size of area affected
                  Location
             Population
                  Number
                  Distribution
                  Makeup
             Institutions
                  Type
                  Population in
                  Care required

             Farms

                  Size
                  Type
                  Product values

             Business and Industry

                  Type
                  Size
                  Work force
                  Product value

             Mode of Travel

             Number of Evacuators Required

             Shelters Needed

             Duration of the Evacuation

             Anti-looting Efforts
                        1.39

-------
        to arrive  "t a decision.




1.6.3.3   Access Controj.




            Access control can be a very effective protective action to




        avoid exposure of personnel who might otherwise enter high exposure




        areas unnecessarily.  Whether or not it can be applied effectively




        at all sites trill depend upon several considerations which are site




        specific.  For example, the time required to establish the necessary




        roadblocks way be longer than the exposure time.  The cost of main-




        taining the capability for roadblocks and control of access points




        may be prohibitive.  Furthermore, personnel that would be used in




        maintaining roadblocks might be more effectively used for other




        emergency functions.  All of these factors must be considered in




        deciding whether to plan for full or partial access control during




        the early phases of an incident.




1.6.3.4   Respiratory Protection




            Radiation exposure from inhalation of gaseous or particulate




        radionuclides may be reduced by the use of respirators.  These devices




       protect the wearer by removing radioiodines (the primary gaseous nuclide




       of concern) on activiated charcoal and by removing particulate material




       by filtration.   Several types of respirators are commercially available




       for use by odult male workers in contaminated atmospheres.  However,




       respirators designed for women and children, i.e., the most radiation




       sensitive part  of the population, may not be readily available.  The




       first constraint on the use of respirators,  therefore, is whether




       suitable devices are available.   Secondly, for respirators to be
                                      1.40

-------
         effective  for  the  general population,  they should be kept on hand by




         each person  for  immediate use upon notification and they must have been




         individually fitted.  This means they  should be distributed to the




         population at  risk prior to a nuclear  incident, and training should be




         provided for their use.  The logistics of distributing such devices




         after an incident  would greatly reduce their effectiveness by limiting




         their time of  use.  The cost of providing respirators for the entire




         population at  risk is also a constraint, especially for large popula-




         tions.  Additional constraints include upsetting the population by




         acknowledging  the  danger with visible means and the failure of




         individuals  to have their respirators personally available over long




         periods (years)    Even if funding is available to provide the necessary




         respirators,  ic should be noted that use of such devices can only be




        a short tern action of 2 to 3 hours.  Therefore, they might best be




        used in conjunction with other protective actions such as seeking




        shelter or ( vacuation.  It should also be kept in mind that respirators




        would not be of value where the exposure of concern was from direct




        radiation aud not from inhalation of iodines or particulate material.




        Respirators may be most effective for emergency workers or other




        persons requlrad to remain in evacuation zones.




1.6.3.5  Prophylaxis (Thyroid Protection)




             The uptake of inhaled or ingested radioiodine by the thyroid




        gland may be  reduced by the ingestion of stable iodine.   The oral




        administration  of about 100 milligrams of potassium iodide will result
                                       1.41

-------
        in sufficient accumulation of stable iodine in the thyroid to prevent




        significant uptake of radioiodine.  The main constraint in the use




        of this me^ns of thyroid protection is that potassium iodide is




        normally administered only by prescription and would have to be dis-




        tributed in accordance with State health laws.  Potassium iodide as




        a prophylaxis is only effective if the exposure of concern is from




        radioiodine and only if the stable iodine is administered before or




        shortly aft^r the start of intake of radioiodine.  All emergency




        workers for areas possibly involving radioiodine contamination should




        receive this kind of thyroid protection, especially if appropirate




        respirators are not available.  The cost constraint would not be




        significant for potassium iodide itself, but the cost for administering




        this material should be considered, including the cost of testing




        emergency workers for sensitivity to iodine prior to issue or use.




             The usrf of stable iodine as a protective action for emergency




        workers has bean recommended by EPA, but only in accordance with State




        health laws and under the direction of State medical officials as indica-




        ted above.  However, the efficacy of administering stable iodine as  a




        protective rction for the general population is still under consideration




        by government agencies and should not be construed to be the policy  of




        EPA at this tiro*.




1.6.3.6  Milk Control



             In order to protect  the population  from exposure  to ingestion of




        contaminated milk,  the planner has  two basic alternative actions, which




        are:
                                        1.42

-------
     (1)  Cow-feed or pasture control to'prevent the ingestion of




          radioactive materials by dairy cattle, or




     (2)  Milk control either by diverting the milk to other uses




          that allow the radioactivity to decay before ingestion or




          by destroying the milk and substituting uncontaminated milk




          from other areas.




     The optimum action would be to prevent, through pasture and feed




control, contamination of the milk.  This would be followed up by




milk control only in contaminated areas where pasture and feed control




were not carried out or were not adequate.  Local constraints may reduce




the acceptability or effectiveness of these two protective actions.




The alternatives to taking these actions include:




     (1)  Permitting the population to receive higher dosage.




          (Thyroid cancer is generally not fatal.)




     (2)  Suggest voluntary avoidance of the use of contaminated milk




          by children and pregnant women.  (Children are more sensitive




          than adults because of greater intake of milk and greater




          concentration within the thyroid.)




     (3)  Administer stable iodine as discussed earlier under thyroid




          protection (section 1.6.3.5).




     The local constraints on the control of dairy cow feed or pasture




may include the following:




     (1)  A shortage of uncontaminated feed.
                               1.43

-------
     (2)  A shortage of personnel to carry out feed and pasture controls




          in ovacuated areas.




     (3)  The short time available to implement feed and pasture con-




          trols over a large area (possibly hundreds of square miles)




          r-ay create communication problems and uncertainties as to




          the areas where pasture and feed control should be implemen-




          > ed.




     (4)  The cost of the stored feed and the cost of transporting it




          to needed areas might be prohibitive.




     Local constraints on the control of milk may include:




     (1)  The shortage of nearby processing plants.




     (2)  Inadequate storage capacity to wait for radioactive decay.




     (3)  Objections to shipment of contaminated milk to other juris-




          dictions for processing.




     (4)  Pollution from disposal of large volumes of milk.




     (5)  Snorfage of monitoring personnel and equipment for all milk




          producers.




     (6)  Shortage of milk for critical users.




     (7)  Costs associated with transporting, storage, or disposal of




          miJk.




     The dos'J to the thyroid of a child from drinking milk contaminated




with radioicdine through the atmosphere-pasture-cow-milk exposure path-




way may be hundreds of times the thyroid dose that would be received




by the same -hild from breathing the air that caused the contamination




of the pasture.  Therefore, the size of the area over which milk might
                               1.44

-------
have to be controlled could be much larger than the size of the area




that would be evacuated to prevent inhalation of the iodine.




     To avoid the problems and constraints assoicated with milk




storage, transport, or disposal, the planner should prepare for pasture




or feed co-itrol in all directions from the plant out to five times the




distance planned for evacuation and in predominantly downwind directions




out to about 50 to 100 miles.  Controls over greater distances could




be needed if the wind persisted in a single direction for an extended




period.  If pasture and feed control actions have been implemented (even




if only partially implemented), noncontaminated milk supplies may be




available at least for critical users.




     All mill: producers in the affected area should be restricted from




using or distributing milk until monitored.  If monitoring of all milk




supplies is a constraint, monitoring efforts could be concentrated on




milk suppl:-as where pasture and feed control had been implemented and




on the frirges of the contaminated area.




     The planner can reduce the effect of constraints related to uncon-




taminated feed supplies and processing plants by identifying their




locations and procedure for access.




     Resistance by milk producers to protective actions for milk may




be reduced by the planner having answers to questions regarding reim-




bursements of costs incurred by the producer.
                               1.45

-------
1.6.3.7  Food Control
              Food exposed to airborne radioactive materials may become




         contaminated ey deposition of radioiodine and particulate material.




         To avoid population exposure from ingestion of these materials,  the




         response planner should consider the following protective actions  for




         short term protection.




              (1)  Prohibition on use of potentially contaminated food such




                   as field and orchard crops and substitution from uncontamina-




                   ced supplies.




              (2)  Decontamination.




              The primary constraint on the use of these controls will be the




         availability of adequate substitute supplies at a reasonable cost.




         If other supplias are not available or the cost is high, then it may




         be necessary to implement decontamination procedures.  For protection




         beyond a fe~? days where availability and cost constraints would  be




         more critical,  then decontamination may be even more cost effective.




         The primary .neans of decontamination would be through washing and




         peeling (where  appropriate) of fresh fruits and vegetables.   The con-




         straints on fuch procedures would be the ability to monitor the  decon-




         taminated items to assure adequate decontamination.  Monitoring  of




         food will likely be a much demanded service both by the individual




         farmer-consumer and by the distributor.




              Other alternative controls would be to impound food stocks  and




         store them to allow decay of radiation levels or destroy them to prevent




         consumption.  The main constraint on these alternatives would be spoilage
                                          1.46

-------
        and the vaiuc of the food stocks in relation to the costs of storage




        or destruction.




1.6.3.8  Water Control




             Water may be contaminated either by direct release of radio-




        nuclides t<  surface waters or by deposition from an atmospheric




        release.  V,?ter reservoirs supplied by land surface run-off or




        cisterns sipplied by roof run-off would be most severely affected




        by atmospheric deposition, whereas reservoirs supplied from streams




        and lakes would be most affected by contaminated liquid effluents.




        Spring and well water  should not be affected by an accidental release




        of radioactive material to the atmosphere or to waterways.  However,




        springs or wells that  appear muddy after a rain might be suspect and




        should be monitored after a rain if they are in the area receiving




        heavy deposition.  Some accident scenarios involve fuel melting its




        way into the soil, and such a condition could contaminate underground




        water supplies.




             The protective actions for water can be either to prevent contamina-




        tion or decontamination of the water supply or to condemn the use of




        the water fo/ consumption.




             In the ~ase of reservoirs supplied from surface or roof run-off,




        prevention OL reservoir contamination would not be possible unless




        methods exis.ed for diverting the  run-off.  Reservoirs receiving  their




        supply from a stream or lake normally are filled  through pumping  and




        filtration stations which are controlled by operators.  These stations




        could be shut off if the source of the water supply became contaminated.
                                        1.47

-------
      This may also be true for food processors using a stream or lake




      directly for their water supply.  Many reservoirs supply water to




      municipal Lystems through a filtration plant.  Such a plant would




      tend to decontaminate the water supply, and monitoring of water after




      filtration world provide data that should be taken into consideration




      in the process of deciding whether or not to condemn the supply.




           The constraints associated with restrictions on supplies to




      reservoirs or condemnation of water systems are related to the




      difficulties, hardships, and costs associated with the resulting




      shortage of wa :er supplies.  If the planner determines that these




      protective act'.ons may be appropriate for particular water systems,




      he should also identify the hardships that may result and plan methods




      for alternatxve supplies.  These may include rationing of uncontaminated




      supplies, substitution of other beverages, importing water from other




      uncontaminated areas, and the designation of certain critical users




      that could be allowed to use contaminated supplies.  These might be




      fire-water jystems and process cooling systems,




1.6.3.9  Restorative Actions




           A.  Lilting Protection Controls




           The lifting of controls for protective actions may be justified




      on the basis of cost savings when the corresponding health risks have




      been adequately reduced.  For example, the costs to the public and




      the State in maintaining access control, pasture control, milk control,




      or food and wacer control will exceed the risk reduction value of
                                     1.48

-------
these controls after some period, and then the controls should be




lifted.  The costs for maintaining these controls will be relatively




constant wi'th respect to time while their significance in reducing




risk will decrease as the source of radionuclides is halted and




the released naclides disperse or decay away.  Therefore, it may be




desirable to lift controls even though some additional dose may be




accrued.




     B.  Reentry




     After evacuation, persons will be allowed to reenter the zone




when the potential radiation risk has been averted or reduced to




guide levels for members of the general population.  However, it may




be necessary for certain essential personnel to return even before




the dose is reduced to these guide levels.  In addition, reentry




may be allowed earlier for less radiosensitive persons such as adult




males who n.ay need to return to their homes or jobs.  The criteria




for reentry will require a balancing of remaining radiation risk




such as from ground contamination and the cost of disrupted services,




lost income, etc. resulting from the evacuation.  Time is not a




constraint on reentry except as a factor in the cost of  remaining out




of the evacrated area.




     C.  Decontaminat ion




     The movement of radionuclides along several pathways involving




milk, food, and water may result in prolonged contamination.  Each of




these elements may require processing to remove radioactive contaminants
                               1.49

-------
prior to consumption.  In each case, the radionuclide concentrations




would be r duced to levels "as low as practicable" commensurate with




treatment costs.
                              1.50

-------
                                 CHAPTER  2
                    Protective Action Guides for Exposure
                      to Airborne Radioactive Materials
2.0  Introduction
          Following an incident involving a release of radioactive

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

     to  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 unti1. perhaps  two  to  four days after  the event occurs.

     During this ->eriod, 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.

         It is important to recognize that the  PAGs  are defined in

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

     received by tne population if  no  protective action  were  taken.  For
                                    2.1

-------
     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 gonrna exposure to whole body dose requires a correction




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




     ties in proie2Cing 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 externr1  exposure to radionuclides in the atmosphere are




     summarized fn 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

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


Emergen y workers                                25


Lifesaving activities                            75
   (a)When ranges are shown, the lowest value should be used if
there ate no major local constraints in providing protection at
that level, especially to sensitive populations.  Local con-
straints n?ay 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 valui should be used ±f 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 giseous portion of a radioactive plume may consist of




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




       will not cnuse 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 particulate material




       in the plume.




2.2.1  Exposure to Radioiodines in a Plume




            Due l D the ability of the thyroid to concentrate iodines,




       the thyroi'd  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

-------
    Table 1,2  Protective Action Guides for Thryoid Dose
           Due to Inhalation from a Passing Plume
                                       Projected Thyroid Dose
  Population at Risk                             rem
                                                     (a)
General population                              5-25
Emergency workers                               125


Lifesaving activities                           (b)
   (a)
   ^ 'Wl.en 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 ni&y make lower values Impractical to use, but in no
case should the higher value be exceeded in determining the need
for protective action.

      Nc specific upper limit is 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 respirators and/or thyroid protection for
rescue personnel are available as the result of adequate
planning.
                              2.5

-------
2.2.2  Exposure to ^articulate 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 frcm early effects of radiation and maintaining the




       delayed biological effects at a low probability.  Consideration




       has been nade of the higher sensitivity of children and pregnant




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




       sideratiot. 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

-------
 action are not more hazardous than the 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 tbi 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 iL£y exceed the  good,  so some  restrictions must be made.




      Because of  the variations in sensitivity of  the 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

-------
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 radioiodine 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,
                                  2Q
                                 . O

-------
                           CHAPTER 3







Protective Action Guides for Exposure from Foodstuffs or Water







                3.1  Whole Body External Exposure




                3.2  Ingestion




                     3.2.1  Milk




                     3.2.2  Food




                     3.2.3  Water
                   (Guidance  to be Developed)
                              3.1

-------
                          CHAPTER 4


                  Protective Action Guides
for Exposure from Material Deposited on Property or Equipment


                4.1  Reentry and Release

                4.2  Decontamination

                4.3  Land Use
                 (Guidance to be Developed)
                            4.1

-------
                                 CHAPTER 5

                  Application  of Protective Action Guides
               for Exposure to Airborne Radioactive Materials
5.0  Introducticn

          Following notification that a radiological incident has

     occurred involving an atmospheric release that may require

     protection of the public, the State authorities will need

     information for decisions on what protective actions to

     implement.  The types of information needed are (1)  Protective

     Action Guides (dose limits) adjusted for local situations and

     (2) projected doses in specific areas for comparison to the

     Guides.  Projected doses must be determined on the basis of

     data available following the incident.  These data may come

     from either onsite measurements and conditions or offsite

     environmen-.al measurements.  This chapter deals with methods

     for estimating population dose from exposure to a radioactive

     cloud or p_utne and comparison of the projected dose with

     PAGs for decipions on protective actions.  These methods are

     recommended for use by State and local officials for develop-

     ment of operational plans for responding to incidents at nuclear

     facilities,  The guidance in this chapter Is directly related

     to releases to the atmosphere that have been postulated for

     nuclear power facilities.
                                      5.1

-------
5.1  Release Assumptions




          The types of protective actions that should be planned to




     reduce population exposure are related to the characteristics




     of the relea3e that might occur.  A recent publication of the




     NRC, WASH-1400 (1), 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 depen-




     ding on the severity and the exact sequence of the failure modes.




     Significant releases of radioactivity may occur within 1-1/2 to




     2-1/2 hou-T of the initiating cause of the incident; therefore,




     if protective actions are to be effective, they must be taken




     promptly.




          Incidences of relatively small environmental impact may




     involve a loss of coolant for the reactor but without a meltdown




     of the reactcr core.  For this class of accidents, the release to




     the atmosphere should be restricted to mostly radioactive noble




     gases and iodines.



          Accidents of increasingly larger environmental impact would




     involve a meltdown of the reactor core and eventual loss of con-




     tainment integrity.  This class of accident will release quantities




     of radioactive particulate matter as well as the radioactive noble




     gases and iodiaes.
                                      5.2

-------
5.1.1  Noble Gases and Radi_qioditie Releases

            For an atmospheric release at a nuclear power facility that

       involves only noble gases and radioiodines, it is usually con-

       servative to assume that 100 percent of the equilibrium noble

       gases 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 opera-

       tor regarding the release composition, it would be conservative

       to assume  hat this composition is released to the environment

       at the design leakrate.  The relative abundance of radioiodines

       and noble j,ases i° 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.

            Table 5,1 summarizes the total quantities of radiologically

       significant gaseous radionuclides that are available to be

       released to the containment vessel following a loss of coolant

       accident at d 1,000 megawatt-electrical nuclear power reactor

       assuming 100 percent of the noble gases and 25 percent of  the

       radioiodines escape from the core.  These values may be adjusted

       linearly fo - reactors of other  sizes.
            "'"This assumption  is  in agreement  with NRC  guidance (_2,5.,j>) on
       assumptions that may be used in  evaluating the  radiological  conse-
       quences of an accident at a light  water cooled  nuclear  power facility,
                                        5.3

-------
Table  5.1   Initial  inventory  of  the  radiologically signit'ic.mt
                     noble  gases  and  iodines
  Nuclide
                           Megacuries
                                      (a)
available for
 release from
 containment
                 Sum of kryptons      192 MCi

                 Sum of xenons        258 MCi
                 Sum of noble gases = 425 MCi

                 Sum of iodines     = 184 MCi
                                                      Half life
Krypton- 8 5m
Krypton-85
Krypton-87
Krypton-88
Iodine-131
Iodine-132
Iodine-133
Xenon- 13 3m
Xenon-133
lodine-134
Iodine-135
Xenon- 13 5m
Xenon-135
33.5
0.66
64.4
93.0
18.7
28.5
45.9
4.0
164.3
51.5
39.5
19.0
46.4
4.4 hr.
10 yr.
76 min.
2.8 hr.
8.1 day
1.3 hr.
20 hr.
2.3 day
5.3 day
52 min.
6.7 hr.
16 min.
9.1 hr.
                 Ratio of
  iodines   _ 184
noble gases   425
        Based on equilibrium inventory developed from maximum full
power operation of a 1000 megawatt electrical light-water-cooled
nuclear power reactor.  This includes 100 percent of the noble
gases and 25 percent of the iodines.
                               5.4

-------
             Calculations of the projected population dose based on




        the relative quantities shown in table 5.1 indicate that the




        thyroid dnne from inhalation of radioiodine ranges up to 1,000




        times grer-.tet than the whole body gamma dose from noble gases




        and radioiodines.  If the engineered  safeguards function as




        designed, chsy should reduce the iodine concentration such that




        the whole body gamma radiation exposure to noble gases will be




        the controlling pathway.




5.1.2   Radioactive Particulate Material Releases




             This section is being developed.




             Initial studies indicate that except for the most severe




        and improbable accidents postulated by WASH-1400, protective




        actions (pjophylaxis iodine excepted) chosen on the basis of




        assuming .ihat the iodine exposure pathway is critical (figure




        5.2)  will be sufficient to provide protection from radioactive




        particular material.   This particulate material will deliver




        an additicnal dose to  the lung and to the whole body from




        material located  in the lung,  but these doses are not likely




        to be greater than the  thyroid dose.




   5.2   Application of Protective Actions




             Following an incident at  a nuclear power facility in-




        volving  a  release to the atmosphere,  the most urgent actions




        in terms of  response time will be those to protect  the popu-




        lation from  inhalation  of  radioactive materials  in  the plume
                                        5.5

-------
and from direct whole body exposure  to gamma radiation from the




plume.  The time of  exposure to  the  plume can be conveniently




divided into two periods;  (1) the period immediately following




the incident when  little or no environmental data are avail-




able 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 may be




exceeded.  Furthermore, environmental measurements made during




this period may have little meaning  because of uncertainties




concerning plume location when measurements are made or changes




in release rate due  to changes in pressure and radionuclide con-




centrations within containment.  Therefore, it may be necessary




to initiate early  protective actions on the basis of dose




projections provided by the facility operator followed by




adjustments tD these actions based on more detailed environ-




mental measurements.




     For accidents involving a release to the atmosphere at a




nuclear power facility, the following sequence of events is




suggested to minimize population exposure.




     (1)  Notification by the facility operator that an inci-




          dent has occurred that is  expected to cause offsite




          projected doses that exceed the PAGs.  This notifica-




          tion should be provided as soon as possible following
                                5.6

-------
                 the incident and prior to the release if possible.




             (2)  Immediate evacuation of a predesignated area.




             (3)  Monitor gamma exposure rates in the environment.




             (4)  Calculate plume centerline exposure rate as




                 inversely proportional to distance from release




                 point, or use prepared isopleths to estimate




                 exposure rate in downwind area.




             (5)  Use exposure rate and estimated exposure duration




                 to convert to projected dose.




             (6)  Compare projected dose to PAGs and adjust areas




                 for protective actions as indicated.  Table 5.2




                 summarizes recommended actions as a function of




                 PAG levels for exposure to a gaseous plume.




             (7)  Continue to make adjustments as more data become




                 available.




5.2.1  Actions Based on Licensee Notification




            The AEC Guide and Checklist (_2) indicates that the noti-




       fication from a nuclear power facility to the State and local




       response organizations should include an estimate of the




       projected dose to the population at the site boundary and




       in the Low population zone following an accidental release.




       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 to 1 hour following)
                                       5.7

-------
Table 5.2  Recommended protective actions to avoid whole body and thyroid dose from exposure to a gaseous plume.
Projected Dose (Rem) to
the Population
Whole bocjy <1
Thyroi d <5
Whole body 1 to <5
Thyroid 5 to <25
Whole body 5 and above
Thyroid 25 and above
Projected Dose (Rem) to
Emergency Team Workers
Whole body 25
Thyroid 125
Whole body 75
Recommended Action^9'
•No protective action required.
•State may Issue an advisory to seek shelter and await
further instructions or to voluntarily evacuate.
•Monitor environmental radiation levels.
•Seek shelter and wait further instructions.
•Consider evacuation particularly for children and
pregnant women.
•Monitor environmental radiation levels.
•Control access.
•Conduct mandatory evacuation of populations in the
predetermined area.
•Monitor environmental radiation levels and adjust area
for mandatory evacuation based on these levels.
•Control access.

•Control exposure of emergency team members to these
levels except for lifesavlng missions. (Appropriate
controls for emergency workers, Include time limita-
tions, respirators, and stable Iodine.)
•Control exposure of emergency team members performing
lifesaving missions to this level. (Control of time
of exposure will be most effective.)
Torrents
Previously recommended
protective actions may
be reconsidered or
terminated.

Seeking shelter would
be an alternative 1f
evacuation were not
Immediately possible.

Although respirators
and stable Iodine should
be used where effective
to control dose to emer-
gency team workers , thy-
roid dose may not be a
limiting factor for
lifesaving missions.
         These actions are recommended for planning purposes.  Protective action decisions at the time of the
  incident must take  into consideration the impact of existing constraints.

-------
the incident and prior to the start of the release if possible),




and that it will be provided in units that can be compared to




PAGs (i.e., projected dose to the whole body or thyroid).




     The first indication that an incident has occurred with




potential for population dose in excess of PAGs should come to




State authorities from the facility operator.  Although plans




may include provisions for the facility operator to include




information in the notification regarding projected dose to




the population, such information may not be available.  Further-




more, if dose projections are available, there may be reason to




suspect tLeir accuracy.  Therefore, the State should have planned




a designated  area for immediate evacuation  (or other suitable




action).   Immediate actions would be  taken  in this area  if  the




facility operator's estimate of projected dose was not available




or was  not considered to be on a sound basis.  If the facility




operator provides projections of population dose, then these




projections should be used by the  State  to  determine the area




for  immediate action  in  lieu of  the predesignated area.




     The i-commended  area  to be  designated  for immediate action




is  the  dovnwind sector  (one  sector covers 22-1/2 degrees)  and




the  two adjacent sectors.  The  radial distance for  action should




be  to  the  outsr edge  of  the  low population zone. Other  planned




downwind distances  or widths for immediate action may be justifi-




able for particular sites.
                                 5.9

-------
              A. transparency should be  prepared which  shows  the down-




         wind  area  for immediate action.   The scale  of the transparency




         should be  the same as the map  of the environs around  the facility




         so that the action area can be quickly  identified.




  5.2.2  Actions Based on Environmental Measurements




              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 re-evalu-




         ating the  ueed for additional  protective actions or termination




         of those actions already taken.




5.2.2.1  Dose  Projection for Noble Gas  and Iodine Releases




              A gaseous release from a  light water reactor is assumed  to




         include ndioactive noble gases, and iodines as shown in  table




         5.1.   Unless engineered safeguards were successful in significantly




         reducing che quantity of radioiodines available for release rela-




         tive  to the quantity of noble gases, the dose from the inhalation




         of radioioiine would be the controlling pathway.




              Since field measurements of environmental radioiodine con-




         centrations would  be difficult  and  time-consuming, it is recom-




         mended that thfi State plan  to measure gamma  exposure rate and




         estimate thyroid dose from  inhalation by converting  from gamma




         exposure rate  to  projected  thyroid  dose.   The method for this




         conversion is  discussed  later  in this  section.
                                         5.10

-------
      The -projection of either whole body dose or thyroid dose




 requires a knowledge of the exposure rate and the time period




 of exposure.   The time period of exposure may be difficult  to




 predict.  Exposure would start at a particular site when the




 plume ariived and would be ended by a shift in wind direction




 or by an end  to the release.   Arrangements should be made for




 the State or  local weather forecast center to provide  informa-




 tion on  predicted wind direction persistence during the inci-




 dent.  If neither wind change nor the time until the end  of the




 release  c-n be  predicted,  the period of  exposure could be




 assumed  to be equal to the maximum (or 99% probable maximum)




 duration of wind  direction for that site as determined  from




 previous luute.orological history.




      Having obtained information regarding gamma exposure rate




 at  selected locations in the  environment,  one must  then estimate




 exposure rate in  additional locations in order to identify the




 pattern  of  the  exposed area.   Estimation of exposure rate patterns




 based on a  few  downwind measurements can be conducted in a variety




 of ways.   One simple way is to determine a plume centerline exposure




 rate at  grnuna  level at  some  known  distance from the release point




and use  these data  to calculate  exposure rates  at other designated




distances downwind  by conservatively assuming  that  the cloud center-




line exposure rate  is  inversely proportional  to  the  distance from
                               5.11

-------
                   2
 the release pcint.    The following relationship  can be  used for this

 calculation:
 Where:

         DI  =  exposure rate  measured  at  distance RI

         D_  =  exposure rate  at  distance  R_


 One  could then  develop a  crude and very conservative pattern of

 estimated exposure  rates  by assuming that  the exposure rate calculated

 for  the  plume canterline  would also  exist  at points equidistant from

 the  source  dn the downwind  sector  (22^  degrees) and in the two adja-

 cent sectors.   This  67% degree sector allows for wind meander and

 some uncertainty in  wind  direction.  The use of this method would

 likely result in an  overestimate of  the exposure rate in all areas

 downwind of the measurement  point.   In  addition, one must be sure

 that the exposure rate measurement is taken at or near the plume

 centerline.

     A second and more accurate method  for estimating exposure

 rate pattern? is to  use a series of  prepared exposure isopleths

 (maps with  lines connecting  points of equal exposure rates)
     o
      The canterline exposure rate can be determined by traversing
the plume af. a point sufficiently far downwind (usually greater than
one mile from the site) while taking continuous exposure rate measure-
ments.  The highest rating should be at the centerline of the plume.
                               5.12

-------
plotted on transparencies.  These isopleth plots are fre-




quently available from the licensee thus eliminating the




need for the State to develop them.  Since both the




meteorological stability and the wind speed existing at




the time of the release affect the shape of the exposure




isopleth curves, several sets of curves would be needed to




represent the variety of stability conditions and wind




speeds likely to exist at  that site.  The appropriate trans-




parency can be selected on the basis of wind speed  and




meteorological conditions  at the time of  the incident.  The




transparency can then be  placed over a map  of  the area  such




that  the curves are  properly oriented with  regard to wind




direction.  The isopleth  curves are 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 arer..  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.
                                5.13

-------
      Having established gamma exposure rate patterns in




 the environment and having determined (or estimated) the




 time peUod of exposure, the next task is to estimate the




 projected whole body and thyroid dose to members of the




 population so that the projected dose can be compared with




 appropriate PAGs.   If engineered safeguards operate as




 designed,  they may reduce iodine concentrations to levels




 such that the whole body gamma radiation exposure from




 noble gases will be the controlling pathway.   Otherwise,




 the controlling exposure pathway will be inhalation of




 radioiodrnes resulting in thyroid dose ranging up to




 hundreds  of times  the whole  body gamma dose depending on




 the effectiveness  of the engineered safeguards.




      To avoid  the  necessity  for  calculating projected dose




 at  the time of  the incident,  it  is recommended that dose




 projection  nomograms be developed.   Figures 5.1  and 5.2 are




 examples of such nomograms.   Appendix D  provides details




 regarding their development.




     The projected whole body gamma dose can be  estimated by




 simply multiplying the  gamma  exposure rate  at  a  particular loca-




 tion by the  time period  of exposure.   Figure 5.1  provides this




multiplication.  It  also provides  a relationship  between exposure




 rate in mr/hr and  the noble gas  concentration  based  on the mixture




 of radioactive  noble gases shown  in table 5.1.
                             5.14

-------
1.000,000 9
8
100000 g-
a
2
J 10.000 a
8
'- 7
\ I
2
.
: 1.000 -
9
6
5
.
9




10

jJT
|r 	
\
V
>
s
Sv
— >

\
>

\
X.
V























5
y

S


\

v
>


L •* —
Lj,
v A
\
s

f, —

\
s
s.
s
c 	
[V '
\ N
\




s.
















Si





























































































Jfr
\ — "


s
>

1
^
5



-•
y
S
X





















J
1 i^y* ~






i " ^ST 4* ~
S 7?
*
^
i ^sj1
'^^
^
^p*



^*5
£&
0&*
\











k S
V
s
s


\
^ N
A
..JWI^

>. N
St /
~X















&
S














s
V"




s






















































































•Q ygL

i TMIB I

kB«

»u




LOT THi POINT RIPRIIINTINO
IAMMA RADIATION EXPOtURI
SATE (mR/Sw) AND PROJECTED
IME OF EXPOSURE (HOURS)
STIMATE THE PROJECTED WHOL
«DY DOSE FROM THE CURVES
kBOVE AND BELOW THE POINT




\

5


s
S "
I

s
^ —
s



Si

s
s















•
^k.
^. \
\

v^s
;\
~ • ^~—


s
V
>
s
\
\


\















\


\
^^~
^



V
s
\




s














s
\




\
s
s
s
s


3Z
™

V
\
















































5
s
S '
S^SS
^ k

... 2 I



^
s


TT>8
!TP7
-• .6
44- • 5
" • 3
" . '1
E
—1*10-°
~ -7
~ '6
. -5
-4
• • -3
. 2
- IKIO'1
- • '•&

•6

... 5
• ' -4
•3
.2
— IxlO'2
.9
5 . • 8
" ' • 6

< • -5
•4
• ' -3
-
* -2
/- IxlO-3





• ' - 4
•3
* ' 2
•1X10-*
   o.i
             3  4 5 6 7 8ft
3 4 5 6 7 39
                                                                     .'
                                                                     -
                                                                     i
                                                                     <
                                                                     :

                                                                     a
                      1.0                  10
                PROJECTED TIME PERIOD OF EXPOSURE (HOURS)
                                                  345 678
                           100
FIGURE  5.1-PROJECTED WHOLE BODY GAMMA DOSE  AS A FUNCTION
            OF GAMMA RADIATION EXPOSURE RATE AND PROJECTED
            TIME PERIOD OF EXPOSURE
                               5.15

-------
GAMMA RADIATION DOSE RATE (MREM/HR)
3
3 O r- _ S
-> u u k u » •< •«_ a u » u » >l »«O u u * u » M««O u u • u » xi»«g » u • Id » S»«C

— 5s

s
N.

V
V
_v. .

^s.
V
s
\

h


^v
^w
_s

V
X











TO
~PL<
	 EX
	 BY
AB

1 	 r~~


N

S





s.


X



\

s


V













V

X
N




V
\

\









USE





V (
>»J




N^

S








Tl
















































si









51
N

1s'
s




\
'V
41
s

N







3RA

%
/• ^^"
'^"^
-J-^fc
1 ^

	 '


*O
'4
tf
*V ^y
^v •?

N
tsf" "

t rSc
js~ n
Xv^

^x^ ^ ^sj

«lb?v^l
^^v
>
s

\v^
TV
X
^^
>v

^\ «^
—Sk^J?1
*^t?
N.

PH A
N


s

N





V
















X

_








































































































































DT THE POINT REPRESENTING THE
POSURE AND TIME PERIOD OF EXPOSUR
HMATE THE PROJECTED THYROID DOSE
INTERPOLATION FROM THE CURVES
OVE AND BELOW THE POINT.





2 3 4 S » 7 f














A
'r








fr
X. 6 'o/


fc -
~rx








1 O.
;. J
X 1 TS

X^
\^_~fif


"\^
— v
fv

>>.! Sf)
-_h&«
N. L>s
^S?J?^
, _sft^'
N


^
"\_
1
v ^^»
1^.
S?^






x,
>^/^-
_x^


E




^
U
*7
\
"V






S





s
S



's-

























-
,
































































































-



































-









-7
-6
-3


-3
-1
— ixio-*

-7
-6
- s


~3

-1X10-
J

-«
-3


-3
-J
'-1X10-

*
- A
. - 3


-3

" — 1X10-7
- -7
-*
. - S


~3
1 -j
-•
TAA rt
                                                                                                    . 2,000,000
                                                                                                    . 1,000,000
                                                                                                    .  900,000
                                                                                                      toojooo
                                                                                                      700,000
                                                                                                    ,  600,000
                                                                                                      300,000
                                                                                                      400,000
                                                                                                    ,  300^)00
                                                                                                       500,000
                                                                                              j
                                                                                             -
                                                                                             -
                                                                                             ;
                                                                                             :
                                                                                                      3,000
                                                                                                      1,000
                                                                                                      1,000
                                                                                                      900
                                                                                                      (00
                                                                                                      700
                                                                                                      600
                                                                                                      300
                                                                                                      4OO
                                                                                                      70
                                                                                                      60
                                                                                                      SO
                                                                                                      40
                                                                                                      10
                 PROJECTED TIME  PERIOD  OF  EXPOSURE - HOURS

     FIGURE 5.2 PROJECTED THYROID DOSE AS A FUNCTION  OF GAMMA
RADIATION EXPOSURE RATE AND PROJECTED TIME PERIOD OF EXPOSURE

A. USE OF THIS FIGURE ASSUMES THAT THE  RADIOIODINE/IMOBLE GAS ACTIVITY
RATIO IS 0.3. IF IT IS KNOWN THAT THE RATIO HAS A LOWER  VALUE, THE
CORRECTION FACTOR GIVEN IN FIGURE 5.3 SHOULD BE USED.

                                                                                                              '.
                                                                                                               3.
                                                                                                             O
 100,000
 90,000
 10,000
 70,000
 60,000
 30,0 OO
 40.OOO   'O
         r-
 30,000   X
         M
 10,000   LL
         O
         CO
         LU
 10,000
 9,000
 I.OOO
. r/ioo
 6,000
                                                                                                               :
                                                                                                               s
                                                                                                      3^)OO     _
                                                                                                               •.
          -
          .
          -
          z
          :
          -
          c
          -
          -

-------
     The estimation of projected thyroid dose on the basis of




gamma exposure rates and duration of exposure is more complex




because the projected dose is also a function of the compo-




sition of the release which is a function of the type of




incident, the time after shutdown, and the operation of




engineered safeguards.




     In the most probable event, radioiodines will be present




in a release  but neither the ratio of radioiodines to the




noble gase-5 nor concentrations of radioiodines in the environ-




ment will be known.  If this is the case, the conservative assump-




tion can Le made that the radioiodine is the most critical and




that the radioiodine/noble gas activity ratio is 0.3.  (Although




the initial ratio in containment is assumed to be 0.4 as shown




in table 5.1, this value rapidly decreases with time and 0.3




would be : .ore representative by the time the plume reached the




population).  This assumption allows the direct use of figure 5.2




to estimau^ projected thyroid dose as a function of gamma exposure




rates and tiire period of exposure.  If the actual radioiodine/noble




gas activity ratio has been determined and is less than 0.3,




figure 5.3 mi/ be used to derive the appropriate correction factor




for gamma dose rate values before applying them in figure 5.2  If




radioiodines are known to be absent or reduced to 0.005 or less of




the originj-1 concentration, the critical exposure pathway becomes




that of whols body gamma exposure, and figure 5.1 applies instead




of figure 52.
                              5.17

-------
 :
I
I
2
C
08
06
.04
.03
.02
OO1
.008
.006
.004
O03
002
0001
0008
0006
0004
0003
0002
00001
0












































001































b
u
M
6





































































i




























































t
ELOW THIS RATIC
SE PAC'S FOR
HOLE BODY
WIA RADIATION
_| \



























A




\



/

























































































































\^/
m
3
















































































































































/
/


























/
/

















































/












' '






.





















f













































































































































































































































1






TO USE THIS GRAPH

• rlND
TORR
RAT I
NOB!.
CORR
GAM
' BE U
PRO
FIGU










/
/






















THE CORRtCTION FACTOR
ESPONDING TO THE KNOWN
0 OF RADIOIODINES TO
E GASES. APPLY THIS
ECT10N FACTOR TO THE
A RADIATION LEVEL TO
SED IN DETERMINING THE
ECTED THYROID DOSE IN
RE 5.2









/































/
f































•
































f































f
/



































































/
















































































_/
4


































.002 .003 O04 O06O080.01 .02 .03 .04 .06 .080.1 .2 .3 .4 A .8 1
Gamma Radiation Exposure Rate Correction Factor
1
        FIGURE 5.J  GAMMA  RADIATION EXPOSURE RATE  CORRtCTION FACTOR

                                                         5.18

-------
     A better method for correcting the gamma exposure rate for


use in figure 5.2 to estimate the projected thyroid dose would be


to take one or more iodine concentration measurements at some


locations where gamma exposure rate measurements were taken.


Compare the gairma exposure rates to the corresponding iodine


concentration measurements on figure 5.2 and determine the ratio


of measurer1 concentration to the observed "corresponding" con-


centration.  This ratio can be used to correct other gamma


measurements prior to their use in figure 5.2 to project thyroid


dose.


     Figure 5.2 can also be used to estimate projected thyroid


dose if one kr.ows environmental concentrations in terms of

      o
nCi/cm .  To use figure 5.2 to estimate projected thyroid dose,


one needs the projected time period of exposure and the environ-


mental radioactivity level.  The time period of exposure may be


estimated on the basis of  (1) history of maximum wind direction


persistence for that area,  (2) forecasts of wind change at  the


time of the incident, or  (3) the facility operator's prediction


of the expected duration  of the release based on plant conditions.


     To estimate projected  thyroid dose for a particular site,


plot the  point of figure  5.2 corresponding to the exposure  rate


(gamma exposure rate in mr/hr, or  radioiodine concentrations  in


uCi/cc) and the expected  time period of exposure for persons  at


that location.  Estimate  the projected thyroid dose  from the  dose
                                5.19

-------
    values on  the  curves  below  and  above  the  point.    For example, if

    the  gamma  radiation level is  reported to  be  100 mR/hr and is expec-

    ted  to last  three  hours, then the  projected  adult  thyroid dose is

    approximately  60 rems,  and  the  child  thyroid dose  would be approxi-

    mately 300 rems.   (Refer to table  5.2 for recommended protective

    actions associated with each  projected dose).

          Figure 5.3 is used only in the event that the radioiodine/

     noble gas activity ratio is known and is less than the assumed

     value of  0.3 and only for correcting the gamma exposure rate

     for use  in figure 5.2.  No correction factor is needed if the

     environmental radioactivity level is expressed as iodine con-

     centration.   The measured gamma exposure rate may be multi-

     plied by  the factor obtained from figure 5.3 to give a "corrected"

     gamma exposure rate for use with figure  5.2 to determine

     projected thyroid dose.

          For  example,  if the radioiodine/noble  gas radioactivity

     ratio is  measured and found  to "be 0.01,  the gamma radiation

     level correction factor from figure  5.3  is  0.08.  The "corrected"

     gamma radiation level is then 8 mR/hr for a measured gamma radi-

     ation level of 100 mR/hr.  For a projected  time period of exposure
     3Note that the child thyroid dose  is  five times  the adult thyroid
dose   The child dose would apply to general populations for deciding
whether or not to evacuate, while the adult dose would apply to emergency
teams or other adults.
                                     5.20

-------
of three hours, the actual projected child thyroid dose would




be approximately 25 rem as compared to approximately 300 rem




without use of the correction factor.




     For a puff or continuous release to the atmosphere where




the report of release includes  the number of curies released or




that could potentially be released or where the release rate




and the >xpected duration of the release is reported, the




immediate question becomes; how far downwind should actions




be taken to protect the population from the airborne plume?




Although uore projections based on release information would




normally be. done by facility operators, it is advisable for




State radiological personnel to understand the techniques




involved.   The dose projections can be accomplished by using




nomograms such as those in figures 5.1 and 5.2 to identify the




time-concentration that would produce a projected dose equal




to the PAf and a plot of x^/Q versus downwind distance such as




figure 5.4 to determine the distance where that time-concentra-




tion would exxst.




     To make this determination, one must have information




regarding the principal exposure pathway, the curies released




of the radi->nuclides contributing to that exposure pathway, the




windspeed, and atmospheric stability class.   In  the  absence




of any of these bits of information, one must be prepared to sub-




stitute assumed values and conditions based on a knowledge of the




facility and the environment.
                                5.21

-------
-
                                   These  values assume
                                   an  Inversion 11d at
                                   1000 meters altitude
                                   and a  ground level
                                   release.
                                  \
                                                      u

        0.5
12       5      10     20
  Distance  Downwind  (Miles)
                                        kilometers     100
                                      J	1	I
         ^ 5.4  Typical values for XU/Q as a function of
      atmospheric stability class and downwind distance
                          5.22

-------
     The methods for determining the downwind distance to where  pro-


tective accion should be taken for a puff release are similar to the


methods fcr a longer term release.  However, for purposes of using


the nomograms in figures 5.1 and 5.2, it is convenient to assign


a release time of one hour for the puff release.  The distance


downwind for protective action can be read  from a plot of xu/Q


versus distance  for various  atmospheric stability classes as


shown in figure  5.4.  The  term xU/Q  can be  calculated using the


relationship


                           CU = Q x  xU/Q                       (D


Where:

                                                        o
     C  = environmental  concentration of  concern in  Ci/m  or


         UCi/cm3


     0  = average windspeed in m/sec.  Multiply MPH  by .5 to


         obtain m/sec (approximately)


     Q = release rate in curies/sec


    X/Q = environmental concentration at a particular location


         per ;urie per second being released at the source

                O
          i,sec/mj)


 Then:

                                                              (2\
                                                              V '
          CJ/Q


 For example:


      If the accident  involves a puff release of 20,000 curies


 of iodines and the PAG  is  5  rem to  the  thyroid, then from figure
                                 5.23

-------
 5.2 one can observe  that  the  concentration  of  concern over a

 period of GI^ hour would  be 3.3  x  10~6 uci/cm3.   The release

 rate averaged over one hour would  be  20'000 ci =  5-5 ci/sec.
                                       3600  sec

 Therefore:

             3.3 x 10-6 (uci/cm3) x U(m/sec)
                       5.5 ci/sec

           = 6.7 x 10~7 U

 If:

      0 = ^.0 mph = 5 m/sec

 Then :

      XU/Q = 3 x 10~6


 From figure 5.4 one can observe that a xU/Q value of 3 x 10~6

 would  occur at about 0.6 miles downwind under atmospheric sta-

 bility condition A and about 3j> miles downwind under condition F.

     For tha puff release,  PAGs could be identified (i.e.  5  rem

 to the thyroid)  and  a specific time period for the release could

 be assumet1  (i.e.,  1  hour =  3,600 sec) so that equation 2 could be

 simplified  to:

          jJr/Q  .  3.3  x 1Q"6 UCi/cc x U =      .012U
                      ci/3600 sec        curies released

or:

                 0.012U
                  Ci                                          (3)

     The methods presented in  this Chapter for relating data  at

the time of the incident to projected dose are recommended for
                               5.24

-------
         use in development of operational response plans for gaseous




         releases.   However, planners are encouraged to improve on




         these methods where possible and to alter them as necessary




         to respond to special circumstances.




5.2.2.2  Dose Proj "iction for Particulate Material Releases




              This  section to be developed.
                                        5.25

-------
                         CHAPTER 6






Application of PAGs for Foodstuffs and Water Contamination






              6.1  Relocation




                   6.1.1  Whole Body




                   6.1.2  Organ Exposure




              6.2  Shelter




                   6.2.1  Whole Body




              6.3  Access Control




              6.4  Milk Control




              6.5  Food Control




              6.6  Water Control
                 (Guidance  to be Developed)
                             6.1

-------
                         CHAPTER 7






Application of PAGs for Contaminated Property or Equipment






              7.1  Release and Reentry




              7.2  Decontamination




              7.3  Land Use
                 (Guidance  to be  Developed)
                             7.1

-------
                    CHAPTER 8
Application of PAGs for Transportation Incidents
           (Guidance to be Developed)
                       8.1

-------
                 APPENDIX A
        Summary of  Interim Guidance  on
Offsite Emergency Radiation Measurement Systems
              (to be developed)
                        A-l

-------
                   APPENDIX B
Planner's Evaluation Guide for Protective Actions
                (to be developed)
                       B-l

-------
          APPENDIX C
Summary of Technical Bases for
   Protective Action Guides
       (to be  developed)
               C-l

-------
                APPENDIX D






Technical Bases for Dose Projection Methods











             (to be developed)
                   D-l

-------
                            REFERENCES
(1)   U.S.  ATOMIC ENERGY COMMISSION.  An Assessment of Accident  Risks
     In U.S.  Commercial Nuclear Power Plants. (WASH-1AOO,  draft),
     U.S.  Nuclear Regulatory Commission, Washington,  D.C.   August  1974.

(2)   U.S.  ATOMIC ENERGY COMMISSION.  Guide and Checklist for the
     Development and Evaluation of State and Local Government Radio-
     logical Emergency Response Plans in Support of Fixed Nuclear
     Facilities.  (WASH 1293) U.S. Nuclear Regulatory Commission,
     Washington, D.C.  December 1974.

(3)   HANS, JOSEPH M., JR., and THOMAS C. SELL.  Evacuation Risks -
     an Evaluation.  (EPA-520/6-74-002) U.S. Environmental Protection
     Agency, Washington, D.C.  June 1974.

(4)   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 1974).

(5)   U.S. ATOMIC ENERGY COMMISSION.  Regulatory Guide 1.3.  Assump-
     tions Used for  Evaluating the Potential Radiological Consequences
     of a Loss of Coolant Accident for  Boiling Water Reactors.
     Directorate of  Regulatory Standards, Nuclear Regulatory Commission,
     Washington, D.C.  June  1973.

(6)  U.S. ATOMIC ENERGY COMMISSION.  Regulatory Guide 1.4.  Assump-
     tions Used for  Evaluating the Potential Radiological Consequences
     of a Loss of Coolant Accident for  Pressurized Water Reactors.
     Directorate of  Regulatory Standards, Nuclear Regulatory Commission,
     Washington, D.C.  June  1973.
                                 R-l

-------