UrOST OtuA* 1tl}«l
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v>EPA Levels and Distribution
of Environmental Plutonium
Around the Trinity Site
-------
Technical Note
ORP/LV-7 8-3
LEVELS AND DISTRIBUTION
OF ENVIRONMENTAL PLUTONIUM
AROUND THE TRINITY SITE
Richard L. Douglas
October 1978
OFFICE OF RADIATION PROGRAMS LAS VEGAS FACILITY
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89114
-------
DISCLAIMER
This report has been reviewed by the Office of Radiation
Programs Las Vegas Facility, U. S. Environmental Protection
Agency, and approved for publication. Mention of trade names
or commercial products does not constitute endorsement or recom-
mendation for their use.
-------
FOREWORD
The Office of Radiation Programs (ORP) of the U.S. Environ-
mental Protection Agency (U.S. EPA) carries out a national
i
program designed to evaluate population exposure to ionizing and
non-ionizing radiation, and to promote the controls necessary to
protect the public health and safety. The purpose of this report
is to present the results of a survey of plutonium levels in the
environs of the Trinity atomic bomb test site in central New
Mexico.
Readers of this report are encouraged to inform the authors
of any omissions or errors. Comments or requests for further
information are also invited.
Donald W. Hendricks
Director, Office of
Radiation Programs, LVF
i i i
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CONTENTS
Page
LIST OF FIGURES
vi
LIST OF TABLES
vii
ACKNOWLEDGMENTS
viii
INTRODUCTION
1
STUDY METHODS AND RESULTS
2
1973 Sample Collection
2
1974 Sample Collection
4
Sample Results
5
DISCUSSION OF RESULTS
12
Evaluation of Sampling
and Analytical Methods
12
Distribution of Trinity
Plutonium
16
Soil Profiles
25
Air Sampling
25
SUMMARY AND CONCLUSIONS
27
REFERENCES
29
APPENDIX A
31
v
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LIST OF FIGURES
Number Page
1. Location Within the State of New Mexico of the
Approximate Area Covered by Soil Sampling Program 6
2. Trinity Site Soil Sampling Locations and Results Insert
3. Airborne Plutonium Concentrations at Socorro
During 1975 8
4. Airborne Plutonium Concentrations at Monte Prieto
Ranch During 197 5 9
5. Fraction of Plutonium in Soil Sample Due to Trinity
as a Function of Pu-240/Pu-239 Ratio in the Sample 19
A-l. Depth Profile for Sample No. 118 40
A-2. Depth Profile for Sample No. 109 40
A-3. Depth Profile for Sample No. 115 40
A-4. Depth Profile for Sample No. 20 41
A-5. Depth Profile for Sample No. 27 41
A-6. Depth Profile for Sample No. 32 42
vi
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LIST OF TABLES
Number Page
1. Atom Ratios (Pu- 240/Pu-239) of Airborne Plutonium
Samples 10
2. Results of MCL Analysis of Selected 1973 Soil
Samples 11
3. Results of Replicate Analyses of Three Trinity
Soil Samples 14
4. Deposition and fT Values for Background Samples 21
A-l. Coordinates of November 1973 Soil Sampling Locations 32
A-2. Coordinates of December 1974 Soil Sampling Locations 33
A-3. Radionuclide Concentrations in Trinity Soil Samples
Collected During November 1973 34
A-4. Radionuclide Concentrations in Trinity Soil Samples
Collected During December 1974 36
A-5. Airborne Plutonium Concentrations at Socorro
During 1975 38
A-6. Airborne Plutonium Concentrations at Monte Prieto
Ranch During 1975 39
vii
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ACKNOWLEDGMENTS
The author gratefully acknowledges the contributions of the
following people to this study:
Mr. John Rodgers, formerly with the New Mexico Environmental
Improvement Agency, for his efforts in obtaining land ownership
maps, contacting landowners and residents, obtaining permission
for us to sample, and helping collect the samples.
Messrs. William Moore, Frank Jakobowski, Daniel Wait, and
Thomas Horton, now or formerly at EPA - Las Vegas, for their
assistance during the two field surveys.
Mr. Charles Rosenberry and his staff of the Reynolds Electri-
cal and Engineering Company at the Nevada Test Site, for their
assistance in weighing, drying, and grinding the soil samples.
Mr. Brian Zamora, formerly with the New Mexico Environmental
Improvement Agency in Socorro, and Mr. Matt Williams, formerly
foreman at the Monte Prieto Ranch, for their faithful and conscien-
tious operation of the air samplers at these two locations.
Special thanks are due to Dr. Wes Efurd at the McClellan
Central Laboratory for his efforts in analyzing the samples, and
his technical discussions, particularly in regard to the use and
significance of the Pu-240/Pu-239 ratios.
Mrs. Edith Boyd, for her patient and uncompromising efforts
in typing this report.
vi i i
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INTRODUCTION
The world's first atomic bomb, called Trinity, was detonated
on July 16, 1945. The detonation took place about 60 miles
north-northwest of Alamagordo, New Mexico at a location which is
now part of the U.S. Army's White Sands Missile Range (WSMR).
The plutonium nuclear weapon had a nominal explosive yield of 20
kilotons. The fallout cloud from the test was carried to the
northeast by prevailing winds. The approximate fallout pattern
on the ground was established in the first few weeks after the
test by surveys of the intensity of beta-gamma radiation from
fission product deposition.
Since 1945, studies have been made of the distribution and
environmental behaviour of the Trinity fallout material (Larson
et al, 1951a; Larson et al, 1951b; Olafson et al, 1957; Romney
et al, 1969, and Warren, 1949). However, these contained rela-
tively little specific information on the plutonium component of
the fallout. When the U.S. Environmental Protection Agency's
Office of Radiation Programs (ORP) began work to establish federal
guidance for environmental plutonium contamination, it was recog-
nized, on the basis of the little data available, that the
deposition from the Trinity fallout cloud constituted one of the
significant plutonium-contaminated areas in the United States,
both in terms of quantity of plutonium deposited and areal extent.
To provide documentation of the Trinity plutonium, a study was
initiated in 1973 by the Las Vegas Facility of the Office of
Radiation Programs (ORP-LVF). The purpose of this study was to
document the current levels and extent of the Trinity plutonium
deposition, particularly in regard to those areas outside the
controlled area of the WSMR.
1
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STUDY METHODS AND RESULTS
It was decided that sampling surface soil was the most
sensitive and efficient way to meet the general objective of the
study. Based on fallout deposition data and maps published by
Warren (1949) , a plan for an initial screening survey was worked
out. Basically, this consisted of collecting soil samples at
periodic intervals along highways and major unpaved roads over an
area which was expected to encompass the total residual fallout
area. Since the EPA's primary interest was in the unrestricted
areas, no samples were to be collected on the restricted area of
the WSMR at this stage. Particular emphasis was given to the
Chupadera Mesa, an area beginning about 30 miles northeast of the
detonation point (ground zero, or GZ). From earlier measurements,
this topographically elevated area was known to have received
higher radioactivity deposition than surrounding areas due to
rainout of material from the fallout cloud when it passed over
the mesa.
19 73 SAMPLE COLLECTION
This plan was implemented in November 1973 when two two-man
teams spent five days collecting samples in the designated area.
A total of 37 surface samples and 7 profile samples were collected.
Samples were collected using the method described by Bliss
(1976). Primarily, surface samples (5-cm depth) were collected,
although a few profile samples, using 5-cm horizons, were collected
to evaluate penetration of the plutonium into the soil profile.
The surface samples were collected using a scoop, open on the top
and one end, which had dimensions of 100 cm by 100 cm by 5 cm
deep. A small hole, having one vertical face and a depth somewhat
greater than 5 cm, was dug, and the scoop was placed in the hole.
The open end of the scoop was then pushed into the vertical face
2
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until the scoop was full. Ten such scoops of soil were composited
to form a sample representing a total area of 1000 square centi
meters. The ten scoops were typically collected over an area of
a few square meters. Profile samples were collected by digging a
hole to the desired depth, taking care to maintain one vertical
face. The 5-cm scoop was then pushed into this face, taking a
descending series of samples at 5-cm depth increments (horizons).
One scoop of soil was collected for each horizon.
After collection, the total sample was weighed at field
moisture content. After mixing, an aliquot of the sample (usually
1.5 kg) was weighed, oven dried at 105° C, and re-weighed to
determine moisture content. The moisture content was used to
correct the field weight of the total sample to dry weight. The
aliquot was then ball-milled and sent to the laboratory for
radiochemical analysis. The samples were analyzed at the EPA's
Environmental Monitoring and Support Laboratory (EMSL-Las Vegas),
using the methods described by Johns (1975) and Talvitie (1971
and 1972). Basically, the analytical procedure consisted of
complete dissolution of one gram of sample in hydrofluoric and
nitric acids. Following ion exchange separation, the plutonium
was electrodeposited on a stainless steel planchet for alpha
spectrometic determination. The plutonium recovery was determined
by use of plutonium-236 as an internal tracer. Cesium-137 was
also determined by gamma spectroscopy, using a separate aliquot
of the sample. After the plutonium results were available,
selected samples having higher plutonium levels were analyzed for
americium-241.
After the plutonium concentration (pCi/gram) in the sample
*
was determined, the plutonium deposition (nCi/m2) was calculated
* Numerically equal to mCi/kjn2, a unit frequently used in
references on environmental plutonium. The unit of nCi/m2
is used in this report because it is felt that an individual
sample result is more representative of plutonium deposition
for one square meter than for a square kilometer.
3
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by multiplying the concentration by the dry weight of the total
sample, dividing by the sample area, and applying the appropriate
conversion factors.
1974 SAMPLE COLLECTION
The results of the 1973 survey provided a somewhat clearer
picture of the deposition pattern of the Trinity plutonium. It
was then possible to select locations for further sampling in
order to fill in the gaps and provide more detailed information
on the levels and extent of the deposition. To meet this end, a
second sampling trip, again using two field sampling teams, was
conducted in December 1974. A total of 39 surface and five
profile samples was collected. During this survey, access was
gained to the WSMR, and 12 samples were collected within the
restricted area between ground zero and the northern range
boundary.
The sample collection and preparation procedures for these
samples were essentially the same as those used for the 1973
samples. One exception was that 2.5-cm horizons were used for
the profile samples instead of 5-cm horizons and a few 2.5-cm
depth surface samples were collected. In addition, the 1974
samples were analyzed under contract by the U.S. Air Force
McClellan Central Laboratory (MCL). The plutonium analytical
techniques used by MCL were similar to those used by EMSL,
except that a 10-gram aliquot of the soil was taken for dissolu-
tion, rather than a one-gram aliquot. The samples were also
analyzed by mass spectroscopy as well as alpha spectroscopy in
order to obtain the ratio of plutonium-240 to plutonium-239.
During the December 1974 survey, arrangements were made to
start an air sampling program to measure airborne plutonium
levels. Two sampling stations were established using Gelman
Tempest samplers. These samplers operate continuously and draw
approximately 10 cubic feet of air per minute through a 4-inch
4
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diameter glass fiber filter. The filters were changed weekly.
One station was at the Monte Prieto Ranch on Chupadera Mesa, an
area which the 1973 survey (and previous survey reports) had
shown to have elevated plutonium deposition levels. The other
station was at the State Health Department building in Socorro,
which is a background area relative to Trinity plutonium.
Sampling was begun in February 19 75 and continued into December
of that year. Several laboratories were involved in analyzing
the air filters. Some were analyzed by the EPA's EMSL-LV labora-
tory; others were sent to MCL, Eberline Instrument Corporation,
or Mound Laboratory for partial or total analysis under contract.
SAMPLE RESULTS
As a point of reference, Figure 1 shows the location within
the state of New Mexico of the approximate area covered by the
combined 1973 and 1974 soil sampling programs. Tables A-l and
A-2 show the coordinates of the sampling locations for the 1973
and 1974 surveys, respectively. Tables A-3 and A-4 show the soil
sampling results for the two surveys. The sample identification
number in the left column of Tables A-3 and A-4 is coded as
follows:
Table A-3
Table A-4
First two digits First three digits
Third digit
Fourth digit
Fourth digit
Fifth digit
Explanation
Sample location number (hereafter
referred to as "sample number")
Type of sample: 1 = surface
2 = profile
Sampling depth increment(s):
For surface samples: 6 = 2.5 cm
7 = 5 cm
For profile samples:
A, etc. = 2.5 cm
N, etc. = 5 cm
5
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• Farmington
• Santa Fe
APPROXIMATE AREA COVERED
BY SAMPLING PROGRAM
»Gran s ^ Albuquerque /
/ d Santa Rosa
Wlllard-^ /
Mountalnalr^"™ "Vaughn
Gran Quivlra /
¦ ¦ Corona
Sororro •
Bingham
¦
Carrizozo
/
, wan
TRINITY DETONATION POINT
• Alamagordo
• Las Cruces
Figure 1. Location Within the State of New Mexico of the
Approximate Area Covered by Soil Sampling Program
Table A-3 shows the plutonium-239, 240 concentration (pCi/g)
and deposition (nCi/m2), and the plutonium-238, americium-241,
and cesium-137 concentrations for the 1973 samples. These samples
were analyzed at the EPA's EMSL-LV laboratory. The results of
the soil samples collected in 1974, analyzed by the McClellan
Central Laboratory, are shown in Table A-4.. This table shows the
plutonium-239, 240 concentrations as measured both by alpha
spectroscopy and mass spectroscopy, the plutonium-239, 240
deposition, the atom ratio of plutonium-240 to plutonium-239, and
the plutonium-238 concentration.
The combined results of the 1973 and 1974 soil sampling
surveys are shown in Figure 2. This map shows major roads,
6
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communities, and landmarks in the area covered by the surveys.
Each sampling location is shown, and the calculated plutonium-
239, 240 deposition, in nCi/m2, is shown. The error term shown
for each deposition number is that calculated from the two-sigma
counting error of the concentration in the same manner that the
deposition number was calculated from the concentration. The
atom ratio (Pu-240/Pu-239) is shown in parenthesis below the
deposition number for those samples where the atom ratio was
calculated.
The results of the profile samples are shown in Figures
A-l through A-6. Only those profile -samples which had plutonium
concentrations above the minimum detectable level in at least the
top two horizons are plotted, and the results are only plotted to
the lowest horizon at which detectable plutonium concentrations
were found. In these Figures, the plutonium concentration value
for each horizon is plotted at the midpoint of the depth increment
on the vertical (depth) scale. The zero value on the vertical
scale represents the ground surface.
The analytical results for the air filters collected at
Socorro are tabulated in Table A-5 and plotted as a function of
time in Figure 3. The same data for the air sampling station at
the Monte Prieto Ranch are presented in Table A-6 and Figure 4.
Tables A-5 and A-6 show, for each sample, the starting and ending
dates of each sampling period, the plutonium-239, 240 and
*
plutonium-238 concentrations in aCi/m3 , and a code number which
indicates which laboratory performed the analysis. The samples
collected during August from both stations were lost during the
analytical procedure, so no results can be reported for these
samples. No result for plutonium-238 was obtained on the nine
filters analyzed by MCL, since their analysis on these filters
was by mass spectroscopy for Pu-239, 240 only.
* aCi = attocurie = 10"18 curie
7
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00
%
c
o
s
f)
100-
90-
80-
70-
60-
SO-
40-
30-
20-
c
0
U
1 10-
8"
i ;
i *
3 4-
Q.
E 3
o
A
5 2
• •
• •
• •
, Sa
h.
Samples lost .
in laboratory I
~ Indicates "less-lhan" value
~ A
February ' March 1 April 1 May 1 June 1 July 1 August 1 September ' October 1 November
Figure 3. Airborne Plutonium Concentrations at Socorro
During 1975
-------
100-
90-
80-
70-
60-
50-
40-
30-
« 20-
10-
9-
8-
7-
6-
2 4-
* A
—Samples lost—
in laboratory
|A Indicates "less-than" value |
February 1 March 1 April ' May 1 June ' July 1 August 1 September ' October 1 November 1 December
Figure 4. Airborne Plutonium Concentrations at Monte Prieto
Ranch During 1975
-------
In Figures 3 and 4, only the plutonium-239, 240 results are
plotted, since many of the plutonium-238 results were below the
minimum detectable level. In these figures, the" "less-than"
results for plutonium-239, 240 were not plotted, nor was the
sample collected at Socorro on September 2-9, since the extremely
high result for this sample (230 ± 200 aCi/m3) relative to the
other data appears to be an analytical error.
An attempt was made to determine the atom ratio (Pu-240/
Pu-239) on the filters analyzed by MCL using mass spectroscopy.
Unfortunately, the levels were so low that valid results were
obtained on only five of the nine filters. These results are
shown in Table 1.
TABLE 1. ATOM RATIOS (Pu-240/Pu-239) OF AIRBORNE PLUTONIUM SAMPLES
Atom Ratio
Location
Date
Collected
Pu-240/Pu-239
Monte Prieto Ranch
Oct
31 ¦
- Nov
4
0.107
+
0.028
Monte Prieto Ranch
Nov
4 -
- Nov
11
0.099
+
0.026
Monte Prieto Ranch
Nov
11 -
- Nov
20
Monte Prieto Ranch
Nov
20 ¦
- Dec
2
0.100
±
0.022
Monte Prieto Ranch
Dec
2 ¦
- Dec
15
0.097
+
0.023
Socorro - Health Bldg
Sep
16 ¦
- Sep
23
0.181
+
0.047
Ten of the soil samples collected in 1973, which had previ
ously been analyzed by EMSL-LV, were sent to MCL for analysis by
mass spectroscopy in order to determine the atom ratios of the
plutonium. The results of these MCL analyses', with the correspon-
ding EMSL analytical results, are shown in Table 2. Because the
mass spectroscopic analyses were felt to be more sensitive and
more accurate than the EMSL alpha spectroscopic analyses, new
deposition values (nCi/m2) were calculated from the mass spectro-
scopic analyses and have been used in Figure 2 and in the follow-
ing discussion.
10
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TABLE 2. RESULTS OF McCLELLAN CENTRAL LABORATORY ANALYSIS OF SELECTED 1973 SOIL SAMPLES
Calculated
Plutonium- 23 9, 240 (pCi/gm) Deposition of
Sample
Number
Alpha
Spect.
Mass
Spect.
EMSL*
Atom Ratio
Pu-240/Pu-239
Pu-2 39,240**
(nCi/m2)
0517
0. 008
+
0.0022
0.009
±
0.0005
<0.015
0.189
+
0.014
0.47
+
0.026
1517
0. 012
+
0.0016
0.015
±
0.0015
0.024
+
0.009
0.250
+
0.050
0.79
±
0.079
1617
0.009
+
0.0013
0.012
±
0.0009
0.018
±
0.008
0.190
+
0.030
0.76
±
0.057
1717
0. 013
+
0.0025
0.014
±
0.0004
0.017
+
0.008
0.162
+
0.009
0.82
±
0.023
1917
0. 043
+
0.0031
0.043
±
0.0005
0.071
it
0.021
0.043
+
0.002
2.4
±
0.028
2317
<0.005
0.011
±
0.0017
<0.015
0.263
+
0.066
0.60
±
0.093
2817
0. 075
+
0.0044
0.076
±
0.0008
0.031
±
0.010
0.069
+
0.003
3.6
±
0.038
3817
0. 030
+
0.0042
0.025
±
0.0028
0.073
±
0.020
0. 087
+
0. 017
1.3
±
0.14
4217
0. 073
+
0.0088
0.076
±
0.0033
0.051
Hh
0.011
0.048
+
0.012
4.3
±
0.19
4417
0. 044
+
0.0053
0.051
±
0.0009
0.025
±
0.009
0.071
+
0.003
2.7
±
0.047
Repeated from Table A-3 for comparison (measurement by alpha spectroscopy).
Using the MCL mass spectroscopy concentration values.
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DISCUSSION OF RESULTS
EVALUATION OF SAMPLING AND ANALYTI-CAL METHODS
A total of 88 soil samples were collected and analyzed for
plutonium-239, 240. Excluding three samples which were intended
to be "background" samples (Nos. 4, 16, and 25), this sampling
array covered an area of roughly 4500 square miles, and the
furthest sample from the Trinity detonation point was about 135
miles to the northeast. Obviously, any conclusions drawn from
data based on a sample density averaging one sample per 50 square
miles must be treated with caution. The variability of the
deposition data was so great, and the data points were so wide-
spread in most areas, that any attempt to estimate an inventory
of Trinity plutonium over the large area involyed was considered
fruitless.
It was recognized from the beginning of the study that soil
sampling has several limitations for determining the amount of
plutonium present from a specific point source such as Trinity.
The first of these is the variability of the initial deposition.
For example, as previously mentioned, it is well known that the
Chupadera Mesa, about 30 miles northeast of ground zero, received
heavier initial fallout than did the surrounding areas due to
"rainout" from the Trinity cloud as it passed over this area.
The second variable is redistribution 6f the plutonium due
to wind and water erosion, movement into the soil profile due to
various processes, and human activities. The net effect of all
these processes during the nearly 30 years between detonation and
this study could be expected to be considerable.
A third factor is the variability inherent in the sample
collection and analysis procedures. Considerable variability,
12
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for instance, can arise in the sample collection process alone.
Some obvious sources of variation are in the measurement of the
depth and area of soil collected, weighing errors, and the diffi
culties of obtaining a representative aliquot of the total sample
for analysis. For example, the oven-dry weight of a typical 5-cm
depth surface sample was 5 to 6 kilograms. From this mass of
soil, typically 1.5 kg were taken for ball milling. From this, a
one-gram aliquot (by EMSL) or ten-gram aliquot (by MCL) was actu-
ally analyzed. Analytical errors include weighing and pipetting
errors, errors in tracer calibration, instrument calibration and
gain shift, and random variability in tracer, background, and
sample counts. All these errors and variables are, of course,
compounded through the sampling and analytical processes to
arrive at the final result (Bernhardt, 1976).
Replicate sample collection and analysis to determine the
magnitude of these errors and sources of variability becomes very
expensive. Because of the survey nature of this study, and the
relatively limited resources available for it, no replicate
sample collection was done. However, because difficulties with
the "hot particle" problems had been encountered by EPA and
others during plutonium studies at the Nevada Test Site (Bliss,
personal communication) an attempt was made to evaluate this
problem for the Trinity study.
This was done by analyzing ten replicate aliquots from each
of three different soil samples, selected to represent high
(sample #31), medium (#22), and low (#39) plutonium concentra-
<- tions. The samples were analyzed by MCL using both alpha
spectroscopy and mass spectroscopy. The results are shown in
Tab1e 3.
Both log-probability and arithmetic probability plots were
made of these data. In all cases, the arithmetic probability
plots produced a better approximation of a straight line, indi-
cating that the data are approximately normally distributed. The
13
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TABLE 3. RESULTS OF REPLICATE ANALYSES OF THREE TRINITY SOIL SAMPLES
SAMPLE 03 117 SAMPLE 02217 SAMPLE 03917
Pu-239,240 (pCi/gnQ Ratio Pu-239, 240 (pCi/gm) Ratio Pu-239, 240 (pCi/gm) Ratio
Alpha Spect.
Mass Spect.
Pu-240/239
Alpha Spect
Mass Spect.
Pu-240/239
Alpha Spect.
Mass Spect.
Pu-240/239
1.8 ±
.16
1.7
± .062
.023
± .0041
.099
i .017
.16
+
.0070
.059
± .0097
.035
i .0077
.051 ± .0061
--
1.4 ±
.082
1.5
± .024
.025
± .00090
.099
± .020
.12
+
.0058
.033
± .0059
.026
± .0057
Limit
—
1.3 ±
.13
.96
± .012
.024
± .00072
.096
± .021
.089
+
.0050
.041
± .0059
.023
± .0046
.013 ± .00018
.084 ± .0027
1.3 ±
.79
.96
± .017
.025
± .0011
.085
± .020
.075
+
.0036
.055
± .015
.017
± .0041
Limit
--
1.3 ±
.28
1.3
± .018
.030
± .0017
.084
± .0059
.084
+
.0067
.13
± .065
.017
± .0044
.014 ± .00084
.082 ± .014
1.1 ±
.070
1.0
± .014
.025
± .0013
.078
± .010
.046
±
.022
.043
± .050
.016
± .0038
Limit
—
1.0 ±
.051
1.2
± .028
.026
± .00083
.068
± .022
.074
+
.0034
.030
± .0060
.014
± .0024
Limit
-•
.92±
.071
.94
± .034
.023
± .0033
.067
± .0094
.14
+
.0036
.066
± .0070
.013
± .011
.013 ± .0011
.083 ± .027
<£>
1+
.096
.86
± .0086
.025
± .0012
.061
± .016
.060
+
.0079
Limit
.013
± .0065
Limit
--
.44±
.065
.47
± .013
.028
± .0038
.017
± .0034
.019
+
.00053
.11
± .0076
.012
± .0079
Limit
—
X?to; 1.15 ±
.364
1.09
± .349
.0754± .0246
.08674
.0429
.OlSei .0073
Notes: 1. Error terms are one-sigma counting error.
2. "Limit" indicates activity was below the limit of detection.
-------
coefficients of variation (standard deviation as a percentage of
the,mean) for these data sets are shown below.
Sample
Number
Type of
Analysis
Alpha spectrometry
Mass spectrometry
Mean
(pCi/gram)
1.15
1.09
Coefficient of
Variation
31
32%
32%
22
Alpha spectrometry 0.0754
Mass spectrometry 0.0867
Alpha spectrometry 0.0186
33%
491
39
391
The coefficients of variation show that, at the 95 percent
confidence level (based on 9 degrees of freedom and a t-value of
2.26), one could expect (using alpha spectrometric analyses) a
given -analytical result to be within 72 to 88 percent of the
"true" value for that sample. This variation is not greatly
affected by the plutonium concentration over the approximately
two orders of magnitude involved here, although there is an
apparent slight increase in the coefficient of variation with
i
decreasing concentration. These data provide an estimate of the
variation to be expected from the analytical process itself,
beginning with a ball-milled sample aliquot. It should be recog-
nized .that ball milling is a homogenizing process, and undoubtedly
removes much of the variation which would exist had the aliquots
been taken from an unprocessed sample.
Note that the data do not provide any estimate of "sampling
error", i.e., the variation to be expected if replicate samples
were to be collected at the same sampling location. One estimate
of this sampling variation (including the effects of natural and
man-made redistribution) can be obtained from the series of
samples collected at the Monte Prieto Ranch. After it was decided
to establish an air sampling station at the ranch, four 2.5-cm
depth surface samples (Nos. 164, 166, 167, and 169) were collected
within a radius of approximately 300 meters, with the intention
15
-------
of characterizing the plutonium deposition of this (relatively)
small area in more detail. The plutonium deposition results for
these four samples were respectively 28, 8, 86, and 42 nCi/m2.
While plutonium redistribution around the ranch headquarters is
undoubtedly greater, due to more intensive human and agricultural
activity, than in most other similar-sized areas monitored, this
order-of-magnitude variation is probably not excessive. It
should be noted that the Pu-240/Pu-239 atom ratio is relatively
constant for all four samples, varying from 0.025 to 0.032 (the
four values are not statistically different, considering the
counting errors), indicating that all four samples contained
essentially the same fraction (about 95 percent) of Trinity
plutonium.
DISTRIBUTION OF TRINITY PLUTONIUM
Another problem encountered when using soil sampling to
measure deposited material is in determining the contribution of
Trinity plutonium in the presence of global fallout plutonium.
Near ground zero, the contribution of global fallout is insigni-
ficant compared to the levels of Trinity plutonium. But at
increasing distance from ground zero, as the levels of Trinity
plutonium approach the levels of global fallout, it becomes
increasingly difficult to distinguish between the two.
One useful technique for evaluating this problem is through
the use of the Pu-240/Pu-239 atom ratio. This r^tio has been
shown to be a useful tool for identifying the contribution of a
local source of plutonium to global fallout plutonium, provided
that the atom ratios for the two sources are.sufficiently dif-
ferent (Krey et al., 1976; Krey and Krajewski, 1972; Hardy, 1972;
Efurd, 1975; Krey, 1976). As pointed out by these authors, the
240/239 atom ratio varies according to the conditions under which
the plutonium was formed. Consequently, if the atom ratio of
plutonium in a sample containing two distinct sources of plutonium
is measured, and the atom ratios of the respective sources are
known, measured, or assumed, then a straight-forward calculation
16
-------
yields the contribution of the two sources to the mixture. The
equation is:
T Rip ~ Rp
where f is the fraction
the 240/239 atom ratio,
M respectively indicate
the mixture, or sample.
due to a given source, R is
and the subscripts T, F, and
Trinity, global fallout, and
For the present case, the atom ratio of Trinity plutonium
(Rj in the above equation) is assumed to be 0.023, since this is
the lowest value measured (sample number 121, about 9 kilometers
north of the Trinity GZ). The atom ratio of global fallout (Rp)
is somewhat more difficult to ascertain. Krey and Krajewski
(1972) indicate a 240/239 ratio of 0.1801 ± 0.24 percent (one-
sigma) for global fallout plutonium, based on a sample collected
at Brookhaven National Laboratory. The atom ratio varies some-
what with geographical location, and Krey (1976) used a value of
0.163 for studies at the Rocky Flats plant near Denver. Merrill
et al. (1977) in their comment on Krey's paper, suggested that a
value of 0.169 would be a more appropriate value for the Rocky
Flats area. However, since the Trinity area covered by this study
has presumably had very little, if any, localized effect from the
Nevada Test Site, the value quoted by Krey et al. (1976) of 0.176
has been used here as the atom ratio for global fallout.
The 240/239 atom ratios were reported for 53 soil samples by
MCL for this study. Of these, only five were higher than the
0.176 value. These values were:
17
-------
Sample No.
Atom Ratio, 240/239
103
05
0.177 ± 0.039
0.189 ± 0.014
16
0.190 ± 0.030
15
0.250 ± 0.050
23
0.263 ± 0.066
Considering the counting errors, the first three atom ratios
listed above are not significantly different from the 0.176
value. Sample numbers 15 and 23 were both reported by the analyst
to have ran quite poorly during the mass spectroscopic analysis
(de Jonckheere, 1976; Efurd, 1978). Consequently, it appears that
the value of 0.176 for the 240/239 ratio in global fallout is
applicable to this study area.
Using these two values (Rf = 0.023 and Rp = 0.176), Figure 5
is a graphical presentation of the equation for calculating the
fraction of plutonium due to Trinity in a soil sample having a
given value of R^.
In order to evaluate the contribution of Trinity plutonium,
it is helpful to know the "background" level of global fallout
plutonium on which the Trinity plutonium is superimposed. A
generally accepted level of background plutonium is on the order
of 1 nCi/m2, although this varies widely with geographical
location. Three samples were collected during the November 1973
sampling mission which were intended to evaluate background. The
results of these samples are summarized below.
Pu-239 Deposition
(nCi/m2)
Atom Ratio
Sample No.
04
16
25
<0.57
0.76 ± 0.057
1.1 ± 0.97
Pu-240/239 Type of Analysis
Not measured EMSL-alpha spect.
0.190 ± 0.030 MCL - mass spect.
Not measured EMSL-alpha spect.
18
-------
1.0
0.9
£ 0.8
0.7
0.5
O 0.3
0.1
0.08
0.10
0.12
0.16
0.02
0.06
0.14
0.18
0.04
Pu-240/Pu-239 ATOM RATIO IN SAMPLE (f?M)
Figure 5. Fraction of Plutonium in Soil Sample Due to Trinity
as a Function of Pu-240/Pu-239 Ratio in the Sample
19
-------
As discussed above, the atom ratio of sample #16 is not
significantly different from the 0.176 value which is considered
to be due to global fallout. Since this sample presumably contains
no Trinity plutonium, the deposition value of 0.76 nCi/m2 appears
to be one valid point for estimating the background plutonium
deposition for the Trinity area.
The results of several other samples also appear applicable
to this problem, although these samples were not specifically
intended to be "background" samples. These samples were selected
and evaluated as follows. First, the deposition values for all
samples having concentrations (and consequently, deposition
values) greater than the minimum detectable activity were plotted
on log probability paper. The result was a fairly straight line,
indicating that the entire data set was fairly well characterized
by a log-normal distribution. However, a fairly pronounced break
appeared in the curve at deposition values of about 1.0 to 1.3
nCi/m2, indicating that the portion of the plot below these
values might be represented by a different distribution. Conse-
quently, a separate log-normal plot was made of these deposition
values £ l.Q nCi/m2 (15 values). The result was a curved line,
indicating that this portion of the data set was not well repre-
sented by a log-normal distribution. However, an arithmetic
probability plot of the data resulted in a straight line (the
"goodness of fit", r2, of a linear regression line on these data
was 0.97). This strongly suggested that these data are normally
distributed, and that the mean and standard deviation (0.70 ± 0.22
nCi/m2) are the appropriate parameters to describe this distribu-
tion. Whether fortituous or not, this is a good agreement with
the background value of 0.76 nCi/m2 discussed above.
ThNese samples are listed in Table 4, in order of increasing
deposition value, along with their atom ratio and calculated fT
(when available).
20
-------
TABLE 4. DEPOSITION AND fT VALUES FOR BACKGROUND SAMPLES
f ?
Sample No. Atom Ratio T Deposition (nCi/m )
120
0.165 ± 0.043
.072
0.31
0.20
103
0.177 ± 0.039
0
0.42
±
0.043
05
0.189 ± 0.014
0
0.47
+
0.026
100
Not measured
0.56
+
0.010
104
Not measured
0. 56
+
0.12
23
0.263 ± 0.006
0
0.60
+
0.093
102
0.175 ± 0.12
0
0.61
+
0.23
16
0.190 ± 0.030
0
0.76
+
0.057
15
0.250 ± 0.050
0
0.79
+
0.079
39
Not measured
0.80
+
0.73
17
0.162 ± 0.009
0.092
0.82
±
0.023
112
Not measured
0.91
+
0. 51
101
Not measured
0.93
+
0.65
09
Not measured
-
1.0
+
0.88
109
Not measured
-
1.0
+
0.15
The data in Table 4 are not strictly compatible, since some
of the results are by alpha spectrometric analysis by EMSL, while
others are by mass spectrometric analysis from MCL. Atom ratios
for the four samples having the highest deposition values are not
available, so there could be an undetermined contribution of
Trinity plutonium to these samples. The 9 percent Trinity contri
bution to sample #17 and the 7 percent contribution to #120 may
not be statistically significant, since the atom ratios and their
counting errors are not significantly different from the 0.176
global fallout value at the 95 percent confidence level.
On the basis of the above discussion, several observations
may be made about the areal extent of the Trinity plutonium
deposition. (Refer to Figure 2 for the following discussion.)
Sample #05, the eastern-most sample collected along U.S. 380,
definitely appears to be out of the fallout pattern. Proceeding
west along this highway, samples #06, #07, and #29 appear to have
21
-------
little contribution from Trinity, based on the "less-than" deposi
tion numbers. Since these samples were not analyzed by MCL, the
atom ratios are not available to confirm this. It appears that
the eastern edge of the fallout pattern in this area is somewhat
east of sample #28, which definitely has a contribution of
Trinity plutonium.
Sample #17, about 6 miles east of Corona on N.M. 42, may
have a small contribution of Trinity plutonium, although this may
not be statistically significant, as discussed above. Conse-
quently, the eastern edge of the fallout pattern is probably east
of this point. This sample was originally analyzed by EMSL, and
the deposition figure of 0.98 nCi/m2 indicated that it was
approximately at background, in terms of the data which were
available prior to access to the MCL analytical data. Conse-
quently, no further sampling was done in this area in 1974. Only
after the sample was re-analyzed by MCL in 1975 did it become
apparent that more samples should have been collected to better
define and confirm the eastern edge of the pattern in this area.
The same situation prevails along 1-40 to the north.
Although it was suspected, on the basis of deposition values
calculated from the 1973 sampling, that the northeastern limits
of the fallout pattern had probably not been reached by the 1973
sampling, no further sampling was done in this direction in 1974
because of resource limitations on the study- However, when
three of the eight samples were re-analyzed by MCL, the atom
ratios indicated a definite Trinity contribution (60 - 80 percent)
along this arc, and it appears certain that Trinity plutonium
could be found further to the northeast.
All the samples on the arc along U.S. 60 from Willard to
Vaughn were collected in 1974. Again, the eastern edge of the
pattern was obviously not reached in this area. Sample #113,
about five miles southeast of Vaughn, contains about 87 percent
Trinity plutonium as calculated by the atom ratio.
22
-------
The western edge of the pattern is also not well defined.
Sample #103, five miles east of Willard, appears to be at back-
ground on the basis of both atom ratio and deposition level, as
shown in Table 4. Sample#104, five miles further east, also
appears to be background on the basis of the deposition value of
0.56 nCi/m2, although the atom ratio data are not available to
confirm this. However, sample #24, just south of Willard and
west of both of these samples definitely appears to have Trinity
plutonium with a deposition value of 2.9 nCi/m2, although again,
the atom ratio is not available. This is a good illustration of
the areal inconsistency of the observed Trinity plutonium depo-
sition. As discussed previously, this inconsistency could be
accounted for by one or a combination of three major factors
sampling and analytical variability, natural and human redistri
bution, and initial deposition. For example, most of the samples
were collected along roads. Although every effort was made to
select an "undisturbed" sampling location, it was difficult in
practice to be sure that the site was truly undisturbed over the
past 30 years. Grading and earth-moving activities associated
with road maintenance and construction can be disguised over a
period of time by vegetative growth and minor wind and water
erosion so that the area looks natural. It is possible that
samples #103 and #104 were collected at spots where the topsoil
has been removed since 1945. Consequently, these results could
be due to "sampling error" which resulted in sampling relatively
clean topsoil while Trinity plutonium may have been buried or
removed.
Continuing the discussion of the western edge of the pattern,
the atom ratios of the two samples collected at Gran Quivira
National Monument (#162 and #163) indicate 85 95 percent
Trinity plutonium at this location. The deposition values for
samples #36 (2.4 nCi/m2) and #30 (2.6 nCi/m2) suggest that these
are not background values, and that the fallout pattern extends
west of these locations. Samples #16 (on U.S. 60) and #100,
#101, and #102 (on U.S. 380), as shown in Table 4, appear to be
23
-------
background on the basis of their atom ratios and/or deposition
levels. Therefore, the western edge of the deposition pattern
lies somewhere west of a line trending northeast through Bingham
on U.S. 380, Gran Quivira, and Willard on U.S. 60.
Because the allowed access time for the sampling teams onto
the WSMR was limited to one day, relatively few samples were
collected on the Range. This was not considered to be a signifi
cant shortcoming, however, since the primary objective of the
study was to evaluate plutonium deposition in the off-site
(unrestricted) area. Not surprisingly, the highest plutonium
deposition levels found during the study were from samples on the
Range. No samples were collected inside the fenced area surround-
ing the GZ. A sample collected about one mile south of GZ showed
a relatively low deposition value of 1.1 nCi/m2 and contained
about 32 percent Trinity plutonium. Sampling to the east on the
WSMR was limited by the physical barrier of the Oscura Mountains.
In summary, the above discussion of the data from samples
around the edge of the sampling array indicates that the edges of
the deposition pattern are somewhat outside the edges of the
sampling array on the east and north, and possibly somewhat to
the south. The only area in which the edges of the deposition
pattern are relatively well defined is along U.S. 380. Since
this area is closer to GZ, the original fallout pattern was
narrow at this point and better defined than it was further
downwind as the fallout cloud dispersed.
As mentioned previously, the Chapadera Mesa area was of
particular interest to the study since higher deposition levels
were known to have occurred there. These were confirmed by this
study. The highest deposition value found off the WSMR, 86 nCi/m2,
was at the Monte Prieto Ranch. As shown on Figure 2, several
samples having elevated plutonium deposition values, many in the
tens of nCi/m2, were collected in this area.
24
-------
SOIL PROFILES
A total of 12 soil profiles were sampled to determine the
penetration of plutonium into the soil. Seven of the profiles,
collected in 1973, consisted of 5-cm depth increments, or horizons,
and ranged in total depth from 20 to 35 cm. Five profiles were
collected in 1974 using 2.5-cm horizons, and ranged in total
depth from 10 to 25 cm. The total sampling depth was determined
by soil conditions at each sampling site, but an attempt was made
to collect at least five horizons.
The results are presented graphically in Figures A-l through
A-6 for the six samples which had plutonium concentrations above
the minimum detectable activity in at least the top two horizons.
The remaining six profiles were not plotted because "less-than"
concentration values were found in the top horizons.
The six profiles which are plotted generally show a constant
or decreasing plutonium concentration with depth to the depth
sampled. In those profiles which apparently contained significant
amounts of Trinity plutonium, the concentration decreased rapidly
with depth to about the 10- to 15-cm depth. Sample #115 was
anomalous in that the concentration in the second horizon was
less than the minimum detectable activity, while lower horizons
had definitely detectable plutonium. This result does not appear
real, and may be due to a sample processing or analytical error.
AIR SAMPLING
The results of the air sampling at Socorro and at Monte
Prieto Ranch are shown in Tables A-5 and A-6 and in Figures 3 and
4, respectively. The mean and standard deviation of the results
(excluding less-than values and the outlier at Socorro) are
43 ± 27 for Socorro (n = 31 samples) and 41 ± 27 aCi/m3 for the
Monte Prieto Ranch (n = 35).
Using the Pu-240/Pu-239 atom ratio technique described
previously, and the data shown in Table 1, the contribution of
25
-------
Trinity plutonium to the Monte Prieto samples can be calculated.
If values of Rp = 0.181 (as measured in Socorro, and not statis-
tically different from the 0.176 value assumed for global fallout
in soil) and R,j, = 0.023 (as assumed previously) are used, the
four air filters collected at Monte Prieto which were successfully
analyzed by mass spectroscopy were found to contain an average of
about 50 percent Trinity plutonium.
These air sampling data pose an interesting question. The
average concentrations at the two locations are not statistically
different, even though plutonium deposition on the ground at the
Monte Prieto Ranch is considerably higher than that at Socorro.
Furthermore, resuspension was definitely occurring at the ranch,
since about 50 percent of the plutonium collected on the air
filters was due to Trinity. On the surface, the conclusion might
be drawn that global fallout at the ranch was half that in
Socorro. This is highly unlikely, since the two locations are
only about 40 miles apart.
A possible explanation of this apparent anomaly might lie in
the fact that the concentration data for both locations are
averaged over a period of about 10 months, whereas the atom ratio
data at Monte Prieto are based on four filters collected in
November and early December. Consequently, the 50-percent Trinity
contribution may not be representative of the airborne plutonium
composition at Monte Prieto on an annual average basis.
26
-------
SUMMARY AND CONCLUSIONS
Soil samples were collected from an area in central New
Mexico to evaluate the extent and distribution of plutonium
resulting from the detonation of the Trinity device in 1945. A
total of 88 samples were analyzed, covering an area of roughly
4500 square miles. Emphasis was on sampling in areas accessible
to the public, although some samples were collected on the
restricted area of the White Sands Missile Range, where the'
Trinity ground zero is located. The results indicate that most
of the area sampled contains detectable amounts of Trinity pluto-
nium in the surface 5 cm of soil. The highest levels off the
Missile Range were on the Chupadera Mesa, approximately 30 miles
northeast of the ground zero, and were on the order of 20 90
nCi/m2.
Air samples were collected during 1975 at a location on the
Chupadera Mesa and at Socorro, which is west of the deposition
pattern. The average concentrations at these locations were 41 ±
27 and 43 ± 27 aCi/m3, respectively.
Federal Radiation Protection Guidance currently being promul
gated by the Environmental Protection Agency (FR, 1977) suggests
a "screening level" of 200 nCi (of transuranium elements) per
square meter for soil contamination, in the top 1 cm of soil.
The maximum soil contamination level measured in this study (in
an unrestricted area) was 86 nCi of Pu-239,240 per square meter,
or less than half the proposed screening level. The values
reported from this study are for the top 5 cm of soil, and con-
sequently are higher than the value for the top 1 cm. While
higher plutonium levels could no doubt be found by additional
sampling, the sampling density on the Chupadera Mesa makes it
unlikely that grossly higher values are present in this area.
27
-------
The EPA also derives a recommended air concentration of 1000
aCi/m3 based on an activity median aerodynamic particle diameter
of 0.1 um or less. The measured 10-month average air concentra-
tion at the Monte Prieto Ranch, located on the Chupadera Mesa,
was a factor of 25 below this concentration. (This measurement
included all particles collected.) Furthermore, this average
concentration was not statistically different from the average
concentration during the same time period at Socorro, although
some of the filters collected at the Monte Prieto Ranch were
shown to contain Trinity plutonium.
28
-------
REFERENCES
Bernhardt, D.E. (1976), "Evaluation of Sample Collection and
Analysis Techniques for Environmental Plutonium," ORP/LV-7 6-5,
Office of Radiation Programs, LVF, USEPA, Las Vegas, NV, April
1976.
Bliss, W. (1976), "Nevada Applied Ecology Group Procedures Hand-
book for Environmental Transuranics," edited by M.G. White and
P.B. Dunaway, NVO-166, October 1976.
de Jonckheere, E.T. (1976), letter dated August 10, 1976, trans-
mitting analytical results on Trinity soil samples.
Efurd, D.W. (1975), Personal communication.
Efurd, D.W. (1978), Personal communication.
FR, 1977, Federal Register, Vol. 42, No. 230, pp. 60956-60959,
November 30, 1077.
Hardy, E.P., et al. (1972), "Plutonium Fallout in Utah," HASL-
257, July 1972.
Johns, F.B. (1975) (editor), "Handbook for Radiochemical Analyti
cal Methods," EPA-680/4-75-001, National Environmental Research
Center, USEPA, Las Vegas, NV.
Krey, P.W., et al. (1976), "Mass Isotopic Composition of Global
Fallout Plutonium in Soil," IAEA-SM-199/39, 1976.
Krey, P.W. and B. T. Krajewski (1972), "Plutonium Isotopic Ratios
at Rocky Flats," HASL-249, April 1972.
Krey, P.W. (1976), "Remote Plutonium Contamination and Total
Inventories From Rocky Flats," Health Physics, Vol. 30, pp. 209-
214, February 1976.
Larson, K.H. et al. (1951a), "Alpha Activity due to the 1945
Atomic Bomb Detonation at Trinity, Alamogordo, New Mexico, An
Interim Report," UCLA-108, February 1951.
Larson, K.H. et al. (1951b), "The 1949 and 1950 Radiological Soil
Survey of Fission Product Contamination and Some Soil Plant
Interrelationships of Areas in New Mexico Affected by the First
Atomic Bomb Detonation," UCLA-140, June 1951.
29
-------
Merrill, G.L. et al. (1977), "A Comment on 'Remote Plutonium
Contamination and Total Inventories from Rocky Flats'," Health
Physics, Vol. 33, pp. 105-106, July 1977.
Olafson, J.H. et al. (1945), "The Distribution of Plutonium in
the Soils of Central and Northeastern New Mexico as a Result of
the Atomic Bomb Test of July 16, 1945," UCLA-406, September
1957.
Romney, E.M. et al. (1969), "Persistence of Plutonium in Soil,
Plants, and Small Mammals," UCLA, November 1969.
Talvitie, N.A. (1971), "Radiochemical Determination of Plutonium
in Environmental and Biological Samples by Ion Exchange,"
Analytical Chemistry, Vol. 43, No. 13, November -1971.
Talvitie, N.A. (1972), "Electrodeposition of Actinides for Alpha
Spectrometic Determination," Analytical Chemistry, Vol. 44, No.
2, February 1972.
Warren, S.L. (1949), "The 1948 Radiological and Biological Survey
of Areas in New Mexico Affected by the First Atomic Bomb
Detonation," UCLA-32, November 1949.
30
-------
APPENDIX A
31
-------
TABLE A-l. COORDINATES OF NOVEMBER 1973 SOIL SAMPLING LOCATIONS
Sample Code North Latitude West Longitude
01 33° 52' 30" 106° 28' 15"
02 33° 53' 00" 106° 25' 15"
03 33° 53' 15" 106° 22' 30"
04 33° 31* 15" 106° 02' 00"
05 33° 45' 00" 106° 03' 00"
06 33° 45' 30" 106° 07' 00"
07 33° 46' 45" 106° 09* 30"
08 33° 58' 15" 106° 15' 30"
09 33° 56' 45" 106° 04' 00"
10 34° 00' 00" 106° 06' 00"
11 34° 02' 00" 106° 04' 00"
12 34° 01' 00" 106° 01' 00"
13 33° 59' 00" 106° 00' 00"
14 33° 57' 45" 106° 00' 00"
15 33° 57' 00" 105° 54' 30"
16 34° 25' 00" 106° 38' 00"
17 34° 11* 45" 105° 32' 00"
IB 34° 16' 30" 105° 35' 00"
19 34° 18' 00" 105° 38' 00"
20 34° 22' 30" 105° 42' 00"
21 34° 251 30" 105° 47' 00"
22 34° 28* 30" 105° 52' 00"
23 34° 30' 30" 105° 57' 45"
24 34° 34' 45" 106° 01' 15"
25 Approx. 17 miles east of Holbrook, AZ on I -
26 33° 521 45" 106° 19' 30"
27 33° 50' 45" 106° 17' 30"
28 33° 49' 00" 106° 15 * 00"
29 33° 48* 00" 106° 12' 15"
30 33° 57' 45" 106° 18' 00"
31 33° 59' 15" 106° 13* 00"
32 33° 59' 45" 106° 09' 30"
33 34° 03' 45" 106° 07' 00"
34 34° 06* 00" 106° 11' 00"
35 34° 07' 45" 106° 14' 15"
36 34° 07' 15" 106° 16' 45"
37 34° 56' 45" 104° 42' 15"
38 34° 58* 15" 104° 47' 45"
39 34° 58' 30" 104° 52* 45"
40 34° 58* 30" 104° 48* 00"
41 34° 59' 00" ' 105° 01' 00"
42 34° 59' 15" 105° 10' 00"
43 34° 59' 30" 105° 15' 45"
44 34° 59' 45" 105° 21' 15"
32
-------
TABLE A-2. COORDINATES OF DECEMBER 1974 SOIL SAMPLING LOCATIONS
Sample Code North Latitude West Longitude
100
34°
52'
50"
105°
31'
20'
101
34°
53'
00"
106°
34'
40'
102
34°
53 '
10"
106°
37'
50'
103
34°
35'
10"
105°
56'
30'
104
34°
37 '
30"
105°
52'
20'
105
34°
40'
10"
105°
48*
20
106
34°
41*
00"
105°
43'
20'
107
34°
40'
30"
105°
37'
40'
108
34°
40*
10"
105°
32'
50'
109
34°
42'
50"
105°
29'
00'
110
34°
38'
30"
105°
26'
30'
111
34°
36'
30"
105°
22*
20'
112
34°
35'
10"
105°
17'
30'
113
34°
34'
00"
105°
16'
50'
114
34°
3'
00"
106°
3'
40'
115
34°
6 1
00"
106°
2 1
50'
116
34°
4'
20"
105°
58'
50"
117
34°
1'
30"
105°
57'
40*
118
34°
12'
10"
105°
59'
50*
119
34e
41'
10"
106°
28'
40'
120
34°
43'
20"
106°
29'
50'
121
34°
44«
50"
106°
28'
20'
122
34°
47'
30"
106°
29'
30'
123
34°
48'
00"
106°
29'
00'
124
34°
47'
30"
106°
32'
30'
150
34°
8'
30"
106°
6'
50'
151
34°
8'
25"
106°
2'
40'
152
34°
7.
40"
105°
59'
50'
153
34°
39'
50"
106°
29'
00'
154
34°
44'
30"
106°
26'
40'
155
34°
43'
55"
106°
24'
10*
156
34°
47'
00"
106°
24'
30'
157
34°
49'
00"
106°
24'
00'
158
34°
49'
20"
106°
25'
30'
159
34°
54'
40"
106°
21'
30*
160
34°
55'
30"
106°
15'
50'
161
34°
01'
20"
106°
6'
50'
162 163
34°
15'
20"
106°
5'
40'
164 S 166-169
34°
6'
00"
106°
7'
10'
165
34°
15'
40"
105°
53'
00*
-------
TABLE A-3. RADIONUCLIDE CONCENTRATIONS IN TRINITY SOIL SAMPLES COLLECTED DURING NOVEMBER 1973
P L U T O N I U M-239, 240 Plutonium-238 Americium-241 Cesium-137
Sample Concentration Deposition Concentration Concentration Concentration
Number (pCi/g) (nCi/m2) (pCi/g) (pCi/g) (pCi/g)
Surface Samples - See text for coding description
0117
0.041
+
0.022
2.9
+
1.5
0.021
4
0.017
<0.0052
0.38
0217
0.026
+
0.019
1.8
+
1.3
0.020
+
0.017
<0.0041
0.47
0517
-------
TABLE A-3. RADIONUCLIDE CONCENTRATIONS IN TRINITY SOIL SAMPLES COLLECTFD DURING NOVEMBER 1973 (Continued)
PL UTOWIU M-239, 240 Plutonium-238 Americium-241 Cesium-137
Sample Concentration Deposition Concentration Concentration Concentration
Number (pCi/g) (nCi/m2) (pCi/g) (pCi/g) (pCi/g)
Profile Samples - See text for coding description
032N
0.12 t
0.051
8.5
+
3.5
<0.026
NA
0.34
0320
<0.0094
<0.54
<0.024
NA
0.14
032P
0.12 ±
0.039
6.7
+
2.1
0.025
+
0.021
NA
ND
032Q
<0.034
<2.0
<0.050
NA
ND
032R
<0.021
<1.4
<0.019
NA
ND
042N
<0.011
<0.57
<0.024
NA
ND
0420
<0.014
<0.98
<0.025
ND
042P
<0.008
<0.58
<0.027
NA
ND
042Q
<0.0074
<0.31
<0.023
NA
ND
102N
<0.0081
<0.40
<0.022
NA
0.25
1020
0.057 ±
0.036
2.8
+
1.8
<0.031
NA
ND
102P
0.034 ±
0.033
1.7
+
1.7
<0.036
NA
0.072
102Q
<0.012
<0.51
<0.028
NA
0.14
102R
<0.034
<1.7
<0.031
NA
ND
112N
<0.0086
<0.54
<0.025
NA
0.13
1120
<0.010
<0.66
<0.021
NA
ND
112P
<0.034
<2.1
<0.049
NA
ND
112Q
<0.013
<0.78
<0.021
NA
0.077
202N
0.30 ±
0.057
21
±
4.0
0.033
+
0.020
NA
0.73
2020
0.19 ±
0.044
13
+
3.0
0.025
+
0.018
NA
0.54
202P
0.079 ±
0.030
5.1
4
1.9
0.027
+
0,020
NA
0.080
202Q
0.029 ±
0.020
2.1
+
1.4
0.020
+
0.018
NA
0.065
202R
0.030 ±
0.020
2.0
±
1.3
0.017
+
0.016
<0
.0041
0.064
202S
0.029 ±
0.020
2.2
+
1.5
<0.016
NA
ND
272N
0.050 ±
0.029
2.8
+
1.6
0.027
i
0.023
NA
0.66
2720
0.018 ±
0.016
1.0
±
0.88
0.016
±
0.015
NA
ND
272P
0.027 ±
0.018
0.98
±
0.67
0.020
±
0.017
NA
0.08
272Q
0.051 ±
0.024
1.7
+
0.79
0.029
±
0.019
NA
ND
272R
0.054 ±
0.024
1.3
+
0.57
0.032
±
0.020
NA
ND
272S
0.024 ±
0.018
0.58
+
0.44
0.044
+
0.022
NA
0.095
272T
0.035 ±
0.021
2.0
+
1.2
0.020
±
0.017
NA
ND
322N
0.83 ±
0.11
47
+
6.1
0.056
+
0.026
NA
2.7
3220
0.11 ±
0.033
6.0
±
1.8
0.017
+
0.016
NA
0.30
322P
0.035 ±
0.020
2.1
+
1.2
0.016
±
0.015
<0
.0029
ND
322Q
<0.014
<0.66
<0.014
NA
ND
Notes: 1, Error terms are two-sigma counting error.
2. "<" indicates concentration is less than the stated value.
3. NA indicates no analysis.
4. ND indicates activity was non-detectable.
-------
TABLE A-4. RADIONUCLIDE CONCENTRATIONS IN TRINITY SOIL SAMPLES COLLECTED DURING DECEMBER 1974 (Continued)
PLUTONIUM 239, 240 Plutonium-238
Sample Concentration (pCi/flj Deposition Atom Ratio Concentration
Number Alpha Spectroscopy Mass Spectroscopy (nCi/m2) Pu-240/Pu-239 (pCi/gm)
Profile Samples - See text for coding description
1092A
0.036
+
0.0036
0.034
± 0.0044
1.5
f
0.1S
0.070
t 0.039
Limit
1092B
0.014
+
0.0016
0.015
± 0.0014
0.53
+
0.060
0.104
± 0.021
0.002 ± 0.0009
1092C
<0.039
<0.001
Limit
Limit
109 2D
<0.025
<0.0008
Limit
Limit
1092E
<0.038
Limit
Limit
Limit
1092F
<0.015
<0.023
Limit
Limit
1092G
<0.003
Limit
Limit
Limit
1092H
<0.009
<0.0003
Limit
Limit
10921
<0.030
<0.002
Limit
Limit
1092J
<0.021
<0.002
Limit
Limit
1102A
0.010
+
0.0062
0.0090
± 0.00095
0.27
+
0.17
0.084
± 0.024
Limit
1102B
<0.0090
0.0020
± 0.00015
0.053*
0.0039
Limit
1152A
1.3
+
0.11
1.4
± 0.014
36
+
3.0
0.025
± 0.00060
0.072 ± 0.0060
11S2B
<0,0050
0.0050
± 0.00094
0.17
+
0.031
Limit
1152C
0.255
+
0.0714
0.268
i 0.0038
0.026
± 0.0011
Limit
1152D
0.120
+
0.0432
0.141
± 0.0107
0.029
± 0.0052
Limit
11S2E
0.064
+
0.0218
0.060
± 0.0008
0.029
± 0.0017
Limit
1152F
<0.042
<0.018
Limit
1152G
0.013
+
0.0055
<0.016
Limit
1152H
<0.006
<0.003
Limit
11521
<0.014
<0.001
Limit
1152J
<0.012
<0.007
Limit
1182A
0.088
+
0.015
0.093
± 0.0032
2.1
+
0.36
0.035
± 0.0070
Limit
1182B
0.075
+
0.0065
0.080
± 0.0034
2.0
+
0.17
0.039
± 0.0086
0.0050± 0.0017
1182C
0.086
+
0.0138
<0.100
Limit
1182D
0.066
+
0.01-72
<0.081
Limit
1182E
<0.010
<0.002
Limit
1182F
<0.010
Limit
Limit
1182G
<0.017
Limit
Limit
1182H
<0.013
Limit
Limit
11821
<0.027
Limit
Limit
1182J
<0.008
Limit
Limit
1522A
0.0070
i±'
0.0031
0.0090
± 0.00067
0.19
+
0.083
0.119
± 0.021
Limit
1522B
1.2
+
0.11
1.3
± 0.015
39
+
3.6
0.025
± 0.00065
0.073 ± 0.0085
1522C
<0.019
Limit
Limit
1522D
<0.012
Limit
Limit
1522E
<0.024
Limit
Limit
1522F
<0.015
Limit
Limit
1S22G
<0.007
Limit
Limit
1522H
<0.005
Limit
Limit
15221
<0.006
Limit
Limit
Analysis Codes: 1. Error terms are two-sigma counting error.
2. "Limit" indicates activity was below limit of detection.
3. "<" indicates concentration is less than the stated value.
-------
TABLE A-4. RADIONUCLIDE CONCENTRATIONS IN TRINITY SOIL SAMPLES COLLECTED DURING DECEMBER 1974
PLUTONIUM 239, 240 Plutonium-238
Sample Concentration (pCi/g)" Deposition Atom Ratio Concentration
Number Alpha Spectroscopy Mass Spectroscopy (nCi/m2) Pu-240/Pu-239 f pCi/g)
Surface Samples - See text for coding description
10017
<0.023
0.007
±
0.0013
0.56
± 0.10
Limit
Limit
10117
0.011
+
0.0077
Limit
0.93
± 0.65
Limit
Limit
10217
<0.034
0.008
±
0.003
0.61
± 0.23
0.175 ± 0.12
Limit
10317
<0.021
0.008
±
0.00082
0.42
± 0.043
0.177 ± 0.039
Limit
10417
<0.056
0.009
+
0.002
0.56
± 0.12
Limit
Limit
10517
<0.021
0.025
+
0.013
1.9
± 0.93
Limit
Limit
10617
0.015
+
0.0060
0.011
±
0.00055
1.1
± 0.44
0.135 ± 0.015
Limit
10717
0.077
+
0.0099
0.084
±
0.0024
4.6
± 0.59
0.053 ± 0.0046
Limit
10817
<0.012
Limit
<0.76
Limit
11117
0.096
+
0.050
0.095
±
0.0072
6.1
± 3.2
0.076 ± 0.018
Limit
11217
0.013
+
0.0073
0.019
±
0.014
0.91
± 0.51
Limit
Limit
11317
0.15
+
0.016
0.15
±
0.0034
9.1
± 0.93
0.043 ± 0.0032
Limit
11417
0.53
+
0.038
0.53
±
0.013
28
± 2.0
0.028 ± 0.0024
0.028 ± 0.0032
11617
0.38
+
0.047
0.44
±
0.016
29
±3.5
0.036 ± 0.0086
0.049 ± 0.015
11717
0.068
+
0.0082
0.074
±
0.0066
4.5
± 0.27
0.047 ± 0.021
Limit
11917
14
+
1.8
15
+
0.22
1100
tl30
0.025 ± 0.00030
0.80 ± 0.11
12017
0.004
+
0.0026
0.0060+
0.00067
0.31
± 0.20
0.165 ± 0.043
Limit
12117
1.3
+
0.21
1.4
±
0.019
110
±17
0.023+ 0.0012
0.079 ± 0.019.
12217
0.022
+
0.011
Limit
1.8
+ 0.87
Limit
Limit
12317
0.015
+
0.0030
0.017
±
0.0095
1.2
± 0.24
0.153 ± 0.077
0.005 ± 0.0027
12417
0.013
+
0.0057
0.014
±
0.00070
1.1
± 0.48
0.133 ± 0.015
Limit
15017
0.52
+
0.071
0.47
±
0.013
32
± 4.3
0.026 ± 0.0028
0.027 ± 0.0070
15117
0.24
+
0.023
0.23
±
0.0046
17
± 1.6
0.032 ± 0.0021
0.025 ± 0.0055
15317
0.017
+
0.0095
0.021
±
0.0011
1.1
± 0.62
0.127 ± 0.018
Limit
15417
0.38
+
0.092
0.34
±
0.020
27
± 6.5
0.042 ± 0.0081
Limit
15517
0.022
+
0.0048
0.029
±
0.0015
1.7
± 0.38
0.114 + 0.015
Limit
15617
0.29
+
0.071
0.29
±
0.0047
25
± 5.9
0.038 ± 0.0024
Limit
15717
0.17
+
0.030
0.18
±
0.014
12
± 2.1
0.049 ± 0.0094
Limit
15817
0.14
+
0.020
0.19
±
0.015
10
± 1.4
0.075 ± 0.024
Limit
15917
0.18
+
0.035
0.16
±
0.0065
12
± 2.4
0.031 ± 0.0062
Limit
16017
0.60
+
0.16
0.52
±
0.010
48
±12
0.028 ± 0.0015
0.034 ± 0.016
16117
0.10
+
0.022
0.12
±
0.0097
6.1
± 1.3
0.027 ± 0.014
Limit
16217
0.25
+
0.081
0.24
±
0.019
20
± 6.3
0.048 ± 0.014
0.072 ± 0.035
16317
0.11
+
0.012
0.12
+
0.0030
8.6
± 0.96
0.031 ± 0.0045
0.0070± 0.0025
16416
0.63
+
0.33
1.0
+
0.010
28
±15
0.027 ± 0.00043
Limit
16516
1.2
+
0.42
1.3
+
0.038
45
±15
0.037 ± 0.0033
Limit
16616
0.30
+
0.065
0.29
+
0.0059
8.0
± 1.8
0.027 + 0.0015
Limit
16716
2.8
+
0.73
3.2
+
0.038
86
±22
0.025 ± 0.0011
0.16 ± 0.062
16916
1.5
+
0.26
1.6
+
0.054
42
± 7.2
0.032 ± 0.0062
0.098 ± 0.033
-------
TABLE A-5. AIRBORNE PLUTONIUM CONCENTRATIONS AT SOCORRO DURING 1975
Date On Date Off Plutonium-239,240 Plutonium-238 Analysis
(aCi/m3) (aCi/m3) Code
Feb
4
Feb
12
37
+
8.2
<5.0
1
Feb
12
Feb
18
71
±
11
<6.3
1
Feb
18
Feb
25
64
+
19
<14
1
Feb
25
Mar
3
37
+
3.7
1.9
+
0.84
2
Mar
3
Mar
11
88
+
5.3
2.3
0.86
2
Mar
11
Mar
17
66
±
4.9
3.9
+
1.2
2
Mar
17
Mar
24
62
±
4.4
2.9
+
0.96
2
Mar
24
Apr
1
78
±
5.1
3.7
+
1.1
2
Apr
1
Apr
8
80
+
5.3
ND
2
Apr
8
Apr
15
62
+
4.3
1.6
+
0.67
2
Apr
15
Apr
22
52
+
4.1
2.5
+
0.90
2
Apr
22
Apr
29
67
+
4.8
ND
2
Apr
29
May
6
75
+
6.4
2.3
+
1.1
2
May
6
May
13
89
+
7.5
1.5
+
0.96
2
May
13
May
20
48
+
5.2
1.9
+
1.0
2
May
20
May
26
60
+
6.1
ND
2
May
26
Jun
3
35
3.2
1.3
+
0.61
2
Jun
3
Jun
10
32
+
3.2
ND
2
Jun
10
Jun
17
36
+
3.3
2.1
+
0.81
2
Jun
17
Jun
24
34
+
4.1
3.4
+
1.3
2
Jun
24
Jun
30
33
+
4.2
1.1
+
0.77
2
Jun
30
Jul
8
14
+
2.5
15
+
2.5
2
Jul
8
Jul
16
8.
7±
2.1
ND
2
Jul
16
Jul
22
10
+
1.9
0.7C
+
0.50
2
Jul
22
Jul
29
17
+
2.3
0.62
+
0.44
2
Jul
29
Aug
5
8.
8 +
1.7
1.1
+
0.60
2
Aug
5
Aug
12
NA
NA
1
Aug
12
Aug
19
NA
NA
1
Aug
19
Aug
26
NA
NA
1
Aug
26
Sep
2
NA
NA
1
Sep
.2
Sep
9
230
±200
160
+
94
1
Sep
9
Sep
16
<6.
0
<2.0
3
Sep
16
Sep
23
2.
14±
0.317
NA
4
Sep
23
Sep
30
10
+
7.0
<2.0
3
Sep
30
Oct
7
<14
25
12
3
Oct
7
Oct
16
< 6.
0
<2.0
3
Oct
16
Oct
22
< 2.
0
<2.0
3
Oct
22
Oct
28
22
+
10
9.0
+
6.0
3
Oct
28
Nov
4
< 2.
0
<2.0
3
Nov
4
Nov
10
20
+
15
26
+
18
3
Nov
10
Nov
18
ND
NA
4
Nov
18
Nov
25
7.
40 ±
2.07
NA
4
Nov
25
Dec
2
ND
NA
4
Analysis Codes: 1. Total analysis by EMSL-LV
2. Chemistry and electroplating by EMSL-LV; alpha
spectroscopy by Mound Laboratory
3. Total analysis by Eberline Instrument Corporation
4. Total analysis by McClellan Central Laboratory
using mass spectroscopy
NA = no analysis
ND = non-detectable
38
-------
TABLE A-6. AIRBORNE PLUTONIUM CONCENTRATIONS AT MONTE PRIETO RANCH DURING 1975
Date On Date Off Plutonium-239,240 Plutonium-238 Analysis
(aCi/m3) (aCi/m3) Code
Feb
11
Feb
17
96
+
21
<13
1
Feb
17
Feb
24
60
+
4.3
3.3
± 1.0
2
Feb
24
Mar
3
38
+
3.6
12
± 2.0
2
Mar
3
Mar
10
92
+
5.6
7.3
± 1.6
0
Mar
10
Mar
17
65
+
4.7
2.2
± 0.86
2
Mar
17
Mar
23
54
+
4.4
4.7
± 1.3
2
Mar
23
Mar
29
88
+
5.8
2.5
± 0.97
2
Mar
29
Apr
4
78
+
5.0
3.5
± 1.1
2
Apr
4
Apr
11
49
+
3.8
3.8
± 1.1
2
Apr
11
Apr
18
51
+
4.0
0.62
± 0.44
2
Apr
18
Apr
25
60
+
4.2
2.5
± 0.85
2
Apr
25
May
2
63
+
5.9
2.5
± 1.2
2
May
2
May
8
81
+
7.2
ND
i
May
8
May
15
70
+
6.4
22
± 3.5
2
May
15
May
23
54
+
3.6
1.8
± 0.67
2
May
23
May
31
43
+
3.5
0.94
± 0.51
2
May
31
Jun
6
28
+
2.9
0.95
± 0.54
2
Jun
6
Jun
12
40
+
3.8
1.5
± 0.73
2
.Jun
12
Jun
19
34
+
3.2
1.5
± 0.68
2
Jun
19
Jun
25
34
+
4.4
ND
->
Jun
25
Jul
4
23
+
3.0
3.2
± 1.1
Jul
4
Jul
10
18
+
3.3
1.5
± 0.95
->
Jul
10
Jul
16
15
+
2.4
0.69
± 0.51
i
Jul
lb
Jul
24
11
+
1.7
ND
->
Jul
24
Jul
30
7.
6±
1.6
ND
Jul
30
Aug
5
NA
NLA
1
Aug
5
Aug
12
NA
NA
1
Aug
12
Aug
18
NA
NA
1
Aug
18
Aug
25
NA
NA
1
Aug
25
Aug
31
NA
NA
1
Aug
31
Sep
8
42
+
18
<2.0
3
Sep
8
Sep
15
<6.
0
<2.0
3
Sep
15
Sep
21
20
+
14
<2.0
5
Sep
21
Sep
28
<18
<2.0
3
Sep
28
Oct
6
15
+
8.0
<4.0
3
Oct
6
Oct
15
No sample due to broken sampler
Oct
15
Oct
22
18
+
13
<2.0
3
Oct
22
Oct
31
38
+
16
<4.0
3
Oct
31
Nov
4
14
7±
1.29
NA
4
Nov
4
Nov
11
9
11±
1.02
NA
4
Nov
11
Nov
20
12.
1±
2.66
NA
4
Nov
20
Dec
2
3.
35±
0.30
NA
4
Dec
2
Dec
15
4.
25±
0.38
NA
4
Analysis Codes: 1. Total analysis EMSL-LV
2. Chemistry and electroplating by EMSL-LV;
alpha spectroscopy by Mound Laboratory
3. Total analysis by Eberline Instrument Corporation
4. Total analysis by McClellan Central Laboratory
using mass spectroscopy
NA = no analysis
ND = non-detectable
39
-------
0-1
52 a
o
* 2.5 ^
(O
«
0>
¦J B
c
0)
o
i 7.5-
c.
a.
Q>
a
5-
10
1 1
0 0.1 0.2
Plutonium-239,240 Concentration
(pCi/gram)
Figure A-l.
Depth Profile for
Sample #118
O-i
CO
w
2
.1 B
C
0>
o
52 a
a>
* 2.5 ^
5-
~ 7.5 -
&
s °
10'
¦ Less Than Indicated Value
T
0.1
n
0.2
Plutonium-239,240 Concentration
(pCi/gram)
Figure A-2
Depth Profile for
Sample #109
Less Than Indicated Value
2.5
<¦¦¦¦»»
(A
w
0>
7.5
cB
E
s
c
4>
P
12.5
a.
a>
O
15
17.5
20
1.4
1.2
0.6
1.0
0.2
0.8
0
0.4
Plutonium-239,240 Concentration (pCi/gram)
Figure A-3. Depth Profile for
Sample #115
40
-------
-r-
0.2
—I—
0.3
0 0.1
Plutonium-239,240 Concentration (pCi/gram)
0-i
5-
o
10
p
15-
® °
g 20
£ R
Q.
0>
O
25
s
30-
35 ¦
T
0.1
n
0.2
Plutonium-239,240 Concentration
(pCi/gram)
Figure A-4. Depth Profile for Figure A-5. Depth Profile for
Sample #20 Sample #27
41
-------
Lass Than Indicated Value
0.5
0.9
0.2
0.6
0.7
0
0.1
0.3
0.4
0.8
Plutonium-239,240 Concentration (pCi/gram)
Figure A-6. Depth Profile for
Sample #32
-------
0.82*0.023
(0.162)
1
N
i
Figure 2.
TRINITY SITE
SOIL SAMPLING LOCATIONS AND RESULTS
plutonium-239,240 deposition as nanocuries per square meter
in the top five centimeters of soil (unless otherwise noted)
LEGEND
134 ^ sample location number
8.6 ± 3.4 Pu-239,240 deposition (nCi/m2)
(0.043) — 2-Sigma counting error
Atom ratio: Pu-240/Pu-239
< indicates deposition is less than the stated number
P indicates profile sample
* indicates 2.5 cm depth sample
¦ indicates location sampled in December 1974
• indicates location sampled in November 1973
SCALE
1" = 6 miles
1 cm = 3.8 kilometers
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RADIATION PROGRAMS- IAS VEGAS FACILITY
-------
0.76 ±0.057
(0190)
1
TjirW
WILLARD
24
IMOUNTAINAIR
104
'0.56* 0.12
f s«» 4:09
(0.263)
-4.7± 2.7
[{0.047)
Cede
8.6*0.96 /
'"031) / J$S*_
/ 45*15
-------
43.
4 3*0,19
(0.048)
0 8 XO./i
(0-003)
SANTA ROSA
i in ft?n\
106
ft ± 044
(0.135)
107
O ± 0.59
(0053)
108
NCINO
VAUGHN
rrirl
(0,076)
112
0.91
113
9,1 X 0-93
(0.043)
2.5 ±1-2
gj Guadalupe Co.
§l Lincoln Co.
Cedarvale V
-------
102
0.61 ±0,23
0.93 x 0.65
White Sands
Missile Range
Gran Quivira
National Monument
20 ± 6.3
(0.048)
(0.035)
o
(0.032)
^Claunch
1S2P
40 ± 3.6
32x 4.3
.-36 ....
2.4 ±1.9
(0.026)
34
3.6 ± 1.4
(0.025)
115fi
36 ± 3.0
(0.025)
29 ± 3.5
164' 166 167' 169*
28 ±15 8.0*1.8 86±22 42±7.2
(0.027) (0.025) (0.032)
(0.036)
114
2B * 2.0
(0.028)
(0.027)
Monte Prieto Ranch
. 117
4.5 ±0.27
(0.047)
161
6,1 ± 13
(0,027)
<0,54
5 ±0.99
(0.025)
3.0 ± 1.4
2.6 ± 1.2 %
0,79 ±0.079
160
48 ±13
(0.028)
(0.250)
12 ±2.4
(0.031)
Bingham
0,56 * 0.10
3P
8.5*3.5
01 W
2.9 ±1.5
i.fl ±1.3
158 157
10 ±1.4 12 *2.1
- (0.075) (0.049)
1.2S0.44 m~~m
(0.153)
Socorro Co.
3.S ±0.038
(0.069)
Lincoln Co.
1.1 ±0.48
_2S_
<0.63
156
25 ± 5.9
(0.038)
122
1.8 ±0.87
(0.133)
2JL I OS
<0.84 , 0.47 ± 0.026
(0.189)
<0.71
121 155
110*17 ¦ 1.7 ±0.38
(0.023) ^ (0,114)
120
0.31 ± 0.20
(0.165)
119
1100±130
27 ± 6.5
(0.042)
(0.127)
(0.025) ¦
TRINITY DETONATION POINT*153
1.1 ±0.62
'CARRIZO
<057
\
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO. 2.
ORP/LV-78-3
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Levels and Distribution of Environmental
Plutonium Around the Trinity Site
5. REPORT DATE
October 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Richard L. Douglas
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
U.S. Environmental Protection Agency-
Office of Radiation Programs-Las Vegas Facility
P. 0. Box 15027
Las Vegas, NV 89114
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Same as above
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
A study was conducted in central New Mexico to evaluate the levels
and distribution of plutonium resulting from the detonation of the
Trinity device in 1945. A total of 88 soil samples were collected,
covering an area of roughly 4500 square miles. Air samples were
collected during 1975 at a location within the Trinity fallout pattern,
and at another site outside the pattern. All samples were analyzed for
plutonium-239,240 by alpha spectroscopy, and some were analyzed by mass
spectroscopy for both nuclides. Trinity plutonium can be distinguished
from global fallout plutonium by the ratio of the two plutonium nuclides.
The results indicate that most of the area sampled contains detectable
amounts of Trinity plutonium in the surface 5 cm of soil. The highest
levels of plutonium-239,240 deposition in soil (in unrestricted areas)
were on the order of 90 nCi/m2. The air samples at the site within the
fallout pattern contained about 50 percent Trinity plutonium, but the
average concentration of airborne plutonium at the two locations was the
same.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATl Field/Group
Plutonium
Plutonium-239
Trinity
Environmental
plutonium
0702
1802
18. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
51
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (Roy. 4-77) previous edition is obsolete
------- |