SWRHL-19r
  FINAL REPORT OF OFF-SITE SURVEILLANCE
                     FOR THE
           PHOEBUS 1-A EXPERIMENT
                      by the
    Southwestern Radiological Health Laboratory
            U. S. Public Health Service
   Department of Health, Education, and Welfare
                 January 17, 1966
This surveillance performed under a Memorandum of
           Understanding (No. SF 54 373)
                      for the
       U. S. ATOMIC ENERGY COMMISSION

-------
                         LEGAL NOTICE

This report was prepared as an account of Government-sponsored
work.  Neither the United States,  nor the Atomic Energy Commission,

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 infor-
      mation, 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 dam-
      ages resulting from the use of any information, apparatus,  method,
      or process disclosed in this report.

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

cludes 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, disseminates,

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

contract with the Commission,  or his employment with such contractor.
                Copy No. 5

                       Delbert S. Earth

                       Bioenvironmental Research Proj
                       SWRHL

-------
                                             SWRHL-19r
  FINAL REPORT OF OFF-SITE SURVEILLANCE
                     FOR THE
           PHOEBUS 1-A EXPERIMENT
                      by the
    Southwestern Radiological Health Laboratory
            U. S. Public Health Service
   Department of Health, Education, and Welfare
                Las Vegas,  Nevada
                 January 17, 1966
This surveillance performed under a Memorandum of
           Understanding (No.  SF 54 373)
                      for the
       U. S. ATOMIC ENERGY COMMISSION

-------
                            ABSTRACT

The Southwestern Radiological Health Laboratory provided off-site
radiation surveillance in support of the Phoebus 1-A Experiment
of June 25,  1965.   This  support  consisted of tracking the effluent,
monitoring radiation dosage to the off-site population and collecting
environmental samples in downwind areas.   Although off-site con-
tamination occurred as a result  of the  Phoebus  test,  the data col-
lected indicate that radioactivity levels did not exceed the safety
criteria established by the Atomic Energy Commission  for the off-
site population.

-------
                     TABLE OF CONTENTS


 ABSTRACT                                                    i

 TABLE OF CONTENTS                                        ii

 LIST OF TABLES AND FIGURES                              iii

 INTRODUCTION                                               1

 I.  OPERATIONAL PROCEDURES                               3

    A.  EXTERNAL MEASUREMENTS                           3

        1.  Ground Monitoring                                  3
        2.  Dose Rate Recorders                                3
        3.  Aerial Cloud Tracking                               4
        4.  Film Badges                                        4

    B.  ENVIRONMENTAL MEASUREMENTS                    4

        Milk and Water Samples                                 8
        Vegetation                                             9

 II.  RESULTS                                                 10

    A.  GROUND MONITORING                                10
    B.  DOSE RATE RECORDERS                              10
    C.  FILM BADGES                                         12

    D.  AIR SAMPLES                                         12

    E.  WATER SAMPLES                                     12
    F.  MILK SAMPLES                                       14

    G.  VEGETATION SAMPLES                               17

m' CONCLUSIONS                                            18

 DISTRIBUTION
                                11

-------
                         LIST OF TABLES


Table 1.  Threshold detectability at time of count of several
          radionuclides in air samples(90% confidence level).     8

Table 2.  Meteorological data.                                  11

Table 3.  Analyses  of air samples collected following
          Phoebus 1-A, EP4.                                    13

Table 4.  Potable water samples collected following
          Phoebus 1-A, EP4.                                    14

Table 5.  Analysis of  milk  samples collected  following
          Phoebus 1-A, EP4.                                    15
                        LIST OF FIGURES


Figure 1.  Reactor in testing position.                           2

Figure 2.  Air  surveillance network stations in Nevada.          5

Figure 3.  Special air  sampling and dose rate recorder
           locations following Phoebus 1-A, EP4.               6

Figure 4.  Milk and water sampling locations following
           Phoebus 1-A,  EP4.                                  16
                                111

-------
                         INTRODUCTION

As a part of the ROVER Program, testing and disassembling of a
series of reactors designated Phoebus is being conducted by
Los Alamos Scientific Laboratory at the Nuclear Rocket Devel-
opment Station (NRDS).  The subject of this  report is the off-site
surveillance provided by the Public Health Service (PHS) for the
Atomic Energy Commission (AEC) in support of the Phoebus 1-A
Experiment.
The Phoebus 1-A Experiment was conducted at Test Cell C on
June 25,  1965 under conditions identified as Experimental Plan 4.
The nominal operating power was 1100 megawatts.  Other experi-
mental plans generated such low power that  there was no detectable
off-site radioactivity.  The reactor was tested in an upright
position  so that the hydrogen coolant exhausted upward along with
escaping fission products.  The test configuration is shown in
Figure 1.
Under a Memorandum of Understanding with the Atomic  Energy Com-
mission, the U. S.  Public Health Service conducts a program of radio-
logical monitoring and environmental sampling in the off-site area
surrounding the Nevada  Test Site and the Nellis  Air Force Range.  The
overall complex of  the Nevada Test Site (NTS) and the Nellis Air Force
Range (NAFR) includes the Nuclear Rocket Development Station and
the  Tonopah Test Range (TTR) and for simplicity will be called the
test range complex throughout this report.

-------
Figure 1.  Reactor in testing position.

                                 2
(Photograph courtesy of
 Los Alamos Scientific  Laboratory)

-------
                I.  OPERATIONAL PROCEDURES






A.  EXTERNAL MEASUREMENTS





    1.   Ground Monitoring




    Ground monitors tracked the reactor effluent passage with



    portable instruments.  Each monitor was  equipped with an



    Eberline E-500B, a Precision Model 111 Standard



    "Scintillator", and a Victoreen Radector Model No. AGB-



    50B-SR.




    The Eberline  E-500B has a range of 0 to 200 milliroentgens



    per hour (mR/hr) in four scales with an external halogen



    filled GM tube and a 0 to 2000 mR/hr range from an internal



    Anton 302 tube.  The Precision Model 111 "Scintillator" is



    used primarily for low level detection and provides for a



    range of 0 to 5 mR/hr in six scales. The Radector has a



    range of 0. 05 to 50, 000 mR/hr on two scales.  This instru-



    ment employs an inert gas ionization chamber.  Errors



    associated with these instruments are of the order of +_20%.






    2.   Dose Rate Recorders




    Eberline RM-11 dose rate recorders are placed at twenty-one



    stations around the test range  complex.  These recorders



    utilize a Geiger tube detector to document radiation levels at



    specific locations.  The instrument has a  0. 01 to 100 mR/hr



    range and the gamma dose rate is recorded on a  30-hour



    strip chart.  The  RM-11 is accurate to j^20% as calibrated



    with a  l 37Cs source.

-------
    3.  Aerial Cloud Tracking





    An Air Force U3-A aircraft, manned by two Public Health



    Service monitors equipped with portable instruments iden-



    tical to those of the ground monitors, tracked the reactor



    effluent to position ground monitors.  Public Health Service



    cloud sampling aircraft were also used as aids in cloud



    tracking.  However,  their primary purpose was cloud sam-



    pling in order to determine cloud size and inventory.  The



    results of their  sampling are reported separately by the SWRHL



    Engineering  Development Program.






    4.  Film Badges





    During June, the PHS maintained 86 film badge  stations off



    the test range complex and assigned badges to 168 off-site



    residents.  The badge used is made up of DuPont  type



    555 film.  This  film  is accurate to j^50% in  the 20 to



    100 mR range and +_10% in the 100 to 2000 mR range.   The



    lower limit of detectability is  20 mR.






B.  ENVIRONMENTAL MEASUREMENTS



Ninety-five air samplers  were routinely operated in the western United



States at the time of these experiments.  Thirty-two of these were



located in Nevada and are presented in Figure 2.  Two supplementary



air sampling locations were established for the Phoebus 1-A Experi-



ment  and are  shown  in Figure 3.





All samplers were equipped with Whatman 541 prefilters.   A portion



of the routine  samplers and both supplementary  stations were



equipped with  MSA charcoal cartridges.  All air  sample prefilters



and charcoal cartridges collected following the Phoebus 1-A test



were  returned to the Southwestern Radiological Health Laboratory



in Las Vegas for analysis.




                                 4

-------
                                   N   E   \V    A    D   A
   Q AIM SAMPLER WITH PREFILTER


   • AIR MMPLCN WITH PREFM.TER AND
     CMAHCOAL CARTNIOK
Figure 2.
Air surveillance network stations in Nevada.

-------
                    WARM SPGS.
                         TWIN SPGS
                        OfJODIABLO
    N£LL/S AIR   FORCE
         RANGE
                                                                 0 5  K)    20   30
                                                            D Air Sampler with Prefilter
                                                            B Air Sampler with PrefilMrB
                                                               Charcoal Cartridge
                                                               Temporary Air Sampler
                                                               RM II
Figure 3.  Special air sampling and dose rate recorder locations
            following Phoebus 1-A, EP4.

-------
Prefilters were counted for gross beta activity, and simultaneously



for gross alpha, with a Beckman "Wide Beta" proportional counting



system.  This  system has an efficiency of approximately 45% for



0. 54 Mev betas and a background of 6 +_ 1 counts per minute.  Gross



beta concentrations were computed at the time of count for the



purpose of screening samples and delineating the effluent trajectory.





Samples  which were believed to  contain fresh fission products were



recounted several times within the first 48 hours.  Based  on these



counts, an individual decay constant was computed for each sample.



This constant was used to extrapolate the gross beta result to the



end of the collection period.





Prefilters which indicated activity levels  greater than 10 pCi/m3



were analyzed  for the biologically significant gamma emitting iso-



topes by placement directly upon a 4'x4"  sodium iodide crystal.  All



reported values are corrected for the decay to the  end of the col-



lection period.  Since it was not possible  to define  duration of effluent



passage at all locations,  the reported values given as pCi/m3 assume



an average concentration over each entire sampling period.  Results



are also reported in —	5— to indicate the potential gross beta



inhalation exposure at each location.  This unit is obtained by



multiplying pCi/m3 by the sampling time  in seconds.





All charcoal  cartridges and some prefilters were analyzed for gam-



ma isotopes by placing each  directly on a 4"x4" sodium iodide



crystal coupled to a 400-channel pulse height analyzer set to view



energies from  0 to 2 Mev.  The  activity on the cartridge should



represent primarily the gaseous radioiodines.   Calculations were



performed by an  IBM 1620,  utilizing a matrix technique.   This



method compensates for the  mutual interference between isotopes



for a given spectrum by the simultaneous solution of n equations



                                 7

-------
containing n unknowns, where n represents the number of isotopes

for which solution is sought.   Due to time and memory limitations

on the 1620, a value for n = 8 is employed.  The input to  the com-

puter program is variable  so that solution may be made for any

eight isotopes for which standard  spectra are available.  While this

method is  preferable to others for which it is practical to use the

1620, it is impossible to calculate an error interval.

Threshold detectability of several radionuclides is presented in Table 1

and is the  result of an examination of previous data collected under the following:
     a.   Count time in days after fissioning as indicated by
         footnotes.
     b.   Prefilters  collect unfractionated fission products
         resulting in a complex sprectrum.

     c.   MSA charcoal collects gaseous fission products only
         (primarily  iodines).
     d.   An eight isotope matrix is employed for computation
         and isotopes other than those examined are present in
         amounts which are small  relative to those eight.

     e.   Natural activity on air samples  is approximately  five
         times system background.


Table 1.  Threshold detectability  at time of count  of several radio-
          nuclides  in air samples  (90% confidence level).
Sample Type
Whatman No. 541
(pCi)
MSA Charcoal
(pCi)
131I 132Te-I
500 1000
200
200 400
100
1 3 3 j 1 35j 14
500 1000
200
200 400
100 -
=°Ba-La
500
200
200
100
Length
of Count
10 min
1 0 min
1 0 min
10 min
Notes
1
2
1
2
1 - counted at less than 3 days after fissioning.
2 - counted at 3 days or more after fissioning.


Milk and Water Samples

After the  release of activity from NRDS, milk samples were collected

from three dairy farms and several farms  producing milk for  their

-------
own consumption.  Each milk sample is counted for 40 minutes



using a 400-channel analyzer viewing an energy range from 0 to



2 Mev.  All liquid samples are  counted, with no prior preparation,



in 3. 5 liter inverted well aluminum beakers which are placed over a



4"x4" sodium iodide crystal.  The lower  limit of detection for 1 31I



and l 33I in milk and water is 20 pCi/1 at time of count, and all re-



sults  below that value are reported as non-detectable.  The reported



values have, at time of count,  a 2 sigma error estimate of +_ 15 pCi/1



or + 10%,  whichever is greater.




Vegetation Samples



Vegetation samples were collected in the  suspected effluent trajec-



tory to indicate deposition on the ground.  They were also obtained



at most milk sampling locations, with an  effort made to make the



sample representative of the cows' feed.  These  samples were



taken as early indicators of where milk might be contaminated and



were  not intended to yield intake-excretion data.  For this  reason



the vegetation sample results are reported simply as fresh fission



products present or not present.

-------
                          II.  RESULTS




Experimental Plan 4 was conducted in the approximate time inter-


val 1315 to 1326 hours PDT on June 25,  1965.   A summary of


meteorological conditions on the test day is presented in Table 2.



Heavy rain showers in the area north of NRDS limited aerial


tracking of the effluent; however, initial on-site tracking of the


effluent indicated a 0   bearing.   Off-site  environmental monitoring

                                         o      o
indicated contamination in the sector of 10 to 50 .




A.  GROUND MONITORING



A ground monitor  assigned  to Queen City Summit (65 miles,  15


from  Test Cell C) detected  cloud arrival  at 1615 PDT and measured


a peak dose rate of 0. 065 milliroentgens  per hour at 1631 hours.


Dose  rates above background  persisted at this location and are


believed to have been associated with heavy rain in the area.


Monitoring of Highway 25 north and south  of Queen City Summit


on the evening of June 25 indicated that this location was on the


hot line. Queen City Summit  is unpopulated.




B.  DOSE RATE RECORDERS



Dose  rate recorder data collected from Diablo on June 26 indicated


a cloud arrival time of 1630 PDT on June  25,  1965.  A net peak dose


rate of 0. 05 mR/hr occurred  at 1700 PDT. The dose rate thereafter

            -1.15  ^
decayed  as t     . During previous  reactor tests dose rates fol-


lowing cloud passage have dropped sharply; however,  "rainout" of


fission products in the Diablo area was probably the cause of the


sustained dose rates greater than the normal background of 0. 025 mR/hr.



                                10

-------
Table 2.
Sky condition



Clouds



Visibility
  METEOROLOGICAL, DATA



      PHOEBUS 1-A, EP4



Full Power Test, June  25, 1965



Brkn. Brkn.



.6 Cumulonimbus,  .3 Cirrus



Unrestricted
Upper air data at: Jackass Flats, Nevada, 1310 PDT, 6/25/65
Height
(Ft. MSL)
SFC 3615
4000
5000
6000
7000
8000
9000
10000
11000
12000
13000
14000
15000
Wind Pressure
(Deg/Kts) (mb)
040/08
070/07
140/07
190/10
190/12
190/13
200/13
200/13
200/13
210/13
210/13
210/13
220/13
881
870
839
808
780
750
724
700
673
648
622
599
577
Temperature Dew
( C) Point
<°C)
24.6
23.3
20. 3
17. 0
13. 7
10. 0
7.4
4.8
1.9
-0. 7
-2. 3
-4. 0
-5. 1
4.4
4. 3
3. 5
2.2
1.0
-0. 2
-0.8
-1.6
-3. 0
-4. 2
-5. 2
-6.3
-7. 1
Relative
Humidity
(%)
27
29
33
37
42
49
56
63
70
77
80
84
86
SFC = surface
                                11

-------
The recorder data indicated a return to the background level on



June 26.  The exposure dose to Diablo due to cloud passage, as-



suming a one hour passage  time, was calculated to be 0. 04 mR,



and the infinite dose due to  deposition was estimated to be 1.2 mR.



Diablo was the only populated location that received a measurable



external dose. Recorder data collected from Alamo, Caliente,



Pioche and Lund did not indicate dose rates  greater than



background.






C.  FILM BADGES





Due to the low dose rates encountered off the test range complex



following the Phoebus  1-A test, no film badges were collected



immediately following the experiment.  Film badges collected since



the test date have not indicated  exposures that could be attributed to



the Phoebus  1-A test.






D.  AIR SAMPLES





Charcoal cartridges collected from four locations following



Phoebus 1-A contained isotopes of radioiodine.  The analyses are



presented in Table  3.  Cartridges collected  from Twin  Springs



Ranch,  Warm Springs, Clark Station, Nyala, Currant,  Sunnyside,



Caliente,  and Warm Springs Ranch did not contain radioiodines.



Gross beta analysis of prefilters from these locations did not



indicate concentrations greater than normal background levels



(<2 pCi/m3), although strontium-91 was detected on several pre-



filters in concentrations of  approximately 1  pCi/m3.






E.  WATER SAMPLES





Water samples collected from several potable supplies following



the experiment contained *  31I.  Iodine-133 was not detected in any





                                12

-------
Table 3.  Analyses of air samples collected following Phoebus  1-A,  EP4.
Location Air Date Date Gross Beta Activity
(See Figure 3) Volume Time Time Prefilter at End of
(m3) On Off Collection
t~/~: / — *\ /pv-i-secx

Queen City Summit
(unpopulated)
Diablo 541
Alamo 482
Hiko 499
AEC Standards for
Radiation Protection
XKv-A/iii , v rn3 '
6/25 6/26 , , . ,_ ,.,
1551 1145 1'6 1-15x10*
0700 0920 '46 4'36X1°4
6/25 6/26
0700 0730 ' ' X
6/25 6/26 5
0805 0810 ' '

Gamma Pulse Height Analysis
Activity (pCi/m3) at end of collection
lector 131T 132 T 133I 1 35 I
P
C
P
C
P
C
P
C

7. 7
.63
1. 1
.56
.6
.36
100
3.6
.87
2. 1
.21
1.4
. 24
8000
22
2. 1
2.5
1.8
1. 5
1. 0
1000
15
1. 3
ND
1. 2
ND
. 34
4000
-- = gamma pulse height analysis not performed.
ND= not detectable
P  = prefilter
C  = charcoal cartridge

-------
of the samples.   The results  of the analyses are presented in



Table 4.  The contamination found in the water could possibly reflect



"rainout" and subsequent runoff into water supplies.






Table 4.  Potable water samples  collected following Phoebus 1-A, EP4
Location
(See Figure 4)
Caliente
Pioche
Twin Springs Ranch
Blue Jay Maint. Station
Warm Springs Ranch
Date Collected
June 28
July 7
Aug 4
June 28
July 7
July 7
July 28
July 7
July 28
June 28
Aug 4
Radioassay Data
pCi/1 131I
160
100
ND
50
ND
60
ND
160
ND
130
ND
F.  MILK SAMPLES





Milk -was  sampled at several locations following the Phoebus 1-A



test.  The results of the analyses are presented in Table 5.   Several



samples -were obtained prior to the effluent passage, as denoted by



an asterisk  in the date column.  The data indicate that  radioiodine



contamination of the area northeast of the test range complex



existed prior to the Phoebus effluent passage.  This contamination



is believed due to three prior events:  (1) a Chinese mainland nuclear



detonation on May 14,  1965 which introduced low levels of J  31I into



milk supplies over much of the United States, (2) a test of the nuclear



rocket NRX-A3 which was conducted at NRDS on May 20, 1965,  and



(3) an accidental release of fission products from the Diluted Waters



event conducted at NTS on June 16, 1965.  The latter two events are





                                14

-------
Table 5.  Analysis of milk samples collected following Phoebus 1-A, EP4.
Location
(See Figure 4)

Stewart's Dairy
Alamo







Schofield Dairy
Hiko



Blue Eagle Rn.
Currant





Manzonie Rn.
Currant
Sharpe Ranch
Nyala
Young Ranch
Caliente
Horlacher Rn
Pioche
McKenzie Dairy
Lund
Date ' r
Collected TT
Hay

6/25/65* x
6/26
6/28
6/29
7/02
7/04
7/05
7/07
7/15
6/25/65*
6/26
6/28
7/02
7/07
6/28/65 x
7/01
7/03
7/04
7/05
7/07
7/18
6/19/65* x
6/28
6/29/65 x
7/07
6/28/65 x
7/06
6/28/65 x
7/07
6/28/65 x

* samples obtained before Phoebus
Pasture Radioiodine
or in feed
Gr. Chop
x ND
P
P

P
--

ND
ND
x ND
P
P
ND
ND
x P

P

—
P
--
P
ND
P
ND
x P
ND
x
--
ND

effluent passage
Analysis

ND
ND
20
20
20
50
ND
30
ND
30
40
50
60
ND
100
180
50
50
30
60
ND
50
20
ND
ND
ND
ND
ND
ND
ND


O
133J

ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
40
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND


-- no sample collected
ND = not detectable
P = present




15





-------
                                                     LUND
                                                      A Me K«nzi«
                                                         Dairy
                                           ^Monzonie Rn

                                         URRANT
                     BLUE
                     JAY STA.
                                     A/Blue Eagle
                                        Rn.
                                   Sharp *.Rn.
                                  NYALA
                                                                       PIOCHE
                                                                         Horlocher
                                                                         Rn.
                                                 Schoncld Dairy
                                                                     CALIENTE
                                                                      Young Rn.
NELLIS  AIR   FORCE
                                                  ALAMO
                                                    Stewarts Dairy
                                                         OlWARM SPGS.
                                                         BRANCH
               LATHROP
                 WELLST-
                                                           A MILK SAMPLE
                                                              LOCATIONS
                                                            A WATER  SAMPLE
                                                              LOCATIONS
                                     LAS  VEGAS
Figure 4.  Milk and water sampling locations following Phoebus 1-A  EP4.

                                     16

-------
reported in SWRHL-18r and the PHS interim report for the Diluted
Waters event, issued November 15, 1965.  Some contamination,
however, must be attributed to the Phoebus effluent since    I levels
increased and the presence of l 33I (Ti/2  =  20 hrs) and l 32Te-I
(Tj/2 = 77 hrs) was noted on feed  samples..

G.  VEGETATION SAMPLES
Positive evidence of effluent passage and deposition, as determined
by the presence of 91Sr on vegetation,  was  obtained at Diablo,  Queen
City Summit, and Hiko.  Many vegetation samples contained fission
products of intermediate age such as 140Ba-La and 95Zr-Nb.   This
contamination may also be associated with the  events discussed
above.
                                17

-------
                       III.  CONCLUSIONS

The effluent from the Phoebus  1-A Experiment was detected off the

test range complex, but the levels represented small fractions of

the guides cited in the AEC Standards for Radiation Protection,

AEC Manual,  Chapter 0524* .

The radiation dose  standard for external whole body exposure to an

individual is  500 millirem per  year.   As discussed on page 12,  the

only populated location to receive an external dose was Diablo,

where  0. 04 mR was due to cloud passage and 1. 2 mR was due to

deposition.

The iodine air concentrations as measured by charcoal cartridges

off the test range complex are  presented in Table 3.  Also presented

are the AEC  standards for soluble iodine concentrations.   The stand-

ards represent concentrations  of radioactivity that should not be

exceeded on a continual basis.   For the purpose of applying these

standards, radioactive concentrations in effluents may be averaged

over periods up to one year.  Since the levels presented in Table 3

did not exist  longer  than 27 hours in  any instance, it is evident that

the concentrations represented a small fraction of the protection

standards.
(1)  U. S. Atomic Energy Commission Manual Chapter 0524,
    Standards for Radiation Protection.
                                18

-------
 The charcoal measured iodine concentrations presented in Table 3

 may also be expressed in pCi-sec/m3.  By applying the appropriate

 conversion factors developed by R. S.  Decker   an estimate of the

 potential thyroid dose may be calculated.   The conversion factors

 for l 31I and 1 33I are 3. 24xlO~? and 9. 21 x 10"8 millirad/pCi-sec/m3

 respectively.  The doses due to l 32I and l 3 5I inhalation are negli-

 gible.   The potential inhalation dose to any off-site location following

 Phoebus 1-A was calculated to be less  than 0. 1 mR.  This may be

 compared to the AEC  standard for thyroid exposure to an individual

 which is 1500 millirem per year.

 As  seen in Table 4, water samples from five locations  contained

 1311.  The values are all below 300 pCi/1 of l 31I, the AEC protec-

 tion standard for continuous exposure.   The contamination cannot

 be positively identified with Phoebus effluent since J 3 3I was not

 detected in  the June 28 samples.  In addition, air sampling and

 ground  monitoring  data indicate that Warm Springs Ranch was not

 in the effluent trajectory; therefore, it is  probable that a fraction

 of the 1 311 in water from that and other locations was due to one of

 the three sources previously mentioned -  the Chinese mainland

 detonation,  the NRX reactor run, and the  Diluted Waters event.

 Milk sampling following Phoebus 1-A indicated contamination due

 to the effluent deposition.  If one scales directly from data in
                  (3)
 FRC Report No.  5   , Table 1,  it can be calculated that a dose of

 21 millirad could have been delivered to the thyroids of residents

at Blue  Eagle Ranch.  The dose prediction assumes the conditions
(2)  "Radiological Prediction and Monitoring of Tests at the Nuclear
     Rocket Development Station",  P.  Griffiths and P.  Erickson,
     Space Nuclear Propulsion Off ice--Nevada, November 1965.

(3)  "Background Material for  the Development of Radiation Protection
     Standards" Report No. 5  of the Federal Radiation  Council,  July  1964.

                                19

-------
presented in FRC No. 5 and that the contamination was the result



of Phoebus deposition alone.  As discussed in the milk results



section,  the latter assumption is probably not precise.  The



21 millirad value represents  1. 3% of the 1500 millirem standard.
                                20

-------
                             DISTRIBUTION

  1 - 15    SWRHL,  Las Vegas, Nevada
     16    James E.  Reeves, Manager, NVOO,  AEC,  Las Vegas,  Nev.
     17    R. H. Thalgott, NVOO, AEC,  Las Vegas, Nevada
     18    O. H. Roehlk, NVOO, AEC, Las Vegas,  Nevada
     19    H. G. Vermillion, NVOO, AEC, Las Vegas,  Nevada
     20    Col.  E. G. Halligan, DASA, NVOO, AEC, Las Vegas, Nev.
     21    Central Mail & Records,  NVOO, AEC,  Las Vegas,  Nevada
     22    Bryce L. Rich,  LRL,  Mercury,  Nevada
23 - 25    R. H. Goeckermann, LRL, Livermore, California
     26    H. T. Knight, LASL,  Jackass  Flats, Nevada
     27    Keith Boyer,  LASL, Los  Alamos, New Mexico
     28    W. E.  Ogle, LASL, Los Alamos, New  Mexico
     29    H. S. Jordan, LASL,  Los Alamos, New Mexico
     30    Orin Stopinski,  LASL, Los Alamos, New Mexico
     31    James G.  Terrill, Jr. , DRH,  PHS, Washington,  D.  C.
     32    Raymond Moore,  DRH, PHS,  Dallas, Texas
     33    Vincent Vespe,  ALOO, AEC',  Albuquerque, N.  Mex.
34 - 36    G. M.  Dunning, AEC, Washington, D.  C.
     37    R. E. Baker, AEC, Washington, D.  C.
     38    J.  S.  Kelly, AEC, Washington, D. C.
     39    Brig. Gen. D. L.  Crowson, DMA, AEC,  Washington,  D. C.
     40    P. W. Allen, ARFRO, ESSA,  NVOO, Las Vegas, Nevada
     41    H. Mueller, ARFRO,  ESSA, NVOO,  Las Vegas, Nevada
     42    M. I. Goldman, NUS,  Washington, D. C.
43 - 46    B. P. Helgeson, SNPO-N,  Jackass Flats, Nevada
     47    David Smith,  SNPO-C, Cleveland, Ohio
     48    R. S. Decker, SNPO,  USAEC,  Washington,  D. C.
49 - 50    J.  E. Faulkner, WANL,  Pittsburg, Pennsylvania

-------
Distribution - continued







51    Perry Davidson, WANL, NRDS, Jackass Flats,  Nevada



52    V. M. Milligan, REECo, Mercury, Nevada



53    N. E. Erickson, Aerojet General Corp., Jackass Flats, Nev.



54    H. G. Simens,  Aerojet General Corp. ,  Jackass Flats, Nevada

-------