SWRHL-32r

                FINAL REPORT OF OFF-SITE SURVEILLANCE
                                    FOR  THE
                              NRX-A5 TEST SERIES
                                      by the
                   Southwestern Radiological Health Laboratory

                  Department of Health,  Education, and Welfare
                              Public Health Service
                     National Center for Radiological Health
                                 October  15,  1968
              This surveillance performed under a Memorandum of
                          Understanding (No. SF 54  373)
                                     for the
                      U. S. ATOMIC ENERGY COMMISSION

rr *fw"i|t"i •*rtriij_ipi»ipii jj_iiimgOi''^."'rjj'~   ^^fi —Z,
                                lm
                             £~^i ffijj

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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 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 in-
 formation contained in this report,  or that the use of any information,
 apparatus, method, or process disclosed in this report may not in-
 fringe 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 pro-
 cess 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, dissemin-
 ates, or provides access to,  any information pursuant to his employ-
 ment or contract with the Commission,  or his employment with such
 contractor.
      019

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                                             SWRHL-32r

  FINAL REPORT OF OFF-SITE SURVEILLANCE

                     FOR THE

               NRX-A5 TEST SERIES
                       by the
    Southwestern Radiological Health Laboratory

   Department of Health,  Education, and Welfare
               Public Health Service
       National Center for Radiological Health
                  October 15,  1968
This surveillance performed under a Memorandum of
           Understanding (No. SF 54 373)
                      for the
       U. S. ATOMIC ENERGY COMMISSION

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                            ABSTRACT

The Southwestern Radiological Health Laboratory provided off-site
radiological surveillance for the NRX-A5 Project Rover Reactor Test
Series at NRDS,  Test Cell A. During the period in which this series
was conducted, there were four experimental plans (EP's) in the NRX-A5
series, two of which were full power runs (1100 Mw) of about 15 minutes
duration which produced detectable amounts of radioactivity off-site.
Radioactive effluent released by the EP-III on June 8, 1966, was de-
tected by ground  level surveillance in the southwest off-site quadrant.
'Effluent  released by the EP-IV on June  23 was detected by ground level
surveillance along an azimuth of about 30° (20° cloud width) to the Utah-
Nevada border,  about 190 miles from the Test Cell.  Although off-site
contamination occurred from the NRX-A5 test  series,  surveillance
indicated that radioactivity levels did not exceed the radiation protection
               [ '                    •
guides established by the Atomic Energy Commission (AEC  Manual
Chapter  0524) for the off-site population (based on the Federal Radiation
Council Guidelines). The peak potential thyroid dose, for a child with
a 2 gram thyroid, in the off-site area, from this series was about
20 millirad.or less  and the external whole body exposure about  1 mR
(at  different locations).

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                      TABLE OF CONTENTS


ABSTRACT                                                     i

TABLE OF CONTENTS                                          ii

LIST OF TABLES                                               iv

LIST OF FIGURES                                              v

INTRODUCTION                                                1

OPERATIONAL PROCEDURES                                   4

     A.  External Radiation Measurements                        4

          1.  Ground Monitoring                                 4
          .2.  Exposure Rate  Recorders                          5
          3.  Aerial Cloud Tracking                             5
          4.  Film Badges and  TLD's                            5

     B.  Radioactivity  in Environmental Samples                  7

          1.  Air Samples  .                                     7
          2.  Milk Samples                                     .10
          3.  Vegetation Samples                                10
          4.  Water Samples                                     11

RESULTS                                                       12

    A.  NRX-A5,  EP-1 and II                                   12

    B.  NRX-A5,  EP-III                                        12
          1. Sampling Results       ,                            12

              a. Ground monitoring                             12
              b.  Film badges and TLD's                        15
              c.  Air  samples                                   15
              d.  Milk samples                                  18
              e.  Vegetation  samples                            18
              f. :  Water samples                                18
    C.  NRX-A5j  EP-IV                                         19

          1.  Sampling Results       ,                            22

              a.  Ground monitoring,                            22
              b.  Film badges and TLD's                        22
                                11

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Table of Contents (continued)


              c.  Air samples                                   22
              d.  Milk samples                                 25
              e.  Vegetation samples                            29
              f.  Water  samples                                31

CONCLUSIONS                                                  32
REFERENCES                                                  38

APPENDICES                                                   39
DISTRIBUTION
                                111

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                         LIST OF TABLES
Table 1.    NRX-A5 experimental plans.

Table 2.    Threshold detectability in picocuries(pCi) at
            time of count of several radionuclides in air
            samples (90% confidence level).

Table 3A.   Meteorological data taken by ESSA,  ARFRO,
            for NRX-A5,  EP-HI.

Table 3B.   Supplementary winds  aloft:  June 8,  1966.

Table 4.    NRX-A5, EP-III air sample results,
            June 8,  1966.

Table 5.    Vegetation results, NRX-A5,  EP-III,
            June 8,  1966.

Table 6.    Meteorological data taken by ESSA,  ARFRO,
            for NRX-A5,  EP-IV.

Table 7.    External gamma exposures, NRX-A5, EP-IV
            (above background).

Table 8.    NRX-A5, EP-IV gross beta air sample results.

Table 9.    NRX-A5, EP-IV air sarr^ple results.
Table 10.   NRX-A5, EP-IV milk results.

Table 11.   Radiation protection standards.

Table 12.   Principal air concentrations resulting from
            NRX-A5.

Table 13.   Summary of results and doses  from NRX-A5.
13

14


17


19

21


23

23
24

26
33

34

36
                                IV

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                        LIST OF FIGURES
Figure 1.    Hotlines for NRX-A5,  EP-III, June 8, 1966 and
             EP-IV,  June 23,  1966  (arrival times aloft).   .       3

Figure 2.    Location of air samplers and RM-11  exposure rate
             recorders for NRX-A5, June 1966.                  6

Figure 3.    Milk and air sampling  locations  for NRX-A5,
             EP-III,  June 8,  1966.                               16

Figure 4.    Milk and air sampling  locations  for NRX-A5,
             EP-IV,  June 23,  1966.                              20

Figure 5.    Milk concentration vs. time after release at
             the Kirkeby  Ranch,  three miles  north of
             Shoshone, Calif. ,   NRX-A5, EP-IV,
             June 23,  1966.                                     28

Figure 6.    Results  of vegetation samples taken on     >
             Highway 25 following NRX-A5, EP-IV,
             June 23,  1966.                                     30
                                v

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                         INTRODUCTION

This report presents the results of the off-site radiological surveillance
program conducted by the .Public Health Service (PHS) for the NRX-A5
Reactor Test Series (Experimental Plans I,  II, III and IV) at the Nuclear
Rocket Development Station (NRDS).
Under a memorandum of understanding with the Atomic Energy Com-
mission (AEC),  the U. S. Public Health Service conducts a  program
of radiological monitoring and environmental sampling in the off-site
area surrounding the Nevada Test Site (NTS) and the Nellis  Air Force
Range (NAFR) which include the NRDS and Tonopah Test Range.  For
simplicity, this  combined area will, be termed the test range complex
in this report.
The NRX-A5 was the fourth fueled reactor in the NRX series of the
Rover Program. The reactor was  placed so that the hydrogen coolant
and escaping fission products were exhausted upwards.  The primary
objective of the  program was  to obtain accumulated operating time at
design conditions.  The series was conducted at Test Cell A under the
auspices of the Rover Nuclear Engine for Rocket Vehicle Application
(NERVA) program, which is directed by the  Space  Nuclear Propulsion
Office (SNPO).
The reactor was operated at full power for an accumulated time of about
30 minutes;, resulting in an integral power of about 2. 1 x 106Mw-sec.
The peak power  was 1200 Mw.  The experimental plans are outlined
in Table  1.
The effluent from both EP-III and EP-IV was detected in off-site environ-
mental samples. The general hotlines and boundary of the area where
                                1

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fresh fission products or radioactivity above background was found at
ground level are indicated in Figure 1.  The EP-III effluent was spread
over a relatively large arc because of considerable wind shear and
shifting winds during and after the test.  The effluent to the north-
east of NEDS for EP-III was due to the northeasterly flow of surface
level winds at test time which resulted in a small segment of the cloud
going towards Control Point 1. The broken line on Figure 1 indicates
the boundary where the effluent from EP-III was  observed; the arrow
indicates the main cloud trajectory.
 Table 1.  NRX-A5 experimental plans.
Experi-
mental
Plan
EP-I
EP-II
Date .,
1966
.May 2,6
June 8
Time of Opera-
tion, PDT

AM
Integral Power i
Mw -sees
! f,
,; Criticality and |
drum calibration
Low power test
Radioactivity
Detected
Off -Site
No
No
EP-III    June 8     1402-1418
'EP-IV    June  2'3    1035-1050
1.1 x 106
(Full Power)
1. 0 x 106
(Full Power)
                                                               Yes
                                                               Yes

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                          QUEEN CITY™,
                           LSUMMLT_/?a>
                                    ,!	    	
            DANSBY RN.»

             FURNACE
              REEK    2?
               190


        DEATH VALLEY OCT.
      SCALE IN MILES
      5^P^--^
     OB  10 16 20 29
Figure 1.  Hotlines for NRX-A5 EP-III,  June 8, 1966,  and EP-IV, June 23,  1966.

           (Cloud arrival times for EP-IV are based on aircraft tracking).

                                      3

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                  OPERATIONAL PROCEDURES






The Off-Site surveillance program was comprised of routine monitoring



stations (includes air, milk and water) and mobile monitoring teams.



The monitoring teams were initially positioned on the basis of the hot-



line  prediction by the Environmental Science Services Agency, Air



Resources Field Research  Office (ESSA, ARFRO) with final positioning



and sampling based on the airplane  surveillance results  and the moni-



tors' results.





A.  External Radiation Measurements



    1.   Ground Monitoring



    Ground monitors tracked the reactor effluent passage and deter-



    mined exposure rates at several locations with portable instruments.



    Each monitor was equipped with an Eberline E-500B, a Precision



    Model 111  Standard "Scintillator11', and a Victoreen (Radector Model



    No.  AGB-5dB-SR.           '    '                  :




    The  Eberline E-500B is a Geiger Mueller instrument with a range
                                                       i

    of 0  to 200 milliroentgens per hour (mR/hr)  beta and/or gamma



    oh four scales with an  external halogen filled GM tube and a 0 to


    2000 mR/hr,  gamma only, range from an internal Anton  302 6M



    tube.




    The  Precision Model 111 Standard "Scintillator"  is used primarily



    for low-level detection  and an indication of cloud passage.  It has



    a range of  0 to 5 mR/hr on six  linear scales.




    The  Radector has a range of 0.  05 to 50, 000 mR/hr on two loga-
                                    r                   i

    rithmic scales.  This instrument employs an inert gas ionization



    chamber.

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The above instruments are calibrated with l 37Gs and are generally
accurate to about 4^20% for this energy.  Exposure rate readings can
be made to two significant digits.
2.  Exposure Rate Recorders
Eberline RM-11 exposure rate recorders are placed at twenty-one
stations around the test range complex (Figure 2) and are opera-
tional on a routine basis.  These recorders utilize a Geiger Mueller
tube detector to document radiation levels at specific locations.
The instrument has a 0. 01 to 100 mR/hr range on a 4 cycle log
scale.   The gamma exposure rate is recorded on a 30-hour strip chart.
The RM-11 is accurate to 4_20% as  calibrated with a 1 37Cs  source.
3.  Aerial Cloud Tracking                       ><
An Air Force  U3-A aircraft, matined by two Public'Health Service
monitors equipped with portable'monitoring instruments identical
to those of the  ground  monitors (also a Radector ion chamber with
a range of Ot,to 1000 R/hr), tracked the  reactor effluent to  assist
the positioning of ground monitors  and to determine,the general
magnitude o;f the release.  Public Health Service cloud sampling
aircraft were  also used as aids in cloud tracking,  hpwever their
primary purpose was cloud sampling in order to determine cloud
size and inventory.  The results  of their sampling are reported
separately by the SWRHL Engineering Development Program.  Long
range tracking of the  effluent cloud is also done by the NATS and
ARMS aircraft from EG&G who also write a separate report.
4.  Film Badges and TLD's
The PHS routinely maintains approximately 56 film badge stations
(5 badges toi a station) off the teat range complex and assigns  badges
to approximately 120  off-site residents.  DuPont type 555 film is

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                               OROVADA
                                  PARADISE
                                                            DEETH   0/WELLS
                             BATTLE MTN
                             N   E   \V   A   D  A
                                               DUCKWATER
                                           PINE CR RN
                                         OUNDMTN
                                          WARM
                                        SPRINGS
                                        -  NELLIS   AIR  i
                                SCOTTY'S
                                  JUNCTION
                                        LATHRO
                                         WELLS
                                                       INDIAN SPRINGS

                                                       PAHRUMP
 D- AIR SAMPLER WITH PREFILTER

 _   AIR SAMPLER WITH PREFILTER
 "~  AND CHARCOAL CARTRIDGE
 ~-  RM-II DOSE RATE RECORDER
Figure 2.   Location of air samplers and RM-11 dose rate  recorders for
            NRX-A5.  June 1966.

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    used in the badge.  The results of exposures are accurate to +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.  These sensitivities


    assume no heat damage, which produces  interference at some


    locations.




    As part of the external dosimetry program the PHS also has 21


    stations where thermoluminescent dosimeters (TLD) are located


    in conjunction with the film badge stations.  Three EG&G Model


    Tl-12 CaF TLD's are located at each station.  These dosimeters


    have a sensitivity of 5 mR above background with an accuracy of


    + 10% and  standard deviation at the 90% confidence level of 2.8%.


    They have an upper exposure limit of 5, 000 R.





B.  Radioactivity in Environmental  Samples
                                   !

    1.  Air Samples


    During  June, one-hundred and  eight air samplers were routinely


    operated in the western United States, thirty-eight of which were


    located  in Nevada (Figure 2).   Supplementary temporary air sam-


    pler locations were established as deemed necessary to cover


    cloud passage.  The routine samplers were the  Gelman Tempest


    type and were equipped with Whatman 4 inch 541 prefilters.  A


    portion  of the  routine samplers and all supplementary stations


    were equipped with MSA char coil cartridges.




    The Tempest air sampler used  by SWRHL employs a Cast vacuum


    pump driven by a 1/2 or 3/4 horsepower motor.  The  pump runs


    at about 140,0 rpm with an average flow rate of about 10 cfm.


    The supplementary temporary  air samplers consisted of a  Cast


    Model No. 0(740 positive displacement pressure-vacuum pump


    coupled to a';Rockwell Model No.. 415 gas meter for precise mea-



    surement of,air flow.  The  flow rate  of these systems averages


    about 6  cfm.



                               7

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All air sample prefilters and charcoal cartridges collected follow-
ing the NRX-EST  series were returned to the Southwestern Radio-
logical Health Laboratory in Las Vegas for analysis.  Prefilters
were counted simultaneously for gross beta and alpha activity with
a Beckman "Wide Beta" 4-inch low background (6 cpm beta) pro- .
portional counting system.  This system has an efficiency of approx-
imately 45% for 0. 54 MeV betas.  Gross beta concentrations were
computed at the time of count for the purpose of screening samples
and delineating the effluent trajectory.  Samples  which were be-
lieved to contain fresh fission products were recounted several
times.  Based on these counts, an individual decay constant was
computed for each sample.  This constant was used to extrapolate
           i ;                    . ,'                 : 1
the gross beta result to the end of  the collection period.
                               i                  p
All prefilters were analyzed for,the predominant biologically
significant gamma emitting isotopes by using a 4" bjy 4"  sodium
iodide crystal and multi-channel analyzer.   Reported values are
corrected for radioactive decay,fo  the  end of the  collection period.
                               f
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 —	?	p	 .   This unit is obtained by
                         m.i    i                            /
multiplying pCi/m3 by the sampling time in seconds (or hours)
and results in the  total cloud pas.sage exposure.   ;
                               •, i                 . i
All charcoal  cartridges were analyzed for gamma isotopes using
a 4"x 4"  sodium iodide crystal coupled to a multi-channel pulse
height analyser set to view energies from 0 to 2 MeV. The activity
on the cartridge should represent primarily the gaseous  radio-
                                                  i
iodines.    .,                     ;

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    The analyses of the gamma spectra were performed by an IBM 1620,

    utilizing a matrix technique.   This method compensates for the

    interference between isotopes for a given spectrum by the simul-

    taneous solution of n equations containing n unknowns,  where n

    represents the number of isotopes for which solution is sought.
    Due to time and memory limitations on the  1620,  the matrix is
    limited to eight (n=8) isotopes.  The input to the computer program
    is variable so that a determination may be made for any eight
    isotopes for  which standard spectra are available.

    The threshold detectability for several radionuclides in air  samples
    is presented in Table  2.  These yalues are  based  on an examina-
    tion of previous data collected under the following conditions and
    assumptions:
         a.   Count time in days afte^ fissioning as indicated by  footnotes.

         b.   Prefilters collect unfractionated fission  products resulting
             in a complex spectrum.,.,

         c.   Only the gaseous fission products (primarily iodines) are
             collected on the MSA charcoal cartridge. .,
         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.
                                    i'
Table 2.  Threshold detectability in  picocuries (pCi)*  at time cf count of
          several radionuclides in air samples (90% confidence level).
Sample Type
Whatman No. 541

MSA Charcoal

'131I
500
200
200
100
132Te-I
1000
-
400
-
1B3]-
500
200
2Q'0
100
135J
1000 '
-
400
-
140Ba-La
500
200'1
200'
100
Length
of Count
10 min.
10 min.
10 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.
*1 pCi = 10"12  curie.                 ,
                                9

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2.   Milk Samples
After the release of radioactivity from NRDS,  milk samples were
collected from dairy farms and farms producing milk for their
own consumption, which were believed to have been in the'cloud
path.  All liquid samples  are counted, with no prior preparation,
in 3. 5 liter inverted well aluminum beakers which are placed over
a 4Mx 4" sodium iodide crystal.  Each milk sample is counted for
40 minutes  using a multi-channel analyzer viewing an energy range
from 0 to 2 MeV. The lower lirq.it of detection for 131I and 133I
in milk is about  20 pCi/1 at time of count (if l 3 7Cs <100 pCi/1),
and  all results below that value ^,re reported as non-detectable.
The reported values have, at tirr,|e of count, a  2 sigma error estimate
of +15 pCi/l;or +10%,  whichever is greater.
Biological discrimination limitsff;he number of radiqnuclides present
in a milk sample.  The time delay between ingestion by the cow,
production of milk, and its analysis also removes short half-life
isotopes such as l 32 I and 1 3 5I. .                   ,
3.   Vegetation Samples
Vegetation samples were collected in the suspected1 effluent tra-
jectory to indicate deposition oh'^he ground and thus the general
cloud trajectory.  They were als,p obtained at most milk  sampling
locations, with an effort made to make the sample representative
of the cows' feed.  These samples were taken  as ea'rly indicators
of where milk might be contaminated  and the general level of con-
tamination.                     ,,                  ..
The  limit of idetectability for  specific isotopes  in vegetation sam-
ples is  several hundred picocuries per kilogram and' is dependent
on the interference from other is,otopes and sample size.
                            10

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4.  Water Samples
Water samples are routinely collected from about 30 locations
around the test range complex.  In addition special samples may
be taken in the area of suspected effluent passage.  The sensitivity
for detection of radioiodine in water is about the same as that for
milk if significant quantities of other gamma emitters are not
present.
                            11

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                             RESULTS

A.  NRX-A5, EP-I and II
Experimental Plan I (EP-I) was the criticality and drum calibration
test and EP-II was a low power test.  There was not a significant re-
lease of radioactivity and radioactive effluent was not detected off-site.
The PHS had people on standby for both ground and aerial monitoring
for both tests.

B.  NRX-A5, EP-III
Experimental Plan III was the first full power  run on the NRX- A5
reactor.  As a result of the aerial cloud tracking results, ground
monitoring was  performed in the southwest quadrant off-site.  PHS
aerial monitoring results indicated that the effluent cloud was split
into two sections at about 8, 000 and 9, 000 feet MSL by the large wind
shear which existed at test time (meteorological data fr'om ESSA, ARFRO
in Table 3).  The low altitude  section of the cloud went towards CP-1
at a bearing of about 40°.  The main cloud went in a westerly direction
with an initial be'aring of about 270 i'or about 25 miles and later in a
more southerly  direction.  The peak exposure reading in the airplane
was 7 mR/hr at about 8 miles from the reactor,  with the highest off-
site reading being 3 mR/hr at the  south boundary of NRDS.  The ground
                                .r,
sampling locations for air and milk are shown in Figure 3.
    1.   Sampling Results
         a.   Gr,ound Monitoring                       M
         Qround monitors were located on U.S. 95 at the time and loca-
         tion of  :cloud passage.  The|monitors did not detect gamma
         exposure rates above background.  The RM-ll;recorders did
         not indicate any exposure rates above background.
                                12 '

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Table 3A. Meteorological data taken by ESSA, ARFRO,  for NRX-A5,
          EP-III.

Sky Condition:  5000' Sctd. , Est. 18, 000' Overcast
Clouds:  4/10 Cumulus, 6/10 Altocumulus
Visibility:  Unrestricted
Upper Air Data At:  Jackass Flats, Nevada,  1400 PDT,  6/8/66
Height Wind
(Ft.MSL) (Deg/Kts)
SFC 3615
4000
4068
4816
5000
6000
6201
6955
7000
8000
9000
10000
10151
11000
11680 .
12000
13000
14000
14534
.15000
15026
15420
16000
17000
18000
18806
210/10
220/11
' 210/11
' 210/07
210/07
180/04
190/03
200/01
210/01
120/02
• 10d/04
080/09
090'/ 08
M .,
M ,,
14Q/04
130/03
060/03
060/04
080/04
100/05
110/06
120/08
130/15
13Q/20
M ,
Pressure
(mb)
887
876
871
850
841
814
807
785
784
757
730
703
700
677
660
652
627 .
604
593
583
582
572
558
536
516
500
_ . Dew Relative
Temperature _. .
o Point Humidity
. ( U) (°c) (%)
24.9
22. 3
21.5
19.3
18.8
15.4
' 14.6
13.4
13.4
1 10.8
" 8.0
5.2
^ 4.9
- 2.6
-: 0. 5
-0. 1
. -2.9
.5.2
-6.4
-6.9
-6.9
-7.2
-8.6
i-10.9
-13.0
-14.9
1. 1
1.9
2. 2
1. 3
0.9
-1. 3
-1. 0
-1. 5
-1. 5
-2.6
-4. 1
-5. 5
-5.8
-7 . 0-
-8. 5
-8.9
-11.0.
-13. 0
-13.6
-16.9
-16.9
-17.4
-18. 5
-20. 2
-21.7
-23.4
21
26
28
30
30
32
34
36
36
39
42
46
46
49
51
52
53
54
56
47
47
44
45
46
47
48
SFC = Surface
  M = Missing
                                13

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      Table 3B.  Supplementary winds aloft:  June  8, 1966.
                 Data (Degrees/Knots)
Observational Point :
Time of Ob. (PDT) :
Type of Measurement :
H Surface
E
I
G
H
T

(Ft. MSL)





Time of
Type of
H
E
I
G
H
T

(Ft. MSL)






4000
5000
6000
7000
8000
9000
10000
11000.
12000
13000
14000
15000
Ob. (PDT) :
Measurement :
Surface
4000
5000
6000
7000
8000
9000
10000
11000
12000

13000 ;
14000
15000
Jackass Flats,
1030 1100
Radar Radar
170/04 290/02
170/02
HO/
090/
080/
080/
100/
no/
120 /
130 /
150/
160/
ISO/
131
01
05
10
1.4
10
07
12
11
11
08
11
5
Radar
220/
230/
220/
ISO/
130/
120/
06
09
07
07
07
06
110/05
100/

	

	
	
	 	
10
-
-

-
-
-
290/01
280/
200/
120 /
lOQ/
080/
09 O/
110/
130/
150/
170/
ISO/
01
03
06
11
13
12
13
10
13
10
11
1330
Radar
230/
240/
220/
190/
ISO/
170/
090/
10
08
11
10
07
04
06
090/08
	
• 	

	
	

-
_

- •
-

Nevada,
1130
Radar
190/06
200/
160/
01
02
090/04
07 O/
070/
080/
080/
090/
ipo/
150/
1.70/
^i70/
06
09
11
13
14
14
10
13
15
1345
Radar
240/
230/
24 O/
240/
210 /
ISO/
080/
080/
	
_ — .
i

	
'r ~ ~
05
05
10
07
03
03
07
08
-
_

-
-
-
Elevation 3615'
1200 1230
Radar Radar
260/05 240/08
250/05
220/09
200/04
130/04
070/03
080/05
090/09
100/12
100/12
140/08
170/07
150/08
1400
Radar
210/10
220/11
210/07
180/04
210/01
120/02
100/04
080/09
M
140/04

130/03
060/03
080/04
230/06
190/02
100/03
100/06
100/09
100/09
100/13
100/12
120/08
160/06
180/05
	
1415
Radar
250/07
250/09
250/12
230/10
210/05
220/02
080/07
080/11
- - - - .


/



----
1245
Radar
240/05
260/04
250/07
200/06
150/08
120/05
100/11
090/12
	


	
	
1430
Radar
240/06
220/06
230/06
220/10
220/11
210/03
080/05
060/08
	 	






	
1300
Radar
210/07
230/07
220/05
170/04
160/06
130/08
110/06
090/09
. 	
	
	
	
	
1500
Radar
230/08
230/10
220/09
230/06
240/05
130/02
090/07
080/07
080/03
080/02

080/02
090/04
110/06
M - missing
                                     14

-------
b.   Film Badges and TLD's
The film badge and TLD results gave no indication of expo-
sures above background due to the reactor effluent.
c.   Air Samples
Fresh fission products were detected on air samples as shown
in Figure 3 with the results given in Table 4.  Gross beta
results which were above background are included, if they
coincide with the date" and area of effluent cloud passage, even
if fresh fission products weren't detected on the sample. These
high gross beta results are due to  several causes:
(1)  Reactor effluent - even those samples with fresh fission
productjs were near the limit pf detectability.'  Thus,  the sam-
ples marked NFFP may have contained fresh fission  products,
but belqw levels of detection.
(?)  Fallout from a non-U. S. test of May 9,  1966.  It was
       c
detected in environmental samples in the vicinity of the site
around June 7 and 8.
(3)  High natural background levels due to normal fallout and
dust, etc.  The general background level during June 1966 was
about 0. 5 pCi/m3  and  occasionally values of about  1 pCi/m3
occurred.
The positive results found to the south and south-southeast of
the site are possibly due to the release of fission products
during 900! down of the reac.tor and to the northerly flow of sur-
face drainage  winds  at night.   They also could have resulted
from the. large wind shear and changing  wind direction after
       i'
testing.;] The potential inhalation exposure from-radioiodines
        1                   :                .
at the sampled locations is  estimated to be less than  1 millirad
to an adult, assuming  a breathing rate of  2. 3 x 10~4 m3/sec
                       15

-------
                                     Round Mountain

                                      5
                                    L.   NELLIS""

                    — • .   r .- ~m. ^-i a i—™^^r i i   /  •"»•• * rWKvrt
                    Bishop
                            Scotty's Jc^'   r
                      Big Pine

                                Springdale£^? '  N.T.S,
                           CALIFORNIA
                                         Silverlake
                                            Boktr
    Fresh fission products detected on air
    samplers
    Gross beta air samples above back-
    ground
    Fresh fission products not defected on
    air samplers
                                                     MILES
                                                    26    00    76
Milk sampling and feed sampling
locations
Figure 3.  Milk and air sampling locations for NRX-A5, EP-III, June 8,  1966.

                                   16

-------
                                      Table 4.  NRX-A5, EP-III air sample results, June 8, 1966.*
Location
Beatty, Nevada
Death Valley Jet., Calif.
Death Valley Jet. , Calif.
Furnace Creek, Calif.
Furnace Creek, Calif.
Furnace Creek, Calif.
Lathrop Wells, Nevada
Pahrump, Nevada
Pahrump, Nevada
Pahrump, Nevada
Shoshone, Calif.
Barstow, Calif.
Ridgecrest, Calif.
Ridgecrest, Calif.
lOmi.S. of Beatty.Nev.
(Hwy. 95)
Springdale, Nev. (Hwy. 95)
Sampling Period
Start Stop
Day Hr Day Hr
08 0742
08 0645
09 0645
08 1130
09 1030
10 1125
08 0755
07 1200
08 1200
09 1200
09 1435
09 0700
08 1308
09 1425
08 1545
08 1540
09 0826
09 0645
10 0645
09 1020
10 1125
11 1155
09 0620
08 1200
09 1200
10 1200
10 1843
10 0700
09 1422
10 1315
09 0930
09 1156
Total
Time
(Hr)
24.
24.
23.
22.
25.
24.
22.
24.
24.
24.
28.
24.
25.
22.
17.
20.
6
0
9
8
0
6
3
0
0
0
2
0
3
9
3
3
Sample
Volume
(m3)
467
485
495
472
518
497
450
435
448
435
468
460
485
415
193
410
Col-
lector
P
C
P
C
P
P
C
P
P
P
C
P
P
P
P
P
P
P
P
C
P
C
Beta
Activity
(PCi/m3)
1. 1
1. 1
1. 1
1'. 8
1.0
1.5
1. 1
1.3
1.7
1.3
1. 1
1. 1
2.3
2. 1
1.9
0.7
Beta 131].
Exposure Notes
(pCi-hr/m3) pCi/m3 pCi-sec/m3
28
26
26
40
25
36
24
31
40
31
31
27
59
48
33
14
ND
ND
ND
ND
NFFP
0.7 5.7xl04
ND
NFFP
NGS
0.5 4.3x10*
1.7 1.4xl05
NGS
ND
NFFP
NFFP
NGS
NGS
NGS
0.7 4.4xl04
1.0 6.2xl04
ND
ND
133I
pCi/m3 pCi-sec/m3
<0. 1
<0. 1
1.4
5.2

0.8
ND


1.8
8.0

1. 1





1.8
2.4
0.4
ND

1. 2xl05
4. 3xl05

6.7x10"


1.4xl05
6.4xl05

9. 5xl04





1. IxlO5
1.5xl05
3. OxlO4
*Results extrapolated to end of collection.
Notes:  NFFP - No fresh fission products detected.
P = Prefilter         C = Charcoal cartridge
NGS - Not gamma scanned.
ND - Not detected.

-------
 (20 m3/day), and using the values for the ICRP standard man'  '
 and assuming equal uptake of iodine associated with both vapor
 and particles (see Appendix A for calculations).
 d.   Milk Samples
 Milk and feed samples were obtained from the locations indi-
 cated in Figure 3.  The only milk samples with a detectable
 level of radioiodine were from Dansby's Ranch,  southwest of
 Lathrop Wells,  which had 40 pCi/1 of * 31I on June 13 and
 50 pCi/1 of l 31I on June 17.  Two samples prior to this (June 9
 and 10) did not have detectable levels of radioiodine, although
 vegetation from the pasture did show the presence of radio-
 iodine (Table 5).  Peak levels do not usually occur in milk
 until  2 to 6 days after deposition  on the pasture.   There are
 two potential sources  of the 1 31I:  fallout from ,a non-U. S.
 nuclear detonation.of May 9,  1966, which was observed in air
 samples about this time and/or the reactor effluent.
 e.  Vegetation  Samples    >•                  i
 Vegetation samples were taken at five mile intervals on U.S. 95
 between; Springdale and Lathrop Wells,  Nevada .on June 9.  No
 fresh fi'ssion products were detected in these samples except
 for, those collected 10 miles] south of Springdalei and 5 miles
 south of Beatty  (see Table 5).   Vegetation samples were also
 taken at'Peacock Ranch nearj Springdale and at Dansby's Ranch.
 The results for  samples containing fresh fission products are
 given ii> Table 5.
f.   Water Samples
 Fresh fi'ssion products were not detected in water samples
 collected from Dansby's Ranch and near Springdale, Nevada.
                        18

-------
Table 5.  Vegetation results, NRX-A5,  EP-III,  June 8,  1966.*
Location
10 miles south of Springdale
5 miles south of Beatty
Dansby Ranch, near Lathrop Wells
Dansby Ranch; near Lathrop Wells
Dansby Ranch, near Lathrop Wells
Dansby Ranch, near Lathrop Wells
Date
6/09/66
6/09/66
6/09/66
6/10/66
6/13/66
6/17/66
131J
pCi/kg
ND
ND
ND
230
560
420
133I
pCi/kg
600
1500
800
600
ND
ND
^Results extrapolated to end of collection time.


C.  NRX-A5, EP-IV

The EP-IV was the second and final full power run on the NRX-A5

reactor.  The EP-V which had been tentatively scheduled was canceled.
                                    \

Ground monitoring and environmental surveillance was performed in
               >.
the northeast quadrant of the off-site area based on aerial monitoring

results and initial ground monitoring.  A reading of about 2 mR/hr in
               n
the airplane near Coyote Summit (60 miles from the reactor) was

detected.   An initial hotline of about  £5   changing  to about 30  beyond

60 miles was indicated.  The effluent was tracked to the area around

Rapid City, South Dakota.  Cloud effluent levels had decreased to the

point where further tracking could not be accomplished and the aircraft

returned to Las Vegas.  The transport speed for distances greater

than 60 miles was about 26 mph.  Fresh fission products were detected

in off-site samples of air, vegetation,  and m-'lk; gamma exposure rates

were recorded by portable survey  meters and the  RM-ll recorders.

The air and milk sampling locations  are indicated in Figure 4.  Meteor-

ological data for the time of reactor  run, taken by ESSA, ARFRO, is

given in Table 6.
                                19

-------
                                                                      -xYelland Rn.

                                                                      Rogers Ra'Af
                                                                        Sacramento
                                                                             Pass
                                                                             Baker
                                                                          Cummings R
                                                                             GonGdaerrr18o
                                                                KirkebyR
                                                                Geyser Rn.w
                                                                     Geyser Maint. St.
                                           Blue Eagle Rn.
     Springs

25     **Nyala
        Warm Springs^:
                               Queen City Summit
                                i   A    Coyote Summit
                            Goss Rn.W )V
                     NEVADA
                      TEST
                       SITE
          NELLIS
           AIR FORCE
            RANGE
                                Positive air  samples

                                Positive milk samples

                                Negative air samples

                                Negative milk samples

                                Air samples with gross
                                beta above background
                o Death Valley'Jet
Figure 4.  Milk and air sampling locations for  NRX-A5,  EP-IV,  June  23, 1966.


                                     20

-------
       Table 6.  Meteorological data taken by ESSA, ARFRO, for NRX-A5,
                 EP-IV.
SFC
       Sky Condition:  Clear
       Clouds: None
       Visibility:  Unrestricted
       UPPER AIR DATA AT: Jackass Flats, Nevada 1035 PDT, 6/23/66.
Height
(Ft.MSL.)
3615
4000
4400
4728
5000
6000
7000
8000
9000
10000
10125
11000
12000
13000
13040
14000
15000
16000
17000
18000
18957
Wind
(Deg/Kts)
220/04
220/04
210/04
200/03
200/02
210/0'3
190/05
190/11
200/17
210/21
210/21
200/2:2
220/21
230/18
220/18
240/19
260/24
250/34
250/34
250/34
260/42
Pressure
(mb)
884
874
860
850
841 .
812
784
755
729
703
700
676
651
627
626
604
582
560
538
518
500
Temperature
(°C)
25.0
22.6
22.6
21.7
21.0
18.4
15.4
14/1
12. 1
9.9
9.4
7.2
4.. 6
2. 1
1.9
0.7
-0.7
-2.6
-4.4
-7. 0
-9.1
Dew Point
(°C)
-6.3
-2.9
-2.9
-3.7
-4. 2
-6.3
-8.8
-9.9
-11. 5
-13. 3
-13.8
-15. 5
-17.7
-19.8
-19.9
-21.6
-21.6
-24. 3
-25.2
-26.8
-28. 0
Rel. Humidity
(%)
12
18
18
18
18
18
18
18
18
18
18
18
18
18
18
17
17
17
18
19
20
                                       21

-------
    1.  Sampling Results


        a.   Ground Monitoring


        Monitors on Highway 25 between Queen City Summit and Coyote


        Summit detected the cloud passage with portable survey instru-


        ments.  The highest off-site ground level external gamma


        exposure* detected was at Goss1 Ranch (60  miles from the


        reactor at an azimuth of 25G).  Cloud passage was also indi-


        cated by RM-11 recorders  at Sunnyside and Lund, Nevada.


        The results are given in Table 7.



        Air monitoring results did  not  show fresh fission products  at


        Lund.   Thus,  it is assumed that the cloud did pass over Lund


        (confirmed by aerial surveillance  results),  but .remained aloft.



        b.   Film Badges and TLD'sJ

                <-                   h                  X
        Film badge and TLD results gave  no indication'of the  reactor


        effluent passage.



        c.   Air Samples
                f                   r                  '•':

        Air samplers were operated at the locations indicated in
                                                     r,

        Figure 4.  In addition, air samples  (including charcoal car-


        tridges) were also taken throughout Utah.  The positive air


        sample results are given in Tables 8 and 9-  The results from


        Utah,  except Garrison,  indicated the absence of  fresh fission


        products.  The gross beta results  from Garrison and  Geyser


        Maintenance Station were above background, but specific


        isotope'ianalysis is not available.



        The potential  inhalation exposure to  an adult's thyroid, based
                                                     . i
        on air  sampling results  and the method of calculation  outlined
';For purposes of this report, exposure in mR -will be considered equiv-

 alent to dose iri millirad.  Also a dose in rads is assurhed to be equal

 to rems (i.e. , !RBE of 1) for the doses  in this report. r



                                22  ,

-------
 Table 7.  External gamma exposures, NRX-A5, EP-IV (above background),
Location
GOBS' Ranch
Coyote Summit
Sunny side
Lund

Distance
From
NRDS
60
60
130
150

Arrival
Time
(PDT)
1300
1300
1540
1600

Instrument
for
Measurement
E-500B
E-500B
RM-11
RM-11

Peak Expo-
sure Rate
mR/hr
l.Z
0. 1
0.02
above
bkgd.
Integrated*
Exposure
mR
1
0.06
0.05
<0.01

 *This exposure is based on an integration of instrument readings over time
  and  is  thus representing primarily cloud passage.  Residual activity was
  not noted and, therefore, is not included (the sensitivity of the instru-
  ments was not sufficient to determine fallout at these low levels).
 Table 8.  NRX-A5, EP-IV gross betja air sample results.*

                Sampling Period   Total  Sample   Beta     Beta
 Location       .Start       Stop  Time** Volume  Activity  Exposure   Notes
	    Day Hr  Day Hr   (Hr)     (m3)  (pCi/;m3) (pCi-hr/m3)

 Goss1 Ranch                                          ;j
 (NW of Coyote                     f
 Summit)       231314  231500   o'l.S      17    14,4oO    26,000
 Coyote Summit,
Hwy. 25
Sunny side, Nev.
Geyser Maint.
Station, Nev.
Garrison, Utah
.23
23
23
23
1135
0730
1602
0800
23
24
24
24
1540
0726
1610
0800
04.
23.
i •
24.
22.
1
9
6
7
40
470
446
458
527
138
10. 1
3. 1
2, 160
3, 320
247
71


NGS
NGS
  ^Results extrapolated to end of collection time.
 **Based on running time indicator .rather than time on and off.
   NGS = Not gamma scanned.       ;•'                  ',-,
                                 23

-------
Table 9.  NRX-A5,  EP-IV air sample results. ;
Location
Goss'
Ranch
Coyote
Summit
Sunny-
side
Col-
13 '-I
Time lector pCi/m 3
6/23 1314
6/23 1500
6/23 1135
6/23 1540
6/23 0730
6/24 0726
P
C
P
C
P
C
9. IxlO2
6.2xl02
ND
40
9.9
4.7
13Z
pCi-sec/m3 pCi/m3
5.8xl06
3.9xl06
ND
5.9xl05
8.6xl05
4. IxlO5
ND
1.2xl03
ND
50
ND
5. 1
I
133 !
UBj
pCi-sec/m3 pCi/m3 pCi-sec/m3
ND
7. 6xl06
ND
7.4xl05
ND
4.4xl05
1.6xl03
1. 7xl03
70
80
23
17
l.OxlO7
1. IxlO7
1. OxlO6
1.2xl06
2. OxlO6
1.5xl06
pCi/m3
1.6xl03
1. IxlO3
80
100
ND
4.8
pCi-sec/m3
l.OxlO7
7. OxlO6
1. 2xl06
l.SxlO6
ND
4. 2xl05
Potential adult
Inhalation
Dose(mrad)
5. 3
< 1
1
^Results extrapolated to end of collection time.
P - Prefilter.    C - Charcoal cartridge.    ND - Not detectable.
132 I is not reported on the prefilter because of interference from 97Zr.

-------
in Appendix A was about 5 millirad at Goss' Ranch, which was


near the hotline at a distance of 60 miles from the reactor.


An evaluation of this exposure on the basis of the new ICRP

      4                               '
model  gives very similar  results (assume 90% of vapor de-


posited in respiratory system and a mass median diameter


of 1 micron for the particulate radioactivity).  A similar


analysis gives  a thyroid inhalation dose of about 1 millirad


at Sunnyside,  Nevada.



The air sampler at Goss1 Ranch was not started until after


cloud arrival.   By estimating the total integrated air concen-


tration based on ground monitored results of exposure rates


versus time, the total potential adult thyroid inhalation dose


at GOSSH Ranch would be about 7 millirad.     i



d.  Mil'k Samples          '


Milk and feed samples were obtained as  indicated in Figure  4.


Samples were also obtained .'from the standby network in Utah.


A complete list of milk  samples is  given in App'endix B;   The


results of milk samples containing  fresh fission products  are


given in Table  10.   The samples from Utah did not have


detectable levels of fresh fission products.    ,|



The maximum  milk concentration found was at'the Kirkeby


Ranch, about 3 miles north 'of Shoshone,  Nevada.   The poten-


tial dose to a child's thyroid'(2 gram) was estimated from this


concentration to be 40 millirad based on the assumptions  in


FRC-5 |  (38 millirad from 1 31I and some contribution from


133I) which assumes an effective half-life of l 3|* I in milk  of


about 5,'days.   However, the' milk results from,-Kirkeby Ranch


did not if it the expected decay curve of an effective half-life
                        25

-------
Table  10.  NRX-A5, EP-IV  milk results.*
Location
3 mi. N. of Shoshone
(Kirkeby Ranch)
3 mi. N. . of Shoshone
(Kirkeby Ranch)
3 mi. N. of Shoshone.
(Kirkeby Ranch)
3 mi. N. of Shoshone
(Kirkeby Ranch)
3 mi. N. of Shoshone
(Kirkeby Ranch)
3 mi. N. of Shoshone
(Kirkeby Ranch).
3 mi. S. of Baker, Nev.
(Baker Ranch) ..
3 mi. S. of Baker', Nev.
(Baker Ranch) '
13 mi. N. of Shoshone
(Harbecke Ranch)
13 mi. N. of Shoshone
(Harbecke Ranch)
5 mi. S. of Baker'
(E. J. Cummings Ranch)
5 mi. S. of Baker1**
(E.J. Cumming's Ranch)
Nyala !'
I.
Date
6/24
6/25
6/26
6/27
6/30
7/01
6/30
7/01
6/26
6/27
6/26
6/27
6/24
Milk
20
80
240
90
•ND
' ND
50
20
50
60
.pCi/1
133][
1. 3x1
20
310
60
ND
ND
ND
ND
50
ND
not available
110
;' 30
30
ND
Pasturage pCi/kg
131I 133I
O3

830 2.7xl03
640 IxlO3

ND ND
i
ND ND'
680 l.SxlO3
4;20 ND
?70 2xl03
ND ND
ND ND
^Activity extrapolated to end of collection time.
**Samples were not available after th\.s date.
ND - Not detectable.
                                  26

-------
        456
in milk.  '  '   Rather, the effective half-life was about one day


or less (Figure 5).  Thus, the estimated potential dose based


upon integration of the daily concentrations was calculated to


be 12 millirad for a child with a 2 gram thyroid.



There are  several possible reasons for the rapid decay:


(1)  These  results are based on individual samples from only


1 or 2 cows.  Theoretical values are based on average results

                                              i
from several cows where the results from individual cows


may vary by.several factors.  '



(2)  The deposition of effluent was very spotty due to the rough


terrain.  The cow grazed in a large pasture and varying


amounts  of deposition in  different areas of the pasture could


have been analogous to changing the feed to uncontaminated


feed (this results in a half-life for l 31I in the milk of  about

     6 -•                   =                  .]
1 day )i  The cow was given some supplemental feed which


could a^so  have influenced the results.



(3)  Part of the cow's intake' of radioiodine may' have been due


to inhalation of radioiodine in the particulate, elemental, and/or


methylf!iodine form (shows a. much shorter half-life in milk).


It has b'een reported   that 'the deposition of methyl iodine on


pastura,ge is very minimal and that inhalation b,y the cow may


be important.  The fraction of methyl iodine  present in the


reactor effluent is not known at this time.     '.


                          :\
The other milk results  give'yi in Table 10 generally represent


only 1 cow.  If the milk from these cows was ilsed for human


consumption, the potential dose  for a child with a two gram

       l                   "• 4
thyroid',  based on the FRC-5  assumptions would be about


20 millirad or less (100 pCil/liter peak milk concentration is
                        27

-------


300
•X.
_l
i
- 200
OC
UJ
H
_J
V.
O
o.



100



>


_ I concentration, in milk as a function
of time.
: A
/ \
/ \
/ \
i \
§ •
i \
/ \
/ \
I *
/ \
_ 1 «
**^
f ^T^
•^ ^^^ ^^
™" ^T^ -^
/ X
__ * ^^ Net D»»«elobl«
f **>^^^

-------
 equivalent to about 16 miUirad).  This dose estimate assumes
.that the peak 131I concentration in milk occurs at about three
 to four days when the cow is exposed via ingestion.  If the ex-
 posure to the  cow is  by inhalation, the effective half-life of
 1 31I in milk is much less than five days and thus the integrated
 dose is less.
 e.   Vegetation Samples
 Natural vegetation samples were  taken on Highway 25 between
 Hancock Summit and Queen City Summit on June 23, to help
 delineate the hotline. The vegetation samples south of Coyote
 Summit did not show the presence of fresh fission products.
 The results of the samples between Queen  City Summit and .
 Coyote iSummit are given graphically in Figure 6.  The high
 results near Queen City Summit are possibly due to the increased
 elevation in this  area.  The^ hotline  was considered to be 5 to
 10 miles from Coyote Summit on  the basis  of aerial monitoring
 and other surveillance results.
 Vegetation samples were taken from Sacramento Pass, Nevada
 to Garrison, Utah (Figure 41*  on July 1 to detect, the area of
 cloud passage.  Fresh fission products were not detected on
 any of the samples.  The time delay between possible deposi-
 tion and collection of samples would have allowed a factor of
 about four decay which may.'explain the absence of fresh fission
 products.
 Natural vegetation and pastdirage  samples were' taken at the
 same lo'cations where milk samples  were collected and are
 reported along with the milk'results in Table 1(9.
                        29

-------
pC
                                                  Concentration of radio -
                                                  iodine on natural vegetation
                                                  after  cloud passage.
            I     1     II     1     I.I     1     \     II      l
    9UEEN CITY
     SUMMIT
ACTIVITY
8
RELATIVE GROSS GAMMA
5
                                                  Relative gross gamma
                                                  activity on natural vegeta
                                                  tion after cloud passage.
            1     I.I     1      1
                 4     6     8     10    "12     14    16     18    2O

                    DISTANCE IN MILES! FROM QUEEN CITY SUMMIT
24
26
Figure 6.  Results of vegetation samples taken on Highway 25 foil owing' NRX-A5,
          EP-IV, June 23,  1966.
                                    30

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f.   Water Samples
Water samples from near Alamo, Hiko, Warm Springs, and
Shoshone, Nevada area did not show detectable levels of fresh
fission products.
                       31

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                          CONCLUSIONS




The effluent from two of the tests (EP-III and IV) in the NRX-A5 series

was detected off-site.  The potential dose to the off-site population was

below the standards listed in the AEC Manual Chapter 0524, which

generally follows the FRC guidelines.


The AEC radiation protection standards (RPS) for the average dose to

a suitable sample of the population are;


         Average for Suitable Sample       Average for Individual

         Whole Body - 170 millirem/year     500 millirem/year

         Thyroid - 500 millirem/year        1500 millirem/year


The standards for radioiodine concentrations  in air in an uncontrolled

area for the principal soluble radioiodines are given in Table 11.


The principal air exposures from EB-III and EP-IV are., given in Table 12.

Comparison of these results with the-radiation standard^  in Table  11

gives the conclusions  listed below,  ^or  comparing areas with significant

population--Ridgecrest, Lathrop Wells,  Sunnyside--l/3 of the values

listed in Table 11 should be used.
                                   .1

         (1)  Based on the instantaneous values, i.e., not averaged

         for a year as intended by AEC Manual Chapter 0524, three

         of the results are above the RPS for  gross unidentified
               f '                   )                   (
         isotopes, but are not above the RPS for specific  isotopes

         (exceptr Goss' Ranch).   The'Intent is not to show that the

         RPS was exceeded, but rather to show the advantage of

         specific isotope analysis.
                                32

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Table 11.  Radiation protection standards.
Air Cone. Integrated Air Cone. ' Integrated Air Cone. '
pCi/m3 pCi-sec/m3 pCi-sec/m3
Day
131I(3) 102 8.64 x 106
133I(4) . 103 8.64xl07
Unknown*5^ 102 8.64xl06
Year
3. 16 x 109
3.16 x 1010
3.16 x 109 :'
NOTES:  (1) Derived from AEC Manual Chapter 0524 by converting

         units of uCi/ml to pCi/m3.  The values are based on.exposures

         to individuals and should be.reduced by a factor of three if

         applied to an average exposure to a sample of the population.

         When more than one  isotope, is present, the summation of

         ratios of  quantity of isotope present to respective RPS should

         be less than one.
                                   i'                   i

         (2) Derived from the Radiation Protection Standard air con-

         centration by integrating it over a period of one (1) day, i.e. ,

         multiply pCi/m3 times seconds in a day.  The  column on the

         right is integrated for a year.


         (3) The standard for  l 311 is based on a child with a two

         gram thyroid breathing 3 mi?/day.              :

        •'   •   . '                 .                .     r
         (4) The standard for  * 33I is based on the  standard  adult (ICRP).
                                                      !,•'•'

         (5) Bas,ed on Sr-90,  1-129, Pb-210, Ac-227, Ra-228, Pa-230,

         Pu<-241, Bk-249 and  alpha emitters not being present as

         defined in reference  8.  Strontium-90 is assumed not present

         because of reactor operating  history; if it were present, the
               r
         value would  be 10.
                                33

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      Table 12.  Principal air concentrations  resulting from NRX-A5. *
OJ
      EP   Location
   Gross Beta               isij--                  I33p;:;;;

pCi/m3  pCi-sec/m3   pCi/m3  pCi-sec/m3   pCi/m3   pCi-sec/m3
Ill Ridgecrest, California***
10 mi. S. of Beatty (Hwy. 95)
(unpopulated)
Lathrop Wells
IV Goss1 Ranch
Coyote Summit (unpopulated)
Sunnyside
Geyser Maint. Station***
2.3
1.9

1. 1
14,4


00
527
1

38
10
2.
1.

8.
9.
7.
1.
8.
IxlO5
2xl05

8xl04
4xl07
8xl06
2xl07
9xlCP
NGS
1.7

2. 2
1. 5xl03
40
15
NGS
1.

1.
9.
5.
1.

IxlO5

8xl05
7x1 06
9xl05
3xl06

NGS
4.2

9.8
3. 3xl03
1. 5xl02
40
NGS
2.

7.
2.
2.
3.

6x1 05

8xl05
IxlO7
2xl06
5xl06

      ^Results extrapolated to end of collection time.
      **The iodine activities for both the prefilter and charcoal cartridge have been added.
     ###Cloud passage at this location was not noted until after the fact; therefore, gamma spectrum analysis
        was not performed on these two samples because the gross beta count did not fall above the  control
        limit set for determining whether this analysis should be performed.
      NGS  - Not gamma scanned.

-------
         (2)  Further, if the integrated concentrations are used,  the


         result from Goss1  Ranch is equivalent to less than two days


         exposure at the RPS level (2nd column from right indicates


         1  day of exposure to RPS).  AEC Manual Chapter 0524


         specifies that concentrations may be averaged over a period


         of a year (column on right in Table 11).  The RPS  concen-


         trations are based on continuous exposure and thus are not


         strictly applicable to short term air concentrations.   The'


         concept of integrated concentration guides allows comparison


         of short term concentrations to the guides.



The peak external gamma dose from the NRX-A5 series was about


1 millirad  at Go,ss' Ranch (based on E-500B survey meter).  The


highest dose  at a reasonably dense populated area was about 0. 05 milli-


rad at Sunnyside,,,  Nevada based on tfye RM-11  results.  ,,Both of these


exposures  were .from the EP-IV.



The milk samples in this report all dome from ranches 'where the milk


is used locally.  '' The age of individuals  using the various milk supplies

                r-                   ii                   •*•
varies.  The term potential dose has been used when it is not actually


known if someone received  the dose.  Doses varying from the potential

                }                '                      ,T      .
dose could result from variation in individuals milk consumption,


biological variability of individuals from the "critical receptor" used


in calculations (child with 2 gram thyroid and iCRP assumptions  on


uptake), etc.  This frame of "potential dose" also applies to the other


doses or exposures  reported in this report.
                                   i


The summation'of doses for several locations  are  giveri'in Table 13.


This summation includes the dose from cloud passage,  inhalation and


ingestion.
                                35 '

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                                          Table 13.  Summary of results and doses from NRX-A5.
Location
(Nevada)
Lathrop Wells
Dansby's Ranch,
Lathrop Wells
Goss' Ranch
Sunny side
Kirkeby Ranch/3*
Sho shone
E. J. Cummings,
Baker
EP
III
III
IV
IV
IV
IV
Date
6-8
6-8
6-23
6-23
6-23
6-23
Air
Gross Beta
pCi/m3
1. 1
14,400
138
pCi-sec/m3
8.8xl04
9.4xl07
l.ZxlO7
131!
pCi/m3
2. 2
1. 5xl03
15
pCi-sec/m3
l.SxlO5
9.7xl06
1.3xl06
133!
pCi/m3
9.8
3.3xl03
40
pCi-sec/m3
7. 8xl05
2. IxlO7
3.5xl06
Thyroid
Dose
Inhalation
Child
mR
0.40
2.3
Adult
mR
0. 13
7
0.8
External
Exposure
Rate Total
mR/hr
ND
1.2
0. 02
mR

1
0. 05
.02
.02
Milk
Peak
pCi/1
13l!
No r
50

240
110
1^!
nilk
ND

1300
30
Potential
Ingestion
Dose
millirad
PeakfT)
8

17(8)
18
Actual{(
8(1)

9(4,8)
5(5)
Total
Thyroid
Dose (6)
millirad
< 1
8
8
2
9
5
Notes:
(1)  A child of about one year old was present.
(2)  Sampler not started till after cloud arrival; dose based on extrapolation to estimated arrival time.
(3)  Gamma exposure based on extrapolation from Sunnyside(distance to the minus three power).  Total thyroid dose includes contribution from gamma
(4)  Youngest child present four  years old - assume 4 gram thyroid.                             exposure and inhalation(inhalation extrapolated from
(5)  Youngest child present eight years old - assume 8 gram thyroid.                             Sunnyside results using distance to the minus two
(6)  Based on age of child present.                                                              power).
(7)  The peak value is based on a child with a 2 gram thyroid drinking 1 liter of milk per day.  It is assumed a peak value of 100 pCi per liter in milk
    results in an integrated dose of 16 millirads (reference 4).
(8)  The dose calculation is based on the observed half-life in milk, about 1 day,  rather than the value of 5 days from FRC No. 5 (reference 4).

-------
Although the peak milk concentration,  240 pCi/liter was detected at
Kirkeby's Ranch, it is noted that it might not have resulted in the  peak
dose because of the. short effective half-life of the  1 31I in the milk.
Thus the result from the E. J. Cummings Ranch is included in Table 13.
Insufficient data are available to determine the effective half-life in the
Cummings sample,thus a value of about 5 days is  used.
Two sets of results are  given  in Table 13 for Kirkeby's and Cummings1.
One set gives the potential  dose for a 1 year old child, the second for
the youngest child known to be present.
A comparison of the two graphs in Figure 6 shows that the 1 31I, 1 33I,
and gross gamma results for vegetation follow the same trend.  If
future  results also demonstrate this !trend,  analysis  of vegetation  sam-
ples to determine trajectories may be limited to gross gamma.  Specific
analysis should still be performed on' selected samples to demonstrate
the presence of fresh  fission products and indicate the levels of various
isotopes.
                                37

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                           REFERENCES







 1.   "Synopsis of Meteorological Data for the NRX-A5 Reactor EP-III,"



     June 1966, U.S. Department of Commerce,  ESSA,  ARFRO.





 2.   Recommendations  of the International Commission on Radiological



     Protection, ICRP Publication 2,  1959.




 3.   Task Group on Lung Dynamics, Committee II of the ICRP, "Deposition



     and Retention Models for Internal Dosimetry of the  Human Respiratory



     Tract." Health Physics, Vol. 12, No. 2, February 1966, p. 173.




4.   Staff Report of the Federal Radiation Council,  "Background Material



     for the Development of Radiation Protection Standards," Report



     No. 5, July 1964.





5'..   Final  Report of the Off-Site Surveillance for the NRX-A4/EST, SWRHL-30r.




6.   D.  S.  Barth' and J.  G. Veater, "Dairy Farm Radioiodine Study Follow-



     ing the Pike Study, " SWRHL-14r, Nov. 23, 1964.




7.   C.A. Hawley,  "Controlled Environmental  Radioiodine Tests at the



     National Reactor Testing Station,"  IDO-12047,  February 1966.




8.   U.. S. AEC Manual,  Chapter 0524J  "Standards for Radiation Protection."




9.   "Final Report of Aerial  Surveillance for the  NRX/EST, " Engineering



     Development Program, SWRHL,  May 31, 1966.




10.  D.F. Bunch, "The Comparative Environmental Hazards from a



     Release of Methyl Iodine of Elemental Iodine,"  Idaho Operations



     Office, AEC,  given at 9th AEC Air Cleaning Conference, Sept. 1966.
                                38

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                          APPENDICES
Appendix A   Thyroid Inhalation Exposure from Radioiodine      39

Appendix B   Milk and Associated Feed Results, NRX-A5,
              EP-IV, June 23, 1966                             42
                                 39

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                           APPENDIX A

           Thyroid Inhalation Exposure from Radioiodine
Absorbed dose is the quotient of the energy imparted by ionizing radia-
tion to the matter in an "element of volume. "

Dose rate is the rate at which the energy is absorbed.  For tissue
containing a beta emitter the amount of energy absorbed  per unit
volume is equal to the  energy emitted  per unit volume.  This assumes
the radioisotope is essentially uniformly distributed in tissue  of
uniform composition with dimensions large compared to  the  range of
the beta particles.  These assumptions can be applied to the calcula-
tion of thyroid dose from radioiodines, if an effective energy based  on
the thyroid  dimensions is used.   Thus, for the dose  rate (DR):

       DR  = KEA exp- \ ff t                             Eq.  1
          t              eii

          Where:  DR   - The dose rate at time t

                   K    - Conversion parameter

                   E    - Effective energy (Mev)  per disentegration (d)

                   A    - Activity at lime deposited in organ  (Gi/gan)

                   \ ff  - Effective decay.constant for radioisotope of interest

                i  t     - Time after Deposition in organ


To obtain the infinite or total dose, Aquation 1 must  be integrated -with
respect to time between zero and inf'i:nity( oo).
                       rCO          ,
       Dose = KEA    I  exp -X  .,. t dt
                      •'o       eff

       Dose = KEA   (-1/X ,, exp -X  rr t)'°°
                           eii       ••eii
                                         o

Thus,  Dose = KEA  (-1/X ,, (0-1)) '
                           eff

       Dose = KEA/X .,                                  Eq. 2
                     eii
                                40

-------
The numerical values for the parameters are:

       -  3.7xl010d  8.64xl04 sec  1.602 ergs       rad
       K —     - - r  _  «•     ...._._-..  	v     	g-._. y 	--,  -  	 L
            Ci-sec      day          106 Mev    100 erg/grr


       K = 5. IZxlO7 (gram-rad-d/Ci-day-Mev

       E - 0. 23 Mev for * 31I (ICRP-2)

       ,A = X  (Ci-sec/M3) x R(M3/sec) x f  x l/m(gm)  (Assumes no decay
           during uptake)

       Where:  X - integrated air concentration for isotope of interest

                R - 2. 32x10 4 M3/sec - breathing rate for average
                    adult (ICRP)

                f  - 0. 23 (for iodine)  - fraction of inhaled activity reaching
                    thyroid (ICRP)

                m - 20 grams  - mass of adult thyroid


       A = XRf/m  (Ci/gm)

       X.   =  . 693/t  ,, - t ,, is the effective half-life in days -7.6 days
         eff        eff   eff                              '
              for 131I (ICRP)

Substituting these parameters into equation 2;

    Dose = 5. 12xl07 (gm-rad-d/Ci-day-Mev) x E (Mev/d) x XRf/m) x t £f/. 693(-day);

    Dose = 7. 39xl07 XERf t  ff/m (rad)                   Eq.  3
                            eff                              .

Substituting the ICRP parameters for  131I and standard man:

    D =  7. 39xl07 x 0. 23 x 2. 32xlO"4 x 0. 23 x 7.6 x X
                         20

    Dose (rads) = 3.44xl02  (Ci-sec/M3)^

Converting this to pCi and mrad:

    Dose (mrad) =  3. 44xlO'7 (pCi-sec/M3)* for J 311

                                41

-------
This same calculation can be performed for other isotopes using the
appropriate parameters (ICRP2)  .  It should also be noted that if more
than one radioiodine isotope is present, the doses should be summed
to obtain total dose.  The general equation for this would be (using
equation 3):


     Total dose from radioiodines = 7. 39x107 Rf   Y      E t  fr X
                                            —   £->,.      eff
                                            m   iodines
*If the dose conversion constant K is rounded to 5. IxlO7  the signifi-
 cant digits are 3. 42
                               42

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         APPENDIX B

Milk and Associated Feed Results
 NRX-A5, EP-IV, June 23, 1966
Location
3 mi. N. Shoshone, Nev.
(Kirkeby Ranch)





1 3 mi. N. Shoshone, Nev.
(Harbecke Ranch)

15 mi.SW Shoshone,.
Nev. (Geyser Rch)

5 mi. S. Baker, Nev.
(E. J. Cummings)





3 mi.S. Baker, Nev.
(Baker Ranch)

Baker, Nevada
' 20 mi.NNW Baker,
Nev. (H.T.Rogers)

Caliente, Nevada
(Young Ranch)

Date

6/24
6/25
6/26
6/27
6/30
7/01

6/26
6/27

6/26
6/27

6/26

6/27
7/01

7/05

6/30
7/01
7/01

6/26
6/27

6/24

Milk pCi/1
1 31 j 1 3 3j

20
80
240
90
ND
ND

50
60


ND

not
avail.
110
not
avail.
ND

50
20



ND

ND
43

1. 3xl03
20
310
60
ND
ND

50
ND


ND



30


ND

ND
ND



ND

ND

Vegetation pCi/kg
1 31 j 1 3 3j



830
640

ND

680
420

ND
890


7.7xl02
ND

ND
ND


ND
ND

ND
ND

ND




2.7xl03
1. OxlO3 past.

ND

1. 5xl03
ND past.

ND
ND
•

2xl03 grass
ND past.

ND past.
ND past.


ND hay
ND

ND nat.
ND nat.

ND


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Location
Nyala, Nevada (Sharp)

Lund, Nevada
(McKenzie)
Moapa, Nevada
• (Searles Dairy)
Hiko, Nevada
(Schofield Dairy)
Currant, Nevada
(Manzonie Ranch)
Lockes, Nevada
(Blue Eagle Ranch)
Pioche, Nevada
(Horlacher Ranch)
15 mi.E. Ely, Nev.
(Yelland Ranch)
Garrison, Utah
(Gonders Ranch)

Ogden, Utah
(Maple Leaf Dairy)
Date
6/24
6/25

6/24
6/25
6/24
6/23
6/24
6/24
6/24
6/25
6/24
6/26
6/27
6/30
7/01

6/30
7/01
7/02
7/05
Milk
131I
30

ND
ND

ND
ND
ND .
ND
ND
ND
ND
ND

ND
ND
ND
ND
pCi/1
1 3 3j
ND

ND
ND

ND
ND
ND
ND
ND
ND
ND
ND

.ND
ND
ND
ND
Vegetation pCi/kg
1 31 j 1 33j
ND ND
ND ND nat. &
past.
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND
ND ND past.
ND ND hay &
past.

44

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Location Date
Mt. Pleasant, Utah
(Brooktown Creamery) 6/29
6/30
7/01
7/02
• 7/03
Springfield, Utah
(Cache Valley Dairy) 7/01
7/02
7/05
Milk pCi/1 Vegetation* pCi/kg
1 31 j 1 33j 1 31 j 1 33j

ND
ND
ND
ND
ND

ND
ND
ND

ND
ND
ND
ND
ND

ND
ND
ND
Notes:   ND - not detected
         Blanks indicate no sample.
         Results extrapolated to time of collection.
         Past. = Pasture
         Nat. = Natural vegetation
                                45

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                        DISTRIBUTION
-  1 - 15   SWRHL,  Las Vegas, Nevada
     16   James E. Reeves, Manager,  NVOO/AEC, Las Vegas, Nevada
     17   Robert H. Thalgott, NVOO/AEC,, Las Vegas, Nevada
     18  .Henry G.  Vermillion, NVOO/AEC, Las Vegas,  Nevada
     19   D. H. Edwards, Safety Evaluation, NVOO/AEC, Las Vegas, Nev.
     20   D. W. Hendricks,  Rad.  Safe. Br. , NVOO/AEC, Las Vegas, Nev.
     21   Central Mail & Records, NVOO/AEC, Mercury, Nevada
     22   A. J. Whitman,  NTSSO, NVOO/AEC, Mercury,  Nevada
23-24   R. Decker, SNPO, Washington, D. G.
     25   D. Smith, SNPO-C, Cleveland,  Ohio
26 - 27   J.  P. Jewett,  SNPO-N,  Jackass Flats, Nevada
28 - 31   R. Nelson, SNPO-N, NRDS, Jackass Flats,  Nevada
     32   William C. King, LRL,  Mercury, Nevada
     33   Roger Batzel, LRL, Livermore, California
     34   H. L. Reynolds, LRL, Livermore,  California
35 - 36   H. T. Knight, LASL,  Jackass Flats, Nevada
     37   P. Gothels,  LASL, Los  Alamos, New Mexico
     38   H. S,. Jordan, .LASL,  Los Alamos, New Mexico
     39   Charles I. Browne, LASL, Los Alamos,  New Mexico
     40   William E. Ogle, LASL, Los Alamos, New Mexico
     41   H. G. Simens, NTO, Aerojet-General Corp. , Jackass Flats, Nev.
     42   G. Grandy, WANL, NRDS, Jackass  Flats, Nevada
43-44   E. Hemmerle, WANL, Pittsburgh, Pennsylvania
45 -46   S.  Z. Mikhail, NRDL, San. Francisco, California
47 - 48   M. I. Goldman,  NUS,  Washington, D. C.
49 - 50   J.  Mohrbacher,  Pan Am. World Airways, Jackass Flats, Nev.
     51   P. Allen,  ARL,  ESSA, Las Vegas, Nevada

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    52   H. Booth, ARL, ESSA, Las Vegas, Nevada
    53   C. Anderson,  EG&G,  Las Vegas, Nevada
    54   Byron Murphey, Sandia Corporation,  Albuquerque,  New Mexico
    55   Brig. Gen. Edward B. Ciller, DMA, USAEC, Washington, D. C.
56 - 57   Chief, NOB/DASA,  NVOO/AEC, Las Vegas, Nevada
58 - 62   Charles L. Weaver, USPHS, NCRH, Rockville,  Md.
    63   Victor M. Milligan, REECo, Mercury, Nevada
64 - 65   DTIE, USAEC, Oak Ridge, Tennessee

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