SWRHL-92r
SUMMARY OF HYPOTHETICAL WHOLE-BODY GAMMA EXPOSURES AND
    INFANT THYROID DOSES RESULTING OFF-SITE FROM PROJECT
          ROVER NUCLEAR REACTOR/ENGINE TESTS AT THE
             NUCLEAR ROCKET DEVELOPMENT STATION
                                   by
                            R. F.  Grossman
                       Environmental Surveillance
               Southwestern Radiological Health Laboratory
           U. S.  Department of Health,  Education
                          Public Health Service
                      Environmental Health Service
and Welfare
                              August 1970
              This work performed under a Memorandum of
                      Understanding (No. SF 54 373)
                                 for the
                  U. S. ATOMIC ENERGY COMMISSION

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                         LEGAL NOTICE






This report was prepared as an account of Government sponsored



work.  Neither the United States,  nor the Atomic Energy Com-



mission, nor any person acting on behalf of the Commission:






A.  makes any warranty or representation, expressed or implied,



with respect to the accuracy,  completeness, or usefulness of the



information contained in this report, or that the use of any inform-



ation, apparatus,  method,  or process disclosed in this report



may not infringe privately  owned rights; or






B.  assumes any liabilities with respect to the use of, or for damages



resulting from the use of any information, apparatus, method,  or



proces^j disclosed in this report.






As used in the above, "person acting on behalf of the Commission"



includes any employee or contractor of the Commission,  or employee



of such contractor, to the extent that such employee or contractor



of the Commission, or employee of  such contractor prepares, dis-



seminates,  or provides access to, any information pursuant to his



employment or contract with the Commission, or his employment with



such contractor.
  001

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                                                          SWRHL-92r
SUMMARY OF HYPOTHETICAL WHOLE-BODY GAMMA EXPOSURES AND

 INFANT THYROID DOSES RESULTING OFF-SITE FROM PROJECT

      ROVER NUCLEAR REACTOR/ENGINE TESTS AT THE

          NUCLEAR ROCKET DEVELOPMENT STATION
                   By R.  F.  Grossman
               Environmental Surveillance
       Southwestern Radiological Health Laboratory

    U.  S.  Department of Health,  Education and Welfare
                   Public Health Service
                Environmental Health Service
           Environmental Control Administration
               Bureau of Radiological Health
                     Las Vegas,  Nevada
        This work  performed  under  a Memorandum of
              Understanding  (No. SF-54-373)
                         for the
              U. S.  Atomic Energy  Commission

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                                 ABSTRACT
From 1959 through 1969, thirty-one nuclear reactor engine tests, conducted
at the Nuclear Rocket Development Station (NRDS) as part of Project Rover,
released airborne radioactivity which was detected in the area surrounding
the Test Range Complex (NRDS, Nevada Test Site, Tonopah Test Range, and
Nellis Air Force Range).   For these tests the Southwestern Radiological
Health Laboratory (SWRHL) performed radiological monitoring and sampling.
From the radiation exposure information reported by SWRHL, whole-body gamma
exposures and infant thyroid doses were postulated for hypothetical receptors
and summarized by year and sector from NRDS.  A comparison of the Radiation
Protection Standards of AEC Manual Chapter 0524 with this, summary indicated
that for each year of testing, the off-site whole-body exposures and infant
thyroid doses were below 12% and 14%, respectively, of the Radiation Pro-
tection Standards for a population sample.

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                                   PREFACE
In accordance with Memorandum of Understanding,  SF-54-373,  the
Southwestern Radiological Health Laboratory  (SWRHL) provides  an  off-site
radiological safety program for the Atomic Energy Commission  in  support
of nucleajp tests conducted at the Nevada Test Site  (NTS) and  at  the
Nuclear Rocket Development Station  (NRDS) which lies adjacent to NTS.
In this capacity SWRHL is responsible for the following during reactor
tests:
     1.  Documenting the radiological situation  in  off-site areas
         through comprehensive environmental sampling and radiation
         monitoring.
     2.  Assuring continuous protection of public health and  safety
         by determining potential and past exposures to radioactivity,
         and implementing protective measures as directed by  the Test
         Manager, AEC.
     3.  Conducting a public contact and information program  in  the
         off-site area to assure local residents that all reasonable
         safeguards are being employed to protect public health  and
         property from radiation hazards.
     4.  Collecting information regarding incidents which may be
         Attributed to radioactive releases to the  off-site area.

Off-site .areas are considered those areas outside the boundaries of NTS, NRDS,
         ]i                                                              *      *
the Tonop,ah Test Range, and the Nellis Air Force Range, which together are
referred f.o as the Test Range Complex.

The Southwestern Radiological Health Laboratory  also represents  the Bureau
of Radiological Health (BRH), Environmental Control Administration, Environ-
mental Health Services, Department of Health, Education, and Welfare, and
thereby maintains close working relationships with  other components of BRH
                                     11

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and the surrounding states.  When any off-site radiological safety operation
is conducted, all appropriate parties are kept advised and all state and BRH
surveillance networks are alerted, as appropriate, to assist in documenting
levels of radioactivity.
                                     iii

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                             TABLE OF CONTENTS




                                                                   Page  No.




Abstract                                                              i




Preface                                                               ii




List of Figures and Tables                                            v




Introduction                                                          1




Monitoring Methods                                                    1




Calculations and Assumptions                                          3




Conclusion                                                            5




References                                                            13




Appendix                                                              \ £,
                                      IV

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                              LIST OF FIGURES

Figure                                                             Page No.
 1.  Off-Site Whole-Body Gamma Exposures and  Infant Thyroid            6
    Doses Resulting From Project Rover Reactor/Engine Tests
    From CY 1959 to 1963

 2.  Off-Site Whole-Body Gamma Exposures and  Infant Thyroid            7
    Doses Resulting From Project Rover Reactor/Engine Tests
    During CY 1964

 3.  Off-Site Whole-Body Gamma Exposures and  Infant Thyroid            8
    Doses Resulting From Project Rover Reactor/Engine Tests
    During CY 1965

 4.  Off-Site Whole-Body Gamma Exposures and  Infant Thyroid            9
    Doses Resulting From Project Rover Reactor/Engine Tests
    During CY 1966

 5.  Off-Site Whole-Body Gamma Exposures and  Infant Thyroid        -    10
    Doses Resulting From Project Rover Reactor/Engine Tests
    During CY 1967

 6.  Off-Site Whole-Body Gamma Exposures and  Infant Thyroid            H
    Doses Resulting From Project Rover Reactor/Engine Tests
    During CY 1968

 7.  Off-Site Whole-Body Gamma Exposures and  Infant Thyroid            12
    Doses Resulting From Project Rover Reactor/Engine Tests
    During CY 1969
                         LIST OF TABLES

Table

1.  Project Rover Reactor/Engine Tests at NRDS From Which
    Airborne Radioactivity Was Detected Off-Site

2.  Comparison of Maximum Hypothetical Whole-Body Gamma
    Exposures and Infant Thyroid Doses with Radiation
    Protection Standards.

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Introduction
Thirty-one nuclear reactor/engine tests (Table 1) conducted as part of
Project Rover at the Nuclear Rocket Development Station (NRDS) between
1959 and 1969 have produced airborne radioactivity which was detected in
the areas surrounding the Test Range Complex (NRDS, Nevada Test Site,
Tonopah Test Range, and Nellis Air Force Range).  The results of the radio-
logical monitoring and sampling performed by the Southwestern Radiological
Health Laboratory (SWRHL) for these tests are contained in reports for
each test series (1-18).  For the purpose of comparing the radiological
effects that these tests had in off-site areas, the radiation exposure
information in these reports was summarized by year and sector from NRDS.

Monitoring Methods
When the first Kiwi reactor was tested in 1959, SWRHL operated a network
of 12 air sampling stations and a network of 28 film badge stations in the
immediate off-site area.  During the reactor tests, mobile monitoring per-
sonnel (monitors) were used to supplement information from the networks.
Prior to each test, the monitors were positioned at populated locations and
on existing highways which crossed the predicted effluent trajectory to
measure radiation levels and to collect environmental samples (milk, water,
cow feed) should airborne radioactivity be released.  They were equipped
with Geiger-Mueller (G-M) survey instruments, portable gamma-rate recorders
with G-M detectors and supplies for collecting environmental samples.  Since
the monitors were in two-way radio contact with a control center which
followed reactor test operations and meteorological conditions, they could
be repositioned, as required.

During the following years, several changes in monitoring techniques and
expansions in SWRHL routine monitoring networks were made.  Beginning in
1961, self-powered air samplers were included with the monitor's equipment,
making the air sampling coverage for tests more adaptable.  In the same year,
the monitoring 'of NRDS test effluents by aircraft was begun, aiding in the
locating of effluent trajectories and in the positioning of ground monitors.

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            Table  1.  Project Rover Reactor/Engine Tests at NRDS
                      From Which Airborne Radioactivity Was
                      Detected Off-Site
Reactor/Engine
Kiwi A
Kiwi A'
Kiwi A-3
Kiwi B-1A
Kiwi B-1B
Kiwi B-4A
Kiwi B-4D
Kiwi B-4E

NRX-A2

Kiwi
NRX-A3
Phoebus 1A
NRX-A4/EST
NRX-A5

Phoebus IB

NRX-A6
Phoebus 2A
Pewee 1
XE Prime.
Experimental Plan
     XVI
     VII-116-B
     VII-216-B
     VI/A
     IV
     VI
     IV
     V
     VI
     IV
     V
     (TNT)
     IV
     V
     VI
     IV
     IIB
     III
     IV
     IVA
     III
     IV
     III
     IV
     IIIA
     III
     IV
     V
     III
     VC
     IXA
Date
7/1/59
7/8/60
10/19/60
12/7/61
9/1/62
11/30/62
5/13/64
8/28/64
9/10/64
9/24/64
10/15/64
1/12/65
4/23/65
5/20/65
5/28/65
6/25/65
2/3/66
3/3/66
3/16/66
3/25/66
6/8/66
6/23/66
2/10/67
2/23/67
12/15/67
6/8/68
6/26/68
7/18/68
12/4/68
6/11/69
8/28/69

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In 1963, gamma-rate recorders were placed at 16 of the air sampling locations.
In 1965, Model TL-12 thermoluminescent dosimeters by Edgerton, Germeshausen
& Grier, Inc., were included in the film badge network and used off-site by
mobile monitors.  However, off-site radiation exposures from reactor tests were
never detected by SWRHL with the more sensitive TLD's nor with the film badges.
The film badge and air sampling networks were expanded after the latter part
of 1961, due to the resumption of nuclear weapons testing.  These off-site
networks were gradually expanded through the years so that they now include
102 off-site air sampling stations in Nevada and the Western United States,
32 gamma-rate recorders, and 9'6 fixed stations with thermoluminescent dosi-
meters.  The use of film badges at the fixed dosimetry stations was terminated
in April 1970.  Film badges were also assigned to a number of off-site resi-
dents beginning in 1963; the number varying from 60 to 200 with testing
activities.

Calculations and Assumptions
The modes of radiation exposure or dosage considered for the SWRHL monitoring
data were whole-body gamma exposures from cloud passage and deposition, infant
thyroid doses calculated from the hypothetical inhalation of airborne radio-
activity, and infant thyroid doses calculated from the assumed ingestion of
milk contaminated with radioiodine.  Radiation exposures or doses less than
1 mR or 1 mrad, respectively, were considered to be negligible.  The whole-
body exposures and infant thyroid doses are generally for a hypothetical
receptor since air samples were often taken at unpopulated locations and
infants were not present at any of the locations where air and/or milk samples
were collected.

Since film badges and TLD's,have never detected releases of airborne radio-
activity from reactor/engine tests, whole-body gamma exposures were estimated
from G-M survey instrument data.  The exposure rate readings from cloud
passage and deposition were integrated from cloud arrival time to infinity
or from cloud arrival time to end of cloud passage, if no measurable deposition
occurred.  No exposures were measured by film badges or TLD's for two reasons:
1) The minimum detectable exposure of the film badge and the TLD is 30 mR
and 1-5 mR, respectively; 2) film badges  and/or TLD's were not always located
directly within the paths of the test effluents.

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The infant thyroid doses from inhalation were estimated by multiplying
the adult thyroid doses by a factor of 3.  The adult thyroid doses were
determined by the product of the time-integrated concentrations of air-
borne radioiodine (pCi'sec/m ) and the following conversion factors:
                                     mrad-m /yCi'sec
          ISOTOPE
          131I
          132X
ESSA
0.341
0.0124
0.0922
0.0284
SWRHL
0.34
0.051
0.093
0.029
          135I

The factor of 3 compensated for differences in thyroid weight and breathing
rates (m /day) between an adult and an infant (3 =  [20 g/2 g][(6 m /day)/
(20 m /day)]}.  The two sets of conversion factors  above were used within
the referenced SWRHL reports; the first set is that used by the Air Resources
Laboratory of Environmental Science Services Administration (ESSA) (19)
in their dose predictions for each reactor/engine test, and the other set is
one derived by SWRHL (Appendix).  Little difference exists between the two
                           132
sets of factors except for    I, which contributes only a small percentage of
                                                                     132
the total dose.  The higher SWRHL factor is based upon the fact that    Te,
                 132
the precursor of    I, is also inhaled and contributes an increase in the
            1 -JO
quantity of    I which reaches the thyroid (20, 21).

The infant thyroid doses from milk ingestion were estimated from a product
of the following conversion factors and the time-integrated radioiodine con-
centrations (pCi'day/1) for those situations when milk samples were collected
at regular intervals for as long as radioactivity was detected in the milk:
          ISOTOPE                    mrad-1/pCi'day
          131I                          0.019
          133
             I                          0.0052
                                        0.0016

When only the peak radioiodine concentrations in milk were measured, the
equivalence of 16 mrad for a 100 pCi/1 peak concentration was used (22).

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Once the whole-body gamma exposures and the infant thyroid doses from inhalation
and ingestion determined by the above procedures were summarized for each reactor/
engine test within a given year, the maximum exposure and dose for each test
was selected within each sector in which an exposure occurred.  The maximums for
each test occurring within each year and a given sector were then summed and
entered within the appropriate sector.  The blank sectors indicate that no
radioactivity was detected, or if it was detected by air samples, the potential
infant thyroid dose from inhalation was <1 mrad and no milk samples were considered
necessary.  Since radiation exposures during the years 1959 through 1962 were
negligible and no reactor/engine tests released airborne radioactivity during
1963, these exposures were summarized in one illustration, Figure 1.  Figures 2-7
represent the exposure and dose summaries for each calendar year 1964 through
1969.

Conclusion
Table 2 compares the Radiation Protection Standards of AEC Manual Chapter
0524 with the maximum whole-body gamma exposures and  the maximum infant
thyroid doses received by hypothetical receptors during the above periods.

         Table 2.  Comparison of Maximum Hypothetical Whole-Body
                   Gamma Exposures and Infant Thyroid Doses with
                   Radiation Protection Standards
Radiation
Protection
Standard*
170 mrem/yr
500 mrem/yr
Maximum Whole-Body Gamma Exposure (mR)
and Infant Thyroid Doses (mrad)**
'59-'63 '64 '65 '66 '67 '68 '69
ND <1 6 20 2<1<1
< 3 24 72 36 18 13 2
Type of Exposure/Dose
Whole-body gamma exposur
Thyroid dose

 *Standards are for sample of population, AEC Manual Chapter 0524.
**Units in mR and mrad are equivalent to mrem for this comparison.

For any given year the whole-body gamma exposures and infant thyroid doses were
below 12% and 14%, respectively, of the radiation protection standards for a
sample of the population.

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               WINNEMUCCA
                     VLONE PINE
            BAKERSFIELD
              225°   BARSTOW
ND: Not Detected
TOP NUMBER:
(PROJECT ROVER)
  Hypothetical whole-body gamma exposure in mR
BOTTOM NUMBER:
  Hypothetical infant thyroid dose in mrad
                                 FIGURE 1
  OFF-SITE WHOLE-BODY GAMMA EXPOSURES AND INFANT THYROID DOSES
      RESULTING FROM REACTOR/ENGINE TESTS FROM CY 1959 TO 1963

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               WINNEMUCCA
                                              
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                WINNEMUCCA
                                      lOOIIlES
                                 TONOPA
                                                        NO
                                              J   \    10\mrad
                                                    i
          NO

     BEATTY
                        LONE PJNE
             BAKERSFIELD
               2250   BARSTOW
ND: Not Detected
TOP NUMBER:
(PROJECT ROVER)
  Hypothetical whole-body gamma exposure in mR
BOTTOM NUMBER:
  Hypothetical infant thyroid dose in mrad
ESTIMATED INFANT INHALATION DOSE.
WHOLE-BODY COUNT OF SWRHL PERSONNEL INDICATED 3 mrad TO THYROID.
                                    FIGURE 3
  OFF-SITE WHOLE-BODY GAMMA EXPOSURES AND INFANT THYROID DOSES
         RESULTING FROM REACTOR/ENGINE TESTS  DURING  CY  1965

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               WINNEMUCCA
                                           0
                                            <1mR
                                   100_MIIES  3mrad
                              TONOPA
                                                                  St. GEORGE
                                                                        ^•««

                                                                        90°
LONE PINE
            BAKERSFIELD
                      BARSTOW
ND: Not Detected
TOP NUMBER:
(PROJECT ROVER)
  Hypothetical whole-body gamma exposure in mR
BOTTOM NUMBER:
  Hypothetical infant thyroid dose in mrad
                                 FIGURE 5
  OFF-SITE WHOLE-BODY GAMMA EXPOSURES AND INFANT THYROID DOSES
        RESULTING FROM REACTOR/ENGINE TESTS DURING CY  1967
                                     10

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               WINNEMUCCA
                                   100_MILES
                              TONOPA
                                                                  St. GEORGE
                                                                        •^•^^

                                                                        90°
LONE PINE
                                      V)
                                       LAS VEGAS
            BAKERSFIELD
                     BARSTOW
ND: Not Detected
TOP NUMBER:
(PROJECT ROVER)
  Hypothetical whole-body gamma exposure in mR
BOTTOM NUMBER:
  Hypothetical infant thyroid dose in mrad
                                FIGURE 6
  OFF-SITE  WHOLE-BODY GAMMA  EXPOSURES AND INFANT THYROID DOSES
        RESULTING FROM REACTOR/ENGINE TESTS DURING CY 1968
                                    11

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               WINNEMUCCA
                                   100J1ILES
                               TONOPA
                                                                   St. GEORGE
                      LONE PINE
                                        LAS VEGAS
            BAKERSFIELD
              2250   BARSTOW
ND: Not Detected
TOP NUMBER:
(PROJECT ROVER)
  Hypothetical whole-body gamma exposure in mR
BOTTOM NUMBER:
  Hypothetical infant thyroid dose in mrad
                                  FIGURE 7
  OFF-SITE WHOLE-BODY GAMMA EXPOSURES  AND INFANT THYROID DOSES
         RESULTING FROM REACTOR/ENGINE TESTS DURING CY 1969
                                     12

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                                 REFERENCES
 Reports by Southwestern Radiological Health Laboratory, Las Vegas, Nevada
 1.  "Off-Site Rad-Safety, Report on Kiwi Operations," 28 July 1959.

 2.  "Off-Site Rad-Safety Final Report, Kiwi-A Prime and Three,ir
     OTO-60-1.  1960.

 3.  "Kiwi B Report, United States Public Health Service Off-Site
     Radiological Safety Organization."  (No date given, but distributed
     7 December 1961.)

 4.  "Off-Site Rad-Safety Final Report, Kiwi B Reactors B-1B and B-4A."
     1 September 1962.

 5.  "Final Report of Off-Site Surveillance for the NRX-A2 Experiment."
     SWRHL - 16r, 3 February 1965.

 6.  "Final Report of Off-Site Surveillance for the Kiwi B-4D
     Experiment."  SWRHL - 7r, 23 July 1964.

 7.  "Final Report of Off-Site Surveillance for the Kiwi B-4E Experiment."
     SWRHL - 15r, 25 January 1965.

 8.  "Final Report of Off-Site Surveillance for the NRX-A3."
     SWRHL - 18r, 8 October 1965.

 9.  "Final Report of Off-Site Surveillance for the Kiwi TNT Experiment."
     SWRHL - 17r, 6 August 1965.

10.  "Final Report of Off-Site Surveillance for the Phoebus 1A Experiment."
     SWRHL - 19r, 17 January 1966.

11.  "Final Report of Off-Site Surveillance for the NRX-A4/EST Test
     Series."  SWRHL - 30r,  19 September 1966.

12.  "Final Report of Off-Site Surveillance for the NRX-A5 Test Series."
     SWRHL - 32r, 15 October 1968.
                                       13

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                           REFERENCES (continued)

13.  "Final Report of Off-Site Surveillance for the Phoebus IB, EP-I,
     EP-II, EP-III, EP-IV Reactor Test Series,"  SWRHL - 45r, July 1969.

14.  "Preliminary Report of Off-Site Surveillance for the Phoebus IB
     Test Series."  9 March 1967.

15.  "Final Report of Off-Site Surveillance for NRX-A6 Test Series."
     SWRHL - 78r.  (To he published.)

16.  "Final Report of Off-Site Surveillance for Phoebus 2A Reactor Test
     Series."  SWRHL - 72r. (To be published.)

17.  "Final Report of Environmental Surveillance for Pewee 1, Experimental
     Plans II and III, November 21 and December 4, 1968."  SWRHL - 87r.
     (To be published.)

18.  "Final Report of Environmental Surveillance for XE Prime Reactor
     Test Series."  (To be published.)

Other rcferenc.cH
19.  Wilson, Dean A.  "An Evaluation of Radiation Prediction Models Used
     by ARFRO at the NRDS." NRDS Branch, Environmental Science Services
     Administration, Air Resources Field Research Office, Las Vegas,
     Nevada.  March 1967.  p.  20.

20.  "Protection of the Public in the Event of Radiation Accidents."
     Proceedings of a seminar sponsored by FAO/UN, IAEA, and World
     Health Organization on 18 November 1963 at Geneva, Switzerland,
     1965.   p.  210.

21.  Le Grand,  J. and Dousset, M.   "Evolution DuDebit D'Equivalent DeDose
     Delivree A La Glande Thyroide Apres Inhalation Instantanee De Tellure -
     132 (French)."  Health Physics, Vol.  12, No. 10, October 1966.  p. 1407.
                                      14

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                           REFERENCES (continued)

22.   "Background Material for the Development of Radiation Protection
     Standards."  Staff Report No. 5 of the Federal Radiation Council.
     Superintendent of Documents, U. S. Government Printing Office,
     Washington, D. C.  July 1964.  pp. 14-16.
                                    15

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                              APPENDIX
                     Calculation of Thyroid Dose

The dose rate to the thyroid may be described by the equation
     dD/dt = KEA exp - (X   t) where:


               dD/dt = dose rate per unit time
               K     = dimensional constant
               E     = effective energy of beta and gamma radiation,
                       MeV per disintegration
               A     = concentration of radioiodine in thyroid,
                       yCi/g
               A     = effective decay constant, I/unit time
               t     = time after deposition in thyroid

This assumes that the radioiodine is uniformly distributed throughout the
thyroid and that the size of the thyroid is large compared to the range
of the beta particles.

The total dose is estimated by integrating the above equation from time
zero to infinity assuming D = 0 at time zero.
               D = KEA /  exp -(X r.t) dt
                        o        ef f
               D = <-lAeff) KEA exp -(Xgfft)
               D = 0 + KEA/X ._
                            err
Dose from Inhalation of Radioiodines
                                                              131
The actual values for the parameters in the dose equation for    I
are as follows:
                 =   1 rad          erg        3.7xlQ4 dis   8.64x104 sec
                   100 erg/g  X 6.24X1CP MeV x yCi'sec     X      day
                 - 51.2 rad-g-dis
                   MeV-yCi-d.ay
                                  16

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                E =  0.23 MeV  (1)
               A =     , where:
                    m

                    X =  time-integrated  concentration of radioactivity,
                        yCi'sec/m3
                                                                  /  O
                    B =  breathing rate of standard man, 2.32 x  10  m /sec  (1)
                        (averaged over 24 hours)

                    f =  fraction of  inhaled radioiodine reaching the
                        thyroid, 0.23 (1)

                    m =  thyroid weight of standard man, 20 g

                    (2.32 x 10~4m3/sec)(o.23)x
                             20 g
                                                     1 01
               Xeff = °-693/(effective half-life for    I)


                      (°-693)/7-6
Substituting these parameters, the dose equation becomes:

                 = (51.2)(0.23)(2.32 x 10"4)(0.23)(7.6)x
                            (20)(0.693)

                                    /       *3
               D(rads) = (3.44 x 10~  rads-m )x (yCi'sec)
                         (            yCi-sec)  (m?)

               or   D(mrad) = (0.34 mrad'm )x (yCi'sec) rounded off to two
                              (     yCi-sec)  (  m3)

               significant figures.
For the dose to a child's thyroid the above equation must be multiplied by

a factor of 3 to account for differences in thyroid weight and breathing

rates (m3/day) between an adult and a child (3 = [(20g/2g)][(6m3/day)/
(20m3/day)]}.
For other radioiodines the dose equation changes according to differences

in effective half-life and effective decay energies.  The dose equations
for    I and    I are as follows:

                                  17

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               133I, D(mrad) =  (0.093 mrad-m3/uCi'sec)x  for  E =  0.54 MeV  and


               A  ,  = 0.693/0.87d
               err



                                            T
                 I, D(mrad) =  (0.029 mrad-mJ/ijCi.sec)x  for  E =  0.52 MeV  and


               A  ,, = 0.693/0.28d
               err




 In addition  to differences in  effective half-life and effective  beta

                                         132
 particle energies, the dose equation for    I is effected by the rapid

         132
 decay of     I  in the blood stream before it gets to  the thyroid  and by

                  132                     132
 the decay rate of    Te,  the precursor of    I  (2, 3).  With these

                                            132
 effects incorporated, the dose equation for    I becomes


                                 -2       3
               D(mrad) =  (5.1 x 10   mrad'm  /yCi*sec)x

                                                132
 where x is tne time-integrated concentration of    Te.
Dose from Ingestion of Milk Containing Radioiodine



For ingestion, parameter A, integrated concentration of radioiodine in  the


thyroid, is defined by A = CVf where,

                            m



              C = the time-integrated concentration of radioiodine in milk,


                  pCi-day/1 (time-integrated concentration from  time zero


                  to infinity assuming that the effective half-lifes of

                  131T  133T     , 135T      ....      c  ,     01 ,
                     I,    I, and    I in milk are 5 days, 21 hours, and


                  6.7 hours, respectively)



              V = the rate by which milk is consumed by a child  one year


                  old or less, 1 liter/day  (4)



              f = fraction of ingested radioiodine reaching the  thyroid,


                  0.3 (1)



              m = thyroid weight of a child one year old or less, 2 g (4)



With the values for V, f, and m substituted,



              A = (1 liter/day)(0.3) C, or

                          2 g



              A = 0.15 liter C

                    dayg
                                   18

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For    I the dose equation D = KEA/A   f becomes applicable  to milk
ingestion with  the  above expression for A substituted.

             D(mrad) =  (5.12 x 10~2 mrad-g-dis)(0.23 MeV)(0.15  1)(7.6 day)C
                        (            MeV-pCi-day)     dis  (dayg ) (0.693   )
             or, D  = (1.9 x 10~2 mrad-1) C  (pCi'day)
                     (          pCi-day)      liter
For other radioiodines, the above dose equation  changes  according  to
differences in effective half-life and effective decay energies
to become:
                           — 2                               — 1         1 "\"\
             D =  (5.12 x 10  )(0.54)(0.15)(0.87) =  (5.2  x 10  ) C  for    I  and
                             0.693
                           -9                               -"}
             D =  (5.12 x 10 Z)(0.52)(0.15)(0.28) =  (1.6 x 10 J) C for
                             0.693
                             References
1.  "Recommendations of  the  International Commission on  Radiological
    Protection - Report  of Committee II on Permissible Dose  for  Internal
    Radiation."  ICRP-2.  Pergamon Press, New York, London,  Paris,
    Los Angeles, 1959.
2.  "Protection of the Public in the Event of Radiation  Accidents."
    Proceedings of a seminar sponsored by FAO/UN, IAEA,  and  World Health
    Organization on 18 November 1963 at Geneva, Switzerland, 1965, p. 210.
3.  Le Grand, J. and Dousi?et, M.  "Evolution DuDebit D'Equivalent DeDose
    Delivree A La Glande Thyroide Apres Inhalation Instantanee. De Tellure -
    132 (French)."  Health Physics, Vol. 12, No. 10, October 1966, p. 1407.
4.  "Background Material for the Development of Radiation Protection
    Standards."  Staff Report No.  5 of the Federal Radiation Council.
    Superintendent of Documents, U.  S.  Government Printing Office,
    Washington,  D.  C.   July 1964.   pp.  14-16.
                                  19

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                             DISTRIBUTION

 1-15   SWRHL, Las  Vegas,  Nevada
     16   Robert E.  Miller, Manager, AEC/NVOO, Las Vegas,  Nevada
17 - 18   Robert H.  Thalgott,  Test Manager, AEC/NVOO,  Las Vegas, Nev.
19 - 20   Henry G. Vermillion, AEC/NVOO, Las Vegas, Nevada
21 - 22   D.  W. Hendricks, AEC/NVOO,  Las Vegas,  Nevada
     23   Robert R.  Loux, AEC/NVOO, Las  Vegas, Nevada
     24   Central Mail & Records, AEC/NVOO,  Las Vegas, Nevada
     25   D.  Hamil,  Technical Library, AEC/NVOO,  Las Vegas, Nevada
     26   Chief, NOB/DASA, AEC/NVOO,  Las Vegas, Nevada
     27   P.  Allen, ARL/ESSA, AEC/NVOO, Las Vegas, Nevada
     28   M.  Klein,  SNPO,  Washington, D.  C.
     29   R.  Decker, SNPO, Washington,  D. C.
     30   R.  Hartfield,  SNPO-C, Cleveland,  Ohio
     31   J.  P.  Jewett, SNPO-N, Jackass Flats, Nevada
32 - 41   R.  Nelson,  SNPO-N, NRDS, Jackass Flats, Nevada
     42   Wm.  C. King, LRL,  Mercury, Nevada
     43   Roger Batzel, LRL,   Livermore, California
     44   J.  E.  Carothers,  LRL, Livermore, California
     45   H.  T.  Knight, LASL, Jackass Flats,  Nevada
     46   P.  Gothels, LASL, Los Alamos, New  Mexico
     47   H.  S.  Jordan, LASL, Los Alamos, New Mexico
     48   Charles I.  Browne,  LASL,  Los  Alamos, New Mexico
     49   Wm.  E. Ogle, LASL,' Los Alamos, New Mexico
     50   R.  E.  Smith,  LASL,  NRDS,  Jackass Flats,  Nevada
     51   Keith Boyer,  LASL,   NRDS, Jackass Flats,  Nevada
52 - 54   Wm.  W. Allaire,  AEC/NVOO,  Las Vegas, Nevada
     55   G.  Hoover, AEC/OCC, Mercury,  Nevada

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     Distribution (continued)






     56   D. Gray, NRTO,  NRDS,  Jackass Flats, Nevada



     57   J.  Powell,  NRTO, NRDS, Jackass Flats,  Nevada



     58   H. G. Simens,  NRTO, Aero-jet General Corp. , Jackass Flats, Nev.



     59   R. A. Smith, NRTO,  NRDS, Jackass Flats, Nevada



     60   G. Grandy, WANL, NRDS, Jackass Flats, Nevada



     61   E. Hemmerle,  WANL, Pittsburgh,  Pennsylvania



     62   H. Mueller, ARL/ESSA, AEC/NVOO,  Las Vegas, Nevada



     63   J.  Doyle, EG&G, Las Vegas,  Nevada



     64   J.  Gallimore,  Pan. Am. World Airways, Jackass Flats, Nevada



     65   J.  Mohrbacher, Pan. Am. World Airways, Jackass Flats, Nevada



     66   Martin B.  Biles,  DOS, USAEC,  Washington, D. C.



     67   R. S.  Davidson, Battelle Memorial Institute,  Columbus, Ohio



     68   Byron Murphey, Sandia Labs.  , Albuquerque,  New Mexico



69 - 70   Charles L.  Weaver,  PHS, BRH,  Rockville, Maryland



     71   John C. Villforth, Director, BRH,  Rockville, Maryland



     72   John G. Bailey, Office of Information, BRH, Rockville,  Maryland



     73   Wm. Link,  BRH Library, Rockville,  Maryland



     74   Arden E. Bicker, REECo. ,  Mercury,  Nevada



     75   Southeastern Rad. Health Lab. ,  Montgomery, Alabama



     76   Northeastern Rad. Health Lab. , Winchester,  Mass.



77 - 78   DTIE,  USAEC,  Oak Ridge, Tennessee

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