United States
Environmental Protection
Agency
Office of
Radiation Programs
Washington, D.C. 20460
EPA 520/1-8&013
August 1986
Radiation
vvEPA
Report on the Survey of
Abandoned Uraniferous
Lignite Mines in
Southwestern North Dakota
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REPORT ON THE SURVEY OF
ABANDONED URANIFEROUS LIGNITE MINES IN
SOUTHWESTERN NORTH DAKOTA
by
Robert J. Lyon*
Daphne Prochaska*
Jeffrey L. Burgess**
Dale Patrick**
March 1986
*U.S. Environmental Protection Agency
Office of Radiation Programs-Las Vegas Facility
P.O. Box 18416, Las Vegas, Nevada 89114
**North Dakota State Department of Health
Bismarck, North Dakota 58501
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DISCLAIMER
This report was prepared and approved for publication
by the United States Environmental Protection Agency. Reference
to any specific commercial product, process, or service does
not indicate its endorsement or recommendation for use by the
United States Government or any agency thereof.
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FOREWORD
The Office of Radiation Programs (ORP) of the U.S. Environmental
Protection Agency (EPA) carries out a national program to evaluate population
exposure to ionizing and nonionizing radiation and to promote the development
of controls necessary to protect the public health and safety.
Within the Office of Radiation Programs, the Las Vegas Facility
(ORP-LVF) conducts in-depth field studies of various radiation sources
(e.g., nuclear facilities, uranium mill tailings, and phosphate mills) to
provide technical data for environmental impact assessments as well as
information on source characteristics, environmental transport, critical
pathways for population exposure, and dose model validation. The ORP-LVF
also provides, upon request, technical assistance to Western States and to
other Federal agencies. The ORP-LVF conducted a radiological survey of
abandoned uraniferous lignite mines in southwestern North Dakota. This
survey was done with the assistance of the North Dakota State Department of
Health and EPA's Region 8. Results, analysis, and recommendations for
cleanup are included in this report.
Readers of this report are encouraged to inform the ORP-LVF of any
omissions or errors. Comments or requests for further information are also
invited.
Sheldon Meyers, Director
Office of Radiation Programs
m
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ABSTRACT
A radiation survey was conducted in October 1983 as part of the
proposed reclamation plan of abandoned uraniferous lignite mines in
southwestern North Dakota. This survey was made to determine the extent of
contamination caused by mining operations in the 1960's. Radiation
measurements were made and soil samples were taken at approximately 300
locations around six mine sites comprising eleven lignite mine pits. Toxic
element analysis was also done on 50 of the soil samples. This information
is needed in order to estimate the area around the pits which should be
decontaminated during reclamation operations. The general radium-226
background in the area (4.2 pCi/gm) is affected by uranium ore outcroppings
and is approximately four times the average background (1.2 pCi/gm) of
radium-226 content. Concentrations of radium-226 ranged from 1.0 to 250
pCi/gm for all the soils sampled. Although several samples taken near the
edges of some pits had radium-226 concentrations in excess of 50 pCi/gm, in
general the soil samples taken near the pits were in the range of 10-20 pCi
of radium-226 per gram of dry soil. Based on the toxic element analysis,
there does not appear to be a potential risk from these elements at the mine
sites. If the standards for remedial actions at inactive uranium processing
sites are applied to this reclamation operation, an area of approximately
130 acres and a volume of 110,000 cubic yards will be disposed of or
controlled.
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CONTENTS
PAGE
Disclaimer ii
Foreword iii
Abstract iv
List of Figures and Tables yi
Acknowledgements vii
Summary and Conclusions viii
1. Introduction ; 1
2. Method 2
Sampling Procedure 2
Toxic Element Analysis 6
3. Results and Discussion 7
Determination of Background Levels 7
Exhalation Measurements 9
Validation and Adjustment of Scintillometer Measurements . 9
Fractionated Samples 11
Assessment of Mine Site Contamination and Cleanup 11
Palaniuk Mine Site 14
Talkington Mine Site 14
Frank Mine Site 14
Klym Mine Site 17
Smith Mine Site 17
Fritz Mine Site 17
References 22
Appendixes
A. Aerial Photographs 24
B. Acid Extractable Metals 30
C. Radium-226 in Background Soil Samples 33
D. Correlation of Scintillometer Measurements
with PIC Readings 37
E. Ra-226 Analysis of Fractionated Samples 41
F. Radium-226 Analysis 44
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LIST OF FIGURES AND TABLES
Figure Page
1. Smith mine site (West pit) 5
2. Frequency distribution of background samples 8
3. Correlation of Ra-226 concentrations and Rn-222 exhalation ... 10
4. Frequency distribution of Ra-226 concentrations in soil up
to 31 pCi/g .,. . 12
5. Frequency distribution of Ra-226 concentrations in all
soil samples 13
6. Ra-226 concentrations in soils around the Palaniuk mine site . . 15
7. Ra-226 concentrations in soils around the Talkington mine site . 16
8. Ra-226 concentrations in soils around the Frank mine site ... 18
9. Ra-226 concentrations in soils around the Klym mine site .... 19
10. Ra-226 concentrations in soils around the Smith mine site ... 20
11. Ra-226 concentrations in soils around the Fritz mine site ... 21
Table
1. Rn-222 exhalation and Ra-226 in soil
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ACKNOWLEDGEMENTS
We would like to acknowledge the assistance of the following people on
the survey part of this study.
John Giedt EPA, Region 8
Steve Charlton North Dakota State Department of Health
Rodney Peterson North Dakota State Department of Health
Edith Boyd EPA, Office of Radiation Programs-LVF
Joseph Hans EPA, Office of Radiation Programs-LVF
Paul Wagner EPA, Office of Radiation Programs-LVF
We would also like to acknowledge the analytical assistance of
Milton Lamniering, Chief, Analytical Support Branch, EPA, Denver, Colorado.
vn
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SUMMARY AND CONCLUSIONS
In April 1983, the North Dakota State Department of Health in
conjunction with the North Dakota Public Service Commission requested
technical assistance, cleanup, decommissioning guidance and equipment from
EPA to proceed in a joint effort to plan for and reclaim six uraniferous
lignite mine sites (eleven pits).
In October 1983, approximately 300 locations around lignite pits were
surveyed. Measurements of external gamma exposure were made with pressurized
ionization chambers (PIC) and scintillometers. Soil samples from most
locations were taken for gamma spectral analyses. Radon exhalation
measurements were made at about 30 locations at two mine sites.
A very good correlation of scintillometer and PIC measurements was
found. Soil radium content and scintillometer reading correlations were
also very good. There appeared to be no correlation between radium
concentration in soil and radon exhalation from the soil.
The analyses of soil for toxic metals indicate no health hazard from
these elements.
The mean background level of radium-226 in soil was 4.2 pCi/g dry soil
which is higher than the U.S. average of 1.2 pCi/g. Thirty percent of the
soil samples were in the background range of 1-6 pCi/g. Seventy percent of
the samples indicated contamination from the lignite mines. If the standards
for remedial action at inactive uranium processing sites are applied to this
reclamation operation, approximately 110,000 cubic yards of soil will be
disposed of or stabilized.
vm
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INTRODUCTION
In the mid 1960's, uraniferous lignite was suface mined for its uranium
content at several sites in southwestern North Dakota. The ore was burned in
or near the lignite pits, or ashed at nearby rotary kilns. The ash was then
shipped to mills in New Mexico, South Dakota, and Colorado for processing.
The rotary kiln sites at Bowman and Belfield, North Dakota, have been
designated by the Department of Energy (DOE) as inactive'uranium processing
sites and are deemed eligible for the Uranium Mill Tailings Remedial Action
(UMTRA) Program. Since the mine sites did not have mechanical processing
equipment such as the rotary kilns at Bowman and Belfield, DOE has decided
that they are not eligible for the program even though ashing (upgrading or
beneficiation) was done in open pits.
In 1979 representatives of the North Dakota State Department of Health
(SDH) and the Office of Surface Mining obtained limited water, soil, and
vegetation samples as well as gamma radiation measurements from the mining
and ashing sites. This cursory environmental survey indicated varying
degrees of contamination.
In mid-1980 the North Dakota Public Service Commission (PSC) was
notified by the Office of Surface Mining that the abandoned uraniferous
lignite mines were considered eligible for discretionary funds for
reclamation. The Howie site was selected as a pilot reclamation project
because it is located on State-owned land. Extensive preliminary radiation
surveys were made by the North Dakota State Department of Health in
conjunction with the Environmental Protection Agency's (EPA's) Office of
Radiation Programs-Las Vegas Facility (ORP-LVF). The site was reclaimed by
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Dickinson State College, under contract to the Public Service Commission
(PSC), making limited use of the suggestions and recommendations of the
State Health Department and EPA. Aesthetic reclamation appears to have been
successful; however, post reclamation survey results indicate elevated
radiation levels.
In September of 1982, the North Dakota PSC and the State Department of
Health entered into a contract for the performance of radiation surveys at
six abandoned uraniferous lignite mines in North Dakota. In April 1983, the
North Dakota State Department of Health formally requested technical
assistance, cleanup and decommissioning guidance, and equipment from EPA to
proceed in a joint effort to plan for and reclaim these six mine sites (11
pits).
In July 1983, an aerial radiological survey of the uraniferous lignite
mines was conducted by EG&G for the EPA (C184). The aerial photographs were
used as a basis for the ground survey. The photographs are included herein
as Appendix A.
In October 1983, approximately 300 locations around the uraniferous
lignite pits were surveyed by measuring external gamma exposure, soil
'sampling, or both. Follow-up sampling in November 1983 and April 1984
resulted in additional gamma measurements being made as well as soil
sampling. A total of approximately 1000 gamma exposure measurements and 300
soil samples were taken to better define the extent of contamination.
"~ METHOD
SAMPLING PROCEDURE
The aerial radiological survey of the lignite mine sites done under
contract by EG&G in July 1983 revealed extensive ore outcroppings (C184).
Because of this, the usual survey procedure around uranium mine and milling
operations was modified (Do75) to account for expected ore outcroppings.
I 2
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The following measurements were made at various points around the
lignite pits:
1. Scintillometer measurements at three feet above ground level, at
ground level (open shield), and at ground level (closed shield)
(D075).
2. Pressurized ion chamber (PIC) measurements at three feet above the
ground.
3. Soil samples were taken at most of the points at which
scintillometer measurements were made.
4. Charcoal canisters used to measure Rn-222 exhalation were placed
sparingly at two separate mine sites.
Gamrna exposure readings with Nal (TI) scintillometers were- taken
starting at the edge of each pit. (Number and directions of radials were
determined for each pit at the time of the survey, see below for numbering
system.) The crystal of the scintillometer was then shielded with a lead
shield. If the difference between the readings was 5 yR/hr or greater, a
soil sample was taken. Most soil samples were taken to a depth of 15
centimeters with a golf course auger. A right cylinder soil sample 8 cm in
diameter and 15 cm in length was obtained. Another gamma exposure reading
was taken at a point 100 feet from the pit edge in the direction of the
radial. In general, measurements were taken and soils sampled at 100-foot
intervals going away from the pit edge in the eight compass directions:
north, south, east, west, northeast, southeast, northwest, and southwest
directions. The sampling continued outward until the difference between the
closed-shield and open-shield gamma measurements was 5 uR/hr or less. The
last or outermost soil sample on any given radial around a pit was to
represent the background levels around that pit. (See Figure 1 for graphic
description of the survey plan.)
Identification of Radials and Sampling Locations
In order to specifically identify the sampling locations for each
lignite pit, the following identification system was devised. The appendixes
contain raw data using this identification system.
3
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Each sampling location is identified by a six-digit number. The first
three digits signify the approximate compass direction and the radial. The
second three digits signify the distance away from the pit in 100-foot
intervals.
For each pit, the northern-most radial is numbered 010.... The number
increases in a clockwise direction; the total number of radials varies with
each pit. For example, Smith B pit has just four radials: 010..., 020...,
030..., and 040.... In contrast, Fritz pit has sixteen radials: 010...,
020..., 030..., 040..., 050..., 060..., 070..., 080..., 090..., 100...,
110..., 120..., 130..., 140..., 150..., and 160 (Fritz pit also has two
radials on which duplicate samples were taken and these radials are labelled
with the original radial number and a "1" in the third spot to signify a
duplicate. These two radials are labelled 041... and 051...).
For each radial on each pit, the sampling location is identified as to
distance from the pit edge. For example, on Smith B pit, the northern-most
radial is labelled 010... and has four sampling locations:
1. 010000 (at the pit edge)
2. 010001 (100 feet from the pit edge)
3. 010002 (200 feet from the pit edge)
4. 010003 (300 feet from the pit edge)
Therefore, when referring to the raw data in the appendices it is easy
to identify the approximate direction and location from each pit for each
sample.
At a limited number of locations (six or seven at each pit) a PIC
measurement was made at locations where scintillometer measurements were
also made. PIC measurements were used as the criterion to validate the
scintillometer measurements and to obtain true gamma exposure rate
measurements.
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010
020
040
1"=200 feet
Figure 1. Smith mine site (West pit).
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Two mine sites were used to measure Rn-222 exhalation. The Howie mine,
which was previously reclaimed, has been extensively studied. During this
study charcoal canisters were placed at various locations at which
scintillometer measurements and soil samples were taken. The canisters
remained on the ground about three days. Canisters were similarly placed at
selected locations at the Smith A mine site.
Sample Preparation and Analysis Procedure
The soil samples were mixed by hand, put into standard tuna cans, and
then dried overnight in an oven at 110 degrees centigrade. The soil was not
sifted to remove vegetation, rocks, and other matter. They were then canned
and counted with a GeLi detector for gamma emitters, specifically radium-226
progeny. When some of the samples were counted immediately after -canning
and then several days later, it was noted that simple handling of the soil
by mixing and pouring disturbed the radium/radon equilibrium. To correct
for this problem, and reestablish equilibrium, all soil samples were counted
not earlier than two weeks after canning.
The data were statistically analyzed using various techniques such as:
1. Measurement of central tendencies.
2. Correlation coefficients (Pearson r).
3. Measurements of variance.
4. Plotting log-normal distributions.
TOXIC ELEMENT ANALYSIS
It was decided to analyze some of the soil samples for non-radioactive
toxic elements because of the possibility of these elements contributing to
the contamination at the mine sites. Approximately 50 aliquots of the soil
samples from eight of the pits were sent to the EPA Analytical Support Branch
in Denver, Colorado. (The analysis was done through Milton W. Lammering,
Chief, ASB). The soil samples were dried, quartered, ground, put into
solution, and analyzed for toxic elements such as arsenic, molybdenum, and
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lead. The data are tabulated in Appendix B. Although heavy metals or toxic
elements are present in measurable amounts, the non-radioactive elements do
not present a health hazard (AC6IH 84).
RESULTS AND DISCUSSION
DETERMINATION OF BACKGROUND LEVELS
The contamination levels around the pits are based on radium-226 content
of soil to a depth of 15 cm. The radium-226 background in soil was difficult
to define due to the abundant uranium ore outcroppings in the area of the
mine sites. If the unshielded scintillometer measurement at the ground was
less than 30 nR/hr and the difference of the shielded and unshielded
measurement was less than 5, the sample was considered background. The
average background for the United States is 1.2 pCi Ra-226 per gram (EPA83).
A background radium-226 concentration of 4.2 pCi is estimated per gram of dry
soil near the mine sites. Approximately 30 percent of the soil samples were
considered to be background based on these values. Background sample data
are tabulated in Appendix C. Also, Figure 2 is a frequency distribution of
all background samples.
The Standard (40CFR192) for cleanup for inactive mill tailings states
that remedial action should be conducted so that the radium-226 concentration
averaged over 100 square meters shall not exceed background level by more
than 5 pCi/g averaged over the first 15 cm of soil below the surface. If
these guidelines were applied to the North Dakota lignite mine sites, the
cleanup area should include sampling locations with radium-226 concentrations
greater than 9.5 pCi/g of soil.
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00
0
02468
10 12 14 16 18 20
Radium 226 (|pCi/g)
Figure 2. Frequency distribution of background samples.
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EXHALATION MEASUREMENTS
Table 1 compares Ra-226 concentration in soil to Rn-222 exhalation at
that location. Figure 3 shows the lack of correlation between these measure-
ments. This is in part due to the non-uniformity of the contamination.
TABLE 1. Rn-222 EXHALATION AND Ra-226 IN SOIL
Smith A
Radial
010000
010001
010002
030000
030001
030002
030003
040000
040001
040002
Ra-226
(pCi/g
dry soil )
39.9
6.9
6.8
12.9
7.8
5.4
4.4
15.0
2.9
2.2
Rn-222~
(pCi/m2
sec)
10.3
9.1
15.5
4.5
7.6
5.8
2.5
2.3
1.5
2.8
Howie
Radial
020002
020004
020006
020008
020010
020012
020014
040000
040002
040004
040006
040007
040008
Ra-226
(pCi/g
dry soil )
9.1
13.0
27.6
29.7
23.0
10.9
3.9
20.0
22.3
33.7
4.3
6.4
4.5
Rn-2229
(pCi/m2
sec)
7.2
5.0
9.1
45.1
9.6
9.5
2.1
11.6
8.0
16.6
3.3
2.1
9.6
VALIDATION AND ADJUSTMENT OF SCINTILLOMETER MEASUREMENTS
Although the contamination survey and soil sampling were based on
scintillometer measurements, these measurements needed to be corrected to
provide external gamma exposure. Eighty-four pressurized ion chamber (PIC)
measurements were made for this reason. The scintillometer reading can be
converted to gamma exposure using the equation:
yR/hr = 0.48 x Scintillometer Measurement at 3 feet + 4
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o
0)
in
\
E
*
E
o
Q.
CM
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A correlation between the PIC and scintillometer measurements at three feet
was calculated to be 0.96 (see Appendix D).
The radium-226 concentrations in the soil were also correlated with the
scintillometer measurements. The radium-226 concentration and the delta
value correlated 0.92, while the radium-226 concentration and the scintillo-
meter ground (open shield) measurement correlated 0.91. The equations to
convert the scintillometer measurement to radium concentration are:
Ra-226 (pCi/gm ) = 1.18 x Delta Measurement - 0.50 and
Ra-226 (pCi/gm) = 0.49 x unshielded ground scintillometer measurements - 6.12
FRACTIONATED SAMPLES
In order to determine depth of contamination, several fractionated soil
samples were taken at the following depths: 0-5 cm, 5-10 cm, and 10-15 cm.
The Ra-226 concentrations of these fractionated samples are included as
Appendix E. It is clear from these results that contamination due to Ra-226
is generally found in the first five centimeters of soil.
ASSESSMENT OF MINE SITE CONTAMINATION AND CLEANUP
Four of the six mine sites (Palaniuk, Talkington, Frank, and Klym) are
located north of Belfield, North Dakota, and two sites (Smith and Fritz) are
south of Belfield. The areas and volumes of contaminated soil have been
calculated based on the application of the inactive mill tailings standards.
Appendix F contains the Ra-226 data for non-background samples. Figure 4 is
a frequency distribution of the Ra-226 concentrations in soil samples except
those in excess of 31 pCi/g. Figure 5 is a frequency distribution of the
Ra-226 concentrations in all soil samples.
11
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0
0
Radium 226 (pCi/g)
Figure 4. Frequency distribution of Ra-226 concentrations in soil up to 31 pCi/g.
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40
35 -
30 -
M
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Palaniuk Mine Site
The Palaniuk mine site is located approximately 12 miles north of
Belfield and is comprised of four pits and three spoils piles (Figure 6).
The pits usually contain water and have been used for swimming on occasion.
The water from three of the pits was sampled and each had less than 20 pCi
radium-226 per liter and about 20-80 pCi uranium-234 per liter (0.06 - 0.25
mg uranium/liter).
The four pits are 4 x 105 feet2 (9 acres). Most of the
contamination is at the edges of the pits. Some extended contamination
occurred west of one of the pits. The cleanup area is only 4 x 10
>
feet (9 acres) and it is estimated 7.6 thousand cubic yards of soil need
to be removed (scraped to a depth of 15 cm). There are also two large
spoils piles of about 150 thousand cubic yards that will need to be moved.
Talkington Mine Site
The Talkington mine site is located approximately 12 miles north
northwest of Belfield and has one pit (Figure 7). The pit is about 1500
feet by 500 feet in area. The land that needs to be cleaned up is about
3 x 105 feet2 (6 2/3 acres). Most of the contamination is within 50
feet of the pit edge, except in the northwest direction. If the contaminated
soil were removed to a depth of six inches, 5400 cubic yards of soil would
be removed.
Frank Mine Site
The Frank mine site is located approximately eleven miles north of
Belfield (one mile south of the Palaniuk site) and is comprised of two pits
separated by a county road (Figures 8). The pits themselves are only
c p
20 x 10 feet (4.5 acres). However, the contaminated area is much
c 2
larger (36 x 10 feet ). This cleanup will remove 67,000 cubic yards of
soil.
I 14
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\
NORTH
(050) (010)
(040)
f 020)
(050)
(030)1?^ q>*
Ğu. }ğ-Ğ--( 010)
3.8V.. ..->-?
(040)
(010) '(030)
(020)
-1
(020)
(010)
(080)
(070)-
(060)
(050)
(030)
I I 1
0 500 1000 (-feet)
x = SOIL
o = NO SOIL
Concentrations in pCi/g
(p i coCur i es/gram)
(SPOILS PILE }
X X X 0(020)
Figure 6. Ra-226 concentrations in soil around the Palaniuk mine site.
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\
NORTH
0
I I
500 1000 (feet)
CT>
(070)-..
o
i * . ? '+;
12G.5
(0G0)
/(010)
(050)
^l-U,Vl
(030)
x = SOIL
o = NO SOIL
Concentrations in pCi/g
(p icoCur ies/gram)
'(040)
Figure 7. Ra-226 concentrations in soils around the Talkington mine site.
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Klym Mine Site
The Klym mine site is located approximately 14 miles north-northeast of
Belfield (Figure 9). The site has two pits; however, since they are
separated by only a dirt road, they can be considered a single mine. The
pit measures 2500 by 1250 feet. Most of the contamination lies within 50
feet of the pit edge. A large area just east of the pit is contaminated and
contains a spoils pile. The area of contamination around the pit is
c p
6 x 10 feet (14 acres), and about 11,000 cubic yards of soil should be
removed.
Smith Mine Site
The Smith mine site is located approximately 12 miles south of Belfield
and is comprised of two small pits (Figure 10). The smallest pit (east of
the large pit) is not contaminated. In fact, it has lower radium
concentrations than the general area background. The larger pit shows
contamination at the pit edge or within 50 feet of the edge with the
exception of the area northwest of the pit. In the northwestern direction
contamination is evident out to 550 feet from the edge of the pit. The
5 2
cleanup area is 2 x 10 feet (4.6 acres) which requires the removal of
3900 cubic yards of soil.
Fritz Mine Site
The Fritz mine site is located approximately 18 miles south of Belfield
and is the largest pit surveyed (Figure 11). The pit is 4500 feet long and
1700 feet wide; however, contamination around the pit is limited to the
5 2
eastern edge. The contaminated area is 7 x 10 feet requiring removal
of 13 thousand cubic yards of soil.
17
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\
(040)-
oo
(010)
~-x
vV"ğ * -'
^ Ğ ?>? <>
**-*:" ^ Na /
'x- x /-f
"-.^J (s
(030)
(010)
NORTH
0
1 - 1
500 1000 (-feet)
x - SOIL
o = NO SOIL
Concentrations in pCi/g
(picoCuries/gr am)
I SPOILS PILE }
(020)
(030)
Figure 8. Ra-226 concentrations in soils around the Frank mine site.
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\
NORTH
( 160)
( 150)
(020)
'vS>
(070)
(0G0)
0
500 1000 (-feet)
x = SOIL
° = NO SOIL
Concentrations in pCf/g
(p i coCuries/gram)
!SPOILS PILE )
Figure 9. Ra-226 concentrations in soils around the Klym mine sites.
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\
NORTH
I I I
0 500 1000 (-feet)
(010)
(050)
(040)
(020)
(040)
x - SOIL
o = NO SOIL
Concentrations in pCi/g
(p i coCur i es/gr am)
fSPOILS PILE)
(030)
/(010)
/I. 8
(020)
Figure 10. Ra-226 concentrations in soils around the Smith mine site.
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7
NORTH
I I I
0 500 1000 (feet)
(130) (140)
( 150)
( 100)
( 1 1 0 ) ( 1 2 0 )
( 160)
x - SOIL
o = NO SOIL
Concentrations in pCi/g
(p i coCu r i e s/g ram)
(080)
(010)
(070)
(040)
Figure 11. Ra-226 concentrations in soils around the Fritz mine site.
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REFERENCES
(ACGIH84) American Conference of.Governmental Industrial Hygienists, "TLVs
for Chemical Substances in the Work Env," ACGH, 1984.
(C184) Clark, H.W., An Aerial Radiological Survey of Uraniferous
Lignite Mines Near Belfield, North Dakota, (July 1983), EG&G
Letter Report, EPA-8402, January 1984.
(D075) Douglas, R.L., and J.M. Hans, Jr., Gamma Radiation Surveys at
Inactive Uranium Mill Sites, August 1975, ORP-LVF, U.S. EPA,
ORP/LV-75-5 Technical Note.
(EPA83) Environmental Protection Agency, June 1983. "Potential Hazards
of Uranium Mine Wastes" EPA 520/1-83-007.
22
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APPENDIX A
AERIAL PHOTOGRAPHS
Aerial photographs were taken of eight uraniferous lignite mine sites
near Belfield, North Dakota, in July 1983. The aerial radiological surveys
were conducted for the EPA by EG&G and DOE.
The aerial surveys were done to "map the spatial extent and degree of
contamination due to mining operations and to document the natural radio-
logical environment surrounding these sites." (C184, pi). This appendix
contains the aerial photographs and superimposed isoradiation contours of
terrestrial gamma ray exposure for the mine sites. For a detailed
description and methodology involved in creating these photographs and
isoradiation contours, please see the publication by H.W. Clark listed in
the references.
23
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1000
2000
3000 FEET
200 400 600 800 1000 METERS
LETTER
LABEL1
A
B
C
D
E
F
G
H
I
J
K
TERRESTRIAL EXPOSURE
RATE' (/;R/h)
2- 4
4- 6
6- 8
8- 10
10- 12
12 - 14
14- 20
20- 30
30- 50
50- 80
80- 130
1 Presence o( letter label in conversion scale does
not necessarily imply existence of corresponding
contour interval in plot.
"Contours indicate gamma exposure rate extra-
polated to 1 m above the ground, interred trom
gamma count rate observed at 75 It above the
ground. Extrapolation valid only over large areas
comparable to the detector's lield-ol-view. Cosmic
rays contribute an additional 4.4 ;;R.'h to the
reported values.
ISORADIATION CONTOURS OF TERRESTRIAL GAMMA RAY EXPOSURE RATE SUPERIMPOSED ON AN AERIAL
PHOTOGRAPH OF THE TALKINGTON AND FRANK URANIFEROUS LIGNITE MINE SITES NEAR BELFIELD.
NORTH DAKOTA (T140-R100-SW)
24
-------
i
N
I
1000
2000
200
400 600 800
Presence ol leliet label m conversion scale does
nol necessarily imply existence of corresponding
conloiif interval in plot.
Contours indicate ganinia exposure rate extra-
polated to 1 m ahovr the ground, inferred from
pnninia count rale observed at 75 ft above the
ground Extrapolation valid only over large areas
comparable lo Ihp detector's field-ot-view Cosmic
rays conlrihule an additional 44 //R h to the
reported values
000 FEET
1000 METERS
CONVERSION SCALE
LETTER
LABEL1
TERRESTRIAL EXPOSURE
RATE'(wR'h)
2 A
..:.__* !
B i 4-6 |
D
E
F
G
H
I
J
K
L
6-8 !
8-10
'lO- 12
12 - 14
14 - 20
20- 30
30- 50
50 - 80
80- 130
130- 200
ISORADIATION CONTOURS OF TERRESTRIAL GAMMA RAY EXPOSURE RATE SUPERIMPOSED ON AN AERIAL
PHOTOGRAPH OF THE PALANIUK AND FRANK URANIFEROUS LIGNITE MINE SITES NEAR BELFIELD.
NORTH DAKOTA (T140-R99-S6.7> 25
-------
CONVERSION SCALE
LETTER
(LABEL1
TERRESTRIAL EXPOSURE
1 Presence o( letter label in conversion scale does
not necessarily imply existence ol corresponding
contour interval in plot.
'Contours indicate gamma exposure rate extra-
polated to 1 m above the ground, inferred from
gamma count rate observed at 75 ft above the
ground. Extrapolation valid only over large areas
comparable to the detector's field-of-view Cosmic
rays contribute an additional 4.4 /jR h to the
reported values.
ISORADIATION CONTOURS OF TERRESTRIAL GAMMA RAY EXPOSURE RATE SUPERIMPOSED ON AN AERIAL
PHOTOGRAPH OF THE KLYM URANIFEROUS LIGNITE MINE SITE NEAR BELFIELD, NORTH DAKOTA (T142-R99-S26)
26
-------
CONVERSION SCALE
LETTER
LABEL1
TERRESTRIAL EXPOSURE
RATEM/'R/h)
Presence of letter label in conversion scale does
not necessarily imply existence of corresponding
contour interval in plot.
Contours indicate gamma exposure rate extra-
polated to 1 m above the ground, inferred from
gamma count rate observed at 75 ft above the
ground. Extrapolation valid only over large areas
comparable to the detector's I ield-of-view Cosmic
rays contribute an additional 4.4 /jR/h to the
reported values.
ISORADIATION CONTOURS OF TERRESTRIAL GAMMA RAY EXPOSURE RATE SUPERIMPOSED ON AN AERIAL
PHOTOGRAPH OF THE HOWIE URANIFEROUS LIGNITE MINE SITE NEAR BELFIELD. NORTH DAKOTA (T137-RWO-S2)
27
-------
TERRESTRIAL EXPOSURE
200 400 600 800 1000 METERS
Presence of letter label in conversion scale does
not necessarily imply existence ot corresponding
contour interval in plot
Contours indicate gamma exposure rale extra-
polated to 1 m above the ground, interred from
gamma count rate observed at 75 ft above the
ground. Extrapolation valid only over large areas
comparable to the detector's field-of-view Cosmic
rays contribute an additional 4.4 /;R'h to the
reported values.
ISORADIATION CONTOURS OF TERRESTRIAL GAMMA RAY EXPOSURE RATE SUPERIMPOSED ON AN AERIAL
PHOTOGRAPH OF THE SMITH URANIFEROUS LIGNITE MINE SITE NEAR BELFIELD, NORTH DAKOTA fT137-R100-SS>
28
-------
CONVERSION SCALE
LETTER
LABEL1
TERRESTRIAL EXPOSURE
Presence of letter label in conversion scale does
not necessarily imply existence of corresponding
contour interval in plot.
Contours indicate gamma exposure rate extra-
polated to 1 m above the ground, inferred from
gamma count rate observed at 75 ft above the
ground. Extrapolation valid only over large areas
comparable to the detector's field-of-view. Cosmic
rays contribute an additional 4.4 ^/R>h to the
reported value;..
800 1000 METERS
ISORADIATION CONTOURS OF TERRESTRIAL GAMMA RAY EXPOSURE RATE SUPERIMPOSED ON AN AERIAL
PHOTOGRAPH OF THE FRITZ UFtANIFEROUS LIGNITE MINE SITE NEAR BELFIELD. NORTH DAKOTA (T136-R100-SS)
29
-------
APPENDIX B
ACID EXTRACTABLE METALS
(yg metal/g dry soil)
Mine Site
and Radial No. A£ Mg_ Mn_ Mo Plb
Frank A
020000
060002
Frank B
020000
020002
020004
020005
040000
040001
040003
040006
Howie
010000
020002
020004
020006
020008
020010
020012
020014
040002
040004
040006
040007
040008
169
106
99
119
96
101
502
58
72
102
45
93
49
78
67
71
47
67
83
79
59
72
73
4900
5950
4240
4700
4230
4360
7920
4780
5260
8860
1920
3730
2460
4580
3500
3790
3070
4550
3840
4280
4200
3390
3720
289
1460
936
1190
1090
1070
408
3250
1610
1040
175
174
227
551
474
452
369
467
427
366
893
475
402
26
3
24
30
4
<1
722
<1
1
7
119
81
50
39
64
32
15
5
82
66
10
16
3
12
21
-17
"'18
15
18
28
15
12
24
6
13
7
9
12
12
10
16
12
11
17
13
13
30
-------
Acid Extractable Metals (continued)
Mine Site
and Radial No. As_ M£ Mn_ Mo Pb_
Fritz
040000
040001
040002
060000
060002
060005
Palaniuk A
020000
020001
Palaniuk B
020001
050000
Palaniuk C
030000
030001
040001
Palaniuk D
010000
040000
Smith A
060000
060006
Smith B
010000
020000
030000
040000
68
117
63
68
75
81
69
102
69
38
64
120
77
94
87
121
61
22
69
71
67
3680
8000
3390
3000
4000
3840
2230
4160
4070
2350
3870
4960
3690
3260
4410
2440
4070
2300
4000
4700
3660
661
982
773
110
554
522
225
808
583
417
511
310
371
373
386
126
365
199
433
218
498
24
11
17
116
27
7
31
18
'
13
6
11
80
29
132
7
344
9
3
3
7
3
13
21
10
11
14
17
7
15
14
8
10
15
14
14
10
21
16
4
13
13
13
31
-------
Acid Extractable Metals (continued)
Mine Site
and Radial No. As M£ Mn_ Mo Pb
Talkington
030000 74 4010 438 33 12
030002 63 4290 478 4 13
Klym
060000 67 4260 928 15 18
150002 89 3870 1190 12 23
32
-------
APPENDIX C
RADIUM-226 IN BACKGROUND SOIL SAMPLES
Mine Site
and Radial No.
Smith A
020002
020003
030002
030003
040001
040002
050001
041005
011008
Smith B
010000
010001
010002
010003
020000
020001
020002
030000
030001
040000
040004
Talkington
010004
010005
Scintillometer*
at 3 ft. (pR/hr)
18
16.5
16
13
19
15
26
17
15
10
11
10
10
9
11
10
9
9
10
10
25
21
Scintillometer**
at Ground (yR/hr)
18
17.5
18
15
20
16
25
17
15
10
10
12
12
10
11
10.5
9
9
10
10
25
20
Delta
4.5
4.5
5
4
4
4
5
5
4
3
2
4
4
1.5
3
3
2
1
2
1
5
4
Ra-226
(pCi/g
Dry Soil)
2.5
2.8
5.4
4.4
"2.9
2.2
5.3
3.1
2.8
1.8
1.5
1.8
1.8
2.1
1.6
1.8
1.4
1.8
2.2
2.2
4.9
5.9
33
-------
Radium-226 in Background Soil Samples (continued)
Mine Site
and Radial
Talkington
020001
020002
030002
040002
050003
064004
040007
071006
Frank A
010003
020002
030001
030002
040002
061010
011016
Frank B
010004
040006
031010
Palaniuk A
010001
020003
030000
030001
040002
020001
041005
011001
Scintillometer*
No. at 3 ft. (pR/hr)
(continued)
25
18
15
20
23
26
17
22
19
16.5
22
20
18
18
18
19
16
12
16
21
15
13
14
18
17
21
Scintillometer**
at Ground (yR/hr)
24
19
17
20
23
26
17
23
20
17.5
22
20
18
18
19
18
17
15
17
20
14
13
13.5
18
16
21
Delta
5
4.5
4
3
5
4
3
5
5
5
4
5
5
5
4
5
5
4
5
5
3
3
3.5
4
3
4
Ra-226
(pCi/g
Dry Soil)
6.0
5.5
6.4
2.3
4.1
3.7
1.8
5.8
9.7
7.0
4.7
7.6
3.3
4.0
5.9
5.3
3.9
1.9
4.6
5.3
6.2
2.6
6.3
3.7
4.2
4.4
34
-------
Radium-226 in Background Soil Samples (continued)
Mine Site
and Radial No.
Palaniuk B
030000
030001
040002
050001
070000
080000
Palaniuk C
010000
020000
Palaniuk D
020001
040000
021001
021002
031008
Klym
010001
020000
020002
050001
060002
070000
080000
090000
100000
110000
120000
130000
140000
Scintillometer*
at 3 ft. (yR/hr)
17.5
16
30
31
15
28
12
10
17
18
14
13
14
20
26
19
19
19
14
11
13
15
17
17
19
16
Scintillometer**
at Ground (yR/hr)
18.5
16
28
28
15
22
12
11
15
17
16
14
15
21
23
19.5
19
18
13
12
13
15
16
16
19
16
Delta
5.5
3
3
5
1
4
4
2
5
5
4
2
3
5
5.5
5.5
4
5
3
3
4
4
4
3
5
4
Ra-226
(pCi/g
Dry Soil)
7.2
5.4
6.8
4.6
6.6
8.6
2.4
2.4
2.8
3.8
3.1
2.9
3.1
4.4
5.9
3.9
4.3
5.2
2.9
2.4
2.9
4.7
6.9
7.7
8.3
6.3
35
-------
Radium-226 in Background Soil Samples (continued)
Mine Site
ancLRadial No.
Klym (continued)
150001
160000
160001
151012
151007
021010
021005
Fritz
020000
040002
050005
060005
070003
111007
121008
041003
041004
041005
051004
051005
Howie
010010
010012
020014
040006
040008
Scintillometer*
at 3 ft. (yR/hr)
22
20
20
14
21
20
22
18
23
17
19
15
14
8
23
16
17
21
18
17
12
20
20
20
Scintillometer**
at Ground (uR/hr)
22
20
20
13
22
19
23
18
23.5
16.5
19
16
13
10
24
17
17
21
20
17
13
20
22
20
Delta
5
5
5
4
3
4
3
5
4.5
4
5
4
1.5
3
2
4
4
5
5
4
3
5
3
5
Ra-226
(pCi/g
Dry Soil)
7.6
5.1
3.6
2.4
7.7
5.9
9.6
-4.0
5.9
1.9
3.9
1.8
1.3
0.9
4.5
3.5
4.1
3.2
5.5
2.5
2.6
3.9
4.3
4.5
* Scintillometer readings in pR/hr at 3 feet above the ground.
** Scintillometer readings in pR/hr at the surface of the ground.
*** The difference of the scintillometer-gr without a shield and
scintillometer-gr with shield.
36
-------
APPENDIX D
CORRELATION OF SCINTILLOMETER MEASUREMENTS WITH PIC READINGS
Mine Site
and Radial No.
Howie
010000*
010002
010004
010006
010008
010010
010012
020002
020004
020006
020008
020010
020012
020014
030002
030004
030006
030008
040000*
040002
040004
040006
040007
040008
Scintillometer
at 3 ft. (yR/hr)
55
47
40
45
60
17
12
40
48
65
150
40
28
20
43
27
20
16
50
50
45
20
20
20
PIC
(wR/hr)
27.78
25.95
20.37
25.33
32.76
14.06
12.57
21.09
25.75
30.49
73.5
21.44
15.87
13.89
24.94
21.98
16.4
14.95
27.03
27.94
25.21
13.52
13.81
14.47
* 040000 and 010000 are identical location.
37
-------
Correlation of Scintillometer Measurements with PIC Readings (continued)
Mine Site
and Radial No.
Smith A
030000
030001
030002
030003
040000
040001
040002
Smith B
030000
030001
040000
040004
Talkington
040000
040001
040002
060000
060001
060002
060003
060004
Palaniuk A
010000
010001
030000
030001
Scintillometer
at 3 ft. (yR/hr)
29
21
16
13
50
19
15
9
9
10
10
75
25
20
60
40
35
30
26
30
16
15
13
PIC
(yR/hr)
21.05
15.76
14.17
13.1
31.02
13.74
12.56
10.01
10.12
11.27
11.37
32.68
14.3
13.12
31.26
21.23
19.8
16.48
16.13
20.3
14.77
13.74
12.78
38
-------
Correlation of Scintillometer Measurements with PIC Readings (continued)
Mine Site
and Radial No.
Palaniuk B
030000
030001
040000
040001
040002
050000
050001
050002
Palaniuk C
010000
020000
030000
030001
Fritz
040000
040001
040002
040003
050000
050001
050002
Klym
010000
010001
020000
020001
020002
160000
160001
Scintillometer
at 3 ft. (wR/hr)
17.5
16
37
40
30
38
31
24
12
10
150
60
50
43
23
20
50
38
38
40
20
26
20.5
19
20
20
PIC
(jiR/hr)
15.86
13.93
18.77
21.02
16.43
19.64
15.75
14.05
li.ll
11.39
95.28
28.18
23.49
21.74
16.35
14.22
31.57
20.12
20.12
21.15
14.13
15.36
14.42
13.42
13.19
12.44
39
-------
Correlation of Scintillometer Measurements with PIC Readings (continued)
Mine Site
and Radial No.
Frank A
030000
030001
030002
030003
040000
040001
040002
050000
050001
Frank B
020000
020001
020002
020003
020004
020005
Scintillometer
at 3 ft. (pR/hr)
30
22
20
14
30
32
18
32
32
62
65
60
40
40
30
PIC
(uR/hr)
15.74
14.39
13.94
13.34
14.39
18.98
17.14
19.64
19.73
31.19
34.59
30.48
. 20.93
20.15
17.91
40
-------
APPENDIX E
RA-226 ANALYSIS OF FRACTIONATED SAMPLES
Mine Site
and Radial No.
Smith A
041000
041000
041000
061000
061000
061000
Talkington
070000
070000
070000
070001
070001
070001
080000
080000
080000
Palaniuk C
030001
030001
030001
040004
040004
040004
Depth
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
Ra-226
(pCi/gm)
38.6
4.0
2.2
48.0
58.6
68.4
102.4
50.6
51.8
19.0
9.8
11.5
26.6
10.8
8.1
27.3
15.2
4.8
10.7
11.5
18.7
41
-------
Ra-226 Analysis of Fractionated Samples (continued)
Mine Site
and Radial No.
Palaniuk D
010000
010000
010000
020000
020000
020000
020001
020001
020001
021001
021001
021001
021002
021002
021002
Fritz
041000
041000
041000
041001
041001
041001
041002
041002
041002
041003
, 041003
041003
041004
Depth
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm"
10-15 cm
0-5 cm
Ra-226
(pCi/gm)
33.4
6.0
3.2
13.4
9.5
14.9
3.1
2.9
3.0
3.1
3.0
3.2
2.9
2.6
2.6
22.2
3.1
3.4
5.7
5.6
8.1
14.4
6.1
5.0
5.2
3.9
4.5
6.7
42
-------
Ra-226 Analysis of Fractionated Samples (continued)
Mine Site
and Radial No.
Fritz (continued)
041004
041004
041005
041005
041005
051000
051000
051000
051001
051001
051001
051002
051002
051002
051003
051003
051003
051004
051004
051004
051005
051005
051005
Depth
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
0-5 cm
5-10 cm
10-15 cm
Ra-226
(pCi/gm)
1.8
1.9
7.3
2.5
2.6
17.2
13.0
10.0
14.8
3.3
3.6
10.8
3.5
3.7
' 6.5'
2.9
2.7
3.2
2.9
3.4
7.6
4.3
4.7
43
-------
APPENDIX F
RADIUM-226 ANALYSIS
Scintillometer (y/hr)
3 ft. Ground
Mine Site
and Radial No.
Smith A
010000
010001
010002
010003
010004
010005
020000
020001
030000
030001
040000
050000
060000
060001
060002
060003
060004
060005
060006
060007
(open)
100
30
21
24
25
22
50
24
29
21
50
55
80
42
35
35
30
24
23
24
(open)
95
32
24
27
28
21
50
24
29
22
49
55
80
45
35
34
25
26
22
27
Delta
30
10
8
9
9
6
15
6
5
6
11
15
25
15
15
13
9
10
6
7
pCi/gram
- 39.9
6.9
6.8
10.0
7.9
6.3
19.8
7.8
12.9
7.8
15.0
16.2
13.8
14.8
11.0
15.8
11.5
10.8
6.1
8.8
44
-------
Radium 226 Analysis (continued)
Scintillometer (p/hr)
3 ft. Ground
Mine Site
and Radial No.
Talkington
010000
010001
010002
010003
020000
030000
030001
040000
040001
050000
050001
050002
060000
060001
060002
060003
Frank A
010000
010001
010002
020000
020001
030000
040000
040001
050000
050001
060000
(open)
85
35
30
28
48
75
40
75
25
70
50
28
60
40
35
30
42
34
29
68
19
30
30
32
32
32
50
(open)
45
35
30
28
42
85
42
80
27
60
48
29
70
40
35
30
38
34
30
68
19
30
30
35
32
32
57 '
Delta
10
7
8
6
7
22
10
30
6
15
13
8
20
5
7
5
9
6
8
23
6
10
10
15
5
5
15
pCi/gram
3.7
2.4
4.4
7.0
3.6
12.1
7.4
...46.5
2.9
25.3
8.1
2.9
21.2
5.3
6.3
6.4
15.6
13.7
9.8
32.1
7.5
7.5
9.0
9.3
12.0
17.0
22.2
45
-------
Radium 226 Analysis (continued)
Scintillometer (n/hr)
3 ft. Ground
Mine Site
and Radial No.
Frank A (continued)
060001
010002
Frank B
010000
010001
010002
010003
020000
020001
020002
020003
020004
020005
030000
030001
030002
030003
030004
040000
040001
040002
040003
040004
040005
Palaniuk A
010000
020000
020001
(open)
37
32
60
45
27
23
62
65
60
40
40
30
72
46
36
28
25
300
85
60
45
35
30
30
60
35
(open)
40
33
60
40
27
24
64
65
62
40
40
30
70
50
38
29
28
450
75
50
40
35
20
30
60
35
Delta
10
6
15
10
7
7
16
15
15
10
10
5
15
10
10
07
08
200
20
11.5
10
8
6
5
20
10
pd'/qram
16.0
10.9
12.5
12.7
12.7
9.8
...10.9
29.0
38.0
14.6
13.2
10.4
29.7
10.3
7.7
3.6
5.1
264.5
17.6
17.7
18.3
8.9
5.5
12.7
24.2
9.4
46
-------
Radium 226 Analysis (continued)
Mine Site
and Radial No.
Palaniuk A (continued)
020002
040000
040001
Palaniuk B
010000
010001
010002
020000
020001
020002
040000
040001
050000
050002
060000
Klym
010000
030000
030001
030002
040000
040002
040004
040006
040008
050000
. 050005
050007
Scintillometer
3 ft.
(open)
28
70
19
70
38
30
55
40
32
37
40
38
24
22
40
42
18
23
42
25
27
38
24
45
20
28
(w/hr)
Ground
(open)
29
60
19
51
38
30
55
40
31
34
38
36
24
24
50
40
26
23
42
26
28
40
24
41
22
30
Delta
9
15
7
11
8
6
15
10
5
6
3
6
6
6
20
10
7
6
10
7
9
12
7
12
6
11
pCi/gram
7.7
12.7
7.5
10.7
7.8
11.5
...6.2
6.6
3.7
6.4
7.5
11.7
3.1
3.5
26.6
10.8
5.8
5.1
17.8
7.4
10.8
23.0
15.3
30.1
8.9
17.9
47
-------
Radium 226 Analysis (continued)
Scintillometer (y/hr)
3 ft. Ground
Mine
and
Klym
Site
Radial No.
060000
060001
150000
(open)
35
25
28
(open)
35
24
25
Delta
10
7
6
pCi/gram
14.5
7.9
11.8
Fritz
010000
010001
030000
030001
040000
040001
050000
050001
050002
050003
060000
060001
060002
060003
070000
070001
080000
080001
080003
090000
090001
090003
090004
150000
160000
30
23
75
45
50
43
50
38
30
50
29
29
23
150
22.5
60
45
23
50
30
25
20
15
31
30
23
70
45
45
45
50
40
45
23
55
30
29
23
175
23.5
50
50
24
50
30
23
23
16
32
8
6
20
10
7
12
15
12
13
6
17
6
8
7
80
6
10
12
7
15
8
8
6
6
9
8.1
1.4
22.5
..12.8
- 6.1
19.2
14.9
9.6
10.8
6.2
11.6
10.8
7.6
3.5
70.5
3.7
3.3
4.1
6.7
8.8
4.4
7.9
14.1
2.0
3.3
48
------- |