f :
MANUAL OF PROTECTIVE
ACTION GUIDES AND
PROTECTIVE ACTIONS
FOR NUCLEAR INCIDENTS
Presented By
The Environmental Protection Agency
at
NASA HEADQUARTERS
date
JUNE 10- II, 1998
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SESSION I
WELCOME AND INTRODUCTIONS
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EPA 400-R-92-001
MANUAL OF PROTECTIVE ACTIONS AND PROTECTIVE
ACTIONS FOR NUCLEAR INCIDENTS WORKSHOP
NASA HEADQUARTERS
300 E STREET, S.W.
WASINGTON D.C.
JUNE 10- II, 1998
Wednesday, June 10, 1998
8:30 - 9:00 am
9:00 - 10:00 an
10:00 - 11:00 am
Hi00 - 12:00 pn
12:00 - 1:00 pm
1:00 - 2:30 pm
2:30 - 4:30 pm
4:30
Thursday, June 11, 1998
8:30 - 10:00 am
10:00
11:00
12:00
1:00
3:30
11:00 pm
12:00 pm
1:00 pm
3:30 pm
4:00 pm
Welcome and Introductions
Overview (How the PAG manual ±B laid out)
Rationale for PAG values (PAG Principles)
Application and Interpretation of PAQs (When to use them and
how)
Lunch
Introduction to Dose Projection (Discussion of Terminology
and EPA assumptions used)
Implementation of Emergency Worker Dose Limits (Who are
Emergency Workers and What limits apply)
End of Day One
Development of DCFs and DRLs (What are they and how do you
apply them)
Dose Projection for Early Phase (Problem solving)
PAOs for Relocation (Assumptions made and rationale for use)
Lunch
Dose Projection for Relocation (Problem solving)
Review and Wrap-up
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SESSION 2
OVERVIEW OF BACKGROUND MATERIALS
SUPPORTING THE WORKSHOP
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TOPICS
Response areas
Organization and content of the PAG Manual
and its major support documents
Exposure pathways
Incident phases
2-1
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PLUME TRAVEL
DIRECTION
2. AR6A FROM WHICH POPULATION IS
RELOCATED (RESTRKTTEO ZONE*.
2-2
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CONTENTS OF THE PAG MANUAL
CHAPTERS SUBJECTS
I Background information
2, 3, & 4 PAGs for plume, ingestion, and
relocation
5, 6, & 7 Implementation guidance for the
3 PAG categories
8 Reserved for recovery guidance
2-3
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CONTENTS OF THE PAG MANUAL
(cont'd)
APPENDICES SUBJECTS
A Definitions of terms
B Risk of health effects from radiation
C Rationale for selecting the early phase
PAG values
D Rationale for food PAGs
E Rationale for Relocation PAGs
2-4
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DOSES N EXCESS OF THE L M TS
FOR EMERGENCY WORKERS
Old limits of 75 and 100 rem present unacceptably high
risk for assignment.
No limit is needed for persons who volunteer for
higher doses if:
- they are fully aware of the risks involved, and
- they are lifesaving or preventing dose to a large
population.
Chart of risks is provided (see page 2-12).
3-19
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BAS S FOR EMERGENCY WORKER
DOSE L M TS
(cont'd)
25 rem limit is justified for:
- life saving
- preventing substantial risks to populations
ICRP-26 recognizes 25 rem as a lifetime limit for
specially justified circumstances.
Acute effects to adults will be avoided.
3-18
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BAS S FOR EMERGENCY WORKER
DOSE L M TS
(cont'd)
10 rem limit for protecting valuable property
- Some emergency situations justify dose limits higher
than 5 rem.
- ICRP-26 recognizes 10 rem as an annual limit for
any single event for workers.
Higher limits are conditional.
3-17
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BAS S FOR EMERGENCY WORKER DOSE L M TS
(pp. C-22 to 24)
5 rem limit unless higher limit is justified
- Occupational guidance should normally govern.
- Limit emergency workers to nonpregnant adults.
- Occupational limits for organs, extremities and lens of
the eye should also apply.
3-16
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MAJOR CONCLUSIONS LEADING TO
THE SELECTION OF I REM AS
THE PAG FOR EVACUATION
(p.C-19)
If sheltering is implemented to 0.5 rem at centerline,
and evacuation to I rem, the avoided dose from
evacuation will be about 0.5 rem.
Therefore, the PAG recommended for evacuation is
I rem.
3-15
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MAJOR CONCLUSIONS LEADING TO THE
SELECTION OF THE PAG FOR EVACUATION
(PP.C-I8&C-I9)
0.5 rem is the selected dose to be avoided.
- This satisfies Principles I and 2.
- Cost of going lower is not justified. (Principle 3)
Net reduction in average risk will occur
(Principle 4).
- Meets acceptable risk to the fetus established for
occupational exposure.
3-14
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AVERAGE VERSUS CENTERLINE DOSE
(p. C-12)
Centerline
Dose (rem)
0.5 to 1
1 to 2
2 to 5
5 to 10
Average Dose Avoided by
Stability Class (mrem per individual)
A
340
670
C
190
380
870
F
70
150
330
750
3-13
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CALCULATION OF RADIATION RISK
VERSUS EVACUATION RISK
(p. C-10)
Estimated risk of death from transportation
= 9E-8/person mile.
Assume 100 mile round trip for evacuation.
Estimated risk of death from radiation
= 3E-4/person rem.
Calculate the equivalent risk (rem/100 miles).
3-12
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UPPER BOUNDS ON DOSE FOR EVACUATION
BASED ON COST OF AVOIDING FATALITIES
(p. C-11 and E-2)
Accident
Category
SST- 1 b
SST-2
Atmospheric
Stability Class
A
C
F
A
C
F
Dose Upper Bounds4
Maximum (rem)
5
5
10
1
3.5
10
Minimum (rem)
0.4
0.4
0.8
0.15
0,25
07
a Based on an assumed range of $400,000 to $7,000,000 per life saved.
b SST means Siting Source Term. See page E-2 of PAG Manual.
3-11
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AVERAGE RISK OF DELAYED HEALTH EFFECTS
IN THE U.S. POPULATION
(pp. B-19 to 25)
Health Effect
Fatal cancers
Nonfatal cancers
Genetic disorders
(all generations)
Effects per Person-rem
Whole
Body
2.8E-4a
2.4E-4
1 .OE-4
Thyroid
3:6E-5b
3.2E-4
Skin
3.0E-6
3.0E-4
a Risk to the fetus is estimated to be 5 to 10 times greater.
b Risk to young children is estimated to be about 1.7 times greater.
Their dose is also about 2 times greater.
3-10
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ACUTE HEALTH EFFECTS: CONCLUSIONS
(cont'd)
Dose Acute Health Effect
10 rad The dose level below which a fetus would not be
expected to suffer teratogenesis.
5 rad The approximate minimum level of detectability for
acute cellular effects using the most sensitive
methods.
3-9
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ACUTE HEALTH EFFECTS: CONCLUSIONS
(P-B-I7)
Dose Acute Health Effect
50 rad Less than 2 % of the exposed expected to
show forewarning symptoms.
25 rad Forewarning symptoms are not expected.
3-8
-------
Based on minimal
medical care
Intensive medical care may
increase the dose threshold
by :>0 percent,
100 100 300 400 BOO
WHOLE IODY ABSOKBIO 0081 (rid)
FIGURE B-1. ACUTE HEALTH EFFECTS AS A FUNCTION
OP WHOLE BODY DOSE.
3-
7
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RADIATION HEALTH EFFECTS
(Appendix B)
Acute (deterministic) health effects
Mental retardation
Radiogenic cancers
Thyroid disorders and cancers
Genetic disorders
3-6
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BASIS FOR SETTING PAG LEVELS
(p. 1-5)
PRINCIPLE STRATEGY
(I) Avoid acute health effects. Stay below threshold dose.
(2) Adequately protect against
cancer and genetic effects
under emergency conditions.
(3) Optimize cost of protective
action versus avoided dose.
(4) Regardless of the above
principles, the risk from a
protective action should not
itself exceed the risk from the
dos th t would be voided.
Set PAG at this level unless
driven down by cost/risk
considerations (3), or up by
risk/risk considerations (4).
Use this principle only if the
the PAG value is driven down.
Use this principle only if the
PAG value is driven up.
3-5
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SHELTERING CONSTRAINTS
(pp. 5-19 to 21 andC-l4to 16)
Sheltering provides only partial protection,
- Protection factor decreases with time.
- Ventilation rates vary.
- Protection varies with building type.
- Risk of shelter failure is significant.
3-4
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BASIS FOR PROTECTIVE ACTION
DECISIONS DURING THE EARLY PHASE
(p. 5-2)
Plant conditions and utility PARs
Dose projections
Field monitoring results
3-3
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PROTECTIVE ACTIONS
FOR THE EARLY PHASE
(P- 1-4)
Evacuation
Sheltering
Access control
KI administration
Control of surface contamination
3-2
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TOPICS
Protective action effectiveness
PAG Principles
Basis for PAG values and Emergency worker dose limits
3-1
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SESSION 3
RATIONALE FOR PAG VALUES
AND
EMERGENCY WORKER DOSE LIMITS
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INCIDENT PHASES
(pp. I -2 to I -4)
Three phases of a radiological incident
- Early
- Intermediate
- Late
In all phases, the PAGs are independent.
Refer to PAG Manual Page I -4.
2-8
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Airbbrm
Plume :»
2-7
i Innalation
y j**V*A
Gamma Rays
Resi
tn
;estion
*-*
Beta_
Particles
^*-5ss*
Deposited Paniculate Material
the Early Phase
-------
MAJOR SUPPORT DOCUMENTS (cont'd)
Evaluation of Skin and Ingestion Exposure Pathways
(EPA 520/1 -89-016)
Evacuation RisksAn Evaluation
(EPA-520/6/74-002)
An Analysis of Evacuation Options for Nuclear
Accidents (EPA 52071 -87-023)
Economic Criteria for Relocation
(EPA 520/1 -89-015)
2-6
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MAJOR SUPPORT DOCUMENTS
Externa Dose-Rate Conversion Factors for Ca cu ation
of Dose to the Public (DOE/EH 0070)
EPA Federal Guidance Report No. 11
(EPA 52071 -88-020)
EPA Federal Guidance Report No. 12
(EPA 402-R-93-081)
2-5
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SESSION 4
APPLICATION AND INTERPRETATION
OF
PROTECTIVE ACTION GUIDES
AND
EMERGENCY WORKER DOSE LIMITS
FOR
THE EARLY PHASE
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MAIN TOPICS
Definitions and interpretations
Special dose quantities and concepts
PAG values and their application
The use of Kl for emergency workers
The impact of the changes to the guidance
4-1
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APPLICABILITY OF PAGs
(p. 2-1 & 2-2)
PAGs apply to all nuclear incidents or accidents except
nuclear war.
Developed based on nuclear power plant accidents
Dose limits also apply to all
The implementation guidance applies primarily to nuclear
power plants.
4-2
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DEFINITIONS
(pp. I -2 & A-3)
Protective Action Guide (PAG):
The projected dose to individuals in the general
population that warrants protective action.
Projected Dose:
The calculated future dose that would be received by
individuals if no protective actions were taken.
4-3
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PAG INTERPRETATIONS
(pp. l-l,&l-7)
PAGs are:
Decision levels for public officials
Used to minimize risk from an event which is occurring
or has already occurred
4-4
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PAG INTERPRETATIONS
(pp. 2-1,4-1, 2-2, & I -6)
(cont'd)
PAGs are:
Mandatory for planning
- but, professional judgment is required for their
application
Independent of the type or magnitude of the release
4-5
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PAG NTERPRETAT ONS
(pp. -6, &2-2)
(cont'd)
PAGs are:
A supplement to design safety of nuclear facilities
Designed to protect all individuals in the population
4-6
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PAG INTERPRETATIONS
(pp. 1-6, 2-1, 2-4, & 2-10)
(cont'd)
PAGs are not:
The basis for the size of the EPZ
Dose limits
Additive to other doses
4-7
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PAG INTERPRETATIONS
(pp. I -7, & 2-1)
(cont'd)
PAGs do not:
Imply an acceptable level of dose for nonemergency
situations.
Represent the boundary between safe and unsafe
conditions.
Supersede Federal Radiation Council (FRC) Guidance,
4-8
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PAG INTERPRETATIONS
(pp. A-2 & A-3)
(cont'd)
PAGs do not include:
Previous radiation doses.
Safety factors to account for uncertainties in dose
projection procedures.
4-9
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DOSE QUANTITIES USED
FOR EMERGENCY RESPONSE
(pp. B-1 & B-2)
Absorbed dose
Projected dose
Committed dose
4-10
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SPECIAL DOSE QUANTITIES
(p. B-1 & B-2)
Dose equivalent (DE)
- Organ dose
- Risk of cancer
Committed dose equivalent (CDE)
- 50 years
Effective dose equivalent (EDE)
Committed effective dose equivalent (CEDE)
4-11
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TOTAL EFFECTIVE DOSE EQUIVALENT (TEDE)
* TEDE (an NRC term) means the sum of the deep dose
equivalent from external gamma radiations (EDE) and
the committed effective dose equivalent (CEDE) from
internal exposures.
Plume PAGs are expressed as this sum.
"TEDE" is not used in the PAG Manual
EDE from external sources is the same as NRCs term
"deep dose equivalent"
4-12
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EARLY PHASE PAGs
(pp. 2 5 to 2 8 & C 20)
(cont'd)
Projected dose (rem) Action
I to 5 TEDE Evacuation (or, for some
5 to 25 CDE thyroid situations, sheltering)
50 to 250 DE skin should normally be initiated
at the lower end of the range.
25 CDE thyroid Administer stable iodine (Kl)
from radioiodine to the public in accordance with
State medical procedures.
4-13
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OTHER EARLY PHASE GUIDANCE
NOT PAGS
(pp. 2-4 to 2-9)
Projected dose (rem) Action
<0.1 TEDE No action based on risk
<0.5 CDE thyroid from radiation dose.
<5 DE skin
0.1 to < I TEDE Sheltering should be
0.5 to <5 CDE thyroid considered, but this is not a
5 to <50 DE skin PAG for sheltering.
4-14
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DIFFERENCES IN
EMERGENCY WORKER LIMITS
AND PROTECTIVE ACTION GUIDES
Difference in justification
Difference in time period of exposure
Limits vs threshold for decisions
4-15
-------
EMERGENCY WORKER PROTECTION
(pp. 2-9 to 13 and C-22 to 24)
Period of application of emergency worker limits
Emergency worker dose and occupational dose are not
additive unless required by license.
No guidance for keeping records of dose to emergency
workers
Protection of minors and fetuses
4-16
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EMERGENCY WORKER CATEGORIES
(p. C-22)
Designated by State and local authorities
Example categories:
- Law enforcement and traffic control officials
- Medical and public health personnel
- Environmental monitors
- Emergency vehicle operators
- Utility, industrial, and institutional emergency
workers
4-17
-------
PERSPECTIVES FOR
EMERGENCY WORKER LIMITS
(pp. C-22 to 24)
Apply the same dose limits as for occupationally
exposed workers wherever practicable.
Permit higher dose limits when required to prevent
substantial risks to populations or protect valuable
property.
Provide guidance for extreme emergencies.
- Volunteers fully informed of risks
4-18
-------
DOSE L M TS FOR EMERGENCY WORKERS (p. 2- 0)
DOSE
LIMIT
5 rem
10 rem
25 rem
ACTIVITY
all
protecting valuable
property
life saving or protecting
large populations
>25 rem life saving or protecting
large populations
CONDITION
lower dose not
practical
lower dose not
practical
only on a voluntary
basis to persons
fully aware of the
risks.
4-19
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Kl FOR EMERGENCY WORKERS
(pp. 2-11 and 2-13)
Kl is recommended if atmospheric releases include radioiodine
(no dose threshold).
State medical procedures determine its availability and proper
use.
4-20
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SESSION 5
INTRODUCTION TO DOSE PROJECTION
FOR
PROTECTION OF THE PUBLIC
AND
EMERGENCY WORKERS
-------
GENERAL APPROACH
TO DOSE PROJECTION
Determine or estimate source term (Q) and
projected release duration (Tp).
Use atmospheric dispersion model to calculate time
integrated air concentration (Xin).
Use dose models to calculate projected dose (D) by
means of dose conversion factors (DCF).
5-1
-------
GENERAL APPROACH FOR CALCULATING
PROJECTED DOSE
Measure or calculate environmental
concentrations.
Multiply by duration of exposure to get time
integrated concentration (Xin) for each
nuclide or group of nuclides.
Multiply each Xin by the appropriate DCF to
get TEDE or thyroid dose from each nuclide
or group of nuclides.
Sum TEDEs over all nuclides or groups of
nuclides and su thyroid doses to get
projected doses co parable to PAGs.
Concentrations may be for indivi-
dual nuclides or may be grouped
by iodines and noble gases.
True Xh can be calculated if the
total release is used. Not used with
measured concentrations.
Use DCFs from PAG Manual
Table 5.1 for TEDE and 5.2 dose
for CDE to thyroid from single
nuclides. For groups of nuclides,
DCFs must be calculated. A DCF
for participates, as a group, is not
practical.
5-2
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NEEDED SOURCE TERM INFORMATION
Gross noble gas, radioiodine, and participate release
rates
or
curies per second of each radionuclide
Release height (release point information)
Estimated release duration
5-3
-------
NEEDED METEOROLOGY
Wind speed,
Wind direction
Stability Classes
Mixing depth
Predicted changes
Precipitation
5-4
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GAUSSIAN DISPERS ON EQUAT ON
Xu
2a
n a a
y
For a ground level release, release height (h) = 0,
At the centerline, the lateral distance (y) = 0.
Xu 1
n a a
y
5-5
-------
BASIC DOSE EQUATION
Th b sic dose equ tion is:
D = Xin - DCF
D = Dose (rem)
Xln = Time integrated concentration in air
(uCi cm"3 h)
h = duration of exposure (hours)
DCF = Dose conversion factor
(r m p r uCi cm"3 h)
5-6
-------
NEEDED INFORMATION FOR
DOSE CALCULATIONS
Radionuclide air concentration (X)
Expected duration of exposure (Tp)
Dose conversion factors (DCF)
Dose projection procedures
- computer programs
- RASCAL
5-7
-------
INFORMATION NEEDED TO SUPPORT
PROTECTIVE ACTION DECISIONS
Total effective dose equivalent (TEDE).
Committed thyroid dose (CDE).
Measurements of plume gamma rate.
Measurements of gross radioiodine concentrations.
5-8
-------
TIME INTEGRATED
AIR CONCENTRATION, Xin
Air concentration times projected exposure time,
X(uCi/cm3) Tp(hour) = Xin
Permits addition of the dose conversion factors over
the three exposure pathways.
5-9
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TIME INTEGRATED
AIR CONCENTRATION, Xin
(cont'd)
High concentration for short time
Low concentration for long time.
Symbol: Xjn
Matches units of EPA's dose conversion factors.
5-10
-------
TIME INTEGRATED
AIR CONCENTRATION, Xin
(cont'd)
PROBLEM ONE
Xe-133 air concentration is I.OE-4 uCi/cm3,
Expected duration of air concentration is 2 hours.
Xin equals ?????? (uCi cm'3 h).
5-11
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T ME INTEGRATED
A R CONCENTRAT ON, Xin
(cont'd)
PROBLEM TWO
Xe-133 air concentration is 5.0E-5 uCi/cm3.
Expected duration of this air concentration is 240
minutes.
Xin equals ?????? (uCi cm'3 h).
5-12
-------
TIME INTEGRATED
AIR CONCENTRATION, Xjn
(cont'd)
SOLUTIONS TO PROBLEMS I AND 2
Xin = (air concentration) (expected exposure time)
Xin = (I .OE-04 uCi/cm3) (2 h)
= 2.0E-04 uCi cm'3 h
Xin = (5.0E-05 uCi/cm3) (240m/60m/h)
= 2.0E-04 uCi cm'3 h
5-13
-------
DCF DEFINITION
(p. A-1)
Dose Conversion Factors (DCF) change
environmental concentrations (or time integrated
concentrations) to dose.
Dose units (rad = rem)
EPA DCF unit: rem per uCi cm h
5-14
-------
PARAMETERS THAT AFFECT DCFs
Physical characteristics
Chemical characteristics
Breathing rates
Assumed deposition velocities
Biological system clearances
5-15
-------
ASSUMED VALUES FOR CALCULATIONS
Breathing rate = 1.2 m3/h
Deposition velocity EPA RASCAL
- Iodine I cm/s 0.3 cm/s
- Participates 0.1 cm/s 0.3 cm/s
Gamma shielding factor due to ground roughness
EPA = I RASCAL default = 0.7
Public exposure to deposited materials before
relocation is 4 days (96 h)
5-16
-------
DOSE CONVERSION FACTOR TABLES
(TABLE 5-1 AND TABLE 5-2)
Table 5-1: Dose Conversion Factors and Derived
Response Levels for Combined Exposure Pathways
During the Early Phase of a Nuclear Incident.
Table 5-2: Dose Conversion Factors and Derived
Response Levels - Inhalation of Radioiodine.
Refer to EPA Manual
5-17
-------
SKIN DOSE
DCFs for skin are not provided for early phase.
Skin dose is not expected to be controlling.
Skin dose is controlled by bathing and changing
clothing.
5-18
-------
USING DCFs FOR COMBINED PATHWAYS
(TABLE 5-1)
GIVEN:
- The concentration of tritium (H-3) in a plume is
5E-3 Ci/m3.
Exposure to plume expected for 3 hours.
PROBLEM:
- What is the time integrated air concentration?
- What is the dose conversion factor?
- What is the projected dose?
- What kind of dose is it?
5-19
-------
US NG DCFs FOR COMB NED PATHWAYS
(TABLE 5- )
(cont'd)
SOLUTION: Calculate Xjn and look up the DCF.
Xjn = (air concentration) (expected exposure time)
= (5E-3 uCi/cm3) (3 hours)
Xin= l.5E-02uCi-cm-3-h
DCF for tritium from Table 5-1 is
7.7E+01 rem per uCi cm"3 h
5-20
-------
USING DCFs FOR COMBINED PATHWAYS
(TABLE 5-1)
(cont'd)
Projected dose = Xin times DCF
or
(I.5E-2 uCi cm"3 h)(7.7E+l rem per uCi cm"3 h)
Projected dose = 1.2 rem
This projected dose is considered to be total effective
dose equivalent (TEDE). Why?
5-21
-------
US NG DCFs FOR COMB NED PATHWAYS
(TABLE 5- )
(cont'd)
THE PROJECTED DOSE IS THE TEDE BECAUSE:
DCF is based on committed effective dose equivalents.
All significant early phase exposure pathways are
included.
All significant radionuclides are included.
5-22
-------
SUMMARY
n
D = S DCF X
i in, i
= DCF for radionuclide (i)
n = Number of radionuclides present
Xin,i = The time integrated concentration of
radionuclide (i)
5-23
-------
SESSION 6
IMPLEMENTATION OF
EMERGENCY WORKER DOSE LIMITS
-------
MAIN TOPICS
Emergency workers
Relative importance of exposure pathways
Inhalation dose control methods
PAG Subcommittee guidance
Dose for the record
6-1
-------
EMERGENCY WORKERS
(P- 2-9)
State responsibility for defining emergency workers
Example assignments
- Law enforcement/traffic control
- Radiation protection
- Transportation services
6-2
-------
EXPOSURE PATHWAYS FOR
EMERGENCY WORKERS
External gamma radiation
Plume
- Groundshine
Inhalation from the plume and resuspended materials
- Plume inhalation may be the major pathway
External beta radiation
- Plume
- Groundshine
Deposited materials on skin and clothing
6-3
-------
NHALAT ON OF RESUSPENDED MATER AL
R susp sion rat s
- Empirical values range from I0~5 to IO"9 m"1
Importance of pathway
Plume phase
- Post plume phase
- For example, at IO"5 m"1, I mR/h yields about 0.05 mrem
CEDE from inhalation
6-4
-------
EXAMPLE DOSES FROM A REACTOR ACCIDENT
RTM-93 CASE 5; Gap release for one hour; Late release @ 100 % par
No Spray; No protective action; o rain; Met cond. was not
1,000
100
Rem Versus Distance
Thvroid Dose
1
2 5
Dist oe (mil )
10
6-5
-------
EXA RLE DOSES FRO A REACTOR ACCIDENT
RT -93 CASE 16, Severe core damage; 100% per hour leak rate;
No spray; o ra'n; No protective action; et Cond. was not Spec fed.
100,000
10,000
Or 1,000
too
Rem Versus Distance
-~ Thyroid Dose
1
2 5
Distanc (mile )
10
6-6
-------
INHALATION DOSE CONTROL
USING RESPIRATORS
Mentioned, but not promoted by EPA or FEMA
Effectiveness
- Filter type
- Air supplied type
Advantages
- Protects workers from inhalation dose.
- Dose control by dosimeter is simple.
6-7
-------
NHALATION DOSE CONTROL
US NG RESP RATORS
(cont'd)
Disadvantages
- OSHA requirements
Fitting and testing
Training
Medical examinations
- No beards
- Reduced vision, communication, and efficiency
- Discomfort
- Logistics
6-8
-------
PAG SUBCOMMITTEE GUIDANCE
DATED JULY 1994
ISSUE: How should the dose to emergency workers,
especially those exposed to a radioactive plume,
be monitored and controlled to meet the EPA
dose limits in terms of total effective dose
equivalent (TEDE)
Guidance:
- Relates to accidents at nuclear power plants
- Based on current practices
- Other approaches may be acceptable
6-9
-------
PAG SUBCOMMITTEE GUIDANCE
(CONTINUED)
Maintain 5 rem TEDE limit where practicable.
The primary activities for emergency workers within an
airborne plume will be:
- Protection of valuable property,
- Protection of large populations, and
- Monitoring.
States should maintain flexibility in dose limits
6-10
-------
PAG SUBCOMMITTEE GUIDANCE
(cont'd)
Doses up to 10 and 25 rem (and above) should be
accepted and planned for.
DRDs may be used to estimate inhalation dose.
Use of Kl is recommended.
Flexibility in control procedures is granted.
Three acceptable options are presented.
6-11
-------
OPTIONS FOR ADJUSTING EMERGENCY WORKER
GAMMA DOSE LIMITS TO ACCOUNT
FOR SIGNIFICANT PARTICULATE RELEASES
Options1
Evacuation Phase
Post-Evacuation Phase
I
No adjustments
Adjust, if necessary
Fixed admin, limit
set prior to Emrg.
Adjust, if necessary
Contextual
adjustment based
on plant data
Contextual adjustment
based on plant and
environmental data
lOth r options may be co sid r d
6-12
-------
OPTION ONE
Control only whole body gamma and thyroid dose
during evacuation.
Rationale
Not practical to rotate workers
Inhalation dose is controlled for tasks after evacuation,
Evacuation may be completed before plume arrives,
Disadvantages
Higher risk of over-exposure compared to other
options
6-13
-------
OPTION TWO
Pre-established administrative limits
Rationale
- Easy to implement
- Will meet limits for most probable accidents
Disadvantages
- May not provide adequate control for the most
severe accidents
- Possible discontinuity between States
6-14
-------
DOSIMETER ADJUSTMENT FACTORS
Accid nt
Category
BWR-I
PWR-I
BWR-3
PWR-3
PWR-5
PWR-7
Adjustme t Factors3
With Kl
13 to 29
8 to 16
3 to 7
4 to 8
1.4 to 2
1 to 2
Without Kl
16 to 37
1 1 to 26
5 to 12
6 to 14
3 to 6
1 to 2
a Calculated for distances ranging from I to 25 miles, stability classes ranging
from A to F, and for 13 hours of exposure.
6-15
-------
OPTION THREE
Calculate contextual mission limits applicable to the
accident in progress.
Rationale
- Can use same data as for dose projection
- Mission limits would be more defendable.
Disadvantages
- Variable limits may be confusing to implement.
- Necessary data may not be available.
6-16
-------
RETROSPECTIVE EVALUATION OF DOSE
FOR THE RECORD
Applicable to emergency workers who are exposed to
an airborne plume containing iodines and/or participate
materials
Kl administration affects the evaluation.
6-17
-------
RETROSPECTIVE EVALUATION OF DOSE
FOR THE RECORD
(cont'd)
Based on dosimeter readings (primarily TLD) and
- Release composition
- Environmental data (importance of air samples)
Or based on dosimeter readings and
- Release composition
- Whole body counts
- Bioassay
6-18
-------
RETROSPECTIVE ANALYSIS USING
RELEASE AND ENVIRONMENTAL DATA
Need measured dose rates and air sample data.
Dose rate measurements by air sampling teams relate
air concentrations to dosimeter readings.
Calculations of ratio of exposure rate to air
concentration allows worker dosimeter readings to be
related to TEDE - becomes official record.
6-19
-------
RETROSPECTIVE - PROBLEM
Monitoring data at location A:
GM counter (closed beta shield, I m) - 950 mR/h
GM counter (open beta shield, I m - open window pointing up) - significantly higher
Air sample is collected at location A and sent to the laboratory for analysis. The laboratory reports
the following results:
Ce-!4l I.Oe-05 uCi/cm3
Ba-140 I.Oe-04 uCi/cm3
Cs-134 I.Oe-05 uCi/cm3
WHAT CONCLUSIONS CAN BE REACHED IMMEDIATELY FOR LOCATION A?
WHAT ARE THE FOLLOWING FROM A I HR EXPOSURE?
IMMERSION PLUS DEPOSITION DOSE (EDE)?
INHALATION DOSE (CEDE)? (See WORK SHEET on VG 6-22.)
TOTAL DOSE (TEDE)?
WHAT IS THE DOSE TO EMERGENCY WORKERS EXPRESSED AS TEDE PER ROENTGEN AS
READ ON A DOSIMETER?
6-20
-------
RETROSPECT VE - PROBLEM SOLUT ON
Immediate conclusions:
There had been a release of radioactive material .
The plume was present.
Particulates were present.
Actual risk could be much higher than implied by dosimeter readings.
Compare DCFs from plume shine versus ground shine for Cs-l 34. (The DCF for deposited
materials assumes persons remain 96 hours (4 days) at this location - correct for this).
The deposition dose is not significant because the I hr DCF is small compared to the
immersion DCF.
Assuming "mR" is approximately equal to "mrem", the whole body dose rate from gamma radiations
(EDE/h) is:
950 mrem/h
Gamma dose (EDE) due to a I hour external exposure to the plume and groundshine
950 mrem/h I h = 950 mrem = 0.95 rem
6-21
-------
PROBLEM SOLUTION WORK SHEET
Problem Emergency worker Projected Dose at Location A from inhalation
Nuctide(s)
Ce-141
Ba-140
Cs-134
Air
Concentration
(X)
(uCi/cm3)
I.OE-05
I.OE-04
I.OE-05
Projected
Exposure
Time
(h)
Integrated
Air
Concentration
(XJ
(uCi cm "3 h)
DCF from
Table 5-4
(rem per
uCi cm"3 h)
Totals >
Inhalation
Committed
Effective Dose
Equivalent
(CEDE)
(rem)
6-22
-------
PROBLEM SOLUTION
(cont'd)
Total projected dose (TEDE) to worker for nominal I hour exposure to plume:
0.95 rem (EDE) + 1.12 rem (CEDE) -I- 0.00 (EDE) =
2.07 rem (TEDE)
Nominal expected increase in dosimeter reading after I hour is:
0.95 rem (EDE) due to gamma from the plume +
approximately 0.00 rem (EDE) due to gamma from ground shine
total is 0.95 "R" recorded on dosimeter
0.95 "R" Dosimeter reading is equatable to a total dose for the record:
2.07 rem (TEDE)
Retrospective dose for the nominal worker record:
ach 1.0 "R" on dosimeter is quivalent to 2.2 rem (TEDE)
6-23
-------
FACTORS THAT MAY
AFFECT DOSE CALCULATIONS
Insufficient air sample and exposure rate data
Ground shine becomes important.
Emergency workers get significant doses outside the
plume.
Emergency workers do not take Kl.
Emergency workers use respirators.
6-24
-------
PLAN CHANGES NEEDED
TO SUPPORT OPTIONS I OR 2
Specify the administrative dose limits for evacuation
support.
Specify procedures for dose control after evacuation is
complete.
6-25
-------
PLAN CHANGES NEEDED
TO SUPPORT OPTION 3
Specify procedures for contextual determination of
administrative dose limits.
- Calculation models to be used
- Data needs
- Sources of data
Identify communication procedures and equipment.
Procedures for changing the administrative limits if
applicable
6-26
-------
GU DANCE APPLICABLE TO ALL OPT ONS
Other options may be se ected.
- FEMA will review written proposals.
FEMA recommends admin, limits of 2 R or more.
Need procedures for:
Retrospective dose determinations
- Training
Existing dosimetry systems are acceptable.
Kl use is recommended.
6-27
-------
SESSION 7
DEVELOPMENT
OF
DCFs AND DRLs
-------
IMPLEMENTATION OF PAGS
Must compare a projected TEDE or CDE to the
applicable PAG
BASIC DOSE EQUATION
- Dose (TEDE or CDE) = Dose Rate x Time
- Dose Rate = Concentration x Conversion
Factor
- Dose = Time Integrated Concentration x DCF
7-1
-------
DEFINITIONS
Dose Conversion Factor (DCF): A value that
converts an environmental level to dose.
-3
- Tabulated in units of: rem per uCi cm h
Derived Response Level (DRL): Calculated
environmental level that corresponds to a particular
PAG.
- Tabulated in units of: uCi cm"3 h
7-2
-------
PATHWAYS
(PAG Manual - Section 5.6)
Three exposure pathways are included:
- Gammas from the plume (immersion)
- Inhalation from plume
- Gammas from ground shine (deposited
radionuclides)
Pathways considered, but not included:
- Beta due to skin deposition
- Inhalation of resuspended materials
- Beta from the plume
7-3
-------
SUPPORTING DOCUMENTS FOR DCFS
"External Dose-Rate Conversion Factors for
Calculation of Dose to the Public" (DOE/EH 0070)
- Needed for plume and ground shine
"
Limiting Values of Radionuclide Intake and Air
Concentration and, Dose Conversion Factors for
Inhalation, Submersion and Ingestion" (FGR-I I)
EPA 520/1-88-020 (September 1988).
- Needed only to modify EPA DCFs for inhalation
7-4
-------
TIME INTEGRATED
AIR CONCENTRATION, Xin
Air concentration times projected exposure time,
X(uCi/cm3) Tp(hour) = Xin
Permits addition of the dose conversion factors
over the three exposure pathways.
7-5
-------
EXTERNAL EXPOSURE TO GAMMA RADIATION
FROM THE PLUME
(Section 5.6.1)
Table 5-3 (PAG manual, beginning on P. 5-25)
Gamma radiation due to immersion.
Conservative if plume is overhead.
Semi-infinite source assumption.
7-6
-------
EXTERNAL EXPOSURE TO GAMMA RADIATION
FROM THE PLUME
(cont'd)
DCFs yield effective dose equivalent (EDE).
Based on DOE/EH-0070; EPA FGR # 12.
Short-lived daughters are accounted for.
7-7
-------
Table 5-3: Dose Conver ion Factor (DCF) and Derived Re ponse
Leve s (DRL) for Externa Exposure Due to mmer ion in
Contaminated Air
Radionuclide
DCF
rem per
uCi cm h
DRL
uCi
cm
-3
H-3
C-14
Na-22
Na-24
P-32
O.OE+00
O.OE+00
I.3E+03
2.7E+03
O.OE+00
PAG M nu I - beginning on p g 5-25
O.OE+00
O.OE+00
7.8E-04
3.7E-04
O.OE+00
7-8
-------
INHALATION FROM THE PLUME
(Section 562)
Table 5-4 (PAG manual, beginning on 5-31)
Inhalation of radioactive participate material
Alpha, beta and gamma emitters
Chemical and physical form that yields the highest
dose
7-9
-------
INHALATION FROM THE PLUME
(Section 5.6.2)
(cont'd)
Committed effective dose equivalent (CEDE)
Radionuclides may remain in the body,
50 year time frame for dose
Federal Guidance Report No. 11
Standard Person
7-10
-------
Table 5-4: Dose Conversion Factors (DCF) and Derived Response levels
(DRL) for Doses Due to Inhalation
Lung DCF DRL
Radionuclide Class rem per uCi cm"3 h
uCi cm"3 h
H-3 V 7.7E+OI I.3E-02
C-14 LORGC3 2.5E+03 4.0E-04
Na-22 D 9.2E+03 I.IE-04
Na-24 D I.5E+03 6.9E-04
P-32 W I.9E+04 5.4E-05
aL ORG C denotes labelled organic compounds
PAG Manu I - b ginning on pag 5-31
7-11
-------
Table 5-4: Dose Convers'on Factors (DCF) and Derived Response levels
(DRL) for Doses to the Thyro'd Due to Inhalat'on
Lung DCF DRL
Radionuclide Class rem per uCi cm"3 h
uCi cm"3 h
Te/l-132 W/D 2.9E+05 I.8E-05
1-125 D 9.6E+05 5.2E-06
1-129 D 6.9E+06 7.2E-07
1-131 D I.3E+06 3.9E-06
PAG Manual - beginning on page 5-35
Also see Table 5-2 on page 5-15
7-12
-------
EXTERNAL DOSE FROM DEPOSITED MATERIALS
(Section 5.6.3)
Table 5-5 (PAG manual, beginning on 5-37)
Gamma radiation following deposition
Radioiodine and particulates from a plume
Assumes 4-day exposure
Dry deposition
7-13
-------
EXTERNAL DOSE FROM DEPOSITED MATERIALS
(cont'd)
Deposition velocity
- 0.1 cm/s for participate materials
- I cm/s for radioiodine
- Much higher if there is rain
7-14
-------
EXTERNAL DOSE FROM DEPOSITED
MATERIALS
(cont'd)
DCF for deposited materials is the effective dose
equivalent (EDE) in rem per:
- I uCi/cm3 concentration of a radionuclide
- I hour of deposition
- 96 hours of exposure to decaying radionuclides
7-15
-------
TABLE 5-5: DCF EQUATION
FOR GROUND SHINE
(pp. 5-34 and 5-37)
DCF = V DRCF
g
1.14E-3
1-e
-xt
DCF = the dose per unit air concentration
(rem per uCi cm"3 h)
7-16
-------
TABLE 5-5: DCF EQUATION
(cont'd)
Vg = deposition velocity (cm/h)
DRCF = the dose rate conversion factor from
DOE/EH 0070 (mrem/y per uCi/m2)
I. I4E-3 = conversion factor from mrem/y per uCi/m2
to rem/h per uCi/cm2
A = decay constant (h"1)
t = duration (h), assumed to be 96 hours
7-17
-------
Table 5-5: Dose Conversion Factors (DCF) and Derived Response levels
(DRL) for a 4-Day Exposure to Gamma Radiation from
Deposited Radionuclides
DCF DRL
Radionuclide rem per uCi cm"3 h
uCi cm"3 h
H-3 O.OE+00
C-14 O.OE+00
Na-22 8.3E+03 I.2E-04
Na-24 3.IE+03 3.2E-04
P-32 O.OE+00
PAG Manual - beginning on page 5-37.
7-18
-------
MOD FY NG DOSE CONVERS ON FACTORS
Changes in physical characteristics
Changes in chemical characteristics
Changes in breathing rates
Changes in assumed deposition velocities
7-19
-------
COMBINED PATHWAYS
(PAG Manual, Table 5-1)
The DCF and DHL for each pathway is related to the
time integrated air concentration (Xjn). They may be
combined for a particular radionuclide
DoseTotal = DoseExt+ Doselnh + DoseGround Shine
Y -4- nrp Y
Ajn T L/V^li^k A;
+ DCFGS Xin
DoseTotal = Xin (DCF^ DCFinh + DCFGS)
= X- DCF,
"in fc-'^-'1 combined
7-20
-------
Table 5-1: Dose Conversion Factors (DCF) and Derived Response levels
(DRL) for Combined Exposure Pathways During the Early
Phase of a Nuclear Incident
DCF DRL
Radionuclide rem per uCi cm"3 h
uCi cm"3 h
H-3
C-14
Na-22
Na-24
P-32
7.7E+OI
2.5E+03
1 .9E+04
7.3E+03
1 .9E+04
I.3E-02
4.0E-04
5.3E-05
1 .4E-04
5.4E-05
PAG M nual - b ginning on p g 5-9.
7-21
-------
EXAMPLE OF COMBINED PATHWAYS
Nuclide selected
Pathway
External
Inhalation
Ground Shine
Table
5-3
5-4
5-5
Summation
DCF
(rem per uCi cm " 3 h)
xln
(uCi cm"3 h)
1
1
1
Dose
(rem)
1
Combined
5-1
1
7-22
-------
SESSION 8
DOSE PROJECTION PROBLEMS
FOR THE EARLY PHASE
-------
INTRODUCTION
Two student problems
Use of combined pathways DCFs
I a- 1 Thyroid dose at I mile
Ib-l TEDEat I mile
la-2 Thyroid dose at 2 miles
I b-2 TEDE at 2 miles
2. Use of separate pathway DCFs
8-1
-------
STEPS TO DETERMINE THE REQUESTED
PROJECTED DOSES
Determine diffusion coefficients (Xu/Q) at the distances
required.
Determine the wind speed in m/s (0).
Determine the source term in Ci/s (Q).
Solve for X.
8-2
-------
STEPS TO DETERMINE THE REQUESTED
PROJECTED DOSES
(cont'd)
Determine the projected exposure time (Tp).
Calculate the time integrated concentration (Xjn).
Select the specific DCF (rem per pCi cm"3 h).
Calculate the projected dose (rem).
8-3
-------
PROBLEM : PROJECTED DOSE
US NG COMB NED PATHWAY DCFs
Problem la: Determine the Committed Dose Equivalent
(CDE) to the thyroid from a plume containing
l-!3l,and
Problem I b: Determine the Total Effective Dose Equivalent
(TEDE) for a plume with a mix of three
isotopes (Xe-133, I-131, and Cs-134).
And: Determine the above doses at I mile and 2
miles from the release point
8-4
-------
PROBLEM I
Calculate at I mile
- Concentrations (X)
- Time Integrated Concentration (Xin)
- Dose (CDE to Thyroid and TEDE)
Use Worksheet (VG 8-6)
8-5
-------
RAD AT ON ACC DENT ASSESSMENT COURSE
WORK SHEET
Nuclide(s)
& Prblm.
# la-l
1-131
Nuclide
# Ib-l
Xe-133
1-131
Cs-134
Xu/Q
@ 1 mi
(m*2)
Q
(Ci/s)
0
(m/s)
X
@ 1 mi
(pCi/cm3)
\ r
Exp.
time
(h)
t ,
xin
(a) 1 mi
(jjCi cm'3* h)
...
DCF
Table
No.
DCF^
rem
jjCi cm"3- h
DCFcp
TOTAL -
Dose
(CDE)
(rem)
TEDE
(rem)
8-6
-------
PROBLEM I INITIAL CONDITIONS
Time from shutdown to release. 2 hours
Estimated release time: 3 hours
Release height: Ground level
Stability is class D.
Wind speed is 2 m/s (4.5 mph).
Forecast is for no change.
8-7
-------
I
m
Xu/Q AS A FUNCTION OF
DOWNWIND DISTANCE AND
STABILITY CLASS
Values of XQ/Q (m'2)
Di tance
(Mle )
0.5
1
2
3
4
5
7
10
15
Class
A
6.6E-6
1 .OE-6
5.5E-7
3.9E-7
3.0E-7
2.5E-7
1 .9E-7
1 .4E-7
9.9E-8
Class
B
3.0E-5
7.4E-6
I.9E-6
8.4E-7
4.8E-7
3.3E-7
2.5E-7
1 .8E-7
I.3E-7
Class
C
7.6E-5
2. 1 E-5
6. 1 E-6
2.9E-6
1 .7E-6
1 .2E-6
6.3 E-7
3.3E-7
1 .8E-7
Class
D
2. 1 E-4
7.0E-5
2.4E-5
I.3E-5
8.5E-6
6. 1 E-6
3.7E-6
2.3E-6
1 .2E-6
Class
E
4.2E-4
1 .4E-4
5.0E-5
2.8E-5
1 .9E-5
1 .4E-5
8.4E-6
5. 1 E-6
3.1 E-6
Class
F
9.6E-4
3.3E-4
1.2 -4
6.8E-5
4.6 -5
3.3 -5
2.2E-5
1 .4E-5
8.4E-6
A 1250 meter lid is used.
This ' a ground level release.
8-8
-------
PROBLEM I: SOURCE TERM
SOURCE TERM (Q):
- Xe-133 l,700Ci/s
- 1-131 0.17 Ci/s
- Cs-134 0.05 Ci/s
8-9
-------
PROBLEM I a-1
CALCULATE AIR CONCENTRATION (X)
At I mile and for I-131:
XQ/Q = 7.0E-05 (from VG 8-8)
WHERE:
X = air concentration (uCi/cm3)
U = average wind speed (m/s)
Q = source term (Ci/s)
SOLVE FOR X AT I MILE:
8-10
-------
PROBLEM I a-1: CALCULATE
INTEGRATED AIR CONCENTRATION (Xin)
FOR 1-131
Using values recorded on the Work Sheet
Solve for Xin:
Xin = X -1
8-11
-------
PROBLEM I a-1
COMMITTED DOSE EQUIVALENT (CDE)
TO THE THYROID
The committed dose equivalent (CDE) to the
thyroid is:
(Xin DCFth)
The dose model is:
^ = DCF, X. = DCFk
th th in th
Q
17
Xw
~Q
h
8-12
-------
PROBLEM I b-1: PROJECTED DOSE
Calculate the TEDE for three nuclides:
Xe-133,1-131, and Cs-134.
Assumptions: Same as for problem I a-1
Dose Model:
TEDE = DCF X
cp in
= DCF
cp
Q .
u
XJ
Q
h
8-13
-------
PROBLEM Ib-l
SOLVE FOR X AT I MILE
FOR THREE NUCLIDES
Model:
X =
Q
Q
u
Calculate concentrations (X)
Xe-133, Q
/-131, Q
C*-134, Q
I.IE+3
\.1E-1
5.QE-2
7.0£-5 =
Q = 2 m/s
8-14
-------
PROBLEM Ib-l
INTEGRATED AIR CONCENTRATION (Xln)
Using the results from VG 8-14
Solve for Xjn for the three nuclides.
Exposure duration = 3 hours
8-15
-------
PROBLEM la-2
SOLVE FOR (CDE) TO THE THYROID FROM
1-131 AT 2 MILES
L
th
^ X.
th in
Step I. Obtain XQ/Q for 2 mi = 2.4E-5. (VG 8-8)
Step 2.
2.5E-5 m'2 \.lE-\Cils
1 mis
8-16
-------
PROBLEM la-2
SOLVE FOR THE (CDE) TO THE THYROID FROM I-131 AT
2 MILES
Step 3. Xin = X h =
Step 4. Obtain DCFth. The Table is .__
The value is
Step 5. Dose = Xin DCF^ = _
Use the Worksheet on VG 8-18
8-17
-------
RAD AT ON ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem I a-2 & I b-2 : Projected Dose at 2 Mile(s): From thyroid & combined pathway
Nuclide(s)
& Prblm.
# la-2
1-131
Nuclides
# lb-2
Xe-133
1-131
Cs-134
Xu/Q
@2 mi
(m"2)
Q
(Ci/s)
Q
(m/s)
X
@_2j
(pCi/cm3)
Exp.
time
(h)
xin
@^mi
(\iC\ cm"3 h)
DCF
Table
No.
DCF^
rem
jjCi cm"3- h
DCFcp
TOTAL -
Dose
(CDE )
(rem)
TEDE
(rem)
8-18
-------
PROBLEM b-2: DOSE PROJECT ON
TEDE AT 2 M LES
Using the same assumptions for the three radionuclides,
calculate the TEDE at 2 miles.
- Exposure duration = 3 hours
- Stability class = D
- Wind speed = 2 m/s
CDEcp - DCFcp Xin = DCFcp - (Q/u XG/Q h)
8-19
-------
PROBLEM lb-2: FIND TEDE AT 2 MILES
FOR Xe-133,1-131, AND Cs-134
Step I
X, .
2mi
fi
Q
= 2AE-5
1.7E+3
1.7E-1
5.QE-2
* 2
Step 2- X-h = Xin (h = 3)
Step 3 - Xin DCFcp = TEDE
comes from Table
8-20
-------
PROBLEM 2: DOSE PROJECTION USING
SEPARATE PATHWAY DCFs
1 Assumptions:
- Time from shutdown to release: 2 hours
- Estimated release time: 3 hours
- Release height: Ground level
- Stability is class D
- Wind speed is 2 m/s (4.5 mph).
8-21
-------
PROBLEM 2: PROJECTED DOSE AS A FUNCTION OF
PATHWAY
Same source terms, meteorology, and exposure time as for
problem I.
Same integrated air concentrations.
Three separate exposure pathways.
8-22
-------
PROBLEM 2: PROJECTED DOSE AS A FUNCTION OF
PATHWAY (cont'd)
External dose (EDE) from the plume
(Table 5-3)
Plume inhalation dose (CEDE)
(Table 5-4)
External dose (EDE) from deposited radionuclides (Table 5-5)
8-23
-------
PROBLEM!: DOSE MODELS
Dose = DCF X = DCF
P p in p
Q.
u
Xu
Q
(Xu/Q Q/u) h = X h = Xin
For I-131: (2.4E-5) (IJE-1 )/2 = 2.0E-6 Ci/m:
2.0E-6 Ci/m3 3h = 6.0E-6 (jjCi cm'3 h)
Calculate Xin and dose for each nuclide.
Fill in matrixes (VG 8-25, 26, and 27).
h
8-24
-------
RADIOLOGICAL ACCIDENT ASSESSMENT COURSE
WORK SHEET
Problem 2a : Projected Dose at 2 Miie(s): From immersion pathway
Nuclide(s)
& Prblm.
#2a
Xe-133
1-131
Cs-134
XQ/Q
@ 2 mi
(m-2)
Q
(Ci/s)
u
(m/s)
X
@J,mi
(MCi/cm3)
Exp.
time
(h)
xin
@_2_mi
(pCi cm'3 h)
DCF
Table
No.
DCF^
rem
\iC\ - cm"3- h
TOTAL -
Dose
( }
(rem)
8-25
-------
RAD OLOG CAL ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem 2b : Projected Dose at 2 Mile(s): From inhalation pathway
Nuclide(s)
& Prblm.
#2b
Xe-133
1-131
Cs- 1 34
XO/Q
@2mi
(m-2)
Q
(0/3)
u
(mis)
X
@2 mi
(pCi/cm3)
Exp.
time
(h)
x,n
@ 2 mi
(jjCi cm'3 h)
DCF
Table
No.
DCFM
rem
pCi cm"3- h
TOTAL -
Dose
( )
(rem)
8-26
-------
RAD OLOG CAL ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem 2c : Projected Dose at 2 Mlle(s): From deposition pathway
Nuclide(s)
& Prblm.
#_Jc_
Xe-133
1-13!
Cs- 1 34
XQ/Q
@J_mi
(m-2)
Q
(Ci/s)
u
(mis)
X
(§U_mi
(MCi/cm3)
Exp.
time
(h)
xin
@2mi
(pCi cm"3- h)
DCF
Table
No.
DCF^
rem
|jCi cm"3- h
TOTAL -
Dose
< >
(rem)
8-27
-------
RADIOLOGICAL ACCIDENT ASSESSMENT COURSE
WORK SHEET
Problem # 2
The dose model is: Dose = DCF Xin = DCF (Q/u XQ/Q h)
DOSE PROJECTION AT 2 MILES FOR INDIVIDUAL PATHWAYS
Nuclide
1-131
Cs- 1 34
Xe-133
Pathway
immersion
inhalation
deposition
DCF
rem
(|jCi cm"1 h)
2.2E+2
3.9E+4
I.3E+4
xin
(pCi cm'3 h)
6.0E-6
6.0E-6
6.0E-6
Dose
(rem)
I.3E-3
2.4E-I
8.0E-2
TEDE for 1-13 1 3.2E-I
immersion
inhalation
deposition
9.IE+2
5.6E+4
6.2E+3
I.8E-6
I.8E-6
I.8E-6
I.7E-3
I.OE-1
I.IE-2
TEDE for Cs- 134 1.1 E-i
immersion
inhalation
deposition
20
0
0
6.0E-2
6.0E-2
6.0E-2
1.2
0
0
TEDE for Xe-133 1.2
TEDE for all rad ion ucl ides combined
1.5
-------
SESSION 9
PROTECTIVE ACTION GUIDES FOR
RELOCATION AND RETURN
AND
DOSE LIMITS FOR RECOVERY WORKERS
-------
THE "R" WORDS
(p. A-3)
Relocation: The removal or continued exclusion of
people (households) from contaminated areas to avoid
chronic radiation exposure.
Return: The reoccupation of areas cleared for
unrestricted residence or use.
Restricted zone: An area with controlled access from
which the population has been relocated.
9-1
-------
THE "R" WORDS
(p. A-3)
(cont'd)
Reentry: Temporary entry into a restricted zone
under controlled conditions.
Recovery: The process of reducing radiation exposure
rates and concentrations in the environment to
acceptable levels for unconditional occupancy or use.
9-2
-------
POTENTIAL TIME FRAME OF
RESPONSE TO A NUCLEAR INCIDENT
Refer to PAG Manual Page 7-5,
Times are estimates only.
Sequences may vary some.
9-3
-------
EXPOSURE PATHWAYS
(p. 4-2)
Pathways to be evaluated as basis for relocation
- Whole body exposure to gamma radiation
- Inhalation of resuspended materials
Minor pathways (no evaluation needed for reactor
accidents)
- Beta skin exposure
- Inadvertent ingestion of dirt
- Refer to EPA 520/1-89-016
9-4
-------
ESTIMATED DOSE FROM MINOR
EXPOSURE PATHWAYS
Individual3
adult
child
adult or child
Exposure
Pathway
skinb
ingestionc
skin"
ingestionc
groundshine
First Year Dose (rem)
Soil
2.4
0.01
8.1
0.05
1.0
Pavement
8.4
O.I
14
0.5
1.0
aMaximum exposed individuals. Average exposure is about 1/3 to 1/6 lower.
blncludes beta dose from nearby surfaces and from material on the skin.
clnadvertent ing stion of cont mi at d dirt.
9-5
-------
RELOCATION AND RETURN PAGS
(p. 4-4)
Projected Dose From
First Year Exposure
>2 rem TEDE
> 100 rem DE skin
<2 rem TEDE
< 100 rem DE
Protective Action
Establish restricted zone and
relocate the general
population.
Apply simple dose reduction
techniques to skin.
9-6
-------
RELOCATION AND RETURN PAGS
(p. 4-4, 4-5, E-I3,&E-20)
(cont'd)
Additional guidance
- 0.5 rem in any year after the first
- 5 rem in 50 years
Actual dose should be less than projected dose
Shielding
- Mobility
- Special dose reduction efforts
- Refer to tabl s on p ges E-13 and E-20
9-7
-------
ARBITRARY SCALE
PLUME TRAVEL
DIRECTION
LEGEND
1. PUIME DEPOSITKNI
2. AREA FROM WHICH POPULATION « EVACUATED.
3. AREA IN mtKM POPULATION IS 9NBL1BREO.
FROM WHICH LAtnON « RELOCATED (BCSTWCTED ZONE).
9-8
-------
GRADUAL RETURN
(p. 4-5 & 7-4)
Establishment of buffer zone
Gradual return
FEMA option to combine temporary relocation and gradual
return boundaries
- Advantage - no early dose calculations
Disadvantage - large relocation area
- major public disruption
9-9
-------
DOSE REDUCTION FOR RETURNEES
(p. 4-3)
Areas for priority
- Dose in excess of 0.5 rem in I st year
- Residences of pregnant women
Responsibility for actions
9-10
-------
EXAMPLES OF
S MPLE DOSE REDUCT ON TECHN QUES
(pp.4-3, 7-6, E-I3.&E-I9)
Scrub/flush/wipe hard surfaces.
Soak or plow soil.
Cut and remove grass clippings and other foliage.
Remove spots of soil where radioactivity has concentrated.
Disposal of contaminated materials
9-11
-------
SIMPLE DOSE REDUCTION TECHNIQUES
(pp. 4-3, 7-6, E-I3,&E-I9)
(cont'd)
Remove debris.
Spend more time in areas with lower contamination levels
(e.g., indoors).
Replace sandbox sand.
Pay special attention to child hygiene.
9-12
-------
RAT ONALE - FOUR PR NC PLES
Acute health effects
Delayed health effects
Cost of avoiding risk
Risk - risk comparison
9-13
-------
FACTORS NOT NGLUDED N
THE RELOCAT ON PAGs
Physical and mental stress
Past exposures
Dose from ingestion
Dose from occupational exposure
9-14
-------
COST ANALYSIS
(pp. E-8, E-9, & E-10)
Assumptions:
- Value of avoiding a statistical death is $400,000 to
$7,000,000.
- Average daily cost of relocation is $27 - Refer to EPA
520/1-89-015.
Where does the daily cost of relocation equal the
monetary value of average daily risk avoided?
9-15
-------
- 0.2
I I 10 II 10 II 3(
TIM! AfTIM ACCIOINT (tf«y*>
FIQU 6-3. COSt OF AVOIDING STATISTICAL FATALITIES AND
EXPOSURE RATES CORRESPONDING TO VARIOUS
TOTAL FIRST YEAR DOSES (ASSUMES AN SST-2
ACCIDENT AND A $27 PER PERSON-DAY COST OF
RELOCATION).
I-10
9-16
-------
PRINCIPLE
BASIS FOR SETTING PAG LEVELS
(p. I -5)
STRATEGY
(I) Avoid acute health effects.
(2) Adequately protect against
cancer and genetic effects
under emergency conditions.
(3) Optimize cost of protective
action versus avoided dose.
(4) Regardless of the above
principles, the risk from a
protective action should not
itself exceed the risk from the
dose that would be avoided.
Stay below threshold dose.
Set PAG at this level unless
driven down by cost/risk
considerations (3), or up by
risk/risk considerations (4).
Use this principle only if the
the PAG value is driven down.
Use this principle only if the
PAG value is driven up.
9-17
-------
CONCLUSIONS ON APPROPRIATE VALUE
FOR RELOCATION PAG
(p.E-18)
Principle on acute effects is not applicable.
judgment of acceptable level of risk of delayed health
effects:
- 5 rem in 50 years
- 0.5 rem in any single year after the first
2 rem in the first year will meet the above criteria for
nuclear power plant accidents.
9-18
-------
CONCLUSIONS ON APPROPRIATE VALUE
FOR RELOCATION PAG
(p. E-18)
(cont'd)
Cost will not drive the first year dose below 2 rem.
Risk from relocation is assumed to be the same as for
evacuation (i.e., equivalent to the risk from about 30
mrem).
9-19
-------
DOSE LIMITS FOR RECOVERY WORKERS
(pp.46, 7 17, &E 19)
Same as for occupationally exposed workers
- TEDE 5 rem/y
- CDE to any organ 50 rem/y
- One tenth these values to persons under
age 18
- TEDE to declared pregnant
women 0.5 rem/9mo
9-20
-------
SESSION 10
DATA COLLECTION AND DOSE PROJECTION
FOR
RELOCATION AND RETURN DECISIONS
-------
IMPLEMENTING PAGS FOR THE INTERMEDIATE
PHASE
Relocation
Reentry
Return
Early Decontamination
Ingestion of Food and Water
- Independent decision
10-1
-------
OVERV EW OF
MPLEMENTAT ON PROCESS
Collect environmental samples.
Analyze samples.
Calculate
- Exposure rates and projected dose.
- Accident specific DCFs.
- Derived response level.
Make gamma exposure rate measurements.
10-2
-------
OVERV EW OF
MPLEMENTAT ON PROCESS
(cont'd)
Take air samples and calculate projected dose from
inhalation of resuspended materials.
Identify the boundary of the restricted zone.
Relocate the population.
Identify the buffer zones.
Implement gradual return.
10-3
-------
SAMPLE COLLECT ON AND ANALYS S
Purpose of samp es
- Dose projection
- Evaluation of variation in mix by area
Nature of samples
Locations of samples
- Based on exposure rate
- Priorities
- Terrain
Types of analyses
10-4
-------
ALTERNATIVE METHODS
FOR DOSE PROJECTION
METHOD ONE - Sample from each area of interest
- Known size of area in each sample
- Use data from each sample analysis to project dose.
- Plot projected doses on map to identify location of
boundary to the restricted zone.
10-5
-------
ALTERNATIVE METHODS FOR
DOSE PROJECTION
(cont'd)
METHOD TWO - Take a few samples from several
areas.
Determine whether the radionuclide mix is reasonably
constant or predictable. If so:
- Calculate a time-dependent derived response level
corresponding to the PAG.
Use the DRL^ to identify the restricted zone.
10-6
-------
CONS DERAT ON OF METHOD ONE
Requires a arge number of
- samples
- laboratory analyses
- dose projections
May yield wrong result for other than flat terrain
Only method available if radionuclide mix is neither
constant nor predictable
10-7
-------
CONSIDERATION OF METHOD TWO
Not useful for an inconsistent mix of radionuclides.
Greatly reduces the sampling and laboratory effort.
Results are independent of terrain type or presence of
contaminated foliage.
Inaccuracies due to non-representative samples cancel.
10-8
-------
EXAMPLE CALCULATION OF EXPOSURE RATE
- Method One -
Radionuclide
Cs- 1 34
1-131
Concentration
pCi/m2
2E+7
3E+7
Initial exposure Rate @ 1 nrt
(mR/h per pCi/m2)
(table 7-1 or 7-2)
.
Total:
Exposure Rate @ 1 m
(mR/h)
10-9
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
Integrated Dose - Year One
Radionuclide
Cs-134
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
TOTAL
Projected
Dose
(mrem)
No Weathering
DCF
(mrem/pCi/m2)
(Table 7-2)
TOTAL
Projected
Dose
(mrem)
10-10
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
Integrated Dose - Year Two
Radionuclide
Cs- 1 34
1-131
Concentration(
pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
TOTAL
Projected
Dose
(mrem)
No Weathering
DCF
(mrem/pCi/m2)
. (Table 7-2)
TOTAL
Projected
Dose
(mrem)
.
10-11
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
Integrated Dose - Zero to 50 Years
Radionuclide
Cs-134
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
TOTAL
Projected
Dose
(mrem)
No Weathering
DCF
. (mrem/pCi/m2)
(Table 7-2)
TOTAL
Projected
Dose
(mrem)
10-12
-------
METHOD 2
Calculate an accident-specific dose conversion factor
(DCFJ.
- This factor is time dependent.
Use DCFas to calculate a time-dependent derived
response level (DRL^) in mR/h corresponding to the
PAG.
10-13
-------
CALCULAT ON OF ACCIDENT SPEC F C DCF
Method 2
mrem Per
~2» °r 0 to 50 yr
35
Exposure Rate @ I m (mRIti)
Assume weathering and results from VGs 9, 10, II,
and 12, and calculate:
- Year one DCF^ =
Year two DCF,C =
as
Zero to 50 year DCFas =
10-14
-------
CALCULATION OF ACCIDENT SPECIFIC DRL
Method 2
DRL
td
PAG
DCF
as
For the previous example (weathering included):
Year one DRLas =
Year two DRLas =
Zero to 50 year DRLas =
10-15
-------
DCF FOR PROJECTED EXTERNAL GAMMA DOSE
DCF = DSf t* * dt
0
63|l -e ~("" + * } 37(l -e
'*T « '
DCF = DSf
'1
= dose rate per unit deposit (mrem/yr per pCi/m2) (data in DOE EH 0070)
Sf = protection factor for shielding and partial occupancy (assumed to be unity)
AR = radioactive decay constant (yr"1)
A2 = assumed weathering decay constant for 63% of the radionuclide =1.13 yr '
A3 = assumed weathering decay constant for 37% of the radionuclide = 7.48E-3 yr"1
t = time of exposure (yr)
10-16
-------
CALCULATION OF DOSE FROM INHALATION
OF RESUSPENDED MATERIALS (CEDE)
(Table 7-4, p. 7-16)
Hso = I x DCF
WHERE:
Hso = CEDE for 50 y from intake of nuclides
I = total intake (pCi)
DCF = dose per unit intake for the radionuclide
(rem per pCi)
- Data are from EPA FGR No. I I
- Convert to appropriate units
10-17
-------
TOTAL INTAKE FROM INHALATION
OF RESUSPENDED MATERIAL
'-«
WHERE:
I = total intake in I year (pCi)
B = breathing rate, assumed to be I.05E+4 mVyr
C0 = initial air concentration of the resuspended radionuclide (pCi/m3)
AR = radioactive decay constant (yr'1)
A2 = assumed weathering decay constant for 63% of the radionuclide =1.13 yr"1
A3 = assumed weathering decay constant for 37% of the radionuclide = 7.48E-3 yr"1
t = time of exposure (yr)
10-18
-------
WEATHERING OF THE RESUSPENSION FACTOR
EPA assumes gamma weathering for resuspension.
Empirical data for alpha emitters shows much faster
reduction.
Refer to:
- WASH-1400 Appendix VI page E-13 for a time
dependent model.
- IAEA Safety Series 81,1986, page 62 for plot of the
resuspension factor as a function of time and of the
integral.
10-19
-------
CALCULATION OF INHALATION DOSE (CEDE)
FROM RESUSPENDED MATERIALS
Includes weathering? [ ] yes [ ] no
Sample
Radio-
Nuclide
Cs-134
1-131
location Analysis date
Air
Concentration
(pCi/m3)
1200
420
Yr. 1 DCF
(mrem per
pCi/m3)
TOTAL-
Dose From
Yr. 1 Exp.
(mrem)
Yr. 2 DCF
(mrem per
pCi/m3)
TOTAL-
Dose From
Yr. 2 Exp.
(mrem)
10-20
-------
SESS ON
DOSE PROJECTION PROBLEMS
FOR
RELOCATION AND RETURN DECISIONS
-------
PROBLEM I - A: DERIVATION OF AN
ACCIDENT-SPECIFIC DOSE
CONVERSION FACTOR (I)
-Method ONE-
GIVEN:
A surface soil sample is analyzed and is found to
contain the following concentrations (pCi / m2):
Zr-95 7.4 E+6 Cs-134 I2.0E+6
Ru-103 3.1 E+6 Cs-137 1.2 E+6
1-131 4.1 E+6 Ba-140 6.2 E+6
Radioactive decay and weathering will occur.
11-1
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFJ
For? [ x] Year 1 [ ] Year 2 [ ] 50 Years
t
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru- 1 03
1-131
Cs- 1 34
Cs- 1 37
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4E+06
3.IE+06
4. 1 E+06
1 .2E+07
1 .2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
PCi/m2)
TOTAL-
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
.
TOTAL-
Calculated
DOSE
(mrem)
Combined DCF,
mrem per mR/h
(date_
11-2
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ ] Year 1 [ X] Year 2 [ ] 50 Years
»
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs- 1 34
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4E+06
3.IE+06
4. 1 E+06
1.2E+07
I.2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
t
TOTAL-
Calculated
DOSE
(mrem)
Combin d DCF
as
mr m per mR/h
(dt
11-3
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ ] Year 1 [ ] Year 2 [ X] 50 Years
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru- 1 03
1-131
Cs- 1 34
Cs- 1 37
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4E+06
3.IE+06
4. 1 E+06
1 .2E+07
1 .2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Calculated
Exp, Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
f
TOTAL-
Calculated
DOSE
(mrem )
Combin d DCF
as
mr m p r mR/h
(dat
11-4
-------
PROBLEM I - B: DERIVATION OF AN
ACCIDENT-SPECIFIC DOSE
CONVERSION FACTOR (I)
- Method TWO -
GIVEN:
A surface soil sample is analyzed and is found to
contain the following activities (uCi / sample):
Zr-95 7.4 Cs-134 12
Ru-103 3.1 Cs-137 1.2
1-131 4.1 Ba-140 6.2
Radioactive decay and weathering will occur.
11-5
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFJ
For? [ x] Year 1 [ ] Year 2 [ ] 50 Years
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs- 1 34
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/sample)
7.4E+06
3. 1 E+06
4. 1 E+06
1 .2E+07
I.2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pG/m2)
TOTAL-*
Nominal
Calculated
Exp. Rate
(mR/h@lm)
Integrated
Dose
(mrem per
pCi/m2)
TOTAL-
Nominal
Calculated
DOSE
(mrem @ 1 m)
.
Combined DCF
as
mrem per mR/h
(date_
11-6
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ ] Year 1 [ X] Year 2 [ ] 50 Years
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs- 1 34
Cs- 1 37
Ba-140
Measured
Ground
Concentration
(pCi/sample)
7.4E+06
3. 1 E+06
4. 1 E+06
I.2E+07
I.2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
.
TOTAL-
Nominal
Calculated
DOSE
(mrem @ 1 m)
Combined DCF
as
mrem per mR/h
(date_
11-7
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ ] Year 1 [ ] Year 2 [ X] 50 Years
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs- 1 34
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/sample)
7.4E+06
3.IE+06
4.IE+06
1 .2E+07
I.2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
TOTAL-
Nominal
Calculated
DOSE
(mrem @ 1 m)
Combined DCF,
mrem per mR/h
(date_
11-8
-------
PROBLEM 2: DERIVED RESPONSE LEVELS
Using results from Problem I, calculate time-dependent
derived response levels (DRL^) corresponding to:
- year I
- year 2
- 50 years
Interpret the results.
11-9
-------
PROBLEM 3
PROJECTED DOSE
Field teams report the following exposure rates:
Location A 3 mR/h
LocationB 10 mR/h
Location C 30 mR/h
Assume the radionuclide mix from Problem I.
What is the projected dose from gamma radiation at each
location for each of the three time periods?
11-10
-------
V
SESSION 12
COURSE REVIEW AND WRAP-UP
Ritchey C. Lyman
Office of Radiation and Indoor Air
Phone (202) 564-9363
Fax: (202) 565-2037
lyman.ritchey@epa.gov
-------
CALCULATION OF INHALATION DOSE (CEDE)
FROM RESUSPENDED MATERIALS
Includes weathering? [ x ] yes [ ] no
Sample location A Analysis date
Radio-
Nuclide
Zr-95
Ru- 1 03
1-131
Cs- 1 34
Cs- 1 37
Ba-140
Air
Concentration
(pCi/m3)
760
320
420
1200
120
630
Yr. 1 DCF
(mrem per
pCi/m3)
TOTAL-
Dose From
Yr. 1 Exp.
(mrem)
Yr. 2 DCF
(mrem per
pCi/m3)
TOTAL-
Dose From
Yr. 2 Exp.
(mrem)
.
11-13
-------
- PROBLEM SOLUTIONS -
-------
PROBLEM SOLUTION
Problem Emergency worker : Projected Dose at Location A from inhalation
Nuclide(s)
Ce-I4l
Ba-140
Cs-134
Air
Concentration
(X)
(uCi/cm3)
I.OE-05
I.OE-04
I.OE-05
Projected.
Exposure
Time
(h)
1
1
1
Integrated Air
Concentration
(uCi cm"3 h)
0.00001
0.0001
0.00001
DCF from
Table 5-4
(rem per
uCi cm"3 h)
I.IE+04
4.5E+03
5.6E+04
Totals >
Inhalation
Committed
Effective Dose
Equivalent
(CEDE)
(rem)
0.11
0.45
0.56
1.12
6-22a
-------
EXAMPLE OF COMBINED PATHWAYS
SOLUTION
Nuclide selected Co-60
Pathway
External
Inhalation
Ground Shine
Table
5-3
5-4
5-5
Summation
DCF
(rem per uCi cm " 3 h)
I.5E+3
2.6E+5
8.9E+3
xin
(uCi ; cm"3 h)
1
1
1
Dose
(rem)
I.5E+3
2.6E+5
8.9E+3
2.6E+5
Combined
5-1
2.7E+5
1
2.7E+5
7-22a
-------
RAD AT ON ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem la-1 & Ib-l : Projected Dose at I Mile(s): From thyroid & combined pathway
Nuclide(s)
& Prblm.
# la-l
1-131
Nuclide
# Ib-l
Xe-133
1-131
Cs-134
XQ/Q
@ 1 mi
(m-2)
7.0E-5
7.0E-5
7.0E-5
7.0E-5
Q
(Ci/s)
0.17
1700
0.17
0.05
G
(m/s)
2
2
2
2
X
@J_mi
L(MCi/cm3L
6.0E-6
6.0E-2
6.0E-6
I.8E-6
Exp.
time
(h)
3
3
3
3
xin
@J_mi
(pCi cm"3 h)
I.8E-5
I.8E-I
I.8E-5
5.25E-5
DCF
Table
No.
5-2
5-1
5-1
5-1
DCF^
rem
pCi cm"3- h
I.3E+6
DCFcp
2.0E+ 1
5.3E+4
6.3E+4
TOTAL -
Dose
(CDE)
(rem)
23
TEDE
(rem)
3.6
0.95
0.33
4.9
8-6a
-------
RAD AT ON ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem la-2 & lb-2 : Projected Dose at 2 Mile(s): From thyroid & combined pathway
Nuclide(s)
& Prblm.
# la-2
1-131
Nuclides
# lb-2
Xe-133
1-131
Cs-134
XQ/Q
@ 2 mi
(m-2)
2.4E-5
2.4E-5
2.4E-5
2.4E-5
Q
(Ci/s)
0.17
1700
0.17
0.05
Q
(m/s)
2
2
2
2
X
@ 2 mi
(pCi/cm3)
2.0E-6
2.0E-2
2.0E-6
6.0E-7
Exp
time
(h)
3
3
3
3
xin
@ 2 mi
(pCi cm"3- h)
6.0E-6
6.0E-2
6.0E-6
I.8E-6
DCF
Table
No.
5-2
5-1
5-1
5-1
DCF*
rem
\iC\ ' cm"3* h
I.3E+6
DCFcp
2.0E+I
5.3 E+4
6.3E-J-4
TOTAL -
Dose
fCDEl
(rem)
8
TEDE
(rem)
1.2
0.32
0.12
1.6
8-18a
-------
RAD OLOG CAL ACC DENT ASSESSMENT COURSE
WORKSHEET
Problem 2a Projected Dose at 2 Mile(s): From immersion
pathway
Nuclide(s)
& Prblm.
# 2
Xe-133
1-131
Cs- 1 34
Xu/Q
@2 mi
Cm'2)
2.4E-5
2.4E-5
2.4E-5
Q
(Ci/s)
1700
0.17
0.05
U
(m/s)
2
2
2
X
@ 2 mi
(MCi/cm3)
2.0E-2
2.0E-6
6.0E-7
Exp.
time
-------
RAD OLOG CAL ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem 2b : Projected Dose at 2 Mile(s): From inhalation pathway
Nuclide(s)
& Prblm.
# 2b
Xe-133
1-131
Cs- 1 34
XQ/Q
@2 mi
(m-2)
2.4E-5
2.4E-5
2.4E-5
Q
(Ci/s)
1700
0.17
0.05
u
(m/s)
2
2
2
X
@ 2 mi
(pCi/cm3)
2.0E-2
2.0E-6
6.0E-7
Exp.
time
M
3
3
3
xin
@_Lmi
(pCi cm"3- h)
6.0E-2
6.0E-6
1 .8E-6
DCF
Table
No.
5-4
5-4
5-4
DCFinh
rem
MCi cm"3- h
0
3.9E+4
5.6E+4
TOTAL-
Dose
(CEDE)
(rem)
0
2.4E-I
1 .OE- !
3.4E-I
8-26a
-------
RADIOLOGICAL ACCIDENT ASSESSMENT COURSE
WORK SHEET
Problem 2c : Projected Dose at_2_Mile(s): From ground shine pathway
Nuclide(s)
& Prblm.
# 2c
Xe-133
1-131
Cs-134
Xii/Q
@2mi
(m-2)
2.4E-5
2.4E-5
2.4E-5
Q
(Ci/s)
1700
0.17
0.05
u
(m/s)
2
2
2
X
@2mi
(nCi/cm3)
2.0E-2
2.0E-6
6.0E-7
Exp.
time
(h)
3
3
3
XiB
@2mi
(jiCi cm'3- h)
6.0E-2
6.0E-6
1.8E-6
DCF
Table
No.
5.5
5.5
5.5
DCFdep
rem
|iCi cm'3- h
0
1.3E+4
6.2E+3
TOTAL -
Dose
(EDE)
(rem)
0
8.0E-2
UE-2
0.09
8-27a
-------
EXAMPLE CALCULATION OF EXPOSURE RATE
- Method One -
SOLUTION
Radionuclide
Cs-134
1-131
Concentration
pCi/m2
2E+7
3E+7
Initial exposure Rate @ 1m
(mR/h per pCi/m2)
(table 7-1 or 7-2)
2.6E-8
6.6E-9
Total:
Exposure Rate @ 1m
(mR/h)
0.52
0.20
0.72
10-9a
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
-M thodOn -
SOLUTION
Integrated Dose - Year One
Radionuclide
Cs-134
M31
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
l.OE-4
1.3E-6
TOTAL
Projected
Dose
(mrem)
2000
39
2039
No Weathering
DCF
(mrem/pCi/m2)
(table 7-2)
1.3E-4
1.3E-6
TOTAL
Projected
Dose
(mrem)
2600
39
2639
10-10a
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
SOLUTION
Integrated Dose - Year Two
Radionuclide
Cs-134
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
4.7E-5
0
TOTAL
Projected
Dose
(mrem)
940
0
940
No Weathering
DCF
(mrem/pCi/m2)
(Table 7-2)
9.6E-5
0
TOTAL
Projected
Dose
(mrem)
1900
0
1900
10-lla
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
SOLUTION
Integrated Dose - Zero to 50 Years
Radionuclide
Cs-134
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
2.4E-4
1.3E-6
TOTAL
Projected
Dose
(mrem)
4800
39
4839
No Weathering
DCF
(mrem/pCi/m2)
(Table 7-2)
4.7E-4
1.3E-6
TOTAL
Projected
Dose
(mrem)
9400
39
9439
10-12a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF
- Method 2-
SOLUTION
mrem per yr-1, yr-2, or 0 to 50 yr
__ J
Exposure Rate @ 1 /n (mR/h)
Assume weathering and results from VGs 9,10,11, and 12, and
calculate:
- Year one DCFas = 2039 mrem/0.72 mR/h = 2832 mrem/mR/h
- Year two DCFas = 940 mrem/0.72 mR/h = 1305 mrem/mR/h
- 0 to 50 y ar DCFas = 4839 mr m/0.72 mR/h = 6720
10-14a
-------
CALCULATION OF ACCIDENT SPECIFIC DRL
- Method 2 -
SOLUTION
DRL
PAG
ta DCF
as
For the previous example (weathering included):
- Year one DRLas = 2000 mrem + 2832 mrem/mR/h = 0.71 mR/h
- Year two DRLas = 500 mrem -5-1305 mrem/mR/h = 0.38 mR/h
- Zero to 50 year DRLas = 5000 -s- 6720 = 0.74 mR/h
10-15a
-------
CALCULATION OF INHALATION DOSE (CEDE)
FROM RESUSPENDED MATERIALS
Includes weathering? [ x ] yes [ ] no
Sample
Radio-
Nuclide
Cs-134
1-131
location Analysis date
Air
Concentration
(pCi/m3)
1200
420
Yr. 1 DCF
(mrem per
pCi/m3)
3.1E-1
1.1E-2
TOTAL-
Dose From
Yr. 1 Exp.
(mrem)
370
4.6
375
Yr. 2 DCF
(mrem per
pCi/m3)
1.5E-1
0
TOTAL-
Dose From
Yr. 2 Exp.
(mrem)
180
0
180
10-20 a
-------
Problem 1: Derivation of an Accid nt-Sp cific Dose Conv rsion Factor
SOLUTION
Refer to Table 7-1 and, as example, Table 7-3.
Unit of the DCF for the projected external gamma dose is:
xx mrem for each mR/h measured at the beginning of the period
For year one:
1.6E+03 mrem per 4.9E-01 mR/h yields
3.3e+3 mrem per mR/h or 3.3 rem per mR/h
For 0-50 years:
4.0E-03 mrem per 4.9E-01 mR/h
8.2E+3 mrem per mR/h or 8.2 rem per mR/h
ll-la
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [xJYearl [ ] Year 2 [ ] 50 Years
Sample locatioi
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
\ A Weathering*
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6c-08
l.Oe-08
3.2e-09
TOTAL-
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
? [ x] yes [ ] no
Integrated
Dose
(mrem per
pCi/m2)
3.3e-05
7.1e-06
1.3e-06
l.Oe-04
4.5e-05
l.le-05
TOTAL-
Calculated
DOSE
(mrem)
2.4e+02
2.2e+01
5.3e+00
1.2e+03
5.4e+01
6.8e+01
1.6e+03
Co bined DCFas __3.3 e+03__ re per R/h
(date
ll-2a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFJ
For? [ JYearl [x] Year 2 [ ] 50 Years
Sample locat'oi
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
n A Weather ng
Initial Exp.
Rate @ Ini
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
7 [x]yes []
Integrated
Dose
(mreni per
pCi/m2)
4.0e-07
O.Oe+00
O.Oe+00
4.7e-05
2.9e-05
O.Oe+00
TOTAL-
no
Calculated
DOSE
(mrem)
3.0e+00
O.Oe+00
O.Oe+00
5.6e+02
3.5e+01
O.Oe+00
6.0e+02
Co binedDCFas__1.2e+03 re per mR/h (date_
ll-3a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ JYearl [ ] Year 2 [x] 50 Years
Sample locatioi
Radio-
Nuclide
Zr-95
R u -103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
i A Weathering'
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
? [ x] yes [ ] no
Integrated
Dose
(mrem per
pCi/m2)
3.4e-05
7.1e-06
1.3e-06
2.4e-04
6.1e-04
l.le-05
TOTAL-
Calculated
DOSE
(mrem)
2.5e+02
2.2e+01
5.3e+00
2.9e+03
7.3e+02
6.8e+01
4.0e+03
Co bined DCFas _8.2 e+03__mre per R/h
(date
ll-4a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFJ
For? [x]Yearl [ ] Year 2 [ ] 50 Years
Sample locatioi
Radio-
lS u elide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
i A Weathering*
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
? [ x] yes [ ] no
Integrated
Dose
(mrem per
pCi/m2)
3.3e-05
7.1e-06
1.3e-06
l:0e-04
4.5e-05
l.le-05
TOTAL-
Nominal
Calculated
DOSE
(mrem)
2.4e+02
2.2e+01
5.3e+00
1.2e+03
5.4e+01
6.8e+01
1.6e+03
Co bined DCFas _3.3 e+03_ re per R/h
(date.
ll-6a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [
Sample locatioi
Radio-
IS uclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
Yearl [x] Year 2 [ ] 50 Years
n A Weathering
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
? [x]yes []
Integrated
Dose
(mrem per
pCi/m2)
4.0e-07
O.Oe+00
O.Oe+00
4.7e-05
2.9e-05
O.Oe+00
TOTAL-
no
Nominal
Calculated
DOSE
(mrem)
3.0e+00
O.Oe+00
O.Oe+00
5.6e+02
3.5e+01
O.Oe+00
6.0e+02
Combin d DCFas _1.2 e+03_ mrem p r mR/h (d t
ll-7a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ lYearl [ ] Year 2 [x] 50 Years
Sample location A Weathering? I x] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
Integrated
Dose
(mrem per
pCi/m2)
3.4e-05
7.1e-06
1.3e-06
2.4e-04
6.1e-04
l.le-05
TOTAL-
Nominal
Calculated
DOSE
(mrem)
2.5e+02
2.2e+01
5.3e+00
2.9e+03
7.3e+02
6.8e+01
4.0e+03
Co bined DCFas _8.2 e+03_ re per R/h
(date
ll-8a
-------
Problem 2: Derived Respons L v Is
SOLUTION
A time-dependent derived response level (DRLtd) is the meter reading (mR/h @ 1m)
which, at the time of measurement, corresponds to either the year 1, year 2, or 0-50
year dose.
For year one, a meter reading of 1 mR/h at 1 meter above the ground indicates an
external gamma radiation dose of 3.3 rem during the first year. Therefore, the
DCF (rem per mR/h) is 3.3 rem per mR/h.
A meter reading of 2.0/3.3 or about 0.6 mR/h, would indicate that the first year dose
would be 2 rem or greater.
The DRLtd for year 1 is 0.6 mR/h.
The DRLtd for year 2 is 0.5/1.2 or about 0.4 mR/h.
The DRL for ye r 0-50 is 5.0/8.2 or bout 0.61 mR/h.
ll-9a
-------
Problem 2 Derived Response Levels
SOLUTION
(contfd)
Table 4-1: Protective Action Guides for Exposure to Deposited
Radioactivity During the Intermediate Phase of a Nuclear Incident
Relocate if projected dose is greater than 2 rem.
Projected dose includes external gamma radiation dose and the
committed effective dose equivalent from inhalation during the
first year.
Beta skin dose may be up to 50 times higher.
Persons in areas with meter readings above 0.6 mR/h should be
relocated.
-------
Problem 3 Projected Dose
SOLUTION
Location
A
B
C
Meter
Reading
(mR/hr)
3
10
30
Projected
Dose
year one
(rem)
9.9
33
99
DCF for year 1 (rem per mR/h)
DCF for year 2 (rem per mR/h)
DCF for 0 to 50 y (rem per mR/h)
Projected
Dose
year two
(rem)
3.6
12
36
3.3
1.2
8.2
Projected
Dose
0 toSOy
(rem)
24.6
82
246
ll-lla
-------
Prob em 4: Inha ation Do e (CEDE)
SOLUTION
CALCULATION OF INHALATION DOSE (CEDE)
FROM RESUSPENDED MATERIALS
Includes weathering? [ x ] yes [ ] no
S:
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
imple location A Analysis date
Air
Concentration
(pCi/m3)
760
320
420
1200
120
630
Yr. 1 DCF
(mrem per
pCi/m3)
6.5e-02
1.3e-02
l.le-02
3.1e-01
2.5e-01
4.4e-03
TOTAL-
Dose From
Yr. 1 Exp.
(mrem)
4.9e+01
4.2e+00
4.6e+00
3.7e+02
3.0e+01
2.8e+00
4.6e+02
Yr. 2 DCF
(mrem per
pCi/m3)
1.5e-01
1.4e-01
TOTAL-
Dose From
Yr. 2 Exp.
(mrem)
O.Oe+00
O.Oe+00
O.Oe+00
1.8e+02
1.7e+01
O.Oe+00
2.0e+02
-------
Problem 4:1 h latio Dose (CEDE)
SOLUTION
(co t'd)
Year one CEDE - 4.6E+02 mrem or 0.46 rem
Year two CEDE - 2.0E+02 mrem or 0.20 rem
Year one EDE - 9.9 rem (see problem 3)
Year one TEDE - 9.9 + 0.5 = 10.4 rem
Year two EDE - 3.6 rem (see problem 3)
Year two TEDE - 3.6 + 0.20 = 3.8 rem
Normally the lung clearance class and the particle size are not known.
Assume the most conservative condition.
-------
MANUAL OF PROTECTIVE
ACTION GUIDES AND
PROTECTIVE ACTIONS
FOR NUCLEAR INCIDENTS
Presented By
The Environmental Protection Agency
at
NASA HEADQUARTERS
date
JUNE 10-11, 1998
-------
SESSION I
WELCOME AND INTRODUCTIONS
-------
EPA 400-R-92-001
MANUAL OF PROTECTIVE ACTIONS AND PROTECTIVE
ACTIONS FOR NUCLEAR INCIDENTS WORKSHOP
NASA HEADQUARTERS
300 E STREET, S.W.
WASINGTON D.C.
JUNE 10-11, 1998
Wednesday, June 10, 1998
8:30 - 9:00 an Welcome and Introductions
9:00 - 10:00 am
10:00 - 11:00 am
11:00 - 12:00 pm
12:00 - 1:00 pm
1:00 - 2:30 pm
2:30 - 4:30 pm
4:30
Thursday, June 11, 1998
8:30 - 10:00 am
10:00
11:00
12:00
1:00
3:30
11:00 pm
12:00 pm
1:00 pm
3:30 pm
4:00 pm
Overview (Bow th* PAO manual ie laid out)
Rationale for PAG values (PAG Principles)
Application and Interpretation of PAGs (When to use them and
how)
Lunch
Introduction to Dose Projection (Discussion of Terminology
and EPA assumptions used)
Implementation of Emergency Worker Dose Limits (Who are
Emergency Workers and What limits apply)
End of Day One
Development of DCFs and DHLs (What are they and how do you
apply them)
Dose Projection for Early Phase (Problem solving)
PAGs for Relocation (Assumptions made and rationale for use)
Lunch
Dose Projection for Relocation (Problem solving)
Review and Wrap-up
-------
SESSION 2
OVERVIEW OF BACKGROUND MATERIALS
SUPPORTING THE WORKSHOP
-------
TOPICS
Response areas
Organization and content of the PAG Manual
and its major support documents
^
Exposure pathways
Incident phases
2-1
-------
2. AREA FROM WHICH POPULATION IS
ABEAM
PLUME TRAVEL
DIRECTION
RELOCATED (RESTRICTED ZONE).
2-2
-------
CONTENTS OF THE PAG MANUAL
CHAPTERS SUBJECTS
I Background information
2, 3, & 4 PAGs for plume, ingestion, and
relocation
5, 6, & 7 Implementation guidance for the
3 PAG categories
8 Reserved for recovery guidance
2-3
-------
CONTENTS OF THE PAG MANUAL
(cont'd)
APPENDICES SUBJECTS
A Definitions of terms
B Risk of health effects from radiation
C Rationale for selecting the early phase
PAG values
D Rationale for food PAGs
E Rationale for Relocation PAGs
2-4
-------
MAJOR SUPPORT DOCUMENTS
Externa Dose-Rate Conversion Factors for Ca cu ation
of Dose to the Public (DOE/EH 0070)
EPA Federal Guidance Report No. 11
(EPA 520/1 -88-020)
(>
EPA Federal Guidance Report No. 12
(EPA402-R-93-08I)
2-5
-------
MAJOR SUPPORT DOCUMENTS (cont'd)
Evaluat'on of Sk'n and Ingest'on Exposur P thw ys
(EPA 520/1 -89-016)
Evacuation RisksAn Evaluation
(EPA-520/6/74-002)
An Analysis of Evacuation Options for Nuclear
Accidents (EPA 520/1 -87-023)
Economic Criteria for Relocation
(EPA 520/1 -89-015)
2-6
-------
Airborne
Plume
Gamma Rays
Inhalation
Irigestion
Beta
Restispensicm
2-7
Particles
Deposited Paniculate Material
Exposure Pathways for the Early Phase
-------
INCIDENT PHASES
(pp. I -2 to I -4)
Three phases of a radiological incident
- Early
- Intermediate
- Late
In all phases, the PAGs are independent
Refer to PAG Manual Page I -4.
2-8
-------
SESSION 3
RATIONALE FOR PAG VALUES
AND
EMERGENCY WORKER DOSE LIMITS
-------
TOPICS
Protective action effectiveness
PAG Principles
Basis for PAG values and Emergency worker dose limits
3-1
-------
ttfKJSKvatKnti. .a«g3g^:rr^K:'Jvr?;rt:'r.grr.it.'i-:j^^ :> ajj iKK^.j^.-^snfzK-sav-ir.-^,- .
PROTECTIVE ACTIONS
FOR THE EARLY PHASE
(p. 1-4)
Evacuation
Sheltering
Access control
KI administration
Control of surface contamination
3-2
-------
BASIS FOR PROTECTIVE ACTION
DECISIONS DURING THE EARLY PHASE
(p. 5-2)
Plant conditions and utility PARs
Dose projections
Field monitoring results
3-3
-------
SHELTERING CONSTRAINTS
(pp. 5-19 to 21 andC-!4to 16)
Sheltering provides only partial protection.
- Protection factor decreases with time.
- Ventilation rates vary.
- Protection varies with building type.
- Risk of shelter failure is significant.
3-4
-------
BASIS FOR SETTING PAG LEVELS
(p. 1-5)
PRINCIPLE STRATEGY
(I) Avoid acute health effects. Stay below threshold dose.
(2) Adequately protect against
cancer and genetic effects
under emergency conditions.
(3) Optimize cost of protective
action versus avoided dose.
(4) Regardless of the above
principles, the risk from a
protective action should not
itself exceed the risk from the
dose that would be avoided.
Set PAG at this level unless
driven down by cost/risk
considerations (3), or up by
risk/risk considerations (4).
Use this principle only if the
the PAG value is driven down.
Use this principle only if the
PAG value is driven up.
3-5
-------
RADIATION HEALTH EFFECTS
(Appendix B)
Acute (deterministic) health effects
Mental retardation
Radiogenic cancers
Thyroid disorders and cancers
Genetic disorders
3-6
-------
1*0
Based on minimal
medical care
Intensive medical care may_
increase the dose threshold
by :>0 percent
100 100 300 400
WHOL1 IODY ABSORBED 009E (rid)
SOO
800
FIGURE B-1. ACUTE HEALTH EFFECTS AS A FUNCTION
OF WHOLE BODY DOSE.
3-7
-------
ACUTE HEALTH EFFECTS: CONCLUSIONS
(p.B-17)
Dose Acute Health Effect
50 rad Less than 2 % of the exposed expected to
show forewarning symptoms.
25 rad Forewarning symptoms are not expected.
3-8
-------
ACUTE HEALTH EFFECTS: CONCLUSIONS
(cont'd)
Dose Acute Health Effect
10 rad The dose level below which a fetus would not be
expected to suffer teratogenesis.
5 rad The approximate minimum level of detectability for
acute cellular effects using the most sensitive
methods.
3-9
-------
AVERAGE RISK OF DELAYED HEALTH EFFECTS
IN THE U.S. POPULATION
(pp. B-19 to 25)
Health Effect
Fatal cancers
Nonfatal cancers
Genetic disorders
(all generations)
Effects per Person-rem
Whole
Body
2.8E-4a
2.4E-4
1 .OE-4
Thyroid
3r6E-5b
3.2E-4
Skin
3.0E-6
3.0E-4
a Risk to the fetus is estimated to be 5 to 10 times greater.
b Risk to young children is estimated to be about 1.7 times greater.
Their dose is also about 2 times greater.
3-10
-------
UPPER BOUNDS ON DOSE FOR EVACUATION
BASED ON COST OF AVOIDING FATALITIES
(p. C-1 I and E-2)
Accident
Category
SST- 1 b
SST-2
Atmospheric
Stability Class
A
C
F
A
C
F
Dose Upper Bounds3
Maximum (rem)
5
5
10
1
3.5
10
Minimum (rem)
0.4
0.4
0.8
0.15
0.25
0.7
a Based on an assumed range of $400,000 to $7,000,000 per life saved.
6 SST m ans Siting Sourc Term. See page E-2 of PAG Manual.
3-11
-------
CALCULATION OF RADIATION RISK
VERSUS EVACUATION RISK
(p. C-10)
Estimated risk of death from transportation
= 9E-8/person mile.
Assume 100 mile round trip for evacuation.
Estimated risk of death from radiation
= 3E-4/person rem.
Calculate the equivalent risk (rem/100 miles).
3-12
-------
AVERAGE VERSUS CENTERLINE DOSE
(P- C-12)
Centerline
Dose (rem)
0.5 to 1
1 to 2
2 to 5
5 to 10
Average Dose Avoided by
Stability Class (mrem per individual)
A
340
670
C
190
380
870
F
70
150
330
750
3-13
-------
MAJOR CONCLUSIONS LEADING TO THE
SELECTION OF THE PAG FOR EVACUATION
(PP.C-I8&C-I9)
0.5 rem is the selected dose to be avoided.
- This satisfies Principles I and 2.
- Cost of going lower is not justified. (Principle 3)
- Net reduction in average risk will occur
(Principle 4).
- Meets acceptable risk to the fetus established for
occupational exposure.
3-14
-------
MAJOR CONCLUSIONS LEADING TO
THE SELECTION OF I REM AS
THE PAG FOR EVACUATION
(p.C-19)
If sheltering is implemented to 0.5 rem at centerline,
and evacuation to I rem, the avoided dose from
evacuation will be about 0.5 rem.
Therefore, the PAG recommended for evacuation is
I rem.
3-15
-------
BAS S FOR EMERGENCY WORKER DOSE L M TS
(pp. C-22 to 24)
5 rem limit unless higher limit is justified
- Occupational guidance should normally govern.
- Limit emergency workers to nonpregnant adults.
- Occupational limits for organs, extremities and lens of
the eye should also apply.
3-16
-------
BAS S FOR EMERGENCY WORKER
DOSE L M TS
(cont'd)
10 rem limit for protecting valuable property
- Some emergency situations justify dose limits higher
than 5 rem.
- ICRP-26 recognizes 10 rem as an annual limit for
any single event for workers.
Higher limits are conditional.
3-17
-------
BASIS FOR EMERGENCY WORKER
DOSE LIMITS
(cont'd)
25 rem limit is justified for:
- life saving
- preventing substantial risks to populations
ICRP-26 recognizes 25 rem as a lifetime limit for
specially justified circumstances.
Acute effects to adults will be avoided.
3-18
-------
DOSES N EXCESS OF THE L M TS
FOR EMERGENCY WORKERS
Old limits of 75 and 100 rem present unacceptably high
risk for assignment
No limit is needed for persons who volunteer for
higher doses if:
- they are fully aware of the risks involved, and
- they are lifesaving or preventing dose to a large
population.
Chart of risks is provided (see page 2-12).
3-19
-------
SESSION 4
APPLICATION AND INTERPRETATION
OF
PROTECTIVE ACTION GUIDES
AND
EMERGENCY WORKER DOSE LIMITS
FOR
THE EARLY PHASE
-------
MAIN TOPICS
Definitions and interpretations
Special dose quantities and concepts
PAG values and their application
The use of Kl for emergency workers
The impact of the changes to the guidance
4-1
-------
APPLICABILITY OF PAGs
(p. 2-1 & 2-2)
PAGs apply to all nuclear incidents or accidents except
nuclear war.
Developed based on nuclear power plant accidents
Dose limits also apply to all
The implementation guidance applies primarily to nuclear
power plants.
4-2
-------
DEF NITONS
(pp. -2&A-3)
Protective Action Guide (PAG):
The projected dose to individuals in the general
population that warrants protective action.
Projected Dose:
The calculated future dose that would be received by
individuals if no protective actions were taken.
4-3
-------
PAG INTERPRETATIONS
(pp. l-l,&l-7)
PAGs are:
Decision levels for public officials
Used to minimize risk from an event which is occurring
or has already occurred
4-4
-------
PAG INTERPRETATIONS
(pp. 2-1,4-1, 2-2, & I -6)
(cont'd)
PAGs are:
Mandatory for planning
- but, professional judgment is required for their
application
Independent of the type or magnitude of the release
4-5
-------
PAG NTERPRETAT ONS
(pp. -6, &2-2)
(cont'd)
PAGs are:
A supplement to design safety of nuclear facilities
Designed to protect all individuals in the population
4-6
-------
PAG INTERPRETATIONS
(pp. 1-6 2-1 2-4 &2-IO)
(cont'd)
PAGs are not:
The basis for the size of the EPZ
Dose limits
Additive to other doses
4-7
-------
PAG INTERPRETATIONS
(pp. I7&2I)
(cont'd)
PAGs do not:
Imply an acceptable level of dose for nonemergency
situations.
Represent the boundary between safe and unsafe
conditions.
Supersede Federal Radiation Council (FRC) Guidance.
4-8
-------
PAG INTERPRETATIONS
(pp. A-2 & A-3)
(cont'd)
PAGs do not include:
Previous radiation doses.
Safety factors to account for uncertainties in dose
projection procedures.
4-9
-------
DOSE QUANTITIES USED
FOR EMERGENCY RESPONSE
(pp. B-1 & B-2)
Absorbed dose
Projected dose
Committed dose
4-10
-------
SPECIAL DOSE QUANT T ES
(p.B- &B-2)
Dose equivalent (DE)
- Organ dose
- Risk of cancer
Committed dose equivalent (CDE)
- 50 years
Effective dose equivalent (EDE)
Committed effective dose equivalent (CEDE)
4-11
-------
TOTAL EFFECTIVE DOSE EQUIVALENT (TEDE)
TEDE (an NRC term) means the sum of the deep dose
equivalent from external gamma radiations (EDE) and
the committed effective dose equivalent (CEDE) from
internal exposures.
Plume PAGs are expressed as this sum.
"TEDE" is not used in the PAG Manual
EDE from external sources is the same as NRCs term
"deep dose equivalent"
4-12
-------
EARLY PHASE PAGs
(pp. 2 5 to 2 8 & C 20)
(cont'd)
Projected dose (rem) Action
I to 5 TEDE Evacuation (or, for some
5 to 25 CDE thyroid situations, sheltering)
50 to 250 DE skin should normally be initiated
at the lower end of the range.
25 CDE thyroid Administer stable iodine (Kl)
from radioiodine to the public in accordance with
State medical procedures.
4-13
-------
OTHER EARLY PHASE GUIDANCE
NOT PAGS
(pp. 2-4 to 2-9)
Projected dose (rem) Action
<0.1 TEDE No action based on risk
<0.5 CDE thyroid from radiation dose.
<5 DE skin
0.1 to < I TEDE Sheltering should be
0.5 to <5 CDE thyroid considered, but this is not a
5 to <50 DE skin PAG for sh It ring.
4-14
-------
DIFFERENCES IN
EMERGENCY WORKER LIMITS
AND PROTECTIVE ACTION GUIDES
Difference in justification
Difference in time period of exposure
Limits vs threshold for decisions
4-15
-------
EMERGENCY WORKER PROTECTION
(pp. 2-9 to 13 and C-22 to 24)
Period of application of emergency worker limits
Emergency worker dose and occupational dose are not
additive unless required by license.
No guidance for keeping records of dose to emergency
workers
Protection of minors and fetuses
4-16
-------
EMERGENCY WORKER CATEGORIES
(p. C-22)
Designated by State and local authorities
Example categories:
- Law enforcement and traffic control officials
- Medical and public health personnel
- Environmental monitors
- Emergency vehicle operators
- Utility, industrial, and institutional emergency
workers
4-17
-------
PERSPECT VES FOR
EMERGENCY WORKER L M TS
(pp. C-22 to 24)
Apply the same dose limits as for occupational!/
exposed workers wherever practicable.
Permit higher dose limits when required to prevent
substantial risks to populations or protect valuable
property.
Provide guidance for extreme emergencies.
- Volunteers fully informed of risks
4-18
-------
DOSE LIMITS FOR EMERGENCY WORKERS (p. 2-10)
DOSE
LIMIT
5 rem
10 rem
25 rem
ACTIVITY
all
protecting valuable
property
life saving or protecting
large populations
>25 rem life saving or protecting
large populations
CONDITION
lower dose not
practical
lower dose not
practical
only on a voluntary
basis to persons
fully aware of the
risks.
4-19
-------
Kl FOR EMERGENCY WORKERS
(pp. 2-11 and 2-13)
Kl is recommended if atmospheric releases include radioiodine
(no dose threshold).
State medical procedures determine its availability and proper
use.
4-20
-------
SESSION 5
INTRODUCTION TO DOSE PROJECTION
FOR
PROTECTION OF THE PUBLIC
AND
EMERGENCY WORKERS
-------
GENERAL APPROACH
TO DOSE PROJECTION
Determine or estimate source term (Q) and
projected release duration (Tp).
Use atmospheric dispersion model to calculate time
integrated air concentration (Xin).
Use dose models to calculate projected dose (D) by
means of dose conversion factors (DCF).
5-1
-------
GENERAL APPROACH FOR CALCULATING
PROJECTED DOSE
Measure or calculate environmental
concentrations.
Multiply by duration of exposure to get time
integrated concentration (Xin) for each
nuclide or group of nuclides.
Multiply each Xin by the appropriate DCF to
get TEDE or thyroid dose from each nuclide
or group of nuclides.
Sum TEDEs over all nuclides or groups of
nuclides and su thyroid doses to get
projected doses co parable to PAGs.
Concentrations may be for indivi-
dual nuclides or may be grouped
by iodines and noble gases.
True Xin can be calculated if the
total release is used. Not used with
measured concentrations.
Use DCFs from PAG Manual
Table 5.1 for TEDE and 5.2 dose
for CDE to thyroid from single
nuclides. For groups of nuclides,
DCFs must be calculated. A DCF
for participates, as a group, is not
practical.
5-2
-------
NEEDED SOURCE TERM INFORMATION
Gross noble gas, radioiodine, and participate release
rates
or
curies per second of each radionuclide
Release height (release point information)
Estimated release duration
5-3
-------
NEEDED METEOROLOGY
Wind speed,
Wind direction
Stability Classes
Mixing depth
Predicted changes
Precipitation
5-4
-------
GAUSSIAN DISPERSION EQUATION
Xu
^^^^^
Q
\
2
y
n a a
y
2
z
For a ground level release, release height (h) = 0,
At the centerline, the lateral distance (y) = 0.
Xu 1
n a a
y
5-5
-------
BASIC DOSE EQUATION
The basic dose equation is:
D = Xin - DCF
D = Dose (rem)
Xin = Time integrated concentration in air
(uCi cm"3 h)
h = duration of exposure (hours)
DCF = Dose conversion factor
(r m p r uCi - cm"3 h)
5-6
-------
NEEDED NFORMATONFOR
DOSE CALCULAT ONS
Radionuclide air concentration (X)
Expected duration of exposure (Tp)
Dose conversion factors (DCF)
Dose projection procedures
- computer programs
- RASCAL
5-7
-------
INFORMATION NEEDED TO SUPPORT
PROTECTIVE ACTION DECISIONS
Total effective dose equivalent (TEDE).
Committed thyroid dose (CDE).
Measurements of plume gamma rate.
Measurements of gross radioiodine concentrations,
5-8
-------
TIME INTEGRATED
AIR CONCENTRATION, X
in
Air concentration times projected exposure time,
X(uCi/cm3) Tp(hour) = Xin
Permits addition of the dose conversion factors over
the three exposure pathways.
5-9
-------
TIME INTEGRATED
AIR CONCENTRATION, Xin
(cont'd)
High concentration for short time
Low concentration for long time.
Symbol: Xin
Matches units of EPA's dose conversion factors,
5-10
-------
TIME INTEGRATED
AIR CONCENTRATION, Xin
(cont'd)
PROBLEM ONE
Xe-l 33 air concentration is I .OE-4 uCi/cm3
Expected duration of air concentration is 2 hours,
Xin equals ?????? (uCi cnV3 h).
5-11
-------
TIME INTEGRATED
AIR CONCENTRATION, Xin
(cont'd)
PROBLEM TWO
Xe-133 air concentration is 5.0E-5 uCi/cm3.
Expected duration of this air concentration is 240
minutes.
Xin equals ?????? (uCi cm'3 h).
5-12
-------
TIME INTEGRATED
AIR CONCENTRATION, Xjn
(cont'd)
SOLUTIONS TO PROBLEMS I AND 2
Xin = (air concentration) (expected exposure time)
Xin = (I.OE-04uCi/cm3)(2h)
= 2.0E-04 uCi cm'3 h
Xin = (5.0E-05 uCi/cm3) (240m/60m/h)
= 2.0E-04 uCi cnY3 h
5-13
-------
DCF DEFINITION
(p.A-l)
Dose Conversion Factors (DCF) change
environmental concentrations (or time integrated
concentrations) to dose.
Dose units (rad = rem)
-3
EPA DCF unit: rem per uCi cm h
5-14
-------
PARAMETERS THAT AFFECT DCFs
Physical characteristics
Chemical characteristics
Breathing rates
Assumed deposition velocities
Biological system clearances
5-15
-------
ASSUMED VALUES FOR CALCULATIONS
Breathing rate = 1.2 m3/h
Deposition velocity EPA RASCAL
- Iodine I cm/s 0.3 cm/s
- Participates 0.1 cm/s 0.3 cm/s
Gamma shielding factor due to ground roughness
EPA = I RASCAL default = 0.7
Public exposure to deposited materials before
relocation is 4 days (96 h)
5-16
-------
DOSE CONVERSION FACTOR TABLES
(TABLE 5-1 AND TABLE 5-2)
Table 5-1: Dose Conversion Factors and Derived
Response Levels for Combined Exposure Pathways
During the Early Phase of a Nuclear Incident.
Table 5-2: Dose Conversion Factors and Derived
Response Levels - Inhalation of Radioiodine.
Refer to EPA Manual
5-17
-------
SKIN DOSE
DCFs for skin are not provided for early phase.
Skin dose is not expected to be controlling.
Skin dose is controlled by bathing and changing
clothing.
5-18
-------
US NG DCFs FOR COMB NED PATHWAYS
(TABLE 5- )
GIVEN:
- The concentration of tritium (H-3) in a plume is
5E-3 Ci/m3.
Exposure to plume expected for 3 hours.
PROBLEM:
- What is the time integrated air concentration?
- What is the dose conversion factor?
- What is the projected dose?
- What kind of dose is it?
5-19
-------
USING DCFs FOR COMBINED PATHWAYS
(TABLE 5-1)
(cont'd)
SOLUTION: Calculate Xin and look up the DCF.
Xjn = (air concentration) (expected exposure time)
= (5E-3 uCi/cm3) (3 hours)
Xin= l.5E-02uCi-cm-3'h
DCF for tritium from Table 5-1 is
7.7E+01 rem per uCi cm"3 h
5-20
-------
US NG DCFs FOR COMB NED PATHWAYS
(TABLE 5- )
(cont'd)
Projected dose = Xjn times DCF
or
(I.5E-2 uCi cm"3 h)(7.7E+l rem per uCi cm"3 h)
Projected dose = 1.2 rem
This projected dose is considered to be total effective
dose equivalent (TEDE). Why?
5-21
-------
USING DCFs FOR COMBINED PATHWAYS
(TABLE 5-1)
(cont'd)
THE PROJECTED DOSE IS THE TEDE BECAUSE:
DCF is based on committed effective dose equivalents.
All significant early phase exposure pathways are
included.
All significant radionuclides are included.
5-22
-------
SUMMARY
n
D = S DCF ' X
* mm
i in, i
= DCF for radionuclide (i)
n = Number of radionuclides present
Xjn, = The time integrated concentration of
radionuclide (i)
5-23
-------
SESSION 6
IMPLEMENTATION OF
EMERGENCY WORKER DOSE LIMITS
-------
MAIN TOPICS
Emergency workers
Relative importance of exposure pathways
Inhalation dose control methods
PAG Subcommittee guidance
Dose for the record
6-1
-------
EMERGENCY WORKERS
(p. 2-9)
State responsibility for defining emergency workers
Example assignments
- Law enforcement/traffic control
- Radiation protection
- Transportation services
6-2
-------
EXPOSURE PATHWAYS FOR
EMERGENCY WORKERS
External gamma radiation
Plume
- Groundshine
Inhalation from the plume and resuspended materials
Plume inhalation may be the major pathway
External beta radiation
Plume
Groundshine
Deposited materi Is on skin nd clothing
6-3
-------
INHALATION OF RESUSPENDED MATERIAL
R suspension r t s
- Empirical values range from I0~5 to I0~9 nrf1
Importance of pathway
Plume phase
Post plume phase
- For example, at I0~5 m"1, I mR/h yields about 0.05 mrem
CEDE from inhalation
6-4
-------
EXAMPLE DOSES FROM A REACTOR ACCIDENT
RTM-93 CASE 5; Gap release for one hour; Late release @ 100 % per day
No Spray; No protective action; No rain; Met cond. was not
1,000
Rem Versus Distance
Thyroid Dose
-+-TEDE
1
2 5
Distance (miles)
10
6-5
-------
EXAMPLE DOSES FROM A REACTOR ACCIDENT
RT -93 CASE 16 Severe core damage' 100% per hour leak rate-
No spray; o rain; No protective action; et Cond was not Specified.
100,000
10,000
1,000
Rem Versus Distance
Thyroid Dose
TEDE
1
2 5
Distanc (mile )
10
6-6
-------
INHALATION DOSE CONTROL
USING RESPIRATORS
Mentioned, but not promoted by EPA or FEMA
Effectiveness
- Filter type
- Air supplied type
Advantages
- Protects workers from inhalation dose.
- Dose control by dosimeter is simple.
6-7
-------
INHALATION DOSE CONTROL
USING RESPIRATORS
(cont'd)
Disadvantages
- OSHA requirements
Fitting and testing
Training
Medical examinations
- No beards
- Reduced vision, communication, and efficiency
- Discomfort
- Logistics
6-8
-------
PAG SUBCOMMITTEE GUIDANCE
DATED JULY 1994
ISSUE: How should the dose to emergency workers,
especially those exposed to a radioactive plume,
be monitored and controlled to meet the EPA
dose limits in terms of total effective dose
equivalent (TEDE)
Guidance:
- Relates to accidents at nuclear power plants
- Based on current practices
- Other approaches may be acceptable
6-9
-------
PAG SUBCOMMITTEE GUIDANCE
(CONTINUED)
Maintain 5 rem TEDE limit where practicable.
The primary activities for emergency workers within an
airborne plume will be:
- Protection of valuable property,
- Protection of large populations, and
- Monitoring.
States should maintain flexibility in dose limits
6-10
-------
PAG SUBCOMMITTEE GUIDANCE
(cont'd)
Doses up to 10 and 25 rem (and above) should be
accepted and planned for.
DRDs may be used to estimate inhalation dose.
Use of Kl is recommended.
Flexibility in control procedures is granted.
Three acceptable options are presented.
6-11
-------
OPTIONS FOR ADJUSTING EMERGENCY WORKER
GAMMA DOSE LIMITS TO ACCOUNT
FOR SIGNIFICANT PARTICULATE RELEASES
Options'
Evacuation Phase
Post-Evacuation Phase
I
No adjustments
Adjust, if necessary
Fixed admin, limit
set prior to Emrg.
Adjust, if necessary
Contextual
adjustment based
on plant data
Contextual adjustment
based on plant and
environmental data
lOth r options may be consid r d
6-12
-------
OPTION ONE
Control only whole body g mma nd thyroid dose
during evacuation.
Rationale
Not practical to rotate workers
Inhalation dose is controlled for tasks after evacuation.
Evacuation may be completed before plume arrives.
Disadvantages
Higher risk of over-exposure compared to other
options
6-13
-------
OPTION TWO
Pre-established administrative limits
Rationale
- Easy to implement
- Will meet limits for most probable accidents
Disadvantages
- May not provide adequate control for the most
severe accidents
- Possible discontinuity between States
6-14
-------
DOSIMETER ADJUSTMENT FACTORS
Accident
Category
BWR-I
PWR-I
BWR-3
PWR-3
PWR-5
PWR-7
Adjustm nt F ctors3
With Kl
13 to 29
8 to 16
3 to 7
4 to 8
1.4 to 2
1 to 2
Without Kl
16 to 37
1 1 to 26
5 to 12
6 to 14
3 to 6
1 to 2
a Calculated for distances ranging from I to 25 miles, stability classes ranging
from A to F, and for 13 hours of exposure.
6-15
-------
OPTION THREE
Calculate contextual mission limits applicable to the
accident in progress.
Rationale
- Can use same data as for dose projection
- Mission limits would be more defendable.
Disadvantages
- Variable limits may be confusing to implement.
- Necessary data may not be available.
6-16
-------
RETROSPECTIVE EVALUATION OF DOSE
FOR THE RECORD
Applicable to emergency workers who are exposed to
an airborne plume containing iodines and/or participate
materials
Kl administration affects the evaluation.
6-17
-------
RETROSPECTIVE EVALUATION OF DOSE
FOR THE RECORD
(cont'd)
Based on dosimeter readings (primarily TLD) and
- Release composition
- Environmental data (importance of air samples)
Or based on dosimeter readings and
- Release composition
- Whole body counts
- Bioassay
6-18
-------
RETROSPECTIVE ANALYSIS USING
RELEASE AND ENVIRONMENTAL DATA
Need measured dose rates and air sample data.
Dose rate measurements by air sampling teams relate
air concentrations to dosimeter readings.
Calculations of ratio of exposure rate to air
concentration allows worker dosimeter readings to be
related to TEDE - becomes official record.
6-19
-------
RETROSPECTIVE - PROBLEM
Monitoring data at location A:
GM counter (closed beta shield, I m) - 950 mR/h
GM counter (open beta shield, I m - open window pointing up) - significantly higher
Air sample is collected at location A and sent to the laboratory for analysis. The laboratory reports
the following results:
Ce-I4l I.Oe-05 uCi/cm3
Ba-140 I.Oe-04 uCi/cm3
Cs-134 I.Oe-05 uCi/cm3
WHAT CONCLUSIONS CAN BE REACHED IMMEDIATELY FOR LOCATION A?
WHAT ARE THE FOLLOWING FROM A I HR EXPOSURE?
IMMERSION PLUS DEPOSITION DOSE (EDE)?
INHALATION DOSE (CEDE)? (See WORK SHEET on VG 6-22.)
TOTAL DOSE (TEDE)?
WHAT IS THE DOSE TO EMERGENCY WORKERS EXPRESSED AS TEDE PER ROENTGEN AS
READ ON A DOSIMETER?
6-20
-------
RETROSPECTIVE - PROBLEM SOLUTION
Immediate conclusions:
There had been a release of radioactive materials.
The plume was present.
Particulates were present
Actual risk could be much higher than implied by dosimeter readings.
Compare DCFs from plume shine versus ground shine for Cs-l 34. (The DCF for deposited
materials assumes persons remain 96 hours (4 days) at this location - correct for this).
The deposition dose is not significant because the I hr DCF is small compared to the
immersion DCF.
Assuming "mR" is approximately equal to "mrem", the whole body dose rate from gamma radiations
(EDE/h) is:
950 mrem/h
Gamma dose (EDE) due to a I hour external exposure to the plume and groundshine
950 mrem/h I h = 950 mrem = 0.95 rem
6-21
-------
PROBLEM SOLUTION WORK SHEET
Problem Emergency worker : Projected Dose at Location A from inhalation
Nuclide(s)
Ce-I4l
Ba-140
Cs-134
Air
Concentration
(X)
(uCi/cm3)
I.OE-05
I.OE-04
I.OE-05
Projected
Exposure
Time
(h)
Integrated
Air
Concentration
(Xin)
(uCi cm "3 h)
DCF from
Table 5-4
(rem per
uCi cm'3 h)
Totals >
Inhalation
Committed
Effective Dose
Equivalent
(CEDE)
(rem)
6-22
-------
PROBLEM SOLUTION
(cont'd)
Total projected dose (TEDE) to worker for nominal I hour exposure to plume:
0.95 rem (EDE) + 1.12 rem (CEDE) + 0.00 (EDE) =
2.07 rem (TEDE)
* Nominal expected increase in dosimeter reading after I hour is:
0.95 rem (EDE) due to gamma from the plume +
approximately 0.00 rem (EDE) due to gamma from ground shine
total is 0.95 "R" recorded on dosimeter
0.95 "R" Dosimeter reading is equatable to a total dose for the record:
2.07 rem (TEDE)
Retrospective dose for the nominal worker record:
each 1.0 "R" on dosimeter is equivalent to 2.2 rem (TEDE)
6-23
-------
FACTORS THAT MAY
AFFECT DOSE CALCULATIONS
Insufficient air sample and exposure rate data
Ground shine becomes important.
Emergency workers get significant doses outside the
plume.
Emergency workers do not take Kl.
Emergency workers use respirators.
6-24
-------
PLAN CHANGES NEEDED
TO SUPPORT OPTIONS I OR 2
Specify the administrative dose limits for evacuation
support.
Specify procedures for dose control after evacuation is
complete.
6-25
I
-------
PLAN CHANGES NEEDED
TO SUPPORT OPTION 3
Specify procedures for contextual determination of
administrative dose limits.
- Calculation models to be used
- Data needs
- Sources of data
Identify communication procedures and equipment.
Procedures for changing the administrative limits if
applicable
6-26
-------
GU DANCE APPL CABLE TO ALL OPT ONS
Other options may be selected.
- FEMA will review written proposals.
FEMA recommends admin, limits of 2 R or more.
Need procedures for:
- Retrospective dose determinations
- Training
Existing dosimetry systems are acceptable.
Kl use is recommended.
6-27
-------
SESSION 7
DEVELOPMENT
OF
DCFs AND DRLs
-------
IMPLEMENTATION OF PAGS
Must compare a projected TEDE or CDE to the
applicable PAG
BASIC DOSE EQUATION
- Dose (TEDE or CDE) = Dose Rate x Time
- Dose Rate = Concentration x Conversion
Factor
- Dose = Time Integrated Concentration x DCF
7-1
-------
DEF N T ONS
Dose Conversion Factor (DCF): A value that
converts an environmental level to dose.
- Tabulated in units of: rem per uCi cm h
Derived Response Level (DRL): Calculated
environmental level that corresponds to a particular
PAG.
- Tabulated in units of: uCi cm"3 h
7-2
-------
PATHWAYS
(PAG Manual - Section 5.6)
Three exposure pathways are included:
- Gammas from the plume (immersion)
- Inhalation from plume
- Gammas from ground shine (deposited
radionuclides)
Pathways considered, but not included:
- Beta due to skin deposition
- Inhalation of resuspended materials
- Beta from the plume
7-3
-------
SUPPORTING DOCUMENTS FOR DCFS
"External Dose-Rate Conversion Factors for
Calculation of Dose to the Public" (DOE/EH 0070)
- Needed for plume and ground shine
"
Limiting Values of Radionuclide Intake and Air
Concentration and, Dose Conversion Factors for
Inhalation, Submersion and Ingestion" (FGR-I I)
EPA 520/1-88-020 (September 1988).
- Needed only to modify EPA DCFs for inhalation
7-4
-------
TIME INTEGRATED
AIR CONCENTRATION, Xin
Air concentration times projected exposure time.
X(uCi/cm3) Tp(hour) = Xin
Permits addition of the dose conversion factors
over the three exposure pathways.
7-5
-------
EXTERNAL EXPOSURE TO GAMMA RADIATION
FROM THE PLUME
(Section 5.6.1)
Table 5-3 (PAG manual, beginning on P. 5-25)
Gamma radiation due to immersion.
Conservative if plume is overhead.
Semi-infinite source assumption.
7-6
-------
EXTERNAL EXPOSURE TO GAMMA RADIATION
FROM THE PLUME
(cont'd)
DCFs yield effective dose equivalent (EDE).
Based on DOE/EH-0070; EPA FGR #12.
Short-lived daughters are accounted for.
7-7
-------
Table 5-3: Dose Conversion Factors (DCF) and Derived Response
Levels (DRL) for External Exposure Due to Immersion in
Contaminated Air
Radionuclide
DCF
rem per
uCi cm h
DRL
uCi
cm
-3
H-3
C-14
Na-22
Na-24
P-32
O.OE+00
O.OE+00
I.3E+03
2.7E+03
O.OE+00
PAG Manual - beginning on page 5-25
O.OE+00
O.OE+00
7.8E-04
3.7E-04
O.OE+00
7-8
-------
INHALATION FROM THE PLUME
(Section 5.6.2)
Table 5-4 (PAG manual, beginning on 5-31)
Inhalation of radioactive participate material
Alpha, beta and gamma emitters
Chemical and physical form that yields the highest
dose
7-9
-------
INHALATION FROM THE PLUME
(Section 5.6.2)
(cont'd)
Committed effective dose equivalent (CEDE)
Radionuclides may remain in the body,
50 year time frame for dose
Federal Guidance Report No. 11
Standard Person
7-10
-------
Table 5-4: Dose Conversion Factors (DCF) and Derived Response levels
(DRL) for Doses Due to Inhalation
Lung DCF DRL
Radionuclide Class rem per uCi cm"3 h
uCi cm"3 h
H-3 V 7.7E+OI I.3E-02
C-14 LORGC3 2.5E+03 4.0E-04
Na-22 D 9.2E+03 I.IE-04
Na-24 D I.5E+03 6.9E-04
P-32 W I.9E+04 5.4E-05
aL ORG C denotes labelled organic compounds
PAG M nual - beginning on pag 5-31
7-11
-------
Table 5-4: Dose Conversion Factors (DCF) and Derived Response levels
(DRL) for Doses to the Thyroid Due to Inhalation
Lung DCF DRL
Radionuclide Class rem per uCi cm"3 h
uCi cm"3 h
Te/l-132 W/D 2.9E+05 I.8E-05
1-125 D 9.6E+05 5.2E-06
1-129 D 6.9E+06 7.2E-07
1-131 D I.3E+06 3.9E-06
PAG Manual - beginning on page 5-35
Also see Table 5-2 on page 5-15
7-12
-------
EXTERNAL DOSE FROM DEPOSITED MATERIALS
(Section 5.6.3)
Table 5-5 (PAG manual, beginning on 5-37)
Gamma radiation following deposition
Radioiodine and particulates from a plume
Assumes 4-day exposure
Dry deposition
7-13
-------
EXTERNAL DOSE FROM DEPOSITED MATERIALS
(cont'd)
Deposition velocity
- 0.1 cm/s for participate materials
- I cm/s for radioiodine
- Much higher if there is rain
7-14
-------
EXTERNAL DOSE FROM DEPOSITED
MATERIALS
(cont'd)
DCF for deposited materials is the effective dose
equivalent (EDE) in rem per:
- I uCi/cm3 concentration of a radionuclide
- I hour of deposition
- 96 hours of exposure to decaying radionuclides
7-15
-------
TABLE 5-5: DCF EQUATION
FOR GROUND SHINE
(pp. 5-34 and 5-37)
DCF = V DRCF
g
1.14E-3
1-e
-At
A
DCF = the dose per unit air concentration
(rem per uCi cm"3 h)
7-16
-------
TABLE 5-5 DCF EQUATION
(cont d)
»
VB = deposition velocity (cm/h)
o
DRCF = the dose rate conversion factor from
DOE/EH 0070 (mrem/y per uCi/m2)
I. I4E-3 = conversion factor from mrem/y per uCi/m2
to rem/h per uCi/cm2
A = decay constant (h"1)
t = duration (h), assumed to be 96 hours
7-17
-------
Table 5-5: Dose Conversion Factors (DCF) and Derived Response levels
(DRL) for a 4-Day Exposure to Gamma Radiation from
Deposited Radionuclides
DCF DRL
Radionuclide rem per uCi cm"3 h
uCi cm"3 h
H-3 O.OE+00
C-14 O.OE+00
Na-22 8.3E+03 I.2E-04
Na-24 3.IE+03 3.2E-04
P-32 O.OE+00
PAG Manual - beginning on page 5-37.
7-18
-------
MOD FY NG DOSE CONVERS ON FACTORS
Changes in physical characteristics
Changes in chemical characteristics
Changes in breathing rates
Changes in assumed deposition velocities
7-19
-------
COMBINED PATHWAYS
(PAGM nua.T b 5- )
The DCF and DRL for each pathway is related to the
time integrated air concentration (Xin). They may be
combined for a particular radionuclide
DoseTotal = DoseExt+ Doselnh + Dose^^ shine
DoseTotal = DCF^ Xin + DCFlnh Xin
DCFGS Xin
DoseTotal = Xin (DCFB.+ DCFinh + DCFGS)
7-20
-------
Table 5-1: Dose Convers'on Factors (DCF) and Derived Response levels
(DRL) for Comb'ned Exposure Pathways Dur'ng the Early
Phase of a Nuclear Incident
DCF DRL
Radionuclide rem per uCi cm"3 h
uCi cm"3 h
H-3
C-14
Na-22
Na-24
P-32
7.7E+OI
2.5E+03
1 .9E+04
7.3E+03
1 .9E+04
I.3E-02
4.0E-04
5.3E-05
1 .4E-04
5.4E-05
PAG M nual - begin ing on p g 5-9.
7-21
-------
EXAMPLE OF COMBINED PATHWAYS
Nuclide selected
Pathway
External
Inhalation
Ground Shine
Table
5-3
5-4
5-5
Summation
DCF
(rem per uCi cm " 3 h)
xir
(uCi cm"3 h)
1
1
1
Dose
(rem)
Combined
5-1
1
7-22
-------
SESSION 8
DOSE PROJECTION PROBLEMS
FOR THE EARLY PHASE
-------
INTRODUCTION
Two student problems
I. Use of combined pathways DCFs
I a-1 Thyroid dose at I mile
Ib-l TEDEat I mile
la-2 Thyroid dose at 2 miles
I b-2 TEDE at 2 miles
2. Use of separate pathway DCFs
8-1
-------
STEPS TO DETERMINE THE REQUESTED
PROJECTED DOSES
Determine diffusion coefficients (Xu/Q) at the distances
required.
Determine the wind speed in m/s (u).
Determine the source term in Ci/s (Q).
Solve for X.
8-2
-------
STEPS TO DETERMINE THE REQUESTED
PROJECTED DOSES
(cont'd)
Determine the projected exposure time (Tp).
Calculate the time integrated concentration (Xin).
Select the specific DCF (rem per jjCi cm" h).
Calculate the projected dose (rem).
8-3
-------
PROBLEM : PROJECTED DOSE
US NG COMB NED PATHWAY DCFs
t
Problem la: Determine the Committed Dose Equivalent
(CDE) to the thyroid from a plume containing
l-!3l,and
Problem I b: Determine the Total Effective Dose Equivalent
(TEDE) for a plume with a mix of three
isotopes (Xe-133, I-131, and Cs-134).
And: Determine the above doses at I mile and 2
miles from the release point.
8-4
-------
PROBLEM I
Calculate at I mile
- Concentrations (X)
- Time Integrated Concentration (Xjn)
- Dose (CDE to Thyroid and TEDE)
Use Worksheet (VG 8-6)
8-5
-------
1
Problem 1 a -
RAD AT C
& 1 b- 1 : Proiec
Nuclide(s)
& Prblnv
# la-l
1-131
Nuclide
# Ib-l
Xe-133
1-131
Cs-134
Xu/Q
@ 1 mi
(m-2)
Q
(Ci/s)
>NA<
ted Do
u
(m/s)
CCDEr
WOR
se at 1 Mi
X
@J_mi
(pCi/cm3)
sIT ASSESSMENT COURSE
X SHEET
le(s): From thyroid & combined pathway
Exp.
time
(h)"
Xm
@ 1 mi
(pCi cm'3- h)
DCF
Table
No.
DCF^
rem
pCi cm"3- h
DCFCP
TOTAL -
Dose
(CDE)
(rem)
TEDE
(rem)
8-6
-------
PROBLEM I .-INITIAL CONDITIONS
Time from shutdown to release: 2 hours
Estimated release time: 3 hours
Release height: Ground level
Stability is class D.
Wind speed is 2 m/s (4.5 mph).
Forecast is for no change.
8-7
-------
XQ/Q AS A FUNCTION OF
DOWNWIND DISTANCE AND
STABILITY CLASS
Values of Xu/Q (nV2)
Distance
(Miles)
0.5
1
2
3
4
5
7
10
IS
Class
A
6.6E-6
1 .OE-6
5.5E-7
3.9E-7
3.0E-7
2.5 E-7
I.9E-7
1 .4E-7
9.9E-8
Class
B
3.0E-5
7.4E-6
I.9E-6
8.4E-7
4.8E-7
3.3E-7
2.5E-7
1 .8E-7
I.3E-7
Class
C
7.6E-5
2. 1 E-5
6. 1 E-6
2.9E-6
1 JE-6
1 .2E-6
6.3E-7
3.3E-7
1 .8E-7
Class
D
2. 1 E-4
7.0E-5
2.4E-5
I.3E-5
8.5E-6
6. 1 E-6
3.7E-6
2.3E-6
1 .2E-6
Class
E
4.2E-4
I.4E-4
5.0E-5
2.8E-5
1 .9E-5
1 .4E-5
8.4E-6
5. 1 E-6
3. 1 E-6
Ciass
F
9.6E-4
3.3 E-4
1 .2E-4
6.8E-5
4.6E-5
3.3E-5
2.2E-5
1 .4E-5
8.4E-6
A 1250 meter lid is used.
This is a ground level release.
8-8
-------
PROBLEM I: SOURCE TERM
SOURCE TERM (Q):
- Xe-133 l,700Ci/s
- 1-131 0.17 Ci/s
- Cs-134 0.05 Ci/s
8-9
-------
PROBLEM I a-1
CALCULATE AIR CONCENTRATION (X)
At I mile and for I-131:
XQ/Q = 7.0E-05 (from VG 8-8)
WHERE:
X = air concentration (pCi/cm3)
U = average wind speed (mis)
Q = source term (Ci/s)
SOLVE FOR X AT I MILE:
8-10
-------
PROBLEM I a-1: CALCULATE
INTEGRATED AIR CONCENTRATION (XJ
FORI-I3I
Using values recorded on the Work Sheet
Solve for Xin:
Xin = X t
8-11
-------
PROBLEM I a-1
COMMITTED DOSE EQUIVALENT (CDE)
TO THE THYROID
The committed dose equivalent (CDE) to the
thyroid is:
(Xin DCFth)
The dose model is:
,
th
^
th
X =
in
^
th
g.
u
XM
~Q
h
8-12
-------
PROBLEM Ib-l: PROJECTED DOSE
Calculate the TEDE for three nuclides:
Xe-133,1-131, and Cs-134.
Assumptions: Same as for problem I a-1
Dose Model:
TEDE = DCF X
cp in
= DCF
cp
X*/
u Q
h
8-13
-------
PROBLEM Ib-l
SOLVE FOR X AT I MILE
FOR THREE NUCLIDES
Model:
X =
Xu Q
Q »
Calculate concentrations (X)
Xe-133, Q
/-131, Q
Cs-134, Q
I.IE+3
\.7E-l
5.0E-2
7.0E-5 =
Q = 2 m/s
8-14
-------
PROBLEM Ib-l
INTEGRATED AIR CONCENTRATION (Xin)
Using the results from VG 8-14
Solve for X.n for the three nuclides,
'in
Exposure duration = 3 hours
8-15
-------
PROBLEM la-2
SOLVE FOR (CDE) TO THE THYROID FROM
I-131 AT 2 MILES
CDE. = DCF. X.
th th in
Step I. Obtain XG/Q for 2 mi = 2.4E-5. (VG 8-8)
Step 2.
X =
2.5E-5 m~2 \.lE-\Cils
1 mis
8-16
-------
PROBLEM la-2
SOLVE FOR THE (CDE) TO THE THYROID FROM 1-131 AT
2 MILES
Step 3. Xin = X h =
Step 4. Obtain DCFth. The Table is .
The value is
Step 5. Dose = Xin DCFth =
Use the Worksheet on VG 8-18
8-17
-------
RAD AT ON ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem la-2 & lb-2 : Projected Dose at 2 Mile(s): From thyroid & combined pathway
Nuclide(s)
& Prblm.
# la-2
1-131
Nuclides
# lb-2
Xe-133
1-131
Cs- 1 34
XQ/Q
@J_mi
(m-2)
Q
(Ci/s)
0
(m/s)
X
@_2jni
(MCi/cm3)
Exp.
time
(h)
xin
@2mi
(pCi cm"3 h)
DCF
Table
No.
DCF*
rem
pCi cm"3- h
DCFcp
TOTAL -
Dose
rCDE 1
(rem)
TEDE
(rem)
8-18
-------
PROBLEM lb-2: DOSE PROJECTION
TEDE AT 2 MILES
Using the same assumptions for the three radionuclides,
calculate the TEDE at 2 miles.
- Exposure duration = 3 hours
- Stability class = D
- Wind speed = 2 m/s
CDEcp = DCFcp Xin = DCFcp (Q/u XQ/Q h)
8-19
-------
PROBLEM I b 2: FIND TEDE AT 2 MILES
FORXe 133 I 131 AND Cs 134
Step I
X
2mi
Xu . 0
0 tJ
= 2AE-5
LIE+3
LIE-I
5.QE-2
Step2- X-h = Xin (h = 3)
Step 3 - Xin
= TEDE
DCFcp comes from Table
8-20
-------
PROBLEM 2: DOSE PROJECTION USING
SEPARATE PATHWAY DCFs
1 Assumptions:
- Time from shutdown to release: 2 hours
- Estimated release time: 3 hours
- Release height: Ground level
- Stability is class D
- Wind speed is 2 m/s (4.5 mph).
8-21
-------
PROBLEM 2: PROJECTED DOSE AS A FUNCTION OF
PATHWAY
Same source terms, meteorology, and exposure time as for
problem I.
Same integrated air concentrations,
Three separate exposure pathways,
8-22
-------
PROBLEM 2: PROJECTED DOSE AS A FUNCTION OF
PATHWAY (cont'd)
External dose (EDE) from the plume
(Table 5-3)
Plume inhalation dose (CEDE)
(Table 5-4)
External dose (EDE) from deposited radionuclides (Table 5-5)
8-23
-------
PROBLEM!: DOSE MODELS
Dose = DCF X. = DCF
P p in p
Q .
u
XJ
Q
(XQ/Q Q/0) h = X h = Xin
For I-131: (2.4E-5) (17E-1 )/2 = 2.0E-6 Ci/m:
2.0E-6 Ci/m3 3h = 6.0E-6 (uCi cm'3 h)
Calculate Xin and dose for each nuclide.
Fill in matrixes (VG 8-25, 26, and 27).
h
8-24
-------
RAD OLOG CAL ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem 2a : Projected Dose at 2 Mile(s): From immersion pathway
Nuclide(s)
& Prblm.
#2a
Xe-133
1-131
Cs-134
Xu/Q
@2 mi
(m-2)
Q
(Ci/s)
u
(mis)
X
@2mi
(pCi/cm3)
Exp.
time
(h)
xin
@2 mi
(jjCi cm"3 h)
DCF
Table
No.
DCF^
rem
pCi cm'3- h
TOTAL -
Dose
( }
(rem)
8-25
-------
RAD OLOG CAL ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem 2b : Projected Dose at 2 Mile(s): From inhalation pathway
Nuclide(s)
& Prblm.
#2b
Xe-133
1-131
Cs- 1 34
Xu/Q
@2mi
(m-2)
Q
(Ci/s)
0
(m/s)
X
@2mi
(MCi/cm3)
Exp.
time
(h)
xin
@2mi
(pCi cm"3 h)
DCF
Table
No.
DCF^
rem
pCi cm"3- h
TOTAL -
Dose
( )
(rem)
8-26
-------
RADIOLOGICAL ACCIDENT ASSESSMENT COURSE
WORK SHEET
Problem 2c : Projected Dose at 2 Mile(s): From deposition pathway
Nuclide(s)
& Prblm.
# 2c
Xe-133
1-131
Cs- 1 34
Xu/Q
@2mi
(m-2)
Q
(Ci/s)
Q
(m/s)
X
@ 2 mi
(MCi/cm3)
Exp.
time
(h)
xin
@2 mi
(|jCi cm"3- h)
DCF
Table
No.
DCF^
rem
uCi cm"3- h
TOTAL -
Dose
( v
(rem)
8-27
-------
RADIOLOGICAL ACCIDENT ASSESSMENT COURSE
WORK SHEET
Problem # 2
The dose model is: Dose = DCF Xin = DCF (Q/u XG/Q h)
DOSE PROJECTION AT 2 MILES FOR INDIVIDUAL PATHWAYS
Nuclide
1-131
Cs- 1 34
Xe-133
Pathway
immersion
inhalation
deposition
DCF
rem
(pCi -cm*3- h)
2.2E+2
3.9E+4
I.3E+4
xin
(pCi cm"3 h)
6.0E-6
6.0E-6
6.0E-6
Dose
(rem)
I.3E-3
2.4E-I
8.0E-2
TEDE for 1-13 1 3.2E-I
immersion
inhalation
deposition
9.IE+2
5.6E+4
6.2E+3
I.8E-6
I.8E-6
I.8E-6
I.7E-3
I.OE-I
I.IE-2
TEDE for Cs- 134 I.IE-I
immersion
inhalation
deposition
20
0
0
6.0E-2
6.0E-2
6.0E-2
1.2
0
0
TEDE for Xe-133 1.2
TEDE for all radionudides combined
1.5
8-2
-------
SESSION 9
PROTECTIVE ACTION GUIDES FOR
RELOCATION AND RETURN
AND
DOSE LIMITS FOR RECOVERY WORKERS
-------
THE "R" WORDS
(p. A-3)
Relocation: The removal or continued exclusion of
people (households) from contaminated areas to avoid
chronic radiation exposure.
Return: The reoccupation of areas cleared for
unrestricted residence or use.
Restricted zone: An area with controlled access from
which the population has been relocated.
9-1
-------
THE "R" WORDS
(p. A-3)
(cont'd)
Reentry: Temporary entry into a restricted zone
under controlled conditions.
Recovery: The process of reducing radiation exposure
rates and concentrations in the environment to
acceptable levels for unconditional occupancy or use.
9-2
-------
POTENTIAL TIME FRAME OF
RESPONSE TO A NUCLEAR INCIDENT
Refer to PAG Manual Page 7-5.
Times are estimates only.
Sequences may vary some.
9-3
-------
EXPOSURE PATHWAYS
(p. 4-2)
Pathways to be evaluated as basis for relocation
- Whole body exposure to gamma radiation
- Inhalation of resuspended materials
Minor pathways (no evaluation needed for reactor
accidents)
- Beta skin exposure
- Inadvertent ingestion of dirt
- Refer to EPA 520/1-89-016
9-4
-------
ESTIMATED DOSE FROM MINOR
EXPOSURE PATHWAYS
Individual3
adult
child
adult or child
Exposure
Pathway
skinb
ingestionc
skinb
ingestionc
groundshine
First Year Dose (rem)
Soil
2.4
0.01
8.1
0.05
1.0
Pavement
8.4
O.I
14
0.5
1.0
aMaximum exposed individuals. Average exposure is about 1/3 to 1/6 lower.
blncludes beta dose from nearby surfaces and from material on the skin.
inadvertent ing stion of contaminat d dirt.
9-5
-------
RELOCATION AND RETURN PAGS
(p. 4-4)
Projected Dose From
First Year Exposun
>2 rem TEDE
^100 rem DE skin
<2 rem TEDE
< 100 rem DE
Protective Action
Establish restricted zone and
relocate the general
population.
Apply simple dose reduction
techniques to skin.
9-6
-------
RELOCATION AND RETURN PAGS
(p. 4-4 4-5 E-13 & E-20)
(cont'd)
Additional guidance
- 0.5 rem in any year after the first
5 rem in 50 years
Actual dose should be less than projected dose
Shielding
- Mobility
- Special dose reduction efforts
- Refer to tables on pages E-13 and E-20
9-7
-------
PLUME TRAVEL
DIRECTION
LEGEND
LJ
1. PLUME DEPOSITION
2. AREA FHOM WHICH
TOM « EVACUATED.
3.
A M
POPULATION a
4 AREA FHOM VMMOH POPUUMHON O RELOCATED pESmCTEO ZONE).
9-8
-------
GRADUAL RETURN
(p. 4-5 & 7-4)
Establishment of buffer zone
Gradual return
FEMA option to combine temporary relocation and gradual
return boundaries
- Advantage - no early dose calculations
Disadvantage - large relocation area
- major public disruption
9-9
-------
DOSE REDUCTION FOR RETURNEES
(p. 4-3)
Areas for priority
- Dose in excess of 0.5 rem in I st year
- Residences of pregnant women
Responsibility for actions
9-10
-------
EXAMPLES OF
S MPLE DOSE REDUCT ON TECHN QUES
(pp.4-3, 7-6, E-13, &E-I9)
Scrub/flush/wipe hard surfaces.
Soak or plow soil.
Cut and remove grass clippings and other foliage.
Remove spots of soil where radioactivity has concentrated,
Disposal of contaminated materials
9-11
-------
SIMPLE DOSE REDUCTION TECHNIQUES
(pp.43, 76, E-I3,&E 19)
(cont'd)
Remove debris.
Spend more time in areas with lower contamination levels
(e.g., indoors).
Replace sandbox sand.
Pay special attention to child hygiene.
9-12
-------
RAT ONALE - FOUR PR NC PLES
Acute health effects
Delayed health effects
Cost of avoiding risk
Risk - risk comparison
9-13
-------
FACTORS NOT NCLUDED N
THE RELOCAT ON PAGs
Physical and mental stress
Past exposures
Dose from ingestion
Dose from occupational exposure
9-14
-------
COST ANALYSIS
(pp. E-8, E-9, & E-10)
Assumptions:
- Value of avoiding a statistical death is $400,000 to
$7,000,000.
*
- Average daily cost of relocation is $27 - Refer to EPA
520/1-89-015.
Where does the daily cost of relocation equal the
monetary value of average daily risk avoided?
9-15
-------
10 11 10
TIMt AFTBH ACCIOKMT
-------
PRINCIPLE
BASIS FOR SETTING PAG LEVELS
(p. I -5)
STRATEGY
(I) Avoid acute health effects.
(2) Adequately protect against
cancer and genetic effects
under emergency conditions.
(3) Optimize cost of protective
action versus avoided dose.
(4) Regardless of the above
principles, the risk from a
protective action should not
itself exceed the risk from the
dos th t would be void d.
Stay below threshold dose.
Set PAG at this level unless
driven down by cost/risk
considerations (3), or up by
risk/risk considerations (4).
Use this principle only if the
the PAG value is driven down.
Use this principle only if the
PAG value is driven up.
9-17
-------
CONCLUSIONS ON APPROPRIATE VALUE
FOR RELOCATION PAG
(p. E-18)
Principle on acute effects is not applicable.
Judgment of acceptable level of risk of delayed health
effects:
- 5 rem in 50 years
- 0.5 rem in any single year after the first
2 rem in the first year will meet the above criteria for
nuclear power plant accidents.
9-18
-------
CONCLUS ONS ON APPROPR ATE VALUE
FOR RELOCAT ON PAG
(p. E-18)
(cont'd)
Cost will not drive the first year dose below 2 rem,
Risk from relocation is assumed to be the same as for
evacuation (i.e., equivalent to the risk from about 30
mrem).
9-19
-------
DOSE LIMITS FOR RECOVERY WORKERS
(pp.46, 7 17, &E 19)
Same as for occupationally exposed workers
- TEDE 5 rem/y
- CDE to any organ 50 rem/y
- One tenth these values to persons under
age 18
- TEDE to declared pregnant
women 0.5 rem/9mo
9-20
-------
SESSION 10
DATA COLLECTION AND DOSE PROJECTION
FOR
RELOCATION AND RETURN DECISIONS
-------
IMPLEMENTING PAGS FOR THE INTERMEDIATE
PHASE
Relocation
Reentry
Return
Early Decontamination
Ingestion of Food and Water
- Independent decision
10-1
-------
OVERV EW OF
MPLEMENTAT ON PROCESS
Collect environmental samples.
Analyze samples.
Calculate
- Exposure rates and projected dose.
- Accident specific DCFs.
- Derived response level.
Make gamma exposure rate measurements.
10-2
-------
OVERV EW OF
MPLEMENTAT ON PROCESS
(cont'd)
Take air samples and calculate projected dose from
inhalation of resuspended materials.
Identify the boundary of the restricted zone.
Relocate the population.
Identify the buffer zones.
Implement gradual return.
10-3
-------
SAMPLE COLLECTION AND ANALYSIS
Purpose of samples
- Dose projection
- Evaluation of variation in mix by area
Nature of samples
Locations of samples
- Based on exposure rate
- Priorities
- Terrain
Types of analyses
10-4
-------
ALTERNATIVE METHODS
FOR DOSE PROJECTION
METHOD ONE - Sample from each area of interest
- Known size of area in each sample
- Use data from each sample analysis to project dose.
- Plot projected doses on map to identify location of
boundary to the restricted zone.
10-5
-------
ALTERNATIVE METHODS FOR
DOSE PROJECTION
(cont'd)
METHOD TWO - Take a few samples from several
areas.
Determine whether the radionuclide mix is reasonably
constant or predictable. If so:
- Calculate a time-dependent derived response level
(DRL^) corresponding to the PAG.
- Use the DRL^ to identify the restricted zone.
10-6
-------
CONS DERAT ON OF METHOD ONE
Requires a arge number of
- samples
- laboratory analyses
- dose projections
May yield wrong result for other than flat terrain
Only method available if radionuclide mix is neither
constant nor predictable
10-7
-------
CONSIDERATION OF METHOD TWO
Not useful for an inconsistent mix of radionuclides.
Greatly reduces the sampling and laboratory effort.
Results are independent of terrain type or presence of
contaminated foliage.
Inaccuracies due to non-representative samples cancel.
10-8
-------
EXAMPLE CALCULATION OF EXPOSURE RATE
- Method One -
Radionuclide
Cs-134
1-131
Concentration
pCi/m2
2E+7
3E+7
Initial exposure Rate @ 1 m
(mR/h per pCi/m2)
(table 7-1 or 7-2)
Total:
Exposure Rate @ 1 m
(mR/h)
10-9
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
Integrated Dose - Year One
Radionuclide
Cs-134
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
TOTAL
Projected
Dose
(mrem)
No Weathering
DCF
(mrem/pCi/m2)
(Table 7-2)
TOTAL
Projected
Dose
(mrem)
10-10
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
Integrated Dose - Year Two
Radionuclide
Cs-134
1-131
Concentration(
pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
TOTAL
Projected
Dose
(mrem)
No Weathering
DCF
(mrem/pCi/m2)
. (Table 7-2)
TOTAL
Projected
Dose
(mrem)
.
10-11
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
Integrated Dose - Zero to 50 Years
Radionuclide
Cs- 1 34
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
TOTAL
Projected
Dose
(mrem)
No Weathering
DCF
. (mrem/pCi/m2)
(Table 7-2)
TOTAL
Projected
Dose
(mrem)
10-12
-------
METHOD 2
Calculate an accident-specific dose conversion factor
(DCFas).
- This factor is time dependent.
Use DCFas to calculate a time-dependent derived
response level (DRL^) in mR/h corresponding to the
PAG.
10-13
-------
CALCULATION OF ACCIDENT SPECIFIC DCF
Method 2
35
= mrem per yr- 1 , /r-2, or 0 to 50 yr
Exposure Rate @ I m (mRlh)
Assume weathering and results from VGs 9, 10, II,
and 12, and calculate:
Year one DCFas =
Year two DCFas =
Zero to 50 year DCFas =
10-14
-------
CALCULATION OF ACCIDENT SPECIFIC DRL
Method 2
DCF
as
For the previous example (weathering included):
Year one DRLas =
Year two DRLas =
do
Zero to 50 year DRLas =
10-15
-------
DCF FOR PROJECTED EXTERNAL GAMMA DOSE
/ J
0
DCF = DS pi1"*
I ^H "^
D
= dose rate per unit deposit (mrem/yr per pCi/m2) (data in DOE EH 0070)
Sf = protection factor for shielding and partial occupancy (assumed to be unity)
AR = radioactive decay constant (yr"1)
A2 = assumed weathering decay constant for 63% of the radionuclide =1.13 yr"1
A3 = assumed weathering decay constant for 37% of the radionuclide = 7.48E-3 yr"1
t = time of exposure (yr)
10-16
-------
CALCULATION OF DOSE FROM INHALATION
OF RESUSPENDED MATERIALS (CEDE)
(Table 7-4, p. 7-16)
H50 = I x DCF
WHERE:
Hso = CEDE for 50 y from intake of nuclides
I = total intake (pCi)
DCF = dose per unit intake for the radionuclide
(rem per pCi)
- Data are from EPA FGR No. 11
- Convert to appropriate units
10-17
-------
TOTAL NTAKEFROM NHALATON
OF RESUSPENDED MATERIAL
WHERE:
B
/ = BC
o
total intake in I year (pCi)
breathing rate, assumed to be I.05E+4 m3/yr
initial air concentration of the resuspended radionuclide (pCi/m3)
radioactive decay constant (yr"1)
assumed weathering decay constant for 63% of the radionuclide =1.13 yr"1
assumed weathering decay constant for 37% of the radionuclide = 7.48E-3 yr"1
time of exposure (yr)
10-18
-------
WEATHERING OF THE RESUSPENSION FACTOR
EPA assumes gamma weathering for resuspension.
Empirical data for alpha emitters shows much faster
reduction.
Refer to:
- WASH-1400 Appendix VI page E-13 for a time
dependent model.
- IAEA Safety Series 81,1986, page 62 for plot of the
resuspension factor as a function of time and of the
integral.
10-19
-------
CALCULATION OF INHALATION DOSE (CEDE)
FROM RESUSPENDED MATERIALS
Includes weathering? [ ] yes [ ] no
Sample
Radio-
Nuclide
Cs-134
1-131
location Analysis date
Air
Concentration
(pCi/m3)
1200
420
Yr. 1 DCF
(mrem per
pCi/m3)
TOTAL-
Dose From
Yr. 1 Exp.
(mrem)
Yr. 2 DCF
(mrem per
pCi/m3)
TOTAL-
Dose From
Yr. 2 Exp.
(mrem)
.
10-20
-------
SESS ON
DOSE PROJECTION PROBLEMS
FOR
RELOCATION AND RETURN DECISIONS
-------
PROBLEM I - A: DERIVATION OF AN
ACCIDENT-SPECIFIC DOSE
CONVERSION FACTOR (I)
-Method ONE-
GIVEN:
A surface soil sample is analyzed and is found to
contain the following concentrations (pCi / m2):
*
Zr-95 7.4 E+6 Cs-134 I2.0E+6
Ru-103 3.1 E+6 Cs-137 1.2 E+6
1-131 4.1 E+6 Ba-140 6.2 E+6
Radioactive decay and weathering will occur.
11-1
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFJ
For? [ x] Y ar 1 [ ] Ye r 2 [ ] 50 Y rs
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru- 1 03
1-131
Cs- 1 34
Cs- 1 37
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4E+06
3.IE+06
4. 1 E+06
1 .2E+07
1 .2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
TOTAL-
Calculated
DOSE
(mrem)
Combined DCF
as
mrem per mR/h
(date_
11-2
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ ] Year 1 [ X] Year 2 [ ] 50 Years
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru- 1 03
1-131
Cs- 1 34
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4E+06
3.IE+06
4. 1 E+06
1 .2E+07
I.2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
.
TOTAL-
Calculated
DOSE
(mrem)
Combin d DCF
as
mrem p r mR/h
(dt
11-3
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ ] Year 1 [ ] Year 2 [ X] 50 Years
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs- 1 34
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4E+06
3. 1 E+06
4. 1 E+06
I.2E+07
1 .2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
TOTAL-
Calculated
DOSE
(mrem )
Combined DCF
as
mrem per mR/h
(date_
11-4
-------
PROBLEM I - B: DERIVATION OF AN
ACCIDENT-SPECIFIC DOSE
CONVERSION FACTOR (I)
- Method TWO -
GIVEN:
A surface soil sample is analyzed and is found to
contain the following activities (uCi / sample):
Zr-95 7.4 Cs-134 12
Ru-103 3.1 Cs-137 1.2
1-131 4.1 Ba-140 6.2
Radioactive decay and weathering will occur.
11-5
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFJ
For? [ x] Y r 1 [ ] Ye r 2 [ ] 50 Y ars
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru- 1 03
1-131
Cs-134
Cs-137
Ba- 1 40
Measured
Ground
Concentration
(pCi/sample)
7.4E+06
3. 1 E+06
4. 1 E+06
I.2E+07
1 .2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
.
TOTAL-
Nominal
Calculated
DOSE
(mrem @ 1 m)
Combin d DCF,
_mr m p r mR/h
(dat
11-6
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ ] Year 1 [ X] Y ar 2 [ ] 50 Y rs
Sample location Weathering? [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs- 1 34
Cs- 1 37
Ba-140
Measured
Ground
Concentration
(pCi/sample)
7.4E+06
3. 1 E+06
4. 1 E+06
1 .2E+07
I.2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-*
Nominal
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pG/m'l
TOTAL-
Nominal
Calculated
DOSE
(mrem @ 1 m)
Combin d DCFa
_mr m p r mR/h
(d te.
11-7
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFJ
For? [ ] Year 1 [ ] Year 2 [ X] 50 Years
Sample location Weathering' [ ] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/sample)
7.4E+06
3.IE+06
4. 1 E+06
1 .2E+07
1 .2E+06
6.2E+06
Initial Exp.
Rate @ 1 m
(mR/h per
pCi/m2)
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h @ 1 m)
Integrated
Dose
(mrem per
pCi/m2)
TOTAL-
Nominal
Calculated
DOSE
(mrem @ 1 m)
Combin d DCF,
_mr m p r mR/h
(dat
11-8
-------
PROBLEM 2: DERIVED RESPONSE LEVELS
Using results from Problem I, calculate time-dependent
derived response levels (DRL^) corresponding to:
- year I
- year 2
- 50 years
Interpret the results.
11-9
-------
PROBLEM 3
PROJECTED DOSE
Field teams report the following exposure rates:
Location A 3 mR/h
Location B 10 mR/h
Location C 30 mR/h
Assume the radionuclide mix from Problem I.
What is the projected dose from gamma radiation at each
location for each of the three time periods?
11-10
-------
PROBLEM 3: PROJECTED DOSE
(cont'd)
Location
A
B
C
Meter
Reading
(mR/hr)
3
10
30
Projected
dose
year one
(rem)
DCF for year one (rem per mR/h)
DCF for year two (rem per mR/h)
DCF for 0 to 50 y (r m p r mR/h)
Projected
dose
year two
(rem)
3.3
1.2
8.2
Projected
dose
0 to 50 y
(rem)
11-11
-------
PROBLEM 4: INHALATION DOSE
DUE TO RESUSPENDED MATERIALS (I)
Analysis of an air sample collected at location "A" where
the exposure rate is 3 mR/h yields activities as follows
(pCi/m3):
Zr-95 760 Cs-134 1200
Ru-103 320 Cs-137 120
1-131 420 Ba-140 630
Weathering is assumed.
11-12
-------
CALCULATION OF INHALATION DOSE (CEDE)
FROM RESUSPENDED MATERIALS
Includes weathering? [ x ] yes [ ] no
Sample location A Analysis date
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Air
Concentration
(pCi/m3)
760
320
420
1200
120
630
Yr. 1 DCF
(mrem per
PCi/m3)
TOTAL-
Dose From
Yr. 1 Exp.
(mrem)
Yr. 2 DCF
(mrem per
pCi/m3)
TOTAL-
Dose From
Yr. 2 Exp.
(mrem)
11-13
-------
-------
SESSION 12
COURSE REVIEW AND WRAP-UP
Ritchey C. Lyman
Office of Radiation and Indoor Air
Phone (202) 564-9363
Fax: (202) 565-2037
lyman.ritchey@epa.gov
-------
- PROBLEM SOLUTIONS -
-------
PROBLEM SOLUTION
Problem Emergency worker Projected Dose at Location A from inhalation
Nuclide(s)
Ce-I4l
Ba-140
Cs-134
Air
Concentration
(X)
(uCi/cm3)
1 .OE-05
LOE-04
1. OE-05
Projected.
Exposure
Time
(h)
1
1
1
Integrated Air
Concentration
(uCi cm"3 h)
0.00001
0.000 1
0.00001
DCF from
Table 5-4
(rem per
uCi cm"3 h)
I.IE+04
4.5E+03
5.6E+04
Totals >
Inhalation
Committed
Effective Dose
Equivalent
(CEDE)
(rem)
O.I I
0.45
0.56
1.12
6-22a
-------
EXAMPLE OF COMBINED PATHWAYS
SOLUTION
Nuclide selected Co-60
Pathway
External
Inhalation
Ground Shine
Table
5-3
5-4
5-5
Summation
DCF
(rem per uCi cm "3 h)
I.5E+3
2.6E+5
8.9E+3
xin
(uCi ; cm"3 h)
1
1
1
Dose
(rem)
I.5E+3
2.6E+5
8.9E+3
2.6E+5
Combined
5-1
2.7E+5
1
2.7E+5
7-22a
-------
RAD AT ON ACC DENT ASSESSMENT COURSE
WORKSHEET
Problem I a-1 & Ib-l : Projected Dose at I Mile(s): From thyroid & combined pathway
Nuclide(s)
& Prblm.
# la-l
1-131
Nuclide
# Ib-l
Xe-133
1-131
Cs-134
Xu/Q
@J_mi
(m2)
7.0E-5
7.0E-5
7.0E-5
7.0E-5
Q
(Ci/s)
0.17
1700
0.17
0.05
u
(m/s)
2
2
2
2
X
@J_mi
(MCi/cm3)
6.0E-6
6.0E-2
6.0E-6
I.8E-6
Exp.
time
(h)
3
3
3
3
xin
@J_mi
(MCi-cm-3-h)
I.8E-5
I.8E-I
I.8E-5
5.25E-5
DCF
Table
No.
5-2
5-1
5-1
5-1
DCF^
rem
MCi cm"3' h
I.3E+6
DCFcp
2.0E+I
5.3E+4
6.3E+4
TOTAL -
Dose
(CDE)
(rem)
23
TEDE
(rem)
3.6
0.95
0.33
4.9
8-6a
-------
RAD AT ON ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem la-2 & lb-2 : Projected Dose at 2 Mile(s): From thyroid & combined pathway
Nuclide(s)
& Prblm.
# la-2
1-131
Nuclides
# lb-2
Xe-133
1-131
Cs-134
Xu/Q
@_2_mi
(m-2)
2.4E-5
2.4E-5
2.4E-5
2.4E-5
Q
(Ci/s)
0.17
1700
0.17
0.05
u
(m/s)
2
2
2
2
X
@2mi
(pCi/cm3)
2.0E-6
2.0E-2
2.0E-6
6.0E-7
Exp
time
(h)
3
3
3
3
xin
@_2_mi
(pCi cm"3- h)
6.0E-6
6.0E-2
6.0E-6
I.8E-6
DCF
Table
No.
5-2
5-1
5-1
5-1
DCF*
rem
(jCi cm"3- h
I.3E+6
DCFcp
2.0E+I
5.3E+4
6.3E+4
TOTAL -
Dose
(CDE)
(rem)
8
,
TEDE
(rem)
1.2
0.32
0.12
1.6
8-18a
-------
RAD OLOG CAL ACC DENT ASSESSMENT COURSE
WORK SHEET
Problem 2a Projected Dose at 2 Mile(s): From immersion
pathway
Nuclide(s)
& Prblm.
# 2
Xe-133
1-131
Cs-134
XQ/Q
@2mi
(m-2)
2.4E-5
2.4E-5
2.4E-5
Q
(Ci/s)
1700
0.17
0.05
U
(m/s)
2
2
2
X
@2mi
(pCi/cm3)
2.0E-2
2.0E-6
6.0E-7
Exp.
time
(h)
3
3
3
xin
@2 mi
(pCi cm"3- h)
6.0E-2
6.0E-6
1 .8E-6
DCF
Table
No.
5-3
5-3
5-3
DCFim
rem
pCi cm"3- h
20
2.2E+2
9.IE+2
TOTAL-
Dose
(EDE)
(rem)
1.2
I.3E-3
IJE-3
1.2
8-25a
-------
RADIOLOGICAL ACCIDENT ASSESSMENT COURSE
WORK SHEET
Problem 2b : Projected Dose at 2 Mile(s): From inhalation pathway
Nuclide(s)
& Prblm.
# 2b
Xe-133
1-131
Cs-!34
XQ/Q
@_2_mi
(m-2)
2.4E-5
2.4E-5
2.4E-5
Q
(Ci/s)
1700
0.17
0.05
0
(m/s)
2
2
2
X
@2mi
(pCi/cm3)
2.0E-2
2.0E-6
6.0E-7
Exp.
time
(h)
3
3
3
xin
@_2_mi
(|jCi cm"3- h)
6.0E-2
6.0E-6
1 .8E-6
DCF
Table
No.
5-4
5-4
5-4
DCFinh
rem
pCi cm"3- h
0
3.9E+4
5.6E+4
TOTAL-
Dose
(CEDE)
(rem)
0
2.4E-I
I.OE-I
3.4E- 1
8-26a
-------
RADIOLOGICAL ACCIDENT ASSESSMENT COURSE
WORK SHEET
Problem_2c_: Projected Dose at 2 Mile(s): From ground shine pathway
Nuclide(s)
& Prblm.
# 2c
Xe-133
1-131
Cs-134
Xii/Q
@2mi
(m-2)
2.4E-5
2.4E-5
2.4E-5
Q
(Ci/s)
1700
0.17
0.05
u
(m/s)
2
2
2
X
@_2_mi
(nCi/cm3)
2.0E-2
2.0E-6
6.0E-7
Exp.
time
(h)
3
3
3
xin
@_2_mi
(nCi cm'3- h)
6.0E-2
6.0E-6
1.8E-6
DCF
Table
No.
5.5
5.5
5.5
DCFdep
rem
jiCi cm"3- h
0
1.3E+4
6.2E+3
TOTAL -
Dose
(EDE)
(rem)
0
8.0E-2
1.1E-2
0.09
8-27a
-------
EXAMPLE CALCULAT ON OF EXPOSURE RATE
- M thod On -
SOLUTION
Radionuclide
Cs-134
1-131
Concentration
pCi/m2
2E+7
3E+7
Initial exposure Rate @ 1m
(mR/h per pCi/m2)
(table 7-1 or 7-2)
2.6E-8
6.6E-9
Total:
Exposure Rate @ 1m
(mR/h)
0.52
0,20
0.72
10-9a
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
SOLUTION
Integrated Dose - Year One
Radionuclide
Cs-134
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
l.OE-4
1.3E-6
TOTAL
Projected
Dose
(mrem)
2000
39
2039
No Weathering
DCF
(mrem/pCi/m2)
(Table 7-2)
1.3E-4
1.3E-6
TOTAL
Projected
Dose
(mrem)
2600
39
2639
10-10a
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
SOLUTION
Integrated Dose - Year Two
Radionuclide
Cs-134
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
4.7E-5
0
TOTAL
Projected
Dose
(mrem)
940
0
940
No Weathering
DCF
(mrem/pCi/m2)
(Table 7-2)
9.6E-5
0
TOTAL
Projected
Dose
(mrem)
1900
0
1900
10-lla
-------
EXAMPLE CALCULATION OF PROJECTED DOSE
- Method One -
SOLUTION
Integrated Dose - Zero to 50 Years
Radionuclide
Cs-134
1-131
Concentration
(pCi/m2)
2E+7
3E+7
Weathering
DCF
(mrem/pCi/m2)
(Table 7-1)
2.4E-4
1.3E-6
TOTAL
Projected
Dose
(mrem)
4800
39
4839
No Weathering
DCF
(mrem/pCi/m2)
(Table 7-2)
4.7E-4
1.3E-6
TOTAL
Projected
Dose
(mrem)
9400
39
9439
10-12a
-------
CALCULATION OF ACCIDENT SPECIFIC DCF
Method 2
SOLUTION
mrem per yr-1, yr-2, or 0 to 50 yr
Exposure Kate @ 1m (mR/h)
Assume weathering and results from VGs 9,10,11, and 12, and
calculate:
- Year one DCFas = 2039 mrem/0.72 mR/h = 2832 mrem/niR/h
- Year two DCFas = 940 mrem/0.72 mR/h = 1305 mrem/mR/h
- 0 to 50 year DCFas = 4839 rem/0.72 R/h = 6720
10-14a
-------
CALCULATION OF ACCIDENT SPECIFIC DRL
- Method 2 -
SOLUTION
DRL
PAG
td ~ DCF
as
For the previous example (weathering included):
Year one DRLas = 2000 mrem *- 2832 mrem/mR/h = 0.71 mR/h
Year two DRLas = 500 mrem -5-1305 mrem/mR/h = 0.38 mR/h
- Z ro to 50 y r DRLas = 5000 + 6720 = 0.74 mR/h
10-15a
-------
CALCULATION OF INHALATION DOSE (CEDE)
FROM RESUSPENDED MATERIALS
Includes weathering? [ x ] yes [ ] no
Sample
Radio-
Nuclide
Cs-134
1-131
location Analysis date
Air
Concentration
(pCi/m3)
1200
420
Yr. 1 DCF
(mrem per
pCi/m3)
3.1E-1
1.1E-2
TOTAL-
Dose From
Yr. 1 Exp.
(mrem)
370
4.6
375
Yr. 2 DCF
(mrem per
pCi/m3)
1.5E-1
0
TOTAL-
Dose From
Yr. 2 Exp.
(mrem)
180
0
180
10-20 a
-------
Problem 1: Derivation of an Accident-Specific Dose Conversion Factor
SOLUTION
Refer to Table 7-1 and, as example, Table 7-3.
Unit of the DCF for the projected external gamma dose is:
xx mrem for each mR/h measured at the beginning of the period
For year one:
1.6E+03 mrem per 4.9E-01 mR/h yields
3.3e+3 mrem per mR/h or 3.3 rem per mR/h
For 0-50 years:
4.0E-03 mrem per 4.9E-01 mR/h
8.2E+3 mrem per mR/h or 8.2 rem per mR/h
ll-la
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [xIYearl [ I Year 2 [ ] 50 Years
Sample location A Weathering? [ x] yes [ ] no
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
Integrated
Dose
(mrem per
pCi/m2)
3.3e-05
7.1e-06
1.3e-06
l.Oe-04
4.5e-05
l.le-05
TOTAL-
Calculated
DOSE
(mrem)
2.4e+02
2.2e+01
5.3e+00
1.2e+03
5.4e+01
6.8e+01
1.6e+03
Co bined DCFas _3.3 e+03_ re per R/h
(date_
ll-2a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ JYearl [x] Year 2 [ ] 50 Years
Sample locatioi
Radio-
Nuclide
Zr-95
Ru-103
M31
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
n A Weathering
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
9 [x]yes []
Integrated
Dose
(mrem per
pCi/m2)
4.0e-07
O.Oe+00
O.Oe+00
4.7e-05
2.9e-05
O.Oe+00
TOTAL-
no
Calculated
DOSE
(mrem)
3.0e+00
O.Oe+00
O.Oe+00
5.6e+02
3.5e+01
O.Oe+00
6.0e+02
Co binedDCFas___1.2e+03_ re per
R/h (date.
ll-3a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For'' [ JYearl [ ] Year 2 [x] 50 Years
Sample locatioi
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
i A Weathering'
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
? [ x] yes [ ] no
Integrated
Dose
(mrem per
pCi/m2)
3.4e-05
7.1e-06
1.3e-06
2.4e-04
6.1e-04
l.le-05
TOTAL-
Calculated
DOSE
(mrem)
2.5e+02
2.2e+01
5.3e+00
2.9e+03
7.3e+02
6.8e+01
4.0e+03
Co bined DCFas _8.2 e+03_ re per R/h
(date
11-4 a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [xJYearl [ ] Year 2 [ ] 50 Years
Sample locatioi
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
i A Weathering*
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
? [ x] yes [ ] no
Integrated
Dose
(mrem per
pCi/m2)
3.3e-05
7.1e-06
1.3e-06
l.Oe-04
4.5e-05
l.le-05
TOTAL-
Nominal
Calculated
DOSE
(mrem)
2.4e+02
2.2e+01
5.3e+00
1.2e+03
5.4e+01
6.8e+01
1.6e+03
Co bined DCFas _3.3 e+03_ re per R/h
(date_
ll-6a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For'' [ JYearl [x|Year2 [ ] 50 Years
Sample locatioi
Radio-
Nuclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
i A Weathering
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
? [x]yes [
Integrated
Dose
(mrem per
pCi/m2)
4.0e-07
O.Oe+00
O.Oe+00
4.7e-05
2.9e-05
O.Oe+00
TOTAL-
no
Nominal
Calculated
DOSE
(mrem)
3.0e+00
O.Oe-l-00
O.Oe+00
5.6e+02
3.5e+01
O.Oe+00
6.0e+02
Combined DCFas _1.2 e+03_ re per R/h (date.
ll-7a
-------
CALCULATION OF ACCIDENT-SPECIFIC DCF (DCFas)
For? [ JYearl ( J Year 2 [x] 50 Years
Sample locatioi
Radio-
iS uclide
Zr-95
Ru-103
1-131
Cs-134
Cs-137
Ba-140
Measured
Ground
Concentration
(pCi/m2)
7.4e+06
3.1e+06
4.1e+06
1.2e+07
1.2e+06
6.2e+06
i A Weathering*
Initial Exp.
Rate @ 1m
(mR/h per
pCi/m2)
1.2e-08
8.2e-09
6.6e-09
2.6e-08
l.Oe-08
3.2e-09
TOTAL-
Nominal
Calculated
Exp. Rate
(mR/h@lm)
8.9e-02
2.5e-02
2.7e-02
3.1e-01
1.2e-02
2.0e-02
4.9e-01
? [ x] yes [ ] no
Integrated
Dose
(mrem per
pCi/m2)
3.4e-05
7.1e-06
1.3e-06
2.4e-04
6.1e-04
l.le-05
TOTAL-
Nominal
Calculated
DOSE
(mrem)
2.5e+02
2.2e+01
5.3e-i-00
2.9e+03
7.3e+02
6.8e+01
4.0e+03
Co bined DCFas _8.2 e+03_ re per R/h
(date.
11-8 a
-------
Problem 2: Derived Response Levels
SOLUTION
A time-dependent derived response level (DRLtd) is the meter reading (mR/h (a), 1m)
which, at the time of measurement, corresponds to either the year 1, year 2, or 0-50
year dose.
For year one, a meter reading of 1 mR/h at 1 meter above the ground indicates an
external gamma radiation dose of 3.3 rem during the first year. Therefore, the
DCF (rem per mR/h) is 3.3 rem per mR/h.
A meter reading of 2.0/3.3 or about 0.6 mR/h, would indicate that the first year dose
would be 2 rem or greater.
The DRLtd for year 1 is 0.6 mR/h.
The DRLtd for year 2 is 0.5/1.2 or about 0.4 mR/h.
The DRL for year 0-50 is 5.0/8.2 or about 0.61 mR/h.
ll-9a
-------
Proble 2: Derived Response Levels
SOLUTION
(CO tfd)
Table 4-1: Protective Action Guides for Exposure to Deposited
Radioactivity During the Intermediate Phase of a Nuclear Incident
Relocate if projected dose is greater than 2 rem.
Projected dose includes external gamma radiation dose and the
committed effective dose equivalent from inhalation during the
first year.
Beta skin dose may be up to 50 times higher.
Persons in areas with meter readings above 0.6 mR/h should be
r locat d.
-------
Probl m 3 Projected Dos
SOLUTION
Location
A
B
C
Meter
Reading
(mR/hr)
3
10
30
Projected
Dose
year one
(rem)
9.9
33
99
DCF for year 1 (rem per mR/h)
DCF for year 2 (rem per mR/h)
DCF for 0 to 50 y (rem per mR/h)
Projected
Dose
year two
(rem)
3.6
12
36
3.3
1.2
8.2
Projected
Dose
0 toSOy
(rem)
24.6
82
246
ll-lla
-------
PROBLEM 3: PROJECTED DOSE
(cont'd)
Location
A
B
C
Meter
Reading
(mR/hr)
3
10
30
Projected
dose
year one
(rem)
DCF for year one (rem per mR/h)
DCF for year two (rem per mR/h)
DCF for 0 to 50 y (rem per mR/h)
Projected
dose
year two
(rem)
3.3
1.2
8.2
Projected
dose
0 to 50 y
(rem)
11-11
-------
PROBLEM 4: NHALATONDOSE
DUE TO RESUSPENDED MATERIALS ( )
Analysis of an air sample collected at location "A" where
the exposure rate is 3 mR/h yields activities as follows
(pCi/m3):
Zr-95 760 Cs-134 1200
Ru-103 320 Cs-137 120
1-131 420 Ba-140 630
Weathering is assumed.
11-12
-------
Problem 4: Inhalation Dose (CEDE)
SOLUTION
CALCULATION OF INHALATION DOSE (CEDE)
FROM RESUSPENDED MATERIALS
Includes weathering? [ x ] yes [ ] no
Si
Radio-
IS uclide
Zr-95
Ru-103
M31
Cs-134
Cs-137
Ba-140
imple location A Analysis date
Air
Concentration
(pCi/m3)
760
320
420
1200
120
630
Yr. 1 DCF
(nirem per
pCi/m3)
6.5e-02
1.3e-02
l.le-02
3.1e-01
2.5e-01
4.4e-03
TOTAL-
Dose From
Yr. 1 Exp.
(mrem)
4.9e+01
4.2e+00
4.6e+00
3.7e+02
3.0e+01
2.8e+00
4.6e+02
Yr. 2 DCF
(mrem per
pCi/m3)
1.5e-01
1.4e-01
TOTAL-
Dose From
Yr. 2 Exp.
(mrem)
O.Oe+00
O.Oe+00
O.Oe+00
1.8e+02
1.7e+01
O.Oe+00
2.0e+02
-------
P blew 4: Inhalation Do (C D )
SOLUTION
(eont'd)
Year one CEDE - 4.6E+02 mrem or 0.46 rem
Year two CEDE - 2.0E+02 mrem or 0.20 rem
Year one EDE - 9.9 rem (see problem 3)
Year one TEDE - 9.9 + 0.5 = 10.4 rem
Year two EDE - 3.6 rem (see problem 3)
Year two TEDE - 3.6 + 0.20 = 3.8 rem
Normally the lung clearance class and the particle size are not known.
Ass me the most co servative co ditio .
------- |