vvEPA
United States
Environmental Protection
Agency
Environmental Monitoring
Systems Laboratory
P.O. Box 93478
Las Vegas NV 89193-3478
EPA/600/8-87/054
DOE/DP/00539-059
August 1988
Research and Development
Summary of Accidental
Releases of Radioactivity
Detected Off The Nevada
Test Site: 1963-1986
prepared for the
U.S. Department of Energy
under Interagency Agreement
Number DE-AI08-86NV10522
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EPA-600/8-87/054
DOE/DP/00539-059
August 1988
SUMMARY OF ACCIDENTAL RELEASES OF RADIOACTIVITY
DETECTED OFF THE NEVADA TEST SITE: 1963-1986
compiled by
R. G. Patzer, W. G. Phillips
R. F. Grossman, S. C. Black and C. F. Costa
Nuclear Radiation Assessment Division
prepared for the
U.S. Department of Energy
under Interagency Agreement
Number DE-AI08-86NV10522
ENVIRONMENTAL MONITORING SYSTEMS LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89193-3478
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NOTICE
The information in this document has been funded wholly or in part by the
United States Environmental Protection Agency under IAG DE-A108-76DP00539 to
the United States Department of Energy. It has been subject to the Agency's
peer and administrative review, and it has been approved for publication as
an EPA document. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
ii
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CONTENTS
Figures iv
Tables iv
Abbreviations v
Introduction 1
Dose Limits for Members of the Public 4
Summaries of Individual Tests 6
Eagle Test (12/12/63) 6
Pike Test (03/13/64) 8
Alva Test (08/19/64) 11
Drill Test (12/05/64) 13
Parrot Test (12/16/64) 15
Alpaca Test (02/12/65) 17
Tee Test (05/07/65) 19
Diluted Waters Test (06/16/65) 21
Red Hot Test (03/05/66) 23
Fenton Test (04/23/66) 25
Pin Stripe Test (04/25/66) . 27
Double Play Test (06/15/66) 29
Derringer Test (09/12/66) 31
Nash Test (01/19/67) 33
Umber Test (06/29/67) 35
Door Mist Test (08/31/67) 37
Hupmobile Test (01/18/68) 39
Pod Test (10/29/66) 41
Scuttle Test (11/12/69) 43
Snubber Test (04/21/70) 45
Baneberry Test (12/18/70) 47
Diagonal Line Test (11/24/71) 50
Riola Test (09/25/80) 52
Discussion 54
iii
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FIGURES
Number Page
1 Map of the Test Range Complex (shaded) and
Surrounding Area 2
TABLES
Number Page
1 Tests That Accidentally Released Radioactivity
Detectable Off Site 5
2 Highest Concentrations Measured on Air Filters (Pike Event). ... 9
3 Locations With Highest Exposures Compared With Background
Exposures 55
IV
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LIST OF ABBREVIATIONS
ABBREVIATIONS
AEC
Ci
DOE
EMSL
EPA
ERDA
kt
L3
NVOO.NVO
PDT
PHS
PST
rad
rem
SWRHL
WERL.NERC
Atomic Energy Commission
curie: amount of radionuclide that decays at rate of
3.7 x 1010 atoms per second.
U.S. Department of Energy
Present designation of the EPA Laboratory
U.S. Environmental Protection Agency
U.S. Energy Research and Development Administration
kiloton: energy of nuclear explosion that is equivalent to
explosion of 1,000 tons of TNT.
Liter
cubic meter
Nevada Operations Office (NV also used)
Pacific Daylight Time
U.S. Public Health Service
Pacific Standard Time
Amount of radiation that deposits 100 ergs energy per gram
of soft ti ssue.
The rad when modified for the different types of radiation.
Southwestern Radiological Health Lab, U.S. PHS, from 1954
to 1970
Laboratory names after 1970, operated by EPA
PREFIXES
P
n
M
m
k
pi co
Nano
micro
mi Hi
kilo
10-12
10-9
ID'6
10"3
103
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INTRODUCTION
Radiological monitoring and surveillance in the off-site areas around the
Test Range Complex (Nevada Test Site [NTS] plus Nell is Air Force Base Range
Complex), are conducted for the U.S. Department of Energy (DOE) by the Environ-
mental Protection Agency's Environmental Monitoring Systems Laboratory at
Las Vegas (EMSL-LV), through an Interagency Agreement between the two agencies.
Figure lisa map of the local area with the Test Range Complex indicated as a
shaded area. This off-site monitoring was formerly conducted by the U.S.
Public Health Service, Southwestern Radiological Health Laboratory (SWRHL). A
complete description of the off-site monitoring networks is given in annual
reports of which the latest is: Off-Site Environmental Monitoring Report,
Radiation Monitoring Around United States Nuclear Test Areas 1987, EPA-600/4-
88/021, DOE/DP/00539/060, June 1988.
From August 5, 1963 through December 31, 1987, 455 announced nuclear tests
at the NTS were designed to be completely contained. During the same period,
five Plowshare cratering tests, not designed for complete containment, were
conducted at the NTS and ten tests were conducted underground at U.S. sites
other than the NTS. Of the NTS underground tests, 19 inadvertently released
sufficient radioactivity to the atmosphere to be detected by ground monitors
or ground monitoring equipment off the Test Range Complex. Four other tests
(for a total of 23) released radioactivity that was detectable off site only by
means of aerial monitoring. No unannounced test released radioactivity
detectable off site because DOE policy is to announce all such tests. Some of
the releases were detected in states other than Nevada: 8 in California, 3 in
Utah, 2 in Arizona, and 1 (Baneberry) in several western states.
This report is an update of report WASH-1183^. The following information
is provided, if available, for the 23 tests that accidentally released radio-
activity because of containment failure:
1. The name and date of the test.
2. The depth of burial of the device.
3. The quantity of radioactivity released to the atmosphere.
4. The types of radionuclides identified in the release.
5. The highest air concentrations detected in the off-site area.
^•Summary Information on Accidental Releases of Radioactivity to the Atmosphere
from Underground Nuclear Detonations Designed for Containment. August 5, 1963
- June 30, 1971. AEC Report WASH-1183.
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Figure 1. Map of the Test Range Complex (shaded) and surrounding area.
2
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6. The highest gamma exposure levels detected in the off-site area.
7. The highest levels of radioiodine detected in milk.
8. The thyroid dose where sufficient radioiodine was detected that could
lead to a calculatable thyroid dose.
Information on the monitoring results was taken from EMSL-LV and SWRHL
reports while information on the device and quantity of release is from report
NVO-317 and other sources. Estimates of the quantities of radioactivity are
based upon the calculated quantity of the initial release that remains at
twelve hours after the release occurred (R+12 hr). In a prompt venting situa-
tion the major portion of radioactivity consists of very short half-life
radio nuclides. These short half-life radionuclides are of little or no health
significance since they will essentially all decay before reaching the off-NTS
areas, and work areas on the NTS located in the downwind direction from a
scheduled nuclear test are routinely cleared of personnel just prior to the
test. In a delayed seepage type release these short half-life radionuclides
generally represent only a very small fraction of the total release, or may not
be present at all. Hence, to provide a more meaningful estimate of the quan-
tities of radioactivity released to the atmosphere, that could affect man, and
to provide a point for comparison with other releases, the time selected and in
common usage is also the quantity of the radioactivity remaining at 12 hours
following the release (R+12 hr). Throughout this summary, the total quantity
of radioactivity released is expressed in this R+12 hour context.
Where a definite cause for the release of radioactivity could be determined,
this has been indicated. Some of these releases could not be readily ascribed
to a specific cause, but may be categorized as a seepage occurring through very
small cracks and fissures in the ground above the point of detonation. Such
releases are usually small in total quantity and consist primarily of the noble
gases xenon and krypton.
All but 2 of the 23 tests were in the low kiloton yield range (0-20 kt).
The exceptions were the NASH and POD tests which were in the low-intermediate
yield (20-200 kt) range. The actual depth of burial of the low yield tests
ranged between 390 feet and 1465 feet. The low-intermediate yield devices were
buried at depths of 1000 and 1200 feet. The radioactivity released was essen-
tially the gaseous radionuclides of xenon, krypton, and iodine except for the
PIKE, PIN STRIPE, HUPMOBILE and BANEBERRY tests which released particulate
matter as well as gaseous nuclides.
The highest radioiodine content found in milk collected at ranches where
children were living was at the Schofield Dairy near Hiko, Nevada, where a peak
level of 4.8 nanocuries of iodine-131 per liter of milk was recorded following
the PIN STRIPE test. This could have resulted in thyroid exposures less than
one-tenth of the Protective Action Guide of the Federal Radiation Council (FRC)2.
2Federal Radiation Council, 1964, Background Material for the Development of
Radiation Standards, Report No. 5, U.S. Government Printing Office.
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However, to minimize exposures, an arrangement was made by the Atomic Energy
Commission (AEC) with the dairy owner to place his milk cows on dry feed for
about three weeks. In addition, to develop a better understanding of the
thyroid uptake at these low levels of radioiodine, 78 people (including 70
children) residing in this area were examined by measuring the radioiodine in
their thyroids. Low levels of radio-iodines were detected in the thyroid of 19
of these people. The projected doses to the thyroid ranged from 50 to 300
millirems. The FRC's guide for dose to the thyroid is 1,500 millirems per year
from routine operations to an individual in the general population.
The highest potential external whole-body gamma radiation exposure from
these 23 incidences occurred at Cactus Springs, Nevada, following the PIKE
test. The total exposure to an individual at this location was calculated as
about 85 milliroentgens (mR). This amount of radiation exposure can be compared
with the 100 to 150 mR average dose humans receive from natural background
radiation every year. The planning guideline for accidental releases at the
NTS during this time was 3900 mR per year and the FRC's guidance for whole-body
exposure to an individual in a population from routine operations was 500
millirems per year.
Based upon all the monitoring data collected following these 23 accidental
releases, it is concluded that exposures to the public from these tests did not
exceed either the NTS accidental exposure guideline or the Radiation Protection
Guides for the general population recommended by the FRC that were in effect at
the time of the release.
DOSE LIMITS FOR MEMBERS OF THE PUBLIC
The dose limits to individuals in the off-site area differ between
accidental releases of radioactivity from the NTS and planned, controlled
releases; and these have changed with time as have all radiation protection
guides. For the case of an accidental release, there were no federal guidelines
for external exposure to a member of the public so the AEC (followed by DOE)
adopted a planning guide for nuclear weapon tests based on 25% of the
occupational exposure limits at the time the guidance was established. The
radiation protection guides are set forth by time intervals in the following
paragraphs.
From September 1961 through 1976 the guides for population exposure were
as follows:
(1) For planning of tests; 3.9 R to an individual but not to exceed 10 R
in 10 years. Concentrations in air and water not to exceed 10% of
the continuous exposure levels listed in National Bureau of Standards
(NBS) Handbook 69.
(2) For controlled releases; 0.5 R for any individual or 0.17 R for
population groups.
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From 1977 through 1985 the guides for population exposure from NTS activ-
ities were:
(1) For planning of tests; 500 millirem per year for an individual or
170 millirem for population groups, external exposure. Air and
water concentrations of radionuclides were limited to 1/30 of the
continuous exposure levels listed in NBS Handbook 69.
(2) For controlled releases of radioactivity, the guidelines were
identical.
For 1986 the guides for population exposure from NTS activities were:
(1) For planning of tests; no change from those immediately preceding.
(2) For controlled releases of radioactivity the effective dose equiva-
lant may not exceed 500 millirem per year for a few years as long as
the annual average exposure over 70 years does not exceed 100 milli-
rem per year. For controllable airborne releases, the annual
exposures cannot exceed 25 millirem whole-body or 75 millirem to any
organ.
The following table contains a list of the 23 tests which accidentally
released radioactivity that was detected in off-site areas by either aerial or
ground-based surveillance. Each test is summarized in subsequent sections.
TABLE 1. TESTS THAT ACCIDENTALLY RELEASED RADIOACTIVITY DETECTABLE OFF SITE
Name
Date of Test
Name
Date of Test
EAGLE
PIKE
ALVA
DRILL
PARROT
ALPACA
TEE
DILUTED WATERS
RED HOT
FENTON
PIN STRIPE
DOUBLE PLAY
December 12, 1963
March 13, 1964
August 19, 1964
December 5, 1964
December 16, 1964
February 12, 1965
May 7, 1965
June 16, 1965
March 5, 1966
April 23, 1966
April 25, 1966
June 15, 1966
DERRINGER
NASH
UMBER
DOOR MIST
HUPMOBILE
POD
SCUTTLE
SNUBBER
BANEBERRY
DIAGONAL LINE
RIOLA
September 12, 1966
January 19, 1967
June 29, 1967
August 31, 1967
January 18, 1968
October 29, 1969
November 13, 1969
April 21, 1970
December 18, 1970
November 24, 1971
September 25, 1980
Since radiation exposure and dose units and organizational designations
change over time, a list of abbreviations is provided on Page v for reference.
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SUMMARIES OF INDIVIDUAL TESTS
EAGLE TEST
This nuclear weapons related test was conducted in Area 9, Nevada Test
Site, at 0802 PST on December 12, 1963, in a vertical hole at a depth of 541
feet. The explosive yield of the device was less than 20 kt.
Immediately following the detonation, a small puff of gases was observed
to emanate from the Line-Of-Sight (LOS) pipe at surface ground zero (SGZ).
Aircraft sampling of this puff-like cloud did not reveal any radioactivity,
only smoke particles. About thirty seconds later, steam-like radioactive
effluent began emanating from the LOS pipe and continued until the surface
collapsed at 3.3 minutes after the detonation, at which time the release of
radioactivity stopped. This event contained an experiment involving a LOS pipe
to the surface which did not properly seal off as it was designed to do. The
estimated total radioactivity released to the atmosphere, calculated for 12
hours after the release (R+12 hr) was 760 curies (Ci). The major fractions of
the activity identified in this gaseous effluent were: iodine-132, iodine-133,
iodine-135, xenon-135, and tellurium-132.
Following the release, the cloud rose to about 250 feet above the surface.
Surface and near surface winds carried the gaseous effluent to the southwest.
Aerial tracking of the cloud was conducted until, over central southern
California about 140 miles from the point of release, the effluent cloud
became so diffuse that identification of airborne radioactivity could not be
made.
Nine mobile radiation monitoring teams were deployed off site in the
southern sector from the NTS. No gamma radiation levels above background were
detected in the downwind off-site sector. Small amounts of radioactivity were
detected on air filters collected in that area. The highest concentra-
tion of gross beta activity occurred at Death Valley Junction, California,
between 0930 and 1550 hours on December 12, at 24 picocuries/cubic meter
The filter and the charocoal cartridge from the air sampler contained concen-
trations of iodine-133 and -135 at 35 and 10 pCi/nr respectively. Seventeen
milk samples were collected from areas under the cloud trajectory, cesium-137
and potassium-40 but no fresh fission products were detected in these milk
samples. The specifics on this test are summarized on the following form.
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Event Name, Type and Series.
Date/Time, Size and Purpose.
EAGLE Shaft Niblick
12/12/63, 0802 hr, <20 kt, weapons related
Release Characteristics.
Ci @ R + 12 hr.
*Detectable
*Maximum Gamma Exposure Rate
Populated location:....
Unpopulated 1ocati on:..
Prompt venting for 3 min. Drill back release
for 83 hr starting on 12/15
760 vent, <200 drill back
Southwesterly, Nevada, California
None detected
Not measurable
Not detectable on film badge
pCi/m3 on 12/12/63
*Maximum External Gamma Exposure:
*Maximum TLD/Film Badge Exposure:
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Gross beta 1-133 1-135
Air Death Valley Jet 24 35 10
Milk No fresh fission products detected
Other Not collected
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: 0.086 mrem
One-year-old child: 0.19 mrem
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk No radioiodines detected
Adult:
One-year-old chi1d:
Remarks: Direction--SW over Death Valley, central southern California;
detected last about 140 miles beyond point of release by aircraft
only.
*Reference: SWRHL-12r. Final Report of Off-Site Surveillance for Operation
Niblick. April 1966.
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PIKE TEST
This nuclear weapons related test was conducted in Area 3, Nevada Test
Site, at 0802 PST on March 13, 1964, in a vertical hole at a depth of 390 feet.
The explosive yield of the device was less than 20 kt.
Beginning almost immediately after shot time, radioactivity issued from
the SGZ area. This release of radioactivity continued until subsidence occurred
at one minute and nine seconds after the detonation. The cause of this release
has been attributed to the geological weakness of the media, and possibly
preshot drilling induced weakness of the media surrounding the casing. Small
cracks and fissures near SGZ were opened during this release. It is estimated
that about 120 kCi of activity calculated at R+12 hours were released to the
atmosphere.
The radioactive effluent cloud top was measured at 2640 feet above the
terrain. The radioactivity was tracked by aircraft southeastward, past Las
Vegas, Nevada. A second aircraft, equipped with very sensitive detection
instruments, tracked the airborne radioactivity to a distance of about 60 miles
south of Las Vegas. At this point, the instruments in the tracking aircraft
could no longer detect airborne radioactivity. Some spotty patches of low-level
airborne radioactivity (just above background) were detected in southern Arizona
and California on the following days.
The highest potential external gamma radiation exposure at a populated
location was at Cactus Springs, Nevada, where it is estimated that the maximum
whole-body gamma radiation exposure would have been less than 83 mR infinite
exposure. An estimate of possible thyroid dose to children at Cactus Springs,
is one millirad. This is based upon inhalation calculations since no milk was
produced at this location.
Although low levels of radioiodine appeared in some samples of unprocessed
milk from individual farms, none was found in commercially available milk. At
that time of year, all of the cows in the Las Vegas area were on dry feed.
Unprocessed milk samples collected at farms in southern Arizona and California
following this test were found to contain iodine-131, at peak levels of 50-80
picocuries per liter (pCi/L).
The highest concentrations of gross beta air activity and of radioiodines
found on air filters are listed in the following table.
8
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TABLE 2. HIGHEST CONCENTRATIONS IN COMMUNITIES AS MEASURED
ON AIR FILTERS (PIKE EVENT)
Station
Cactus Springs
Cactus Springs
Cactus Springs
Indian Springs
Indian Springs
Indian Springs
Las Vegas
Las Vegas
Las Vegas
Collection
Period
(March 1964)
0840713th to
1120/13th
1128713th to
1503713th
1505713th to
1141/Hth
0852713th to
1102713th
1106713th to
1503713th
1503713th to
1154714th
1140713th to
1445713th
1450713th to
1845713th
1850713th to
2348713th
Gross Beta
(pCi/m3)
50,000
9,000
23
35,000
15,000
42
14,000
680
59
Charcoal Cartrid
1-131
ND
ND
Trace
ND
ND
ND
ND
ND
ND
1-133.
(pCi/m3)
700*
98
4.5
190
123
2.9
60
10
0.8
ges
1-135
510
96
Trace
160
92
ND
100
ND
ND
ND - Not Detectable
* - An ana
Ivsis of the ala
ss fiber filt
er indicate
d an additio
mal
1000 pCi/m3 of 1-131 and 35,000 pCi/m3 of 1-133.
Other specifics for the Pike test are summarized on the following form.
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Event Name, Type and Series PIKE Shaft Niblick
Date/Time, Size and Purpose 3/13/64, 0802 hr., <20 kt, weapons related
Release Characteristics Prompt massive venting
Ci @ R + 12 hr 120,000
*Detectable Southeasterly direction over Cactus Springs
and Las Vegas; Nevada, Arizona, California
*Maximum Gamma Exposure Rate
Populated location: 5.9 mR/hr at Cactus Springs, NV
Unpopulated location: 4.4 mR/hr 1 mi. E. of Cactus Springs on Hwy 95
*Maximum External Gamma Exposure: 83 mR--Cactus Springs**
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fi xed stati on:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air 76,000 pCi/m3 gross beta in air at Hwy 95,
5 miles west of Cactus Springs.
35,700 pCi/m3 of 1-133, 1,000 pCi/m3 of 1-131,
and 510 pCi/m3 of 1-135 in air at Cactus Springs.
Milk (not commercially sold) Maximums--Habbart Farm near Las Vegas:
375 pCi/L of 1-131 in milk from cows eating
green chop.
70 pCi/L of 1-131 in milk from cows eating hay.
Other 4700 pCi/kg of 1-131 in green chop
1300 pCi/kg of 1-131 in hay
Other milk maximums--80 pCi/1 of 1-131 in
milk from Yuma, AZ; and Winterhaven, CA.
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: Not calculated
One-year-old child: 1.9 mrem from inhalation, Cactus Springs
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult: Not calculated
One-year-old child: Approx. 44 mrem, Las Vegas
Remarks: Maximum net beta plus gamma observed was 40 mR/hr 1 mile east of
Cactus Springs. 1-131, 1-133, and 1-135 were detected in release, which
occurred at H+10 seconds and continued for approximately 1 minute, from ground
faults. Fresh fission products were detected as far as 341 miles from SGZ
(Yuma, AZ).
*Reference: SWRHL-12r. Final Report of Off-Site Surveillance for Operation
Niblick. April 1966.
SWRHL 14r, Dairy Farm Radioiodine Study Following the Pike event,
Nov. 1964.
**Using formula: Exposure = 5 x dose-rate x hours since detonation.
10
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ALVA TEST
This nuclear weapons related test was conducted in Area 2, Nevada Test
Site, at 0900 PDT on August 19, 1964, in a vertical hole at a depth of 545
feet. The explosive yield of the device was less than 20 kt.
Seepage occurred from the SGZ area soon after detonation and continued
for an hour or so. The amount released, corrected to R+12 hr, was estimated
to be 6100 Ci, mostly radioactive noble gases. Wind direction was predomin-
antly toward the east.
Air samplers were operating at 37 stations in the off-site area, from
which 24-hour samples were collected daily. Stationary dose-rate recorders
were operating at 16 off-site locations. Fifteen Public Health Service
personnel were on duty for surveillance activities for the event, and aerial
monitoring was performed by the PHS cloud tracking team in a U3-A aircraft.
No radioactivity above normal background levels was detected off site
by ground or aerial monitoring teams, or by the stationary dose-rate recorders,
either after the detonation or during the subsequent sample recovery operations.
No fresh fission products were detected in any air sample collected off site
throughout this period, and none of these samples contained levels of gross
beta activity above normal background. No fresh fission products were found
in 11 milk samples collected in the downwind arc. Other data for this test are
included on the following form.
It was concluded that no radioactive contamination of the off-site pop-
ulated area resulted from this event. (NOTE: See remarks on the following
form).
11
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Event Name, Type and Series ALVA Shaft Whetstone
Date/Time, Size and Purpose 8/19/64, 0900 hr, <20 kt, weapons related
Release Characteristics Seepage
Ci @ R + 12 hr 6100
*Detectable Aircraft only ENE of NTS
*Maximum Gamma Exposure Rate None detected
Populated 1ocati on:
Unpopulated location:
*Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air Not detected
Milk , Not detected
Other Not detected in vegetation
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air No radioiodines detected
Adult:
One-year-old chi1d:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk No radioiodines detected
Adult:
One-year-old child:
Remarks: Approximately 150 cps (slightly detectable) found in the area from
5 miles northwest of St. George to north end of Lake Mead by ARMS
aircraft.
*Reference: Interim Report of Off-Site Surveillance for the Alva Event (SWRHL)
EG&G ARMS Project Interim Report, Radioactive Effluent from Alva,
2 September 1964 (Classified, SRD).
12
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DRILL TEST
This nuclear weapons related test was conducted in Area 2, Nevada Test
Site, at 1315 PST on December 5, 1964, in a vertical hole at a depth of 617
feet. The explosive yield of the device was 3.4 kt.
Gaseous radioactivity seeped through fissures in the ground beginning 20
minutes after detonation and continuing for 9 1/2 hours. The release rate then
decreased considerably, but continued for 5 1/2 days. The total release was
estimated to be 61 kCi corrected to R + 12 hr. The activity moved in a south-
erly direction and was detectable in Nevada and Southeastern California.
Five monitoring teams were deployed downwind at the time of the test and
two aircraft were available for cloud tracking and cloud sampling. Dose-rate
recorders were at 21 locations around the NTS, and air samplers were at 43
locations. Milk and water samples were also collected.
The highest radiation exposure rate at a populated location was 0.055
mR/hr at Lathrop Wells, NV; the maximum external gamma exposure was estimated
to be 0.025 mR at Lathrop Wells. The maximum gross beta concentration for air
samples was 0.6 pCi/m-* at Death Valley Junction, California. The highest expo-
sure rate recorded for an unpopulated location was 0.2 mR/hr on Highway 95, 5
miles east of Lathrop Wells. Up to 300 pCi/kg of iodine-131 and iodine-133 was
detected in vegetation in the Lathrop Wells area. These and other specifics
for this test are listed in the following form.
13
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Event Name, Type and Series DRILL Shaft Whetstone
Date/Time, Size and Purpose 12/5/64, 1315 hr, 3.4 kt, weapons related
Release Characteristics Seep and drill back
Ci @ R + 12 hr 61,100, <416 in drillback
*Detectable Nevada, California. Southerly direction
*Maximum Gamma Exposure Rate
Populated location: 0.055 mR/hr at Lathrop Wells
Unpopulated location: 0.2 mR/hr at 5 mi. east of Lathrop Wells
on Hwy 95
*Maximum External Gamma Exposure: 0.025 mR at Lathrop Wells
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air 0.62 pCi/m3 gross beta at Death Valley Jet., CA
1.6 pCW Xe-135 at Lathrop Wells
1.1 pCi/m3 1-131 in air at Shoshone, CA
Milk No detectable radioiodines
Other Vegetation—Maximum
60 pCi/kg Te-132, 5 mi. east of Lathrop Wells
390 pCi/kg Cs-137, Amargosa Farm area
300 pCi/kg 1-131, Lathrop Wells
300 pCi/kg 1-133, 5 mi. east of Lathrop Wells
60 pCi/kg 1-132, 5 mi. east of Lathrop Wells
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adul t: 0.008 mrem
One-year-old child: 0.017 mrem
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult:
One-year-old child:
No radioiodines detected
Remarks: EG&G NATS plane traced effluent south over the Mojave desert east of
Barstow toward Yuma.
Event release occurred at H+20 min. for a duration of 9.5 hours and
at H+10 hours for a duration of 5.4 days. 1-131, 1-132, 1-133,
Te-132, and Cs-137 were detected.
Drillback release occurred at 1500 hours, 12/14/64 for a duration
of 1.6 days.
*Reference: SWRHL 21r, Final report of Off-Site Surveillance for the Drill
event, Oct. 1965.
14
-------
PARROT TEST
This nuclear weapons related test was conducted in Area 3, Nevada Test
Site, at 1200 PST on December 16, 1964, in a vertical hole at a depth of 600
feet. The explosive yield of the device was 1.3 kt.
This experiment involved a Line-Of-Sight (LOS) pipe to the surface.
Collapse of the SGZ area occurred at about 4 minutes after the detonation.
There was no prompt release through the LOS pipe. However, about eleven min-
utes after the detonation, increased levels of radiation were detected. The
mechanism of this release was later found to be a crack in the LOS pipe below
the surface. The release continued at decreasing levels for about 8 days.
It is difficult to estimate the total curies released from this seepage because
of its duration. However, the estimate made by the Los Alamos National Labor-
atory was about 230 kCi calculated at R+12 hours. The release consisted
primarily of isotopes of the noble gases.
Winds near the surface at shot time were to the north at about seven miles
per hour. The radioactive effluent cloud did not rise to any great heights
above the surface. The direction of the effluent cloud initially was to the
northeast, however, during the night the surface drainage winds reversed direc-
tion bringing the effluent cloud back over the NTS. Over the several days that
seepage occurred, the gaseous plume varied between north and south over the test
site several times, hence the overall cloud activity was widely dispersed, but
localized over and around the NTS.
Twenty PHS personnel were deployed for this test and aircraft were used
for cloud tracking and sampling. The operating surveillance networks included
88 air sampling stations, 42 milk sampling stations, and 27 water sampling
stations.
The only off-site location where ground monitors detected levels of radio-
activity above background was in an unpopulated area along Highway 25 northeast
of the NTS. The peak exposure rate recorded was 0.14 mR/hr. Air samples were
collected in the off-site area for two days following this test. Only two
charcoal filters were found to contain fresh fission products as shown on the
following form. Several other air filters indicated levels of gross beta
activity slightly above the normal background fluctuations, however, no fresh
fission products were identified. Milk and vegetation samples gave no indica-
tion of fresh fission product contamination. A summary of findings is given
on the following form.
15
-------
Event Name, Type and Series PARROT Shaft Whetstone
Date/Time, Size and Purpose 12/16/64, 1200 hr., 1.3 kt, weapons related
Release Characteristics Seep
Ci @ R + 12 hr 230,000
*Detectable Nevada, Utah; northeasterly
*Maximum Gamma Exposure Rate
Popul ated 1 ocati on: Not detected.
Unpopulated location: 0.14 mR/hr 6.3 miles NW of Coyote Summit
*Maximum External Gamma Exposure: Not measurable
*Maximum TTLD/Film Badge Exposure: Not detectable on film badge
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
pCi/m3
Air Location Gross Beta 1-131 1-133 l-l3b
Indian Springs 0.47 ND 6.6 ND
Warm Spr. Ranch 8.5 0.6 0.6 ND
12 mi NW Hancock Sum. 74 ND ND ND
Milk Max Milk Sampling
16 pCi/L Sr-90 Nyala 12/18
130 pCi/L Cs-137 Nyala 12/18
Other Not detected in vegetation samples collected
at Caliente, Moapa, Pahrump, Pioche, and
Queen City Summit
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: 0.016 mrem
One-year-old child: 0.031 mrem
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult: Not detected in milk
One-year-old chi 1 d:
Remarks: Release about 45% each of Cs-138, and Kr-85m, 10% Xe-135, and small
amounts of iodines.
*Reference: Interim Report of Off-Site Surveillance for the Parrot Event
(10/04/65).
SWRHL-22r. Final Report of Off-Site Surveillance Activities of the
Southwestern Radiological Health Laboratory from July through
December 1964. Dec. 1968.
16
-------
ALPACA TEST
This nuclear weapons related test was conducted in Area 2, Nevada Test
Site, at 0710 PST on February 12, 1965, in a vertical hole at a depth of 730
feet. The explosive yield of the device was less than 20 kt.
Soon after detonation, a low-velocity seepage began from the SGZ area and
continued for 8 1/2 hr.
The calculated quantity of radioactivity released and remaining at R+12
hours was 40 kCi. The radioactivity was identified as primarily cesium-138
with small quantities of krypton-85 and xenon-135. Surface winds at the time
of detonation were light and variable toward the south and southwest. Because
of the low level of radioactivity, and the wide dispersion of the cloud, it was
difficult for tracking aircraft to establish a trajectory. The cloud sampling
aircraft collected a sample on a flight between Ash Meadows turnoff and Sandy
Valley which contained low levels of cesium-138.
Ground monitoring was performed by 10 PHS personnel, and aircraft were
used for cloud tracking and sampling. On the day of the test, several radia-
tion intensities of 0.01 mR/hr net gamma were measured in the vicinity of the
junction of the Mercury turn-off and Highway 95. This area is unpopulated
beyond normal highway traffic. Monitors at Ash Meadows, Pahrump, Lathrop
Wells, Nevada and Shoshone, California observed no readings above background.
Charcoal cartridges from thirteen air sampling locations collected and analyzed
on the two days following the test showed no fresh fission products. Cartridges
sent in from stations outside the projected cloud path were also free of fresh
fission products. The maximum gross beta activity detected on an air filter
was 19 pCi/nr at Barstow, California; this sample was collected from 1345
hours, February 12, to 0850 hours, February 13.
The 21 gamma exposure rate recorders operating in the off-site area during
this time showed no evidence of activity above normal background levels. No
fresh fission products were detected in the three milk samples collected follow-
ing this test. The samples were collected at Lathrop Wells, Nevada and Barstow,
California on February 13. Thirty-six vegetation samples were collected from
thirty-three off-site locations. No fresh fission products were detected on
these samples. Other findings are indicated on the following form.
17
-------
Event Name, Type and Series ALPACA Shaft Whetstone
Date/Time, Size and Purpose 2/12/65, 0710 hr., <20 kt, weapons related
Release Characteristics Seep, southerly direction
Ci @ R + 12 hr 40,000
*Detectabl e Nevada, Cal i forni a
*Maximum Gamma Exposure Rate
Populated location: Not detected
Unpopulated location: 0.01 mR/hri Junction Hwy 95 and Mercury turn-off
^Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air 15 pCi/m3 of gross beta at Baker, CA,
and 19 pCi/m3 of gross beta at Barstow, CA
Milk No fresh fission products in samples from
Lathrop Wells and Barstow
Other No fresh fission products in vegetation
samples from 33 locations
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air Radioiodines not detected
Adult:
One-year-old child:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Radioiodines not detected
Adult:
One-year-old child:
Remarks: Event release occurred at H time for duration of 8.5 hours. Xe-133,
-135, -137, -138; 1-131, -133, -135; Sr-89, Rb-89, Kr-89, Cs-137,
and Cs-138 were detected by cloud sampling.
Release was primarily Cs-138.
*Reference: Interim Report of Off-Site Surveillance for the Alpaca event (SWRHL).
SWRHL-23r. Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory, from January through June, 1965.
July 1966.
18
-------
TEE TEST
This nuclear weapons effects test was conducted in Area 2, Nevada Test
Site, at 0847 PDT on May 7, 1965, in a vertical hole at a depth of 640 feet.
The explosive yield of the device was less than 20 kt.
A small release of radioactivity occurred through seepage around the SGZ
area. The airborne radioactivity was tracked to the south by aircraft to a
distance of about 35 miles from the test location (about 10 miles outside the
test site), where the cloud became so diffuse that further detection was not
possible. Analysis of the effluent in the cloud indicated the nuclides released
were primarily krypton, xenon, and cesium-138, with a small quantity of iodine
nuclides. Based upon calculations of the quantity of activity at R+12 hours,
it is estimated that 1570 Ci were released.
Ground monitoring was performed by 9 PHS personnel located in the down-
wind area. Exposure-rate recorders were operating at 21 locations around the
NTS but none showed any increase above background.
Gamma radiation exposure rates above background were detected by ground
monitors along Highway 95 from 4 miles west of the junction of Highway 95 and
the Mercury turn off to 11 miles east of the juction. The maximum reading of
0.04 mR/hr net gamma was observed 4 miles east of the Mercury turn-off on
Highway 95 at 1108 hours. Charcoal cartridges from 8 air samplers were analyzed
for specific gamma-emitting nuclides as were the prefilters from the two Las
Vegas stations. No fresh fission products were detected on these samples. The
maximum gross beta activity on a prefilter was 28 pCi/m3 taken from the sampler
located 4 miles east of the Mercury turn-off on Highway 95 (unpopulated). No
special milk or water samples were collected following this event. Other
findings are listed on the following form.
19
-------
Event Name, Type and Series TEE Shaft Whetstone
Date/Time, Size and Purpose 5/7/65, 0847 hr., <20 kt, weapons effects
Release Characteristics Seep, southerly direction, and drill back
Ci @ R + 12 hr 1,570, and <21 in drillback
*Detectabl e Nevada
*Maximum Gamma Exposure Rate
Populated location: Not detected
Unpopulated location: 0.04 mR/hr, 4 miles east of Mercury turn-off
on Hwy 95
*Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fi xed stati on:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air 28 pCi/m3 gross beta 4 miles east of Mercury
turn-off, Hwy 95
Milk Not collected.
Other 1-133 on sagebrush along Highway 95.
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air Radioiodines not detected
Adult:
One-year-old child:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk No milk collected
Adult:
One-year-old chi1d:
Remarks: Event release occurred at H + 1.2 min. for a duration of 108 hours.
Kryptons, xenons, Cs-138, and iodines were detected. Drillback
releases occurred at 1400 hours on 5/9/85 for a duration of 3 hours.
*Reference: SWRHL-23r, Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from January-June 1965, July 1966.
Interim Report of Off-Site Surveillance for the Tee event, (SWRHL)
20
-------
DILUTED WATERS TEST
This nuclear weapons effects test was conducted in Area 5, Nevada Test
Site, at 0930 PDT on June 16, 1965, in a vertical hole at a depth of 640 feet.
The explosive yield of the device was less than 20 kt.
Immediately following the detonation, radioactivity was released to the
atmosphere through a Line-Of-Sight (LOS) pipe experiment. The closure system
on the LOS pipe did not adequately seal, permitting gaseous radioactivity to be
released. Surface subsidence occurred at four minutes after the release
began and sealed off the release. It is estimated that 30 kCi of radioactive
effluent was released based on R+12 hour calculations.
The winds at the time of the release were toward the east but were light
and variable, hence the effluent cloud remained over the Nevada Test Site for
several hours. Ground monitoring was performed by 8 PHS personnel with 5
additional on standby. RM-11 exposure-rate recorder were operating in 21
locations. Air samplers were operating at 92 locations and milk was collected
from 14 locations. Only two net gamma readings were observed in the area off
the Nevada Test Site; these were both 0.02 mR/hr.
Charcoal cartridges from air samplers operating at Alamo, Hiko, and Ely,
Nevada were analyzed for specific gamma emitting isotopes. No fresh fission
products were detected on these cartridges. Gross beta counting of prefilters
showed no values in excess of normal fluctuations except for a slight rise in
the gross beta count on the filter from Nyala, Nevada. This sample, which was
collected between 0600 on June 16 to 0600 on June 17, contained 7.6 pCi/m^
gross beta. Filters collected at Nyala the day before and the day following
this sample showed normal levels of 1.6 and 2.7 pCi/m^ gross beta, respectively.
Some of the milk samples collected after this test contained iodine-131.
The highest concentration detected in milk was 130 pCi/L at Duckwater. None of
the shorter lived iodines (iodine-132 or 133) were found in these samples.
Milk samples collected at Hiko, Nevada on June 8, 1965 and prior to cloud
arrival on June 16, 1965, also contained detectable quantities of iodine-131.
Two events occurred prior to the Diluted Waters Test and were probably responsible
for the iodine-131 found in the milk samples collected for Diluted Waters. One
was the atmospheric detonation of a nuclear device on the Chinese mainland on
May 14, 1965; the other was test runs of a nuclear rocket engine (not an
explosion), at the Nuclear Rocket Development Station on May 20, 1965. The
radioiodine found in milk samples collected subsequent to the Diluted Waters
Test is probably the result of all three events and it is not possible to
assess the exact contribution of any one source. Specific findings are listed
on the following form,
21
-------
Event Name, Type and Series DILUTED WATERS Shaft Whetstone
Date/Time, Size and Purpose 6/16/65, 0930 hr., <20 kt, weapons effects
Release Characteristics Prompt venting, northeasterly to Hwy 25
Ci @ R + 12 hr 30,000
*Detectable Nevada, Utah
^Maximum Gamma Exposure Rate
Populated location: Not detectable
Unpopulated location: 0.02 mR/hr just off NTS NE boundary
*Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air 7.6 pCi/m3 gross beta at Nyala, NV collected
from 0600 6/16 to 0600 6/17
Milk 130 pCi/L of 1-131 at Duckwater (see remarks)
Other Short-lived radioiodines in vegetation from
Alamo, Currant, and along Highway 25
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air Not detected in air
Adult:
One-year-old child:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult: 2 mrem
One-year-old child: 15 mrem
Remarks: Two events occurred prior to DILUTED WATERS that were probably
responsible for 1-131 found in milk samples during the period. One
was a detonation of a nuclear device on the Chinese mainland on May
14, 1965; the other was a test of nuclear rocket engines at NRDS on
May 20, 1965.
*Reference: SWRHL-23r, Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from January-June 1965, July 1966.
Interim Report of Off-Site Surveillance for the Diluted Waters
event, (SWRHL).
22
-------
RED HOT TEST
This nuclear weapons effects test was conducted in Area 12, Nevada Test
Site, at 1015 PST on March 5, 1966, in a tunnel at a depth of 1330 feet. The
explosive yield of the device was less than 20 kt.
About 7 minutes after the detonation, radioactivity emanated from the
tunnel portal and continued to seep to the atmosphere for several days. The
best estimate of the amount of radionuclides released as of R+12 hours was
1000 kCi. The data indicate that the majority of this effluent was krypton and
xenon with some radioiodines.
Off-site tracking of the effluent cloud to the north and east was done by
aircraft. From this aircraft tracking data, an estimated cloud path was devel-
oped. At a location over eastern Iowa, the concentrations of airborne radio-
activity became so low and the cloud so diffused that further identification
was impossible. Although the random movement of the effluent cloud was tracked
for over 2,000 miles within the U.S., detectable levels of radioactivity were
not deposited on the ground outside the immediate vicinity of the test site.
Ground monitoring was performed by 12 PHS personnel, and 17 RM-11 exposure-
rate recorders were operating at locations around the NTS. Exposures above
background were not detected by either of these monitoring procedures. Air
samplers were operating at 106 locations and samples of milk were collected
from 6 locations, surface water from 3 locations, and 27 vegetation samples
from 24 locations.
The analysis of milk samples collected at off-site locations gave no
indication of iodine-131, or any other fresh fission products. Air sampling
data indicated 81 pCi/m3 of 1-133 and 19 pCi/m3 of 1-131 at Lathrop Wells;
and 80 pCi/m3 of 1-135 at Highway 6, 18 miles west of Clark station.
Although the total quantity of radioactivity inadvertently released to the
atmosphere was larger than for any of the previous tests discussed here, the
nature of the release (principally xenon and krypton nuclides) led to no
significant radiation exposure to the general population. Other data are
listed on the following form.
23
-------
Event Name, Type and Series RED HOT Tunnel Flintlock
Date/Time, Size and Purpose 3/5/66, 1015 hr., <20 kt, weapons effects
Release Characteristics Prompt massive seep, northeasterly
Ci @ R + 12 hr 1,001,100
*Detectable Nevada, Idaho, Wyoming, and California
*Maximum Gamma Exposure Rate None detected
Populated location:
Unpopulated location:
^Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air 81 pCi/m3 of 1-133 in air at Lathrop Wells, NV
19 pCi/m3 of 1-131 in air at Lathrop Wells, NV
80 pCi/m3 of 1-135 in air 18 mi west of
Clark Station, NV, on HWY 6
0.69 pCi/m3 gross beta at Elko, NV
Milk No fresh fission products detected
Other 1-131 and -133 in vegetation from
Battle Mountain, NV
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: 1.5 mrem (all isotopes)
One-year-old child: No children
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Not detected in milk
Adult:
One-year-old child:
Remarks: Two releases: uncontrolled but filtered release from H + 7 to H +
110 m1n. The filter system became non-functional and an uncontrolled
release continued until H + 20 hours. Portal seepage, low level,
continued for several days. Release was predominantly noble gases
but included 2000 Ci of 1-135, 500 Ci of 1-133, and 20 Ci of 1-131,
calculated at zero time.
*Reference:Interim Report of Off-Site Surveillance for the Red Hot Event,
(SWRHL).
SWRHL-37r. Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from January through June 1966.
Jan. 1970.
24
-------
FENTON TEST
This nuclear weapons related test was conducted in Area 2, Nevada Test
Site, at 0656 PST on April 23, 1966, in a vertical hole at a depth of 550 feet.
The explosive yield of the device was less than 20 kt.
Seepage occurred from the SGZ area soon after detonation and continued
for a few minutes. The amount released, corrected to R+12 hr, was estimated
to be 17.3 kCi, mostly radioactive noble gases. Wind direction was predomin-
antly toward the south.
For this event, air samplers were operating at 104 routine stations in
the off-site area. Stationary dose rate recorders were operating at 24 off-
site locations. Thirteen Public Health Service personnel were on duty for
surveillance activities for the event, and aerial monitoring was performed
by the PHS cloud tracking team in a U3-A aircraft.
No radioactivity above normal background levels was detected off site
by ground and aerial monitoring teams, by stationary dose rate recorders, or
in any environmental samples either after the detonation or during the sub-
sequent sample recovery operations. No fresh fission products were detected in
any environmental sample collected off site throughout this period, and no
prefilter air samples contained levels of gross beta activity above normal
background.
It was concluded that no radioactive contamination of the off-site area
resulted from this event. (NOTE: see remarks on following form).
25
-------
Event Name, Type and Series FENTON Shaft Flintlock
Date/Time, Size and Purpose 4/23/66, 0656 hr., <20 kt, weapons related
Release Characteristics Seepage
Ci @ R + 12 hr 17,300
*Detectable Ai rcraft only SSW of NTS
^Maximum Gamma Exposure Rate None detected
Populated location:
Unpopulated location:
^Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fi xed stati on:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air Not detected
Milk Not detected
Other Vegetation not detected.
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: Not calculated
One-year-old child: Not calculated
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult: Not calculated
One-year-old child: Not calculated
Remarks: Activity detected by NATS aircraft near Baker, California.
Radioactivity was not detected by any ground monitoring instrument.
*Reference: Interim Report of Off-Site Surveillance for the Fenton Event
(SWRHL).
26
-------
PIN STRIPE TEST
This nuclear weapons related test was conducted in Area 11, Nevada Test
Site, at 1138 PDT on April 25, 1966, in a vertical hole at a depth of 970 feet.
The explosive yield of the device was less than 20 kt.
A release of radioactivity occurred through a small fissure that opened
at the time of detonation. The radioactivity in this release was identified as
primarily gaseous nuclides of xenon, krypton and iodine. The estimated amount
of radioactivity released and remaining at R+12 hours was 220 kCi.
The airborne effluent cloud moved off the Test Site to the east. Aircraft
tracked it to the eastern part of Kansas and Nebraska where the sensitive
instruments in the aircraft could no longer detect radioactivity.
While most of the radioactivity was deposited within the Nevada Test Site,
some low levels were measured by ground monitors in unpopulated locations off
the test site. On a road 18 miles northeast of Groom Lake a gamma reading of 8
mR/hr was measured. The farthest that ground level gamma radiation was detected
was near Pioche, Nevada at a level of 0.09 mR/hr. The highest external gamma
exposure rate recorded in a populated location was at Hiko, Nevada, at 1.5
mR/hr. Estimated infinite whole-body exposure at this location was about 12 mR.
•
Air concentrations of iodine nuclides collected on an air filter at Hiko,
Nevada, were documented as: 550 pCi/m3 iodine-131, 800 pCi/m3 iodine-133,
5,000 pCi/m3 iodine-135, and 2,200 pCi/m3 iodine-132. The highest gross beta
air activity level in an off-site populated area was at Ash Springs, Nevada with
a value of 25,000 pCi/nr averaged over a period of 3 hours.
The highest value of radioiodine in milk was 4.8 nanocuries per liter of
iodine-131 in a sample collected at Hiko, Nevada. This is less than one-tenth
of the Federal Radiation Council's guide for protective actions. Although the
amount of iodine-131 present was only a small fraction of the FRC's Protective
Action Guide, as a precautionary measure to avoid unnecessary exposures, the
cows were placed on uncontaminated dry feed since it was readily available.
The amount of iodine-131 in milk dropped from 4.8 nCi/L to 0.14 nCi/L in four
days. The maximum concentration outside Nevada was 0.06 nCi/L in milk from
Spanish Fork, Utah and 0.07 nCi/L in milk from Idaho Falls, Idaho.
The actual amount of iodine-131 in human thyroids was determined through
use of a mobile thyroid counter on 70 children and 8 adults living in those
areas of Nevada which had the highest iodine-131 activity in milk. The thyroid
dose estimates were: for 2 persons, 150 to 300 mrad; for 14 persons, 50 to 150
mrad; for 37 persons, between 0 and 50 mrad; and no detectable activity in 25.
A small additional dose could have resulted from milk intake following the
thyroid measurement. These estimates are considerably less than the Federal
Radiation Council's recommendation of 1500 mrad to the thyroid of an individual
in the population. A summary of these data is shown on the following form.
27
-------
Event Name, Type and Series PINSTRIPE Shaft Flintlock
Date/Time, Size and Purpose 4/25/66, 1138 hr., <20 kt, weapons related
Release Characteristics Prompt massive venting, northeasterly
Ci @ R + 12 hr 220,000
*Detectable Nevada, Utah, California, Colorado, Kansas, Nebraska
*Maximum Gamma Exposure Rate
Populated location: 1.5 mR/hr Hiko, NV
Unpopulated location: 8 mR/hr 18 mi NE of Groom Lake
*Maximum External Gamma Exposure: 12 mR Hiko, NV
*Maximum TLD/Film Badge Exposure:
Fixed station: 30 mR Hancock Summit, NV (questionable)
Personnel: Not detectable on film badge
*Maximum Radionuclide Concentra-
tions in sampling media:
Air 50,000 pCi/m3 Gross beta at 6.5 miles W. of
Hancock Summit
5,430 pCi/m3 1-131 at Ash Springs
40,600 pCi/m3 1-132 at 18 mi. NE of Groom Lake
12,880 pCi/m3 1-133 at 18 mi. NE of Groom Lake
94,000 pCi/m3 1-135 at 18 mi. NE of Groom Lake
Milk 4800 pCi/L 1-131 at Schofield Dairy at Hiko
12000 pCi/L 1-133 at Schofield Dairy at Hiko
85 pCi/L Cs-137 at Charlton Rn, Caliente
Other 151 pCi/L Gross Beta, 1.4 pCi/L Gross Alpha,
3860 pCi/L 1-131, 80 pCi/L 1-132, 270
pCi/L 1-133 in surface water at Hiko
Fresh fission products were detected in
95 of 571 vegetation samples.
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: 14.4 mrem, Hiko, calculated
One-year-old child: 47 mrem, Hiko, calculated
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult: <300 mrad as measured by thyroid counting of
One-year-old child:.. 8 adults and 70 children from Hiko and Alamo.
(maximum of 572 mrad was calculated)
Remarks: Maximum outside NV was 70 pCi/L in milk from Idaho Falls, Idaho.
Winds shifted 180° by 4/27. Gross fission products released through
fissure, primarily gaseous xenons, kryptons, and iodines.
*Reference: SWRHL 59r, Final Report of Off-Site Surveillance for the Pin Stripe
Event, Feb. 1972.
28
-------
DOUBLE PLAY TEST
This nuclear weapons effects test was conducted in Area 16, Nevada Test
Site, at 1000 PDT on June 15, 1966, in a tunnel at a depth of 1075 feet. The
explosive yield of the device was less than 20 kt.
Immediately following the detonation radioactivity was released through
the tunnel portal to the atmosphere. An estimate of the amount of radioactivity
released as of R+12 hours was 826 kCi. Aircraft tracking of the radioactive
effluent cloud indicated a trajectory to the northeast. At a distance of about
200 miles from the test site the airborne cloud became so diffuse that further
identification of airborne radioactivity became impossible.
Ground monitoring was performed by 13 PHS personnel and RM-11 exposure-
rate recorders were in operation around the NTS. Air samplers were operating
at 103 off-site locations and milk and vegetation samples were collected in the
downwind area.
Thirty-three air samples, one water sample, four milk samples and eighteen
vegetation samples were collected in the off-site downwind area. These samples
indicated no fresh fission products except for air samples collected at Alamo and
Hiko, Nevada. Neither the ground monitors nor the exposure-rate recorders
detected an increase above the natural background radiation levels. Other data
on this test are listed on the following form.
29
-------
Event Name, Type and Series DOUBLE PLAY Tunnel Flintlock
Date/Time, Size and Purpose 6/15/66, 1000 hr., <20 kt, weapons effects
Release Characteristics Prompt massive seep
Ci @ R + 12 hr 826,000
*Detectable Nevada, northeasterly for about 200 miles
^Maximum Gamma Exposure Rate None detectable
Populated location:
Unpopulated location:
^Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fi xed stati on:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media: pCi/m3
"mi TT33 TT33 Gross Beta
Air Hiko 1.9 1.2 5.6 0.83
Milk Not detected
Other Water and vegetation, not detected.
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: 0.032 mrem
One-year-old child: 0.083 mrem
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Not detected in milk
Adult:
One-year-old child:
Remarks: Four releases: cable hole seepage, partial leakage, filtered
controlled purging, and drill back release on 8/2/66.
*Reference: Interim Report of Off-Site Surveillance for the Double Play
Event of June 15, 1966; (SWRHL).
SWRHL-37r. Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from January through June 1966.
Jan. 1970.
30
-------
DERRINGER TEST
This nuclear weapons effects test was conducted in Area 5, Nevada Test
Site, at 0830 PDT on September 12, 1966, in a vertical hole at a depth of 835
feet. The explosive yield of the device was less than 20 kt.
A seepage of radioactive material occurred immediately after detonation.
This release occurred because the closure mechanism on a Line-Of-Sight (LOS)
pipe failed to function properly. An estimate of the radioactivity released to
the atmosphere and remaining at R+12 hours was 12 kCi. Sampling by aircraft
indicated the radioactive cloud was composed of gaseous nuclides of krypton and
xenon. At a distance of about 150 miles northeast of the test location, the
radioactivity became so diffuse that it was no longer detectable.
Ground monitoring was performed by 15 PHS personnel and RM-11 exposure-
rate recorders were operating at 20 locations around the NTS. Air samplers
were in operation at 108 locations in the western U.S. and milk samples were
collected routinely at about 30 locations.
In the off-site area, milk samples collected on September 13 and 15 at
Alamo, Hiko and Nyala gave no indication of fresh fission products. Thirty
air samples and nine vegetation samples contained no radioactivity above back-
ground. Two positive ground monitoring readings were recorded of less than
twice background in off-site unpopulated locations. These were at Hancock
Summit and 10 miles southeast of Coyote Summit. None of the RM-11 recorders
indicated an exposure above background. Other findings are listed on the
following form.
31
-------
Event Name, Type, and Series DERRINGER Shaft Latchkey
Date/Time, Size and Purpose 9/12/66, 0830 hr., <20 kt, weapons effects
Release Characteristics.. Prompt seep, tracked NE for about 150 mi.
Ci @ R + 12 hr 12,000
*Detectabl e Nevada
*Maximum Gamma Exposure Rate
Populated location: None detected
Unpopulated location: 0.03 mR/hr, Hancock Smt. and 10 mi SE of
Coyote Smt.
*Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on film badge
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air No fresh fission products detected
• '
Milk No fresh fission products detected at Alamo,
Hiko and Nyala
Other Vegetation, no fresh fission products
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: Radioiodines not detected
One-year-old child:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult: Radioiodines not detected
One-year-old child:
Remarks: Effluent contained noble gases and radioiodines (152 Ci of 1-135,
41 Ci of 1-133, and 1.5 Ci of 1-131) at time of release.
*Reference: Interim Report of Off-Site Surveillance for the Derringer Event,
(SWRHL).
SWRHL-38r. Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory July through December 1966.
Dec. 1968.
32
-------
NASH TEST
This nuclear weapons related test was conducted in Area 2, Nevada Test
Site, at 0845 PST on January 19, 1967, in a vertical hole at a depth of 1200
feet. The explosive yield of the device was 20 to 200 kt.
About twelve hours after the detonation, low levels of radiation were
detected near the SGZ. This seepage of gaseous radionuclides continued, at a
diminishing rate, for a period of two days. An estimate of the total radio-
activity released, based upon calculations of R+12 hour debris, was 69 kCi.
Analysis of this gaseous release indicated nuclides of xenon with a small
quantity of krypton-88. The radioactive cloud associated with this seepage was
tracked by aircraft to the southwest of the test site. Within a few miles off
the NTS, the tracking aircraft could no longer detect the very low levels of
radioactivity and all airborne contact with the cloud was lost.
Ground monitoring was performed by 17 PHS personnel and RM-11 exposure-
rate recorders were operating at 25 locations in the off-site area. Of the
103 air sampling stations, 40 were operating in Nevada.
Ground monitors detected slight increases above background from 20 mi
west of Mercury turn-off to 14 mi northwest of Lathrop Wells, Nevada. The
maximum was 0.14 mR/hr above the normal background fluctuation. It should be
noted that prior to this test small fluctuations above normal had been noted in
the area around the NTS as well as the entire southwestern U.S. These fluctua-
tions were caused by radioactive debris from the atmospheric nuclear test
conducted on the Chinese mainland on December 27, 1966.
Air filters and milk samples collected in the off-site areas showed no
fresh fission products above the fluctuating low levels that had previously
been identified as debris from a foreign atmospheric nuclear test. Other data
are listed on the following form.
33
-------
Event Name, Type and Series NASH Shaft Latchkey
Date/Time, Size and Purpose 1/19/67, 0845 hr., 20 to 200 kt, weapons related
Release Characteristics Seep, starting H+12 hrs., tracked to SW
Ci 0 R + 12 hr 69,000
*Detectable Nevada, California
*Maximum Gamma Exposure Rate
Populated location: 0.01 mR/hr, Diablo Maintenance Sta. on 1/20
Unpopulated location: 0.14 mR/hr 21 mi W. of Mercury turnoff on
Hwy 95 on 1/19
*Maximum External Gamma Exposure: 5 RT = 1.2 mR
*Maximum TLD/Film Badge Exposure: No film collected immediately following event
Fi xed stati on:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air Not detectable above world-wide fallout
Milk Not detectable above world-wide fallout
Other Not detectable above world-wide fallout
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air No radioiodines detected
Adult:
One-year-old chiId:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk No radioiodines detected
Adult:
One-year-old child:
Remarks: Iodine-131 was detected but no short-lived radioiodines, assumed to
be from a nuclear test on the Chinese mainland on 12/27/66.
*Reference: Interim Report of Off-Site Surveillance for the Nash Event, (SWRHL).
SWRHL-47r, Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from January-June 1967, March 1970.
34
-------
UMBER TEST
This nuclear weapons effects test was conducted in Area 3, Nevada Test
Site, at 0425 PDT on June 29, 1967, in a vertical hole at a depth of 1020 feet.
The explosive yield of the device was less than 20 kt.
Radioactivity was released to the atmosphere at the time of detonation
through the LOS pipe which, as a result of the ground shock at shot time, was
broken below the closure mechanism, thus, permitting seepage of radioactive
gases through the soil to the surface. The best estimate of the quantity of
gaseous nuclides released and remaining at R+12 hours was 26 kCi. The radio-
active cloud was tracked to the south southwest by aircraft. At a distance of
about 90 to 100 miles from the point of release, the airborne radioactivity
became so diffuse that the sensitive instruments in the aircraft could no
longer detect it.
Ground monitoring was performed by 12 PHS personnel stationed downwind
of the test and RM-11 exposure-rate recorders were operating at 26 locations
around the NTS. Air samplers were operating at 107 locations, 36 in Nevada,
and 3 extra air samplers were placed downwind of the test.
The maximum net gamma radiation exposure rate observed was 0.7 mR/hr at
the junction of Highway 95 and State Road 16 (Ash Meadows turn-off) at 0700
hours. Charcoal cartridges from air samplers located at Death Valley Junction,
California, Lathrop Wells, Nevada, and ten miles east of Lathrop Wells showed
small quantities (less than 90 pCi/m3) of iodine-133 plus iodine-135. No
iodine-131 was detected. The gamma exposure rate recorders at Death Valley
Junction and Shoshone, California, showed a slight rise above normal background
fluctuations. No fresh fission products were detected in milk, water, or
vegetation samples. Specific data are shown on the following form.
35
-------
Event Name, Type and Series UMBER Shaft Latchkey
Date/Time, Size and Purpose 6/29/67, 0425 hr., <20 kt, weapons effects
Release Characteristics Prompt venting southwesterly, tracked by
aircraft for 90-100 miles.
Ci @ R + 12 hr 26,000
*Detectable Nevada, California
*Maximum Gamma Exposure Rate
Populated location: 0.1 mR/hr, Death Valley Jet and Shoshone, CA
Unpopulated location: 0.7 mR/hr, Ash Meadows turn-off, Jet of
Hwys 95 and 16 in Nevada
*Maximum External Gamma Exposure: 0.06 mR, Death Valley Jet and Shoshone
*Maximum TLD/Film Badge Exposure: Not detectable on badges
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
0.25 pCi/m3 gross beta 10 mi E. of
Lathrop Wells
Air 8.0 pCi/m3 1-133 10 mi E. of Lathrop Wells
80 pCi/m3 1-135 10 mi E. of Lathrop Wells
Milk No fresh fission products detected
in 60 samples.
Other No fresh fission products detected on 51
vegetation or in surface water samples
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: 0.008 mrem
One-year-old child: 0.052 mrem
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Not detected in milk
Adult:
One-year-old child:
Remarks: No iodine-131 detected on any sample
*Reference: Interim Report of Off-Site Surveillance for the Umber Event,
(SWRHL).
SWRHL-47r, Off-Site Surveillance Activities of the Southweastern
Radiological Health Laboratory from January-June 1967, Mar. 1970.
36
-------
DOOR MIST TEST
This nuclear weapons effects test was conducted in Area 12, Nevada Test
Site, at 0930 PDT on August 31, 1967, in a tunnel at a depth of 1465 feet. The
explosive yield of the device was less than 20 kt.
About 55 minutes after the detonation a seepage of radioactivity from the
tunnel portal occurred. The calculated quantity of radioactivity accidentally
released to the atmosphere and remaining at R+12 hours was 50 kCi. Gamma-ray
spectra of the emission showed that the release was composed of gaseous nuclides,
primarily krypton-88, iodine-135, and xenon-135. An additional 690 kCi was
released through filters over the next 3 days.
Aircraft tracking of the radioactive effluent cloud off the Nevada Test
Site, to the north, indicated only sporadic and discontinuous contact with the
airborne effluent. The cloud became so diffuse that detection, using very
sensitive radiation detection instruments in the aircraft, was completely lost
at a distance of about 60 miles from SGZ.
Ground monitoring was performed by 11 PHS personnel stationed in the
downwind area and RM-11 exposure-rate recorders were operating at 27 locations
around the NTS.
Analysis of air filters collected at ground locations off site revealed
only one filter containing fresh fission products. This was at Diablo, Nevada.
Levels of 2 pCi/nr of iodine-133 and -135 were recorded. There was no iodine-
131 detected in off-site air filters or on vegetation samples collected in
several off-site locations.
The highest off-site net gamma radiation level detected by ground monitor-
ing was at Clarks Station, Nevada, where 0.003 mR/hr was recorded on a scintil-
lator while the RM-11 at Diablo, Nevada recorded a peak level of 0.01 mR/hr.
No radioactivity was detected in milk or vegetation samples. Specific data are
listed on the following form.
37
-------
Event Name, Type and Series DOOR MIST Tunnel Crosstie
Date/Time, Size and Purpose 8/31/67, 0930 hr., <20 kt, weapons effects
Release Characteristics Prompt release followed by tunnel ventilation
Ci @ R + 12 hr 50,000 then 690,000
*Detectable Nevada; northerly; tracked by aircraft for
about 60 miles
*Maximum Gamma Exposure Rate
Populated location: 0.01 mR/hr, Diablo, NV
Unpopulated location: 0.003 mR/hr, darks Station
*Maximum External Gamma Exposure: Less than 1 mR
*Maximum TLD/Film Badge Exposure: Not collected immediately after event
Fi xed stati on:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air 0.08 pCi/m3 gross beta at Diablo, NV
2 pCi/m3 1-133 at Diablo, NV
2.3 pCi/m3 1-135 at Diablo, NV
Milk No fresh fission products detected
Other No fresh fission products on 43 vegetation
samples
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: 0.02 mrem
One-year-old child: 0.05 mrem
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Not detected in milk
Adult:
One-year-old child:
Remarks: Release was primarily Kr-88, 1-135, and Xe-135.
*Reference: SWRHL-64r, Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from July-December 1967, May 1970.
Interim Report of Off-Site Surveillance for the Door Mist Event,
(SWRHL).
38
-------
HUPMOBILE TEST
This nuclear weapons effects test was conducted in Area 2, Nevada Test
Site, at 0830 PST on January 18, 1968, in a vertical hole at a depth of 810
feet. The explosive yield of the device was 7.4 kt.
Less than 2 minutes after the detonation, radioactivity was released to
the atmosphere through a LOS pipe which did not properly close, however, this
release was stopped about 20 minutes later when the surface collapse occurred.
The calculated quantity of radioactivity released as of R+12 hours was 120 kCi.
Analysis of air samples taken near the area where the release occurred, indi-
cated the presence of volatile gases only.
The airborne radioactive effluent was carried to the southwest. Aircraft
tracking the effluent cloud lost contact over the southern portion of Death
Valley in California and were unable to detect airborne radioactivity past that
location.
Ground monitoring was performed by 10 PHS personnel stationed in the
downwind area and RM-11 exposure-rate recorders were operating at 28 locations
around the NTS. Air samplers were operating at 111 stations including about
40 in Nevada.
The maximum observed ground monitoring reading was 0.7 mR/hr gross gamma
at 1145 hours 4 miles west of Lathrop Wells on Highway 95, and at Dansby s
Ranch at 1200 hours. The maximum air activity level detected on a filter was
at Dansby's Ranch in the Amargosa Farm area about 50 miles south of the Nevada
Test Site. Levels of 9000 pCi/m3 gross beta, 83 pCi/nr of iodine-133 and
1600 pCi/nH of iodine-135, were detected in an air sample collected between
0935 and 1745 hours on January 18, 1968. Fresh fission products were found in
air samples at 7 other locations southwest of the NTS.
Dosimeters placed at several locations downwind recorded no gamma exposures
above natural background. Of the 45 milk samples collected from 16 stations,
only 3 stations showed fresh fission products in 4 samples. These samples were
collected at three ranches in the Amargosa Farm area. The maximum iodine-131
concentration in milk was 110 pCi/L. Also, fresh fission products were detected
in 18 of 46 vegetation samples in the Beatty to Lathrop Wells area. Specific
data are shown on the following form.
39
-------
Event Name, Type and Series HUPMOBILE Shaft Crosstie
Date/Time, Size and Purpose 1/18/68, 0830 hr., 7.4 kt, weapons effects
Release Characteristics Prompt massive venting, southwesterly;
tracked to Death Valley, CA
Ci 0 R + 12 hr 120,000
*Detectable Nevada, California.
*Maximum Gamma Exposure Rate
Populated location: 0.7 mR/hr, Dansby's Ranch
Unpopulated location: 0.7 mR/hr, 4 mi west of Lathrop Wells
*Maximum External Gamma Exposure: Less than 2 mR
*Maximum TLD/Film Badge Exposure: Not collected immediately after event
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media: 9,000 pCi/m3 gross beta at Dansby's Ranch
1 pCi/m3 1-131 at Shoshone
Air 83 pCi/m3 1-133 at Dansby's Ranch
1,600 pCi/m3 1-135 at Dansby's Ranch
84 pCi/m3 Ce-141 at Dansby's Ranch
260 pCi/m3 Te-132 at Dansby's Ranch
Milk 110 pCi/L 1-133 in milk at Hord Ranch,
Lathrop Wells.
30 pCi/L 1-131 in milk at Rooker Ranch,
Lathrop Wells.
Other Fission products detected in a water sample,
from stock tank, at Rooker Ranch; 1-131 in
cow feed was 480 pCi/kg. Fresh fission
products in vegetation from Lathrop Wells,
Death Valley and Ridgecrest, CA.
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: 0.36 mrem
One-year-old child: 4.0 mrem
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult: 0.04 mrem
One-year-old child: 0.67 mrem
Remarks: Release occurred at H + 1.6 min. and continued for about 20 min.
Isotopes detected were: 1-131, -133, -134, -135; Xe-133, -135;
Kr-87, -88; Rb-88. Other radionuclides indicated above.
*Reference: Interim Report of Off-Site Surveillance for the Hupmobile Event,
(SWRHL).
SWRHL-81r, Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from January-June, 1968; Jan. 1972,
40
-------
POD TEST
This nuclear weapons related test was conducted in Area 2, Nevada Test
Site, at 1200 PST on October 29, 1969, in a vertical hole at a depth of 1000
feet. The explosive yield of the device was 20 to 200 kt.
Release started at H + 1 minute at SGZ and lasted for 9 minutes. It is
estimated that 3.9 kCi were released, calculated at R+12 hours. The cloud was
tracked by aircraft to the south of the test site to a distance of about 35
miles from SGZ where the cloud became so diffuse that detection of airborne
radioactivity was no longer possible. The radionuclides identified were the
nuclides of iodine and xenon, and cesium-138.
Ground monitoring was performed by 12 PHS personnel in downwind locations
and RM-11 exposure-rate recorders were operating at 30 locations around the
NTS. Air samplers were operating at 99 locations in the western U.S.
The maximum levels of radioactivity measured by ground monitors off the
Nevada Test Site were reported to be two to three times background radiation or
about 0.06 mR/hr at Lathrop Wells and 10 miles west of Highway 95/16 Junction.
All samples of milk, water, vegetation and air filters analyzed showed no
radioactivity due to fresh fission products. Specific data are shown on the
following form.
41
-------
Event Name, Type and Series POD Shaft Mandrel
Date/Time, Size and Purpose 10/29/69, 1200 hr., 20 to 200 kt, weapons related
Release Characteristics Seep, southerly, tracked by aircraft for
35 miles.
Ci 0 R + 12 hr 3,900
*Detectabl e Nevada
*Maximum Gamma Exposure Rate
Populated location: 0.04 mR/hr net at Lathrop Wells
Unpopulated location: 0.02 mR/hr on Hwy 95, 10 miles west of
junction with Hwy 16
*Maximum External Gamma Exposure: <0.1 mR at Lathrop Wells
*Maximum TLD/Film Badge Exposure: Not detectable on TLD
Fi xed stati on:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air No.fresh fission products detected
Mi 1k 15 mi 1k samples: non-detectable
Other No fresh fission products in vegetation samples
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: Radioiodines not detected
One-year-old chi1d:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Radioiodines not detected
Adult:
One-year-old chiId:
Remarks: Event release at H + 1 min. for duration of 9 min. Detected were:
1-131, -133, -135; Xe-133, -135, Cs-138. Drillback releases at 1000
hours 1 Nov. 69 for 1 hr and 0010 hours 7 Nov. 69 for 20 min (Xe-133).
*Reference: SWRHL-98r, Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from July through December, 1969;
Feb. 1971.
42
-------
SCUTTLE TEST
This nuclear weapons related test was conducted in Area 2, Nevada Test
Site, at 0715 PST on November 13, 1969, in a vertical hole at a depth of 541
feet. The explosive yield of the device was less than 20 kt.
Seepage from the SGZ area began about 5 minutes after detonation. The
release was estimated as 210 Ci corrected to R+12 hr and was drifting southward.
For this event, air samplers were operating at 99 routine stations in
the off-site area, and 12 Public Health Service (PHS) personnel were on duty
for surveillance activities. Aerial monitoring was performed by a PHS cloud
tracking team in a U3-B USAF aircraft. One PHS Turbo-Beech aircraft was air-
borne at the Nevada Test Site for cloud sampling and tracking. Another PHS
Turbo-Beech aircraft was used for cloud sampling and to supplement cloud
tracking as needed.
Following the event, no radioactivity above normal background levels was
detected off site by ground or aerial monitoring teams or by stationary gamma
rate recorders. No event-related activity was detected in any environmental
sample collected off site after the detonation, and no air particulate samples
contained gross beta activity above normal background levels.
By 0850 the aircraft returned to Indian Springs. Since the radioactive
cloud was still moving toward 220° (southwest), it is assumed activity could
have been detectable by aerial monitoring off site if such monitoring had
continued for several more hours. Other data for this test are indicated on
the following form.
43
-------
Event Name, Type and Series SCUTTLE Shaft Mandrel
Date/Time, Size and Purpose 11/13/69, 0715 hr., <20 kt, weapons related
Release Characteristics seep
Ci @ R + 12 hr 210
*Detectable Aircraft only, south of NTS
^Maximum Gamma Exposure Rate: Not detected
Populated location:
Unpopulated location:
*Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on TLD
Fi xed stati on:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Ai r Not detected
Milk Not detected
Other None collected
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air Radioiodine not detected
Adult:
One-year-old child:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Radioiodine not detected
Adult:
One-year-old chi1d:
Remarks: Cloud sampling detected radioactive noble gases and Cs-138.
*Reference: Interim Report of Off-Site Surveillance for the Scuttle Event
(SWRHL).
44
-------
SNUBBER TEST
This nuclear weapons effects test was conducted in Area 3, Nevada Test
Site, at 0630 PST on April 21, 1970, in a vertical hole at a depth of 1125
feet. The explosive yield of the device was less than 20 kt.
Gaseous radioactivity seeped to the atmosphere through the stemming
material in the emplacement shaft. It is estimated that about 55 kCi of
activity calculated at R+12 were released. The radioactive effluent cloud was
tracked to the northeast by aircraft to a location about 90 miles from the
surface ground zero, where bad weather conditions were encountered requiring
termination of aerial tracking.
Ground monitoring was performed by 21 PHS personnel positioned downwind
of the test. Air samplers were operating at 102 locations in the western
U.S., including 49 in Nevada, and RM-11 exposure-rate recorders were in
operation at 32 locations. About 25 milk samples and 90 water samples were
analyzed monthly.
On the ground the radioactivity was detected off site by monitors south-
west of Highway 25 on Valley Road and along Highway 25 from 12 miles northwest
of Coyote Summit to 9 miles southeast of Coyote Summit. The maximum off-site
reading was at Coyote Summit. Levels at this location increased above back-
ground at 0920 hours, peaked at 0945 hours (0.6 mR/hr) and returned to back-
ground at 1025 hours. The net gamma exposure from the integration of these
readings with time at this location was 0.15 mR. No radiation levels were
detected by thermoluminescent dosimeters (TLD's).
The effluent trajectory predictions of the Weather Bureau indicated that
the cloud turned near Lund and Ely, Nevada, during the afternoon of April 21
and travelled over the southwestern corner of Utah into the Grand Canyon area.
Environmental monitoring and sampling along this trajectory on April 21, and 22
found no detectable event-related activity in milk, vegetation, or soil samples.
The only environmental samples containing test-related radioactivity were
snow samples at two locations and air filters obtained at nine different
locations. One snow sample collected at Sunnyside contained 500 pCi/L iodine-
133 and 690 pCi/L iodine-135; and the other, 45 miles north of Hiko on Highway
38, contained 140 pCi/L iodine-133. The maximum air concentration detected
at a populated location was at Koyne's Mill, Nevada, where 36 pCi/m-* of iodine-
133 and 86 pCi/nr* of iodine-135 were measured. Air filters from Nyala, Lund,
Sunnyside, Currant and Ely, Nevada indicated lesser quantities of radioiodine
nuclides during cloud passage. Other data are indicated on the following form.
45
-------
Event Name, Type and Series ..... SNUBBER Shaft Mandrel
Date/Time, Size and Purpose ..... 4/21/70, 0630 hr., <20 kt, weapons effects
Release Characteristics ......... Seep, northeasterly, tracked for 90 miles
Ci @ R + 12 hr ................ 54,800
*Detectabl e ...................... Nevada , Ari zona
*Maximum Gamma Exposure Rate
Populated location:.. ...... Not detected
Unpopulated location: ...... 0.6 mR/hr at Coyote Summit on Hwy 25
*Maximum External Gamma Exposure: 0.15 mR at Coyote Summit
*Maximum TLD/Film Badge Exposure: Not detectable on TLD
Fi xed stati on : .............
Personnel : .................
*Maximum Radionuclide Concentra-
tions in sampling media:
Air ........................ 6 pCi/m-3 gross beta, Coyote Summit
87 pCi/m3 1-133, Coyote Summit
300 pCi/m3 1-135, Coyote Summit
Milk ....................... No fresh fission products in 81 milk samples
from Nevada, Utah and Arizona.
Ci/L of water
pC
Snow 1-133
Other ...................... Sunnyside, NV 500 690
No fresh fission products in vegetation
collected in Nevada, Utah and Arizona.
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: ..................... 0.076 mrem, Kayne's Mill
One-year-old child: ........ None present
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Radioiodines not detected in milk
Adult: .....................
One-year-old child: ........
Remarks: Release occurred at H + 4 minutes and continued for approximately
1485 minutes. Detected were: Xe-131, -133, -135; 1-133, -135.
Later tracked by aircraft 200 mi. to north central Arizona.
*Reference: SWRHL-108r, Off-Site Surveillance Activities of the Southwestern
Radiological Health Laboratory from January through June 1970,
Aug. 1972.
46
-------
BANEBERRY TEST
This nuclear weapons related test was conducted in Area 8, Nevada Test
Site, at 0730 PST on December 18, 1970, in a vertical hole at a depth of 910
feet. The explosive yield of the device was 10 kt.
All of the programmed operations proceeded normally until 3.5 minutes
after the detonation when a release of radioactivity commenced from a fissure
which opened up after the detonation at a distance of about 300 feet from the
emplacement hole. This release continued over an extended period even after
the commonly experienced surface collapse which occurred at 16.5 minutes after
the detonation. The effluent venting rate decreased steadily with time but
visible vapor continued to emanate from the fissure for 24 hours after the
detonation. It is estimated that about 6.7 MCi of radioactivity at R+12 hours
were released to the atmosphere.
Winds, at the time of this release, were generally to the north and north-
east. As this effluent cloud moved away from the test site, winds at different
altitudes dispersed this cloud over Nevada, Utah and Wyoming, with one small
segment moving to California. Aircraft equipped with sensitive detection equip-
ment tracked the main air mass until it broke up over central Wyoming and the
radioactivity decreased to the point it could not be measured. The presence
of the radioactive material was detected in environmental samples from central
and northern Nevada and in most of the western United States.
Ground monitoring was performed by 26 EPA personnel located north of the
NTS and RM-11 exposure-rate recorders were operating at 32 locations off site.
Air samples were collected from 104 continuously operating stations and from
10 standby locations.
The maximum estimated infinite external gamma exposure resulting from the
cloud passage and deposition at a populated location (Blue Jay with five
residents) was 16 mR. The maximum concentration of iodine-131 found in milk
was 810 pCi per liter at a ranch near Beatty, Nevada, about 40 miles from the
SGZ. The highest estimated thyroid exposure from inhalation and milk ingestion
was 130 millirem to a two-year-old child in the Beatty, Nevada area. Although
the highest milk concentration represented a very small fraction of the FRC
Protective Action Guide value, distribution of this milk was terminated from
December 31, 1970 through January 10, 1971, as a precautionary measure.
Radioiodine from BANEBERRY was also detected by EPA in milk samples from
three locations outside Nevada: Jerome, Idaho; and Powell and Laramie, Wyoming.
The highest levels found at these three locations were in commercial milk
samples at Jerome, Idaho and Powell, Wyoming, where the peak iodine-131 concen-
tration was 40 pCi per liter, corresponding to a projected infant thyroid dose
of less than 10 mrad. These estimated thyroid exposures are less than 10
percent of the FRC Radiation Protection Guides specified for normal peacetime
operations.
After the Environmental Protection Agnecy had completed its environmental
sampling program in the off-NTS area, it was learned that sheepherders in the
area north of the Test Site, where radioactivity had been detected, were using
47
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melted snow as a source of drinking and cooking water. They were in an area
about 30 miles east of Eureka, Nevada, on Highway 50 south to Duckwater, Nevada.
Based on sampling results in the general area, on information obtained
from 8 sheepherders about their location and water consumption, and on snowfall
records, EPA estimated the dose to their thyroids from radioiodine at about
0.5 rem plus or minus a factor of 3. The large uncertainty in the estimate
results from the fact that there is no detailed information on the radioactive
contamination levels at the locations where these sheepherders stayed.
In assessing the overall radiological consequences of this accidental
release, the data indicate the radiation exposure to individuals within the
general populations outside the Test Site did not exceed the Radiation Protec-
tion Guides recommended by the Federal Radiation Council for either normal
peacetime operations or for accidental releases. Other data are shown on the
following form.
48
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Event Name, Type and Series BANEBERRY Shaft Emery
Date/Time, Size and Purpose 12/18/70, 0730 hr., 10 kt, weapons related
Release Characteristics Prompt massive venting; northeasterly
Ci @ R + 12 hr 6,700,000
*Detectable NV, UT, WY, CA, OR, WA, MT, ID, WY, ND, SD,
MO, AR, TX, MN
*Maximum Gamma Exposure Rate
Populated location: 0.57 mR/hr Stone Cabin Ranch (people gone
for day)
Unpopulated location: 1.2 mR/hr, Hwy 25
*Maximum External Gamma Exposure: 16 mR Blue Jay Hwy Maint Sta.
*Maximum TLD/Film Badge Exposure:
Fixed station: 20 mR Hwy 6, 17 miles E. of Tonopah
Personnel: 4 mR Diablo Hwy Maint. Sta.
*Maximum Radionuclide Concentra-
tions in sampling media: pCi/m3
Te-132 1-131 Nl33~
Air Stone Cabin Ranch 870 190 2400
Milk 810 pCi/L 1-131 at McCurdy Ranch,
near Springdale, NV
240 pCi/L 1-131 at Martins Ranch,
Eureka (next highest)
pCi/L of water
Te-132 nm NI331-135
Other Snow at Blue Jay Maint. Sta 1.9E06 3.2E05 6.8E05 4.5E05
Water at Reed Ranch 500 78 530 ND
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air
Adult: Not calculated
One-year-old child: 100 mrem Stone Cabin Ranch (people gone
during cloud passage)
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk
Adult: Approximately 500 mrem. (.17-1.5 rem) for 8
shepherders from snow intake, Central NV.
One-year-old child: Max calculated = 130 mrem to 2-yr old in Beatty.
Remarks: Radiation exposure to off-site residents found to be within the
Radiation Protection Standard. All gamma exposure rates measured at
inhabited locations were <1 mR/hr. Whole-body counting of an adult
and teenager from McCurdy's Ranch indicated less than 10 mrem thyroid
dose.
*Reference: SWRHL 107, Final Report of Off-Site Surveillance for the Baneberry
Event of Dec. 18, 1970; Feb. 1972.
49
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DIAGONAL LINE TEST
This nuclear weapons effects test was conducted in Area 11, Nevada Test
Site, at 1215 PST on November 24, 1971, in a vertical hole at a depth of 866
feet. The explosive yield of the device was less than 20 kt.
About 4 hours after detonation, a seep began from the SGZ area. The EPA
monitors and aircraft had been released from their missions prior to this
release but returned to the field at H + 19 hr. The seep continued for about
20 hours with a total release estimated as 6.8 kCi, corrected to H+12 hr.
Ground monitoring was performed by 29 PHS personnel located south and west
of the NTS. Air samplers were operating at 32 locations.
No radioactivity was detected off site by any of the ground monitors or
by the air, milk, or water surveillance networks. The only radioactivity
detected off site was by EG&G aircraft over the Amargosa Valley and this was
identified as due to xenon-135, krypton-88 and rubidium-88. The highest gamma
exposure rate measured by the aircraft crew was only 0.1 mR/hr at an elevation
of 500 feet and 2 miles south of SGZ.
50
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Event Name, Type and Series DIAGONAL LINE Shaft Grommet
Date/Time, Size and Purpose 11/24/71, 1215 hr., <20 kt, weapons effects
Release Characteristics Seep, start at H+4 moving southwest
Ci @ R + 12 hr 6,800
*Detectable Amargosa Valley, aircraft only
*Maximum Gamma Exposure Rate Not detected
Populated 1ocati on:
Unpopulated 1ocati on:
*Maximum External Gamma Exposure: Not measurable
*Maximum TLD/Film Badge Exposure: Not detectable on TLD
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air Not detected
Milk Not detected
Other Water, not detected
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Air Iodines not detected
Adult:
One-year-old child:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Iodines not detected
Adult:
One-year-old child:
Remarks: Release detected by EG&G aircraft over Amargosa Valley, xenon-135,
krypton-88 and rubidium-88 identified. Maximum exposure rate of 0.1
mR/hr was measured over NTS.
*Reference: NERC-LV-539-1. Environmental Monitoring Report for the Nevada Test
Site, January - December 1971. Sept. 1972.
51
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RIOLA TEST
This nuclear weapons related test was conducted in Area 2, Nevada Test
Site, at 0826 PDT on September 25, 1980, in a vertical hole at a depth of 1391
feet. The explosive yield of the device was less than 20 kt.
Seepage of radioactivity through small cracks and fissures began about
11 hours after detonation. It is estimated that 5300 Ci of activity corrected
to R+12 hr were released to the atmosphere over a period of 35 minutes.
Because of low wind speeds, 5 EPA monitors were deployed south and west
of the NTS beginning at H + 23 hours. Portable air samplers and exposure-rate
recorders were added at 3 locations to supplement the normal surveillance
networks. The EPA aircraft collected air samples both on site and off site.
The low-level radioactive cloud traveled in a southerly direction and
the only activity detected off site was xenon-133 and xenon-135 by a noble-
gas sampler at Lathrop Wells, NV. The concentrations were low, and the
estimated maximum dose equivalent to the whole body of a hypothetical receptor
at Lathrop Wells was 11 microrem. The only positive sample collected by the
aircraft was on site near SGZ. Other data are shown on the following form.
52
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Event Name, Type and Series .... RIOLA Shaft Tinderbox
Date/Time, Size and Purpose 9/25/80, 0826 hr., <20 kt, weapons related
Release Characteristics Seep, southerly
Ci @ R + 12 hr 5300
*Detectabl e Nevada
*Maximum Gamma Exposure Rate Not detected
Populated 1ocati on:
Unpopulated location:
*Maximum External Gamma Exposure: 0.011 mrem at Lathrop Wells (noble gases)
*Maximum TLD/Film Badge Exposure: Not detectable on TLD
Fixed station:
Personnel:
*Maximum Radionuclide Concentra-
tions in sampling media:
Air Lathrop Wells - compressed gas sample,
9/24-26/80
34 pCi/m3 of Xe-133
360 pCi/m3 of Xe-135
Milk No special samples collected
Other No special samples collected
*Thyroi.d Dose at Location of Maxi-
mum Radioiodine concentration in
Air Radioiodines not detected
Adult:
One-year-old child:
*Thyroid Dose at Location of Maxi-
mum Radioiodine concentration in
Milk Radioiodines not detected
Adult:
One-year-old chi1d:
Remarks: Xenons at Lathrop Wells was the only activity detected off site. The
estimated dose equivalent to the whole body of a hypothetical receptor
at Lathrop Wells would be 11 microrem. Data from the Noble Gas and
Tritium Surveillance Network indicate no other radioactivity from
NTS tests was detected off site during 1980.
*Reference: EPA-600/4-81-047, Off-Site Environmental Monitoring Report - Radiation
Monitoring Around the United States Nuclear Test Areas, Calendar
Year 1980; June 1981.
53
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DISCUSSION
As noted for each of the nuclear weapons tests discussed in the previous
sections, doses to off-site residents from the accidental releases of radio-
activity were small fractions of the safety guidelines. At present, those
guidelines are: for whole-body doses resulting from external exposure, 500
mrem in any year but not exceed 100 mrem per year when averaged over 70 years;
and thyroid doses should not exceed 1500 mrem per year.
In Table 3, the maximum exposures from each test that accidently released
radioactivity to the off-site area are compared to the background radiation
exposures in those areas. In this table, the external exposure listed in pre-
ceding sections was multiplied by 0.6 to give a conservative estimate of the
actual exposure a person in that area would receive. Also, the total is just
the sum of the adjusted external and the calculated thyroid dose so it is a
thyroid dose rather than a whole-body dose whereas "background" is a whole-body
exposure level.
In the case of thyroid exposure, all calculated doses are based on a
thyroid weight of 2 g since this assumption yields a maximum dose. An adult
having a thyroid that weighs 20g would receive a dose to the thyroid that is
only 10% of the dose shown in the following table if the thyroid contained the
same amount of radioiodine. For inhalation of radioiodines, the adult thyroid
would received about 40% of the dose that the infant thyroid receives. Further-
more, calculations tend to over-estimate dose as indicated for Hiko, in the
table, where the calculated thyroid dose adds up to 619 mrem but the maximum
measured was less than 300 mrem. Internal exposures due to inhalation or
ingestion of other radionuclides are much less.
Exposure to background radiation, caused by naturally occurring radio-
nuclides in the soil plus cosmic radiation, far exceeds the exposure caused by
nuclear explosives testing at the Nevada Test Site. This is true for the
populated locations receiving the maximum from such testing, and much more so
for all other locations not listed in the table. In fact, changing a place of
residence can lead to changes in radiation exposure by as much as 70 mrem per
year because of differences in background radiation.
54
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TABLE 3. LOCATIONS WITH HIGHEST CALCULATED DOSES COMPARED WITH BACKGROUND EXPOSURES*
Thyroid mrem
Locati on
Death Valley, CA
Cactus Spr., NV
Las Vegas, NV
Lathrop Wells, .
NV
Shoshone, CA
01 Ind. Spr., NV
(Jl
Hiko, NV
Diablo, NV
Dansby's, NV
Stone Cabin, NV
Beatty, NV
Duckwater, NV
Test
Eagle
Pike
Pi ke
Dri 1 1
Red Hot
Nash
Pod
Riola
Dri 1 1
Umber
Parrot
Double Play
Pinstripe
Door Mi st
Nash
Hupmobile
Baneberry
Baneberry
Baneberry
Year
1963
1964
1964
1964
1966
1967
1969
1980
1964
1967
1964
1966
1966
1967
1967
1968
1970
1970
1970
Inhal .
0.19
1.9
ND
ND
0.15
NC
ND
ND
0.017
0.05
0.031
0.083
47
0.05
ND
4.0
100
1.3
Inges.
ND
44
ND
ND
NC
ND
ND
ND
ND
ND
ND
572**
ND
ND
0.7
130
0.17-1.5
External
mR
ND
50
<2
0.025
ND
0.4
0.1
0.011
ND
0.03
ND
ND
12
1
0.7
2
5
0.6
Total
mrem
0.19
52
46
0.025
0.15
0.4
0.1
0.011
0.017
0.08
0.031
0.083
630
1.05
0.7
6.6
105
132
500
Background
uR/hr mR/yr
10.6
8.6
12.7
10.0
7.3
10.9
17.4
12
16.9
15.1
93
75
111
88
64
96
153
105
148
132
1963-86
Sum mR
2167
1750
2586
2050
1491
2237
3565
2454
3448
3076
*Many exposures listed here are not on summary sheets because they were not maximum for the test.
**Total thyroid dose was 619 mrem calculated, highest measured (2 of 78 people) was <300 mrem.
NC = not calculated, ND = not detected, — = sample not available.
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