SWRHL-45r
FINAL REPORT OF OFF-SITE SURVEILLANCE
FOR THE
PHOEBUS IB, EP-I, EP-II, EP-III, EP-IV
REACTOR TEST SERIES
by the
Southwestern Radiological Health Laboratory
Department of Health, Education, and Welfare
Public Health Service
Consumer Protection and Environmental Health Service
July 1969
This surveillance performed under a Memorandum, of
Understanding (No. SF 54 373)
for the
U. S. ATOMIC ENERGY COMMISSION
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LEGAL, NOTICE
This report was prepared as an account of Government sponsored
work. Neither the United States, nor the Atomic Energy 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.
-------
SWRHL-45r
FINAL, REPORT OF OFF-SITE SURVEILLANCE
FOR THE
PHOEBUS IB, EP-I, EP-H, EP-III, EP-IV
REACTOR TEST SERIES
by the
Southwestern Radiological Health Laboratory
Department of Health, Education, and Welfare
Public Health Service
Consumer Protection and Environmental Health Service
July 1969
This surveillance performed under a Memorandum of
Understanding (No. SF 54 373)
for the
U. S. ATOMIC ENERGY COMMISSION
-------
ABSTRACT
The Phoebus IB reactor test series consisted of three calibration
operations and a full power run. Effluent from the Experimental
Plan III(EP-III) operation was detected off-site by one ground moni-
tor and by the presence of 28 pCi/m3 139 Ba on a prefilter from a
portable air sampler operating at an unpopulated location on
Highway 95.
Effluent from the Experimental Plan IV(EP-IV) operation was
detected in air, milk, and vegetation samples and by portable and
fixed radiac instruments. The maximum concentration of 131I in
milk was 63 pCi/1 at the Martin Ranch southwest of Eureka, Nevada.
No fresh fission products •were found in water samples.
In addition to the usual gaseous effluent from a reactor operation,
the EP-IV operation resulted in the release of discrete particles
of material that were found downwind as far as 80 miles from
Test Cell "C". Only one particle was found beyond the Test Range
Complex. This particle was found near Diablo, Nevada on Highway
25. This particle had a beta plus gamma reading of 7 mR/hr as
measured with an E-500B survey instrument at approximately 1-inch
above the ground. This particle was collected at about H + 48 hours.
-------
TABLE OF CONTENTS
ABSTRACT i
TABLE OF CONTENTS ii
LIST OF TABLES iv
LIST OF FIGURES v
INTRODUCTION 1
OPERATIONAL PROCEDURES 2
A. External Exposure Measurements 2
1. Ground monitoring 2
2. Aerial cloud tracking 2
3. Exposure rate recorders 3
4. Dosimetry 3
/
B. Environmental Sampling 4
1. Air samples 4
2. Milk samples 7
a. Routine milk sampling network 7
b. Standby milk sampling network 7
c. Special sampling 8
3. Water samples 8
4. Vegetation samples 8
ANALYTICAL PROCEDURES 9
A. Air Samples 9
B. Milk and Water Samples 10
C. Vegetation Samples 10
D. Detection Sensitivity 10
RESULTS 12
A. Experimental Plans I and II 12
B. Experimental Plan III, February 10, 1967 12
1. Ground monitoring 12
2. Air sampling 12
3. Vegetation sampling 13
4. Milk sampling 13
5. Water sampling 13
ii
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Table of Contents (continued)
C. Experimental Plan IV, February 23, 1967 13
1. Ground monitoring 13
2. Exposure rate recorders 14
3. Air sampling 15
4. Vegetation sampling 21
5. Water sampling 22
6. Milk sampling 24
CONCLUSION 26
APPENDICES
DISTRIBUTION
111
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LIST OF TABLES
Table 1. Reactor test schedule. 1
Table 2. Portable survey instruments used for ground
and aerial monitoring. 2
Table 3. Estimated minimum sensitivity at time of count
of several radionuclides in various samples. 11
Table 4. Air sampling stations having gross beta concen-
trations in excess of one pCi/m3. 16
Table 4A. Stations showing detectable amounts of
radioiodines with gross beta below one pCi/m3. 17
Table 5. Isotopic air results from the six stations
having the highest concentrations -Phoebus IB,
EP-IV. 18
Table 6. Vegetation samples containing detectable
fresh fission products. 22
Table 7. Water sampling results. 23
Table 8. Four highest 131I concentrations in milk
samples. 25
IV
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LIST OF FIGURES
Figure 1. Air surveillance network stations in Nevada. 5
Figure 2. Air surveillance network stations other than Nevada. 6
Figure 3. Locations where fresh fission products were
detected. 19
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INTRODUCTION
This report presents the results of the off-site radiological sur-
veillance program conducted by the Public Health Service (PHS)
for the Phoebus IB 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
Commission (AEC), the 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. This includes the NRDS and Tonopah
Test Range. For simplicity, this combined area will be termed
the Test Range Complex in this report.
The test schedule is given below.
Table 1. Reactor test schedule.
Experimental
Plan
EP-I
EP-H
EP-III
EP-IV
Approximate Power
Integral Mw-sec
2.5
300
3 xlO6
Date 1967 Detected
Off -Site
Jan 25-26 No
Feb 2-3 No
F*h 10(131 1 PSTJ Yes
Feb 23(1400- Yes
1430 PST)
The test series took place at Test Cell "C^with the hydrogen
coolant and associated fission products exhausted upwards.
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OPERATIONAL PROCEDURES
A. External Exposure Measurements
1. Ground monitoring
Ground monitors tracked the effluent cloud with the portable
radiation detection instruments described below.
Table 2. Portable survey instruments used for ground and
aerial monitoring.
Instrument Range (mR/hr)
Scales Detector Emission
Baird-Atomic
NE-148
0-3
1 - by 1 -inch Gamma
crystal only
0-200
Eberline
E-500B 0-2000
Victoreen 0. 05-50, 000
Radector
Victoreen
Radector
Mod. II 0.1-1,000,000
(aerial use
only)
External
Geiger tube
Inte rnal
Geiger tube
lonization
Chamber
lonization
Chamber
Beta and
beta/ gamma
Gamma
only
Gamma
only
(as used)*
Gamma
only
(as used)*
PHS monitors do not use the beta/gamma capabilities of this
instrument.
2. Aerial cloud tracking
A U. S. Air Force U-3A aircraft, manned by two PHS monitors
equipped with portable survey instruments identical to those of
the ground monitors, tracked the effluent cloud to inform PHS
personnel at the NRDS control point and to assist in
-------
positioning ground monitors. Two PHS Turbo-Beech aircraft
containing various sampling and measurement devices were
also used as aids in cloud tracking. However, their primary
purpose was cloud sampling and measurement to determine
cloud size and content.
3. Exposure rate recorders
Eberline Model RM-11 exposure rate recorders were located at
twenty-four stations around the Test Range Complex. These
recorders use a Geiger tube detector and have a range of
0.01 to 100 mR/hr gamma only. Exposure rate is recorded
on a 4-cycle log scale continuous strip chart with a capacity of
up to 30 hours continuous recording. These recorders are
accurate to within + 20% as calibrated with a 137Cs source.
4. Dosimetry
During the month of February 1967, eighty-six film badge
stations with five badges at each location and 154 off-site
residents with one badge each comprised the routine off-site
film badge program maintained by the PHS. Dupont type 545
film is used which has a lower limit of detection of 30 mR with
a reading accuracy of + 50% from 30 to 100 mR and + 10%
from 100 to 2000 mR for gamma radiation above 50 keV. In
addition, sixty-nine of these film badge stations were each
equipped with three EG&G Model TL-12 thermoluminescent
dosimeters (TLD). The TLD's have a low energy response
threshold at 50 keV and are not energy dependent in the range
from 50 keV to several MeV.
The film badges and TLD's normally remain in the field for
a one month interval. In such a time period the TLD system
-------
is capable of detecting a 10 mR increase of radioactivity
above background.
B. Environmental Sampling
1. Air samples
During the time of these experiments, the Air Surveillance
Network (ASN) operated by the PHS consisted of 105 air samplers
operating in each state west of the Mississippi River except
Montana and North Dakota. These stations are supplemented
by ten standby stations located in Colorado, Idaho, Montana,
Oklahoma, Utah, and Wyoming. These stations are operated
only when the station operator is notified by the SWRHL to begin
sampling. On February 24, all standby stations were activated
except one each in Oklahoma, Wyoming, Idaho, and Colorado.
In addition, there were seven temporary portable air samplers
placed downwind along Highway 25 from Queen City Summit to
Hancock Summit. This is approximately 65 miles from the
reactor.
The air sampler used by the SWRHL for all stations except
the temporary locations, is a Gelman "Tempest" which
uses a Cast Model 1550 vacuum pump driven by an electric
motor. The pump has a flow rate of approximately 10 cfm.
The sampler is designed to use a 4-inch diameter filter
paper (prefilter) and a 3-1/4-inch diameter by 1-inch thick
charcoal cartridge. The ASN uses Whatman 541 filter paper
for routine air sampling. The total volume of air sampled
is calculated from an average vacuum reading (which in
turn indicates the average flow rate) and the total time of
sampling. Permanent air sampling stations are shown in
Figures 1 and 2.
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AIR SURVEILLANCE NETWORK STATIONS IN
NEVADA.
if Temporary samplers
Figure 1.
-------
NORTH DAKOTA \
•MINNESOTA/ —- *
ABERDEEN* \ I WISCONSIN
SOUTH DAKOTA
HUSKO«EE* \
AIR SURVEILLANCE NETWORK STATIONS
OTHER THAN NEVADA
Figure 2.
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In addition to the "Tempest" samplers, each mobile moni-
toring team was equipped with portable air samplers. The
air mover is a Cast Model No. 7040 positive displacement pump
with a Rockwell Model No. 415 gas meter for measurement of
air flow. All portable air samplers are operated with Whatman
541 filters and charcoal cartridges. Flow rate of this system
averages 6 cfm.
2. Milk samples
The SWRHL milk sampling program consists of a routine milk
sampling network, a standby milk sampling network, and
special sampling in the event of a release of airborne radio-
activity from nuclear testing activities.
a. Routine milk sampling network
Twenty to thirty producing dairy farms and individual
family cows in Nevada, western Utah, and eastern
California are routinely sampled each month. The
number sampled varies because of the varying availability
of lactating cows on ranches producing milk for their own
use. Normally these samples are collected by person-
nel from the laboratory.
b. Standby milk sampling network
Approximately 155 producing dairies in 11 western
states are provided with mail-in milk sample containers
and appropriate instructions. Any or all of these
sampling locations can be activated by telephone through
the regional offices of the Public Health Service. The
samples are collected within 24 hours of the request; the
samples arriving at SWRHL for analysis one to four days
later. Thirty-four of these stations were activated for the
EP-IV operation.
7
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c. Special sampling
The SWRHL also conducts a continuous survey of off-site
milk sampling locations. Possible sources for milk
sampling are indexed and located on milk sampling maps.
In the event of a release of radioactive effluent, monitors
are able to begin sampling an area almost immediately.
3. Water samples
Approximately 90 water samples are routinely collected each
month from wells, streams, ponds, lakes, and urban water
systems. After a release of radioactivity, sampling can be
expanded to include all human and livestock water sources in
the area of concern. Water samples are collected at all
locations where milk samples are collected, with the exception
of the standby milk sampling network. Fifteen water samples
were collected for the EP-IV operation.
4. Vegetation samples
Vegetation samples are collected only after a known release.
These samples are collected to delineate the deposition pattern,
to determine where milk samples should be obtained, and to
estimate expected radioisotope concentrations in milk. In
addition to natural plants such as creosote bush, pasture and
milk cow feed samples are collected when available. Six
vegetation samples were collected after the EP-III operation
and 88 samples were collected following EP-IV.
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ANALYTICAL PROCEDURES
i
A. Air Samples
All air sample filter papers and charcoal cartridges are returned
to the SWRHL in Las Vegas for analysis. Filters are counted
for gross beta activity in a Beckman "Wide Beta" low background
(6+1 cpm beta), proportional system which has an efficiency of
45% for 0. 54 MeV betas. If significant radioactivity (10pCi/m3)is
detected on the initial count, a minimum of two additional counts
are made in the first 48 hours following collection. All other
filters are recounted at five and twelve days after collection.
Computation of activity is based on establishing a decay constant
for each sample and this constant is used to extrapolate the
activity to the end of the collection period. The decay equation
used is A/A = e
o
Gamma emitting isotopes on filter papers and charcoal cartridges
are identified and quantitate,d by placing them directly on a 4"x4M
Nal(Tl) crystal coupled to a TMC Model 404-C gamma pulse height
analyzer calibrated for energies of 0-2 MeV. Quantities deter-
mined are extrapolated to the end of the collection period using
the individual decay constants.
Average concentration of activity during cloud passage cannot
always be calculated since it is not possible to define the duration
of cloud passage at all locations. However, the integrated air
concentrations, expressed as pCi-hr/m3 , may be directly compared
/
for the various stations, besides serving as a measure of the po-
tential inhalation exposure.
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B. Milk and Water Samples
Milk and water samples are collected in one gallon quantities. These
samples are emptied into 3. 5-liter Marinelli beakers and are counted
on the gamma spectrometry system described above. If, for any
reason, a full 3. 5-liter sample cannot be obtained, the sample vol-
ume is increased to 3. 5 liters by the addition of distilled water to
maintain a uniform counting geometry, and appropriate adjustments
are made to calculate the activity concentration in the original
sample. When this is done, the threshold detectabilities given in
Table 3 are proportionately increased. In addition to gamma spectrom-
etry, most milk samples containing radioiodine are analyzed by radio-
chemistry for 89"9°Sr after gamma analysis.
C. Vegetation Samples
Upon arrival in the laboratory, vegetation samples are placed in
clean plastic bags and are given an immediate count for gross gamma
activity on a 4- by 4-inch Nal(Tl) crystal, connected to a single-
channel analyzer and sealer-timer. Vegetation samples showing
higher than background activity are analyzed for specific gamma
emitting isotopes.
D. Detection Sensitivity
Empirical values have been determined as the approximate thresh-
old detectabilities for various isotopes on the sample types usually
collected. These are listed in Table 3 and necessarily include the
following conditions and assumptions:
a. Count time in days after fissioning as indicated by
footnotes.
b. Prefilters collect unfractionated samples of fission
products resulting in a complex spectrum.
c. MSA charcoal collects gaseous fission products only
(primarily iodines).
10
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d. An eight isotope matrix is employed for computation.
Isotopes other than those included in the matrix are present
in amounts which are small relative to those eight.
e. Natural activity on air samples is approximately five
times system background.
Table 3. Estimated minimum sensitivity at time of count of several radio-
nuclides in various samples.
Sample
type
4" filter
(pCi)
Charcoal
cartridge
(pCi)
Water
(pCi/1)
Milk
(pCi/1)
Notes
1
2
1
2
3
4
'»!
500
200
200
100
20
20
132Te-I 133I
1000 500
200
400
40-50 20-30
20-30
135I 137Cs
1000
200
100
40-50
10
u°Ba-La
500
200
400
20
20
Length
of count
10 min.
10 min.
10 min.
10 min.
40 min.
40 min.
1 - Counted at less than 3 days after formation.
2 - Counted at 3 days or more after formation.
3 - With 137Cs=100 pCi
4 - Assuming insignificant amount of unlisted nuclides, and all given isotopes
are less than 10 times the detection limit.
11
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RESULTS
A. Experimental Plans I and II
No radioactive effluent was detected on air samplers following the
EP-I and II tests. Ground monitors were on standby but were not
used, nor was aerial monitoring required.
B. Experimental Plan in, February 10, 1967
Effluent from the EP-IU test was detected off-site by ground monitors,
aerial monitors, vegetation sampling, and air sampling.
1. Ground monitoring
Six ground monitors were positioned along High-way 95 between
the NRDS turnoff (approximately 2. 5 miles west of the Mercury
turnoff) and Lathrop Wells. A monitor located at the junction
of Highway 95 and State Road 16 (Ash Meadows turnoff) ob-
served a reading of approximately two times instrument back-
ground of . 003 mR/hr on a scintillator. This was the only
reading observed above background. The survey instrument
returned to background levels within 30 minutes and a survey
of the area around the truck showed no indication of ground
deposition of radioactive material. The average transport speed
of the effluent to this location was 25 mph.
2. Air sampling
Three portable air sa-nplers with prefilters and charcoal car-
tridges were set up on Highway 95 in the projected cloud path
at the NRDS turnoff, the Ash Meadows turnoff and 5 miles west
of the Ash Meadows turnoff. The prefilter taken from the sam-
pler located at the Ash Meadows turnoff showed 28 pCi/m3 of
139 Ba. Because of the relatively short half-life of 139 Ba, it
is reasonable to assume that this was the result of EP-III
effluent and not residual radioactive material from foreign
nuclear testing.
12
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No radioiodines were detected on any air sample prefilter
or charcoal cartridges.
3. Vegetation sampling
Six vegetation samples were collected along Highway 95 from
the NRDS turnoff to 5 miles east of Lathrop Wells. No fresh
fission products were detected on these samples that could be
definitely attributed to the reactor operation.
Barely detectable levels of *3H On vegetation had been noted
for about a month before this reactor operation. The source
of this iodine is presumed to be from foreign nuclear testing.
Gross gamma counting of the vegetation samples showed a
peak approximately 18 miles southeast of Lathrop Wells on
Highway 95.
4. Milk sampling
Milk samples were collected at the Mills Ranch (195 25 miles
from Test Cell "C") and at the Ishmael Ranch (160° 47 miles
from Test Cell "C"). No fresh fission products were detected.
5. Water sampling
No water samples were collected for this event.
C. Experimental Plan IV, February 23, 1967
The EP-IV resulted in a release of radioactive effluent that was de-
tected by aerial monitoring, ground monitoring, and in all environ-
mental media sampled with the exception of water.
1. Ground monitoring
Initial on- site cloud tracking showed the cloud was moving along
a trajectory of approximately 20 from Test Cell "C". Seven
ground monitors were mobile between six miles southeast of
13
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Hancock Summit, and Queen City Summit on Highway 25.
Ground monitors at Queen City Summit and four miles south-
east of Queen City Summit detected two to three times back-
ground levels during cloud passage. These readings were
taken on a scintillation instrument with a background of
approximately 0. 008 mR/hr. Cloud arrival times at these
locations was about 1830-1845 hours.
Primary effluent trajectory, as shown by air sampling and
vegetation sampling was mostly northwest of Queen City Sum-
mit suggesting that slightly higher levels of activity
would have been detected during cloud passage had ground
monitors been stationed northwest of Queen City Summit.
Thermoluminescent dosimeters placed at two mile intervals
from Hiko, Nevada to eight miles northwest of Queen City
Summit showed no detectable exposures above normal back-
ground levels.
2. Exposure rate recorders
Twenty-four RM-11 stations were in operation at the time of
this experiment.
Three stations showed gross gamma exposures above
instrument background. To the northeast, the stations at
Diablo (13°78 miles from Test Cell "C")and Twin Springs
(5° 95 miles from Test Cell "C")showed a rise of about twice
background. Estimated cloud arrival time at these locations
was 2000 hours and 2030 hours respectively. The average
transport speed was 15 mph based on these estimates. This
trajectory of primary reactor effluent was confirmed by most of the
other environmental sampling. Effluent from reactor pulse-
cooling operations reached Lathrop Wells ( 157° 14 miles from
14
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Test Cell "C") about 2030 hours. The maximum reading on the
RM-11 was less than twice the background of 0. 03 mR/hr. Low
level night time drainage winds, which were about 180 from
the primary wind direction during the day, were responsible for
causing the reactor effluent to travel south.
3. Air sampling
Thirty-six permanent and seven temporary air sampling stations
were in operation in Nevada at off-site locations on the day of the
test. The seven temporary samplers were set up on Highway 25
from Hancock Summit to 12 miles northwest of Coyote Summit.
(Figure 1. ) Sixty-four ASN stations were in operation in other
states during the test, while on the following day two additional
ASN stations and six standby stations were in operation.
Table 4 lists all stations where fresh fission products were de-
tected or where gross beta concentrations were above one pCi/m3.
Table 5 lists the isotopic results from the six stations where the
maximum amounts of fresh fission products were detected. The
value of one pCi/m3 is used as a cut-off in Table 4 because the
great majority of routine air filter results are below this
number. Figures 1 and 2 show the locations of all samplers
operating on February 23 and 24. Figure 3 shows all locations
at which.fresh fission products were detected on any sampling
media.
/
It is possible that small amounts of 1311 were residual on
pastures from a foreign test in December 1966; however,
there are no data to support this assumption. The source
of all fresh fission products found in any environmental
sampling is assumed to be due to the EP-IV operation.
15
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Table 4. Air sampling stations having gross beta concentrations in excess of 1 pCi/m .
Location
Beatty, Nev.
Currant, Nev.
Death Valley Jet. ,
Calif.
Diablo, Nev.
Twin Springs, Nev.
Lathrop Wells, Nev.
Shoshone, Calif.
Warm Springs, Nev.
Eureka, Nev.
Blue Jay, Nev.
Elkq, Nev.
Nyala, Nev.
Boise, Idaho
Wells, Nev.
Clark Sta. , Nev.
Goss Ranch, Nev.
Queen City Summit,
Nev. , unpopulated
Bozeman, Mont.
12 mi west Coyote
Summit, Nev.
February
23-24
On Off
0805
0715
0645
0640
0930
0850
1245
0900
1950
0730
1326
0800
1701
0655
1640
1705
1645
0723
0715
0645
0645
0845
1605
1317
0900
0730
0725
1310
0800
1704
0700
1200
1230
205 1A
Gross
pCi/m3
i.oP
1.4P
5.7P
170P
2. 3P
230P
2.4p*
4lP
7lP
n*
52P
1.2
5.9P
2.2P*
1.7P
34P
1.1
49P
_ February
Beta 24-25
pCi-hr/m3 On Off
24
33
140
4000
54
7100
58
970
850
1200
28
140
52
40
660
22
200
0725
0645
0845
0900
0730
0725
1310
0800
0840
0700
0720
0700
0945
0900
0730
0835
1237
0800
1100
0710
Not operated
Not operated
1110 1050
Not operated
Gross Beta
pCi/m3 pCi-hr/m3
l.lP
2.5
1.6
6.0P
7.2P
14p*
1.2p*
6.0
2.2
1.4P
-- temporary
-- temporary
1.1
-- temporary
25
60
39
140
170
340
28
96**
59
33
sampler
sampler
25
sampler
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Table 4A. Stations showing detectable amounts of radioiodines with gross beta below one pCi/m .
Location
Goldfield, Nev.
Warm Springs Rn. ,
Nev.
Tonopah, Nev.
Round Mtn. ,
Nev.
February
23-24
On Off
0800
0700
' 1635
1908
0800
0700
1137
Gross
pCi/m3
0.3P
o.ic
o.ic
Beta
pCi-hr/m
7.4
3.5
1.2
February
24-25
On Off
0930
Gross Beta
pCi/m3 pCi-hr/m3
0.9? 35
Sampler (**) was operated for 15. 9 hours during this period.
A. Sample removed at 2051 2/23/67.
(3. Radioiodines on both prefilter and charcoal cartridge.
p. Radioiodines found on prefilter only.
c . Radioiodines found on charcoal cartridge only.
p*. Charcoal cartridge was not in use.
(The above notes refer to Table 4 and Table 4A as indicated. )
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Table 5. Isotopic air results from the six stations having the highest concentrations, Phoebua IB EP.-IV.
Location
Nevada
Lathrop Wells,
Diablo .
Blue Jay,
Blue Jay,
Warm Springs,
Warm Springs,
Eureka,
Ranch,
li S of
lo
Time
On Off
0850 1605
2/23 2/24
0640 0645
2/23 2/24
0730 0725
2/23 2/24
0725 0835
2/24 2/25
0900 0900
2/23 2/24
0900 0900
2/24 2/25
1950 0730
2/23 2/24
0730 0730
2/24 2/25
1640 1200
2/23 2/24
i Co1-
Sample
3 lec-
Vol. m tor
PF
662 H
Cll PF
511
CC
PF
505 cc
con PF
52°noCC
PF
485 cc
PF
485 cc
PF
249 cc
497 PF
v cc
PF
CC
Prefilter
Grpss Beta
pCi/m pCi-hr/m
230 7100
170 4000
52 1200
14 340
41 970
6.0 140
71 850
7.2 170
34 660
131I 132Te-I
pCi/m
15
12
14
19
4.7
ND
3. 1
4.4
6.4
1.4
ND
7.2
11
1.5
2.6
2.4
4. 0
pCi-hr/m
470
390
240
440
110
78
110
150
34
86
130
36
62
46
77
pCi/m pC
140
4.5
48
22
15
ND
11
14
6.8
5.2
ND
23
12
5. 3
2.8
8.0
3.0
i-hr/m
4400
140
1100
510
360
280
340
160
120
270
140
130
67
150
58
133I
pCi/m
58
68
57
72
16
ND
8.2
20
29
3. 8
ND
35
16
4.2
8. 2
6.2
7. 7
pCi-hr/m
1800
2100
1300
1700
380
210
480
700
91
420
190
100
200
120
150
135I
3 3
pCi/m pCi-hr/m
ND
ND
ND
24 570
ND
ND
ND
71 1700
ND
ND
ND
180 2100
ND
ND
ND
8.7 170
3.0 58
141Ce
pCi/m pCi-hr/m
83
71
ND
ND
8. 7
ND
2. 3
ND
ND
1.9
ND
ND
ND
1. 1
0.4
2.6
ND
2600
2200
160
58
46
26
10
50
urefilter
:harcoal cartridge
10 detection
NOTE: Integrated concentrations are calculated using the
elapsed time as shown on the timer attached to the
air sampler. The times shown in column 2 are clock
times as noted by the station operator.
-------
NEVADA
Wells
Elko
POSITIVE MILK SAMPLES
ALSO FOUND AT:
QBuhl. Idaho
©Boise, Idaho
©Blackfoot, Idaho
©Coeur d'Alene, Idaho
©Billings, Montana
Eureka
Round Mtn.
•*
Currant!
Lund
Manhattan© _ _.
w • Blue Jay
Warm
Clark Sta. |_
Tonopah(| jB Twin Springs
Springs* g N la
ta. • • ***
jB
•*
$ Alamo
UTAH
© Garrison
Richfield©
Cedar City
©
•Test Cell "C'] ^Varm Springs Ranch
Lathrop WelltP'~"
Death Valley Jet.
LAS VEGAS
©
\
Shoshone
VEGETATION —
MILK
AIR
PHOEBUS 1B-EP IV
Figure 3. Locations where fresh fission products were detected.
19
-------
Air samples from 19 Nevada stations, two California stations, one
Idaho station, and one Montana station showed the presence of fresh
fission products following the test. In addition, the filter from
Twin Falls, Idaho had a gross beta concentration of 0.9 pCi/m3.
This is above normal, but no fresh fission products could be iden-
tified by gamma spectrometry. The highest integrated exposure,
for radioiodines, was found at Lathrop Wells, Nevada, where the
maximum calculated inhalation dose to an adult thyroid was 3 mRad.
Fresh fission products were detected on air sampling filters in all
directions from Test Cell "C", except the 110° - 170° sector. Using
Weather Bureau wind directions , aerial cloud tracking, and other
environmental sampling, the pattern of deposition can be approxi-
mated as follows: The main portion of the cloud moved north to
northeast over Diablo, Warm Springs, Eureka, and Wells. A higher
than normal gross beta concentration of the filter from Boise, Idaho
would suggest that the movement of the cloud was closer to true north.
During the night of February 23, pulse-cooling of the reactor was
started and fresh fission products were carried to the south, south-
west by low level drainage winds. Wind direction changed on the
morning of February 24 carrying some of the effluent northwest
over Beatty and Goldfield.
Fission products from the reactor operation were found on air sam-
pler filters collected in the area northeast of NTS for at least twenty-
four hours, as fresh fission products were found on filters from both
Synopsis of the meteorological conditions associated with the
Phoebus IB Reactor Experimental Plan IV.
U. S. Department of Commerce, Environmental Services Administration,
Air Resources Field Research Office, Las Vegas, Nevada, March 1967.
2Pulse -cooling is the process of removing decay heat of the reactor
core by flowing intermittant pulses of nitrogen gas through the core and
exhausting the coolant gas out the rocket nozzel. This coolant gas picks
up fission products from the core and exhausts them into the atmosphere.
20
-------
the February 23-24 and the February 24-25 sampling periods at
Warm Springs, Clark Station, Blue Jay, and Eureka. Higher than
normal gross beta concentrations on the February 24-25 filters
from Diablo, Nyala, and Twin Springs, tends to confirm this. The
presence of 131I on the charcoal cartridge at Warm Springs Ranch
from the February 23-24 sampling period is difficult to understand
since other stations in the area did not show detectable concentra-
tions of any fresh fission products.
4. Vegetation sampling
A vegetation sample collected at Alamo with detectable 131I would
suggest the possibility that a portion of the upper cloud, which moved
to the northeast, may have been carried south over Alamo and Warm
Springs Ranch by night-time winds, or perhaps the radioactive ma-
terial was from pulse-cooling of the reactor during the night follow-
ing the run. Winds at the time were extremely variable. The con-
centration of 131I on the Warm Springs Ranch filter was only
0.3 pCi/m3. It is possible that other stations, such as Alamo and
Hiko, may have been in the cloud path, but the levels of radioiodines
were so low as to have been below detection limits.
Eighty-eight vegetation samples were collected at seventy-two off-
site locations. Samples were collected at five-mile intervals from
Crystal Springs (Hiko) to Warm Springs along Highway 25; from
Warm Springs to 36. 5 miles northwest of Warm Springs along
Highway 6; and from 12 miles southeast of Lathrop Wells to Beatty
along Highway 95. The remainder of the samples were collected at,
or near, milk sampling locations. Other than pasture and feed
samples, the most frequently collected vegetation was creosote bush
(Larrea divaricata). Past experience has shown this common desert
shrub tends to catch and hold fallout better than most other available
21
-------
plants. Nineteen samples from separate locations had detectable
amounts of one or more radioiodine isotopes.
Table 6 lists those locations where fresh fission products were found
on vegetation samples.
Table 6. Vegetation samples containing detectable fresh fission products.
Date
Location
Collected
Alamo, Nevada
20 mi S
Beatty, Nevada
25 mi S
Beatty, Nevada
Springdale,
Nevada
5 mi W
L/athrop Wells, Nev.
Selbach Ranch
(Lathrop Wells)*
5 mi E
Coyote Summit
10 mi NW
Queen City Summit
15 mi NW
Queen City Summit
Warm Springs, Nev.
2/24
2/24
2/24
2/24
2/24
2/24
2/24
2/24
2/24
2/24
Location
20 mi NW
Queen City Summit
25 mi NW
Queen City Summit
30 mi NW
Queen City Summit
35 mi NW
Queen City Summit
40 mi NW
Queen City Summit
Bradshaw Ranch
(Duckwater, Nev. )*
Sequra Ranch
(Eureka, Nev. )*
Gardners Ranch
(Preston, Nev. )*
Cold Creek Ranch
(Strawberry, Nev. )*
Date
Collected
2/24
2/24
2/24
2/24
2/24
2/28
3/1
2/28
3/1
Nearest map location.
5. Water sampling
Fifteen water samples from thirteen separate locations were analyzed
for specific gamma emitting isotopes. No fresh fission products
were detected. Table 7 lists locations, sources, and gross beta con-
centrations, from all water samples collected.
22
-------
Table 7. Water sampling results
Location
TTT Ranch
Austin, Nevada
Cummings Ranch
Baker, Nevada
Blue Eagle Ranch
Currant, Nevada
Currant Creek
Reservoir
Diablo
Bradshaw Ranch
Duckwater, Nev.
Gardner Dairy
Lund, Nevada
Gardner Dairy
Lund, Nevada
McKenzie Dairy
Lund, Nevada
Scow Dairy
Lund, Nevada
Yelland Ranch
McGill, Nevada
Yelland Ranch
McGill, Nevada
Fallini's Pond
Twin Springs,
Nevada
Fallini's Pond
Twin Springs,
Nevada
Pruess Reservoir
Garrison, Utah
Source
Pond
Pond
Spring
Pond
Tap
Tap
Tap
Tap
Tap
Tap
Stream
Stream
Pond
Pond
Pond
Date
Collected
2/25
2/25
2/26
2/24
2/26
2/25
2/25
2/25
2/25
2/25
2/25
2/26
2/24
2/26
2/25
Gross Beta
pCi/1
3
2
6
3
10
14
4
3
ND
3
1
2
72
63
13
23
-------
6. Milk sampling
Two hundred and eighty milk samples were collected from
seventy-six individual ranches, producing dairies, or pro-
cessing plants following the EP-IV reactor operation. All
were analyzed for specific gamma emitting isotopes and
sixteen were processed and analyzed for 89"90Sr. Fourteen
samples contained detectable amounts of one or more
radioiodine isotopes. The maximum concentration of any
one radioiodine isotope was 92 pCi/1 133I from Garrison, Utah,
and the maximum concentration of 131I was 63 pCi/1 from a
sample collected at the Martin Ranch, close to Eureka,
Nevada.
Detectable amounts of fresh fission products in milk
(131» 133I) were found as far north as Coeur d'Alene, Idaho,
and Billings, Montana. This would indicate the deposition
pattern to be in a sector of approximately 0 - 25° from Test
Cell "C". The Nevada air sampler filters having concentra-
tions of radioiodines would tend to confirm this approximation.
Table 8 shows four milk samples with the maximum concen-
trations of 131I. Appendices A and B list all milk sampling
results. Because of expected low levels of activity in the milk
samples, the samples were counted for longer than usual on
the gamma spectrometer. These long count times resulted in
lowering the minimum detectable amounts below the values
given in Table 3.
24
-------
Table 8. Four highest 131I concentrations in milk samples.
Date of _ pCi/I
89
25
Sr
Martin Ranch 2/24/67 a.m. 22 47 37 4 16
Eureka, Nev. 2/28/67 a.m. 63 ND 26 4 14
m v, 2/27/67 p.m. 39 ND 20 ND 6.8
, Utah
Cammack. Dairy^ ,/,.//- ,, .TT^. ,/ TvTr> r- -,
r,i i * .. TJ i. - 2/25/67 a.m. 21 ND 16 ND 5.7
Blackfoot, Idaho.
-------
CONCLUSION
The radiation exposure to the off-site population was well below the
guidance contained in Standards for Radiation Protection, U. S. Atomic
Energy Commission Manual Chapter 0524, November 8, 1968.
26
-------
APPENDICES
Appendix A. All milk samples containing fresh fission
products (iodine-131, 133), Phoebus IB,
EP-IV. 27
Appendix B. Milk samples showing no fresh fission pro-
ducts (iodine-131, 133, 135), Phoebus IB,
EP-IV. 28
-------
APPENDIX A
All milk samples containing fresh fission products( ' I),
Phoebus IB, EP-IV
Location
Blackfoot, Idaho
Couer D'Alene, Idaho
Boise, Idaho
Buhl, Idaho
Billings , Montana
Sequra Ranch
Near Eureka, Nev.
Martin Ranch
Near Eureka, Nev.
Martin Ranch
Near Eureka, Nev.
Martin Ranch
Near Eureka, Nev.
Manhatten, Nev.
Strawberry, Nevada
Cedar City, Utah
Garrison, Utah
Richland, Utah
Date of
Collection
2/25/67
2/28/67
3/01/67
2/27/67
3/01/67
2/25/67
2/24/67
2/28/67
3/03/67
2/25/67
3/01/67
2/26/67
2/24/67
2/27/67
131i '
21
ND
ND
ND
ND
ND
22
63
12
ND
14
10
9.4
39
133,
ND
9.6
17
12
16
24
47
ND
ND
21
ND
ND
92
14
pCi/1
137^
Cs
16
15
ND
11
11
12
37
26
16
ND
20
5
ND
20
89Sr
0
1
0
0
0
0
4
4
0
0
0
1
1
0
9°Sr
5.7
17
6.0
5.3
4.3
11
17
14
12
8.7
11
4.2
3.1
6.8
27
-------
APPENDIX B
Milk samples showing no fresh fission products( ' ' I),
Phoebus IB, EP-IV
Number Inclusive
Location of dates of
samples Collection
California
Bakersfield
Barstow
Hanford
Newhall
Riverside
Idaho
Blackfoot
Boise
Buhl
Burley
Couer D'Alene
Grangeville
Idaho Falls
Jerome
Lewis ton
Mountain Home
Pocatello
7
7
8
7
5
3
6
6
7
5
7
7
6
6
7
6
3/01/67-
3/07/67
2/28/67-
3/07/67
2/28/67-
3/07/67
2/27/67-
3/05/67
2/28/67-
3/03/67
2/25/67-
3/02/67
2/24/67-
3/02/67
2/24/67-
3/03/67
2/24/67-
3/02/67
2/24/67-
3/02/67
2/25/67-
3/04/67
2/24/67-
3/03/67
2/24/67-
3/01/67
2/25/67-
3/03/67
2/24/67-
3/02/67
2/23/67-
3/02/67
Location
Montana
Big Timber
Billings
Bozeman
Miles City
Missoula
Utah
Cedar City
Minersville
Mt. Pleasant
Ogden
Richfield
St. George
Smithfield
Spanish Fork
Wyoming
Cheyenne
Powell
Rawlins
Number Inclusive
of dates of
samples Collection
7
6
7
7
7
6
9
7
7
5
4
6
4
6
4
4
3/01/67-
3/07/67
3/01/67-
3/07/67
2/28/67-
3/07/67
2/27/67-
3/05/67
2/26/67-
3/05/67
2/24/67-
3/02/67
2/24/67-
3/05/67
2/24/67-
3/02/67
2/24/67-
3/03/67
2/25/67-
3/08/67
2/24/67-
3/01/67
2/24/67-
2/28/67
2/24/67-
3/03/67
2/24/67-
3/05/67
2/24/67-
2/27/67
2/25/67-
^ / n>i / £ T
28
-------
APPENDIX B (continued)
Number Inclusive
Location of dates of
samples Collection
Wyoming (cont'd)
Riverton
Sheridan
Nevada
Alamo
Young Ranch
Austin
TTT Ranch
Austin
Willow Creek Rn.
Austin
Heffern Ranch
Austin
Cummings Rn
Baker ,
Eldridge Rn
Baker
Blue Eagle Rn
Currant
Bradshaw Rn
Duckwater
Sequra Ranch
Eureka
Martin Ranch
Eureka
Hiko
Las Vegas
Selbach Ranch
Lathrop Wells
Cypert Ranch
Lathrop Wells
4
5
2
3
1
1
2
1
2
2
2
2
1
2
2
3
1
2/25/67-
3/02/67
2/25/67-
2/27/67
2/24/67-
2/25/67
2/24/67-
3/01/67
2/26/67
2/25/67
2/26/67-
2/26-67
2/25/67
2/25/67-
2/25/67
2/24/67-
3/01/67
2/25/67-
2/28/67
2/25/67-
3/15/67
3/14/67
2/24/67-
2/25/67
2/28/67-
2/28/67
2/24/67-
2/27/67
2/27/67
Number Inclusive
Location of dates of
samples Collection
Nevada
Nickell Farm
Lathrop Wells
Gardner Ranch
Lund
McKenzie Rn
Lund
Scow Ranch
Lund
W. Gardner Rn
Lund
Jurey Ranch
Lund
Lars en Ranch
Me Gill
Henroid Ranch
Me Gill
Yelland Ranch
Me Gill
Hiatt Ranch
Manhattan
Sharp Ranch
Nyala
Casey Ranch
Nyala
Anderson Rn
Pahrump
Owens Ranch
Pahrump
Wilson Creek Rn
Potts
Gardners Ranch
Preston
Bergs Ranch
Round Mountain
3
1
1
1
1
1
1
1
2
2
2
2
1
1
1
1
2
2/24/67-
2/26/67
2/25/67
2/25/67
2/25/67
2/25/67
2/28/67
2/25/67
2/25/67
2/25/67-
2/26/67
2/24/67-
2/28/67
2/24/67-
3/03/67
2/25/67-
3/03/67
2/25/67
2/24/67
2/26/67
2/28/67
2/25/67-
2/26/67
29
-------
APPENDIX B (continued)
Location
Number
of
samples
Inclusive
dates of
Collection
Nevada (cont'd)
Pope Ranch
Round Mountain
Rhodes Ranch
Shoshone
Peacock Ranch
Springdale
Circle Ranch
Strawberry
Cold Creek Rn
Strawberry
Pumping Station
Tonopah
2/24/67-
2/26/67
2/25/67
2/24/67
3/03/67
3/01/67
2/25/67
30
-------
DISTRIBUTION
1-15 SWRHL, Las Vegas, Nevada
16 Robert E. Miller, 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 - 20 D. W. Hendricks, Rad. Safe. Br., NVOO/AEC, Las Vegas, Nev.
21 Central Mail & Records, NVOO/AEC, Las Vegas, Nevada
22 A. J. Whitman, NTSSO, NVOO/AEC, Mercury, Nevada
23 - 24 R. Decker, SNPO, Washington, D. C.
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. R. Guthals, LASL, Los Alamos, New Mexico
38 - 40 H. S. Jordan, LASL, Los Alamos, New Mexico
41 H. G. Simens, NTO, Ae ro jet-General Corp., Jackass Flats, Nev.
42 G. Grandy, WANL, NRDS, Jackass Flats, Nevada
43 - 44 E. Hemmerle, WANL, Pittsburgh, Pennsylvania
45 RobertH. Loux, AEC, NVOO, Las Vegas, Nevada
46 John Harris, PI, USAEC, Washington, D". C.
47 - 48 M. I. Goldman, NUS, Washington, D. C.
49 - 50 J. Mohrbacher, Pan Am. World Airways, Jackass Flats, Nev.
51 - 52 Philip Allen, ARL, ESSA, Las Vegas, Nevada
53 C. Anderson, EG&G, Las Vegas, Nevada
54 John S. Kelly, USAEC, Washington, D. C.
55 Maj. Gen. Edward B. Ciller, DMA, USAEC, Washington, D.C.
-------
56 - 57 Chief, NOB/DASA, AEC/NVOO, Las Vegas, Nevada
58 - 62 Charles L. Weaver, PHS, BRH, Rockville, Maryland
63 Victor M. Milligan, REECo., Mercury, Nevada
64 Martin B. Biles, DOS, USAEC, Washington, D.C.
65 - 66 DTIE, USAEC, Oak Ridge, Tennessee
67 Byron F. Murphey, Sandia Corp., Albuquerque, N. M.
------- |