4>EPA
United States
Environmental Protection
Agency
Office of Radiation and
Indoor Air
Washington, DC 20460
EPA 402-R-02-003
June 2002
Long Term Hydrological
Monitoring Program:
Amchitka, Alaska
2001
-------
Long Term Hydrological Monitoring Program
Amchitka, Alaska
2001
Max G. Davis and Terry L. Mouck
P ""'1"1 ..,,'"",...- I !~,""
i,Ut t..~a i v'
U.S. EPA Library
L''''' \I""~..l~ t"j <:'~'111g
(}...) 'w - -~ .), ,I L' -
Prepared for the U.S. Department of Energy
under Interagency Agreement
DE-AI08-96NVl1969
RADIATION AND INDOOR ENVIRONMENTS NATIONAL LABORATORY
OFFICE OF RADIATION AND INDOOR AIR
U.S. ENVIRONMENTAL PROTECTION AGENCY
P.O. BOX 98517
LAS VEGAS, NV 89193-8517
-------
NOTICE
The information in this document has been funded wholly, or in part, by the United States
Environmental Protection Agency (EP A) through Interagency Agreement (IAG) DE-AI08-96NV
11969 from the United States Department of Energy (DOE). This document has been subjected
to the Agency's peer and administrative review process, and it has been approved for publication
as an EP A document. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
11
-------
ABSTRACT
Surface water samples were collected on the island of Amchitka, Alaska, from July 31 through
August 4,2001, as part of the Environmental Protection Agency's Long Term Hydrological
Monitoring Program. The samples were scanned for the presence of gamma-ray emitting
radionuc1ides, and analyzed to determine tritium concentrations. Both conventional and
enrichment tritium analytical methods were used. No man made gamma-ray emitters were
detected, and results of the tritium analyses are consistent with historical values. Trends in
decreasing concentration levels of tritium appear to be due to radioactive decay as well as
dilution.
11l
-------
This page left blank intentionally
IV
-------
CONTENTS
Page
Notice. .
. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
. . .. . . . .. . . . .. . . .. .. . . . . . . . . . . .
11
Abstract
. . . . . . . . . . . . . . . . . . . . . . .. . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Figures
. . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VI
Tables. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .. . .. ... . .... . . . .. . . .. . . . . . .. . . . ..o
. VI
Acronyms and Abbreviations
. . .. . . . . . . .. . . . . .... . .. .... .... . .. ..
. . . . . . . . . .. . . . . .
V11
Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V111
Introduction
. . . . . . . . . . . . . . . .. .. . . . .. . . . . . .. . .. .. .. .. . ... . .. .
. . . . . . . . . . . . . . . . . . 1
History. .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .
. . . . . . . . . . . . . . . . . . . . . . . . . 1
Sampling
Sample Analysis
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
. . .. . .
[[[ 6
Water Analysis Results
[[[ 6
Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " . . . . . . . . . . . . . . . . 6
References
. .. . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Glossary of Terms
. . . . . . . . . . . . . . . . .. . .. . .. . .. .. . . .. . . ... . .. .. .. . .. . . . .. . . . . . . .12
Appendix A (Standard Operating Procedures)
Appendix B (Summary of Analytical Procedures)
-------
FIGURES
Page
1. Location of Amchitka Island, Alaska. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Amchitka Island and Camp Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. LongshotJMilrow Surface Ground Zero Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
4. Cannikin Surface Ground Zero Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
TABLES
Page
1. Sampling Locations Established at the Longshot Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2. Sampling Locations Established at the Milrow Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Sampling Locations Established at the Cannikin Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4. Sampling Locations Established to Provide Background Data. . . . . . . . . . . . . . . . . . . . . . . . 10
VI
-------
DCG
DOE
EPA
g
3H
3H+
HpGe
lAG
keV
kg
kt
L
LTHMP
m
MDC
MeV
mm
mL
MT
aRIA
pCi/L
PHS
R&IE
SGZ
SOP
USGS
ACRONYMS AND ABBREVIATIONS
Derived Concentration Guide
U.S. Department of Energy
U.S. Environmental Protection Agency
gram
tri ti urn
enriched tritium
high purity germanium gamma detector
Interagency Agreement
kilo electron volts = thousand electron volts
kilogram, 1000 grams
kiloton (TNT equivalent)
liter
Long-Term Hydrological Monitoring Program
meter
minimum detectable concentration
million electron volts
minute
milliliter = one thousandth of a liter
Megaton = 1,000,000 tons equivalent TNT
Office of Radiation and Indoor Air
picocuries per liter = 10-12 curies per liter = 1/1,000,000,000,000 curies per liter
U.S. Public Health Service
Radiation and Indoor Environments National Laboratory
surface ground zero
standard operating procedure
U.S. Geological Survey
vii
-------
ACKNOWLEDGMENTS
The authors would like to acknowledge Dennis Farmer, Richard Flotard, Pat Honsa,
Rose Houston, and the staff of the hydrological monitoring program, EP A, for their dedication to
quality and their tireless work in the execution of the sampling project. In addition, we would
like to give a special thank you to Dr. Vernon Hodges, PhD, Chemistry, University Nevada,
Las Vegas (UNL V) for his extramural review of this report.
Vlll
-------
INTRODUCTION
Under an Interagency Agreement (lAG) with the DOE, the EPA's Radiation and Indoor
Environments National Laboratory (R&IE) located in Las Vegas, NV. conducts a Long Term
Hydrological Monitoring Program (LTHMP) to measure radioactivity concentrations in water
sources near the sites of underground nuclear explosions. The results of the LTHMP provide
assurance that radioactive materials from the tests have not migrated into drinking water
supplies. This report presents the results for the samples collected from July 31 through
August 4,2001, on Amchitka Island, Alaska.
History
Three nuclear detonations were conducted on Amchitka Island in the Aleutian Island chain of
Alaska. See Figure 1 for location of Amchitka Island, Alaska. Project Longshot, conducted on
October 29, 1965, was an 85-kt yield test emplaced at 2359 ft depth. It was a Vela Uniform
Program, designed to investigate seismic phenomena. Project Longshot resulted in some surface
contamination, even though the chimney did not extend to the surface. Project Milrow,
conducted on October 2, 1969, was an approximately 1-MT "calibration test" of the seismic and
environmental responses to the detonation of large-yield nuclear explosives. The emplacement
depth of Project Milrow was 3990 ft. Project Cannikin, conducted on November 6, 1971, was a
proof test of the Spartan antibalistic missile warhead with less than a 5-MT yield emplaced at
5875 ft depth. See Figures 2, 3, & 4 for sampling locations.
Amchitka Island is composed of several hundred feet of permeable tundra overlaying tertiary
volcanics. The ground water system consists of a freshwater lens floating on seawater; estimates
of the depth to the saline freshwater-interface range from 3900 to 5250 ft (Chapman and Hokett,
1991). It is likely that any migration from the test cavities would discharge to the nearest salt
water body, Project Milrow to the Pacific Ocean, and Projects Longshot and Cannikin to the
Bering Sea (Chapman and Hokett, 1991). The sampling locations on Amchitka Island are
shallow wells and surface sampling sites. Therefore, the monitoring network for Amchitka
Island is restricted to monitoring of surface contamination and drinking water supplies.
Sampling
Sample collection on Amchitka was conducted between July 31 and August 4,2001. Field
collection procedures and sampling locations are described in standard operating procedure
(SOP) CER-203, and the Amchitka, Alaska Long Term Hydrologic Monitoring Plan.
All samples were collected with the exception of several wells that were plugged or mud pits that
were filled. However, samples were taken at or near the original sample location. The samples
will provide background information for future sampling efforts. .
1
-------
~ ~
... ~
~~Cl£' !
~-
--
. --
--
S/£3tR/4
o
o
l
BEAUFORT SEA
I),
I
~
I .
CANADA
I
I
D
.--..-..
NORTH
PACIFIC
OCEAN
I
I
I
I
UNITED
~
STATES
SAN FRANCISCO
I
~
ro
~
en
ro
~
"'='
I::
ro
-
en
-
ro
~
.-
...c:
u
S
-<
......
o
I::
.s:2
......
ro
u
o
~
N
~
QJ
...
~
~
-------
";' e Surface Ground Zero
(B] Water Sampling Locations
Map is not to scale
. ~ : ::~J;h~j~~~:~i ;a!:,'\,:(:
.. : ,. ~..~, .)': ::;,.",',,'.,< ~ . ",'
:,~JiJimlliiiimiiliiilj.
.=
Enginee~s p~ I
Engineer Rd.
(B] Water Sampling
Locations
Map is not to scale
1111111111111111111111111111111111111111111111
Figure 2. Amchitka Island and Camp Area
3
-------
~
N
e Surface Ground Zero
IjJ Water Sampling
Locations
.
.
.
.
ream ...
11113 .
LINEAR /
FRACTURE /
Cleve. nger \4
Creek ~
III ~
.... ~
Map is not to scale
Map is not to scale
MILROW
LONG SHOT
I
o Surface Ground
Zero
~ Long Shot
Pond 3
EI Water Sampling
Locations
- Streams
\
Figure 3. LongshotlMilrow Surface Ground Zero Area
4
-------
,
l-
S
Lf
+
N
8 Surface Ground Zero
o Water Sampling Locations
Map is not to scale
Figure 4. Cannikin Surface Ground Zero Area
5
-------
Sample Analysis
Radiochemical laboratory procedures used to analyze the samples collected for this report are
summarized in R&IE's SOPs listed in Appendix A, and for procedures summary see Appendix
B. These include standard methods to identify natural and man-made gamma-emitting
radionuclides, tritium, plutonium, strontium, and uranium in water samples.
Two types of tritium analyses were performed: conventional and electrolytic enrichment. The
enrichment method lowers the minimum detectable concentration (MDC) from approximately
300 pCiIL to about 5 pCiIL. An upper limit of activity of 700 - 800 pCiIL has been established
for the tritium enrichment method because sample cross-contamination becomes a problem at
higher levels.
In late 1995, it was decided that a maximum of 25 percent of all samples collected would be
analyzed by the low-level enrichment method. This decision was based on the time required for
analysis, budgetary constraints, and an assessment of past results. Under the cUlTent sampling
and analysis protocol for the site, all samples are initially screened for tritium activity by the
conventional method, and selected samples are enriched. At this time, only sampling locations
that are in position to show migration are selected for enrichment. Sufficient sample is collected
from new sampling locations to perform all routine analyses, and a full suite of other
radiochemical determinations including assays for strontium-90, plutonium, and uranium.
Water Analysis Results
The gamma-ray spectrometric analysis results indicate that no man-made gamma-ray emitting
radionuclides were detected in any samples collected from the three sites: Cannikin, Longshot,
and Milrow. Tritium concentrations above normal background at Longshot ranged from 542:t
10 pCiIL at GZ #2 to 16 :t 4 pCiIL at Pond #3. The level at GZ #2 is well below the 20,000
pCiIL level defined in the U.S. EPA Drinking Water Regulation (40 CPR 141). Long term trends
in tritium concentrations on Amchitka Island, Alaska, follow a decreasing trend established from
prior LTHMP sampling. Tritium values for the samples are given in Tables 1,2,3, and 4.
Conclusions
Tritium concentrations on Amchitka Island, Alaska, follow a decreasing trend established from
prior LTHMP sampling. At locations around the Longshot SGZ where contamination is known
to exist, concentrations continue to decrease faster than would be expected from tritium decay
alone, indicating that dilution is also an important factor.
6
-------
Table 1. Sampling Locations Established at the Longshot Site (Figure 3).
Sample Collection Emiched Tritium Tritium (0) Gamma Spectrometry (b)
Location Date pCilL :t 2 SD (MDC) pCilL + 2 SD (MDC) pCilL (MDC)
WL-l 7/31/01 18:t 135 (222) ND (1.6)
WL-2 7/31/01 69 :t 136 (222) ND (1.8)
GZ-l 8/03/01 Gamma only ND (1.6)
GZ-2 8/03/01 542 :t 10 (7.0) ND (1.9)
EP A-I 7/31/01 32 :t 136 (222) ND (1.9)
Surface Locations
Reed Pond 8/03/01 Gamma only ND (1.6)
Mud Pit No.1 8/03/01 96 :t 137 (222) ND (1.9)
Stream(c)
Mud Pit No.2 8/03/01 Gamma only ND (1.5)
Spring(C)
Mud Pit No.3 8/03/01 14:t 4.1 (6.3) ND (1.6)
Spring(C)
Stream East of
Longshot 8/03/01 110:t 136 (221) ND (1.9)
Stream West
ofGZ 8/03/01 11.5 :t 4.0 (6.0) ND ( 1.5)
LS Pond No.1 8/03/01 36 :t 135 (221) ND (1.8)
LS Pond No.2 8/03/01 110:t 136 (221) ND (1.9)
LS Pond No.3 8/03/01 16 :t 4.0 (6.0) ND (1.7)
LS Pond No.4 8/03/01 123 :t 142 (230) ND (1.6)
Vegetation 8/01/01 118:t 142 (230)
(a) Indicates results are less than MDC.
(b) No gamma radionuc1ides detected above MDC.
(c) (Seep or spring, grab sample at or near original sampling location. Sampling locations have been removed or
plugged.
(ND) Non-detected MDC for gamma represents J37Cs.
7
-------
Table 2. Sampling Locations Established at the Milrow Site (Figure 3).
Sample Collection Enriched Tritium Tritium (a) Gamma Spectrometry(b)
Location Date pCiIL :t 2 SD (MDC) pCiIL :t 2 SD (MDC) pCi/L (MDC)
W-l 8/02/01 Sample from stream (well plugged) Gamma only ND (1.6)
W-2 Stream(c) 8/02/01 -14:t 135 (222) ND (1.8)
W-3 Pond(C) 8/02/01 18:t 135 (222) ND (1.6)
W-4 Well Removed (No Sample)
W-5 Well Removed (No Sample)
W -6 Pond(c) 8/02/01 50 :t 136 (222) ND (1.5)
W-7 Well Removed (No Sample)
W -8 Stream(C) 8/02/01 9 :t 135 (222) ND (1.7)
W -9 Stream(c) 8/02/01 73 :t 136 (222) ND (1.8)
W-IO Well Removed (No Sample)
W -11 Pond(c) 8/02/01 Well Plugged 69 :t 136 (222) ND (1.6)
W-12 8/02/01 9.0:t 135 (222) ND (1.6)
W-13 Stream(C) 8/02/01 4.6 :t 134 (221) ND (1.6)
W-14 Well Removed (No Sample)
W-15 Well Removed (No Sample)
W-16 Pond(C) 8/02/01 14:t 134 (221) ND (1.5)
W-17 Well Removed (No Sample)
W-18 8/02/01 -23 :t 133 (221) ND (1.6)
W-19 Well Removed (No Sample)
Surface Locations
Heart Lake(c) 8/02/01 Well Plugged (Gamma only) ND (1.8)
Duck Cove Creek 8/01/01 -18:t 134 (222) ND (1.6)
Clevenger Creek 8/01/01 41 + 136 (222) ND (1.5)
(a)
(b)
(c)
Indicates results are less than MDC.
No gamma radionuclides detected above MDC.
Seep or spring, grab sample at or near original sampling location. Sampling locations have been removed or
plugged.
(ND) Non-detected MDC for gamma represents J37Cs.
8
-------
Table 3. Sampling Locations Established at the Cannikin Site (Figure 4).
Sample Collection Enriched Tritium Tritium(a) Gamma Spectrometry(b)
Location Date pCifL :t 2 SD pCifL :t 2 SD (MDC) pCifL (MDC)
(MDC)
HTH-3 7/31/01 13.6 :t 4.0 (6.3) ND (1.8)
Surface Locations
Cannikin Lake,
north 7/31/01 15 :t 4.2 (6.5) ND ( 1.5)
Cannikin Lake,
south 7/31/01 13.5 :t 4.6 (7.0) ND (1.9)
Ice Box Lake 8/01/01 15 :t 4.2 (6.5) ND (1.9)
Stream SW
Cannikin GZ(c) 8/01/01 59 :t 136 (222) ND (1.6)
DK-45 Lake 8/01/01 -59 :t 133 (221) ND (1.5)
DK-45 Veg 8/01/01 208:t 144 (230)
Decon Pump Well Removed (No Sample)
Decon Sump Well Removed (No Sample)
Constantine Spr Removed (No Sample)
Pumphouse
RX-Site Spr(C) 8/04/01 Removed (No Sample) ND (1.5)
TX-Site Spr 8/04/01 9.0:t 136 (221) ND (1.8)
TX-Site Water Well Removed (No Sample)
Tank House
White Alice
Creek 8/01/01 13 + 4.2 (6.5) ND (1.5)
(a) Indicates results are less than MDC.
(b) No gamma radionuclides detected above ~C. . . . .
(c) Seep or spring, grab sample at or near ongtnal samphng location. Samplmg locatiOns have been removed or
plugged.
& D7C
(ND) Non-detected MDC lor garnrna represents s.
9
-------
Table 4. Sampling Locations Established to Provide Background Data.
Sample Collection Enriched Tritium Tritium(a) Gamma Spectrometry(b)
Location Date pCi/L :t 2 SD (MDC) pCi/L :t 2 SD (MDC) pCiIL (MDC)
Army Well No. I 8/04/01 41 :t 135 (221) ND (1.9)
Army Well No.2 8/02/01 41 :t 135 (221) ND (1.6)
Army Well No.3 Well Removed (No Sample)
Army Well No.4 8/01/01 82 :t 136 (221) ND (1.7)
Site E Hydro Well Removed (No Sample)
Site D Hydro Well Removed (No Sample)
Surface Locations
Jones Lake 8/04/01 87 :t 137 (222) ND (1.6)
Constantine Spr 8/04/01 17 :t 4.2 (6.4) ND (1.9)
Clevenger Lake 8/02/01 64 :t 135 (221) ND (1.6)
Rain Sample 8/03/01 41 :t 135 (221)
Rain Sample 8/04/01 133 :t 137 (221)
(a) Indicates results are less than MDC.
(b) No gamma radionuclides detected above MDC.
(ND) Non-detected MDC for gamma represents I37Cs.
10
-------
REFERENCES
Chapman, J.B. and S.L. Hokett, 1991, Evaluation of Groundwater Monitoring at Offsite Nuclear
Test Areas, DOE Nevada Field Office Report DOE/NV/l0845-07, Las Vegas, NV. CHA1991
Code of Federal Regulations, 1988, Drinking Water Regulations, Title 40, part 141, Washington
D.C. CFR88
Corley, J.P., D.H. Denham, R.E. Jaquish, D.E. Michels, A.R. Olsen, D.A. Waite, 1981. A Guide
for Environmental Radiological Surveillance at U.S. Dept. of Energy Installations, DOE/EP-
0023. Office of Operational Safety Report, US. Department of energy, Washington, D.C.
DOE81
U.S. Atomic Energy Commission. Project (Cannikin. May, 1971 (internal document).
U.S. Department of Energy, Nevada Operations Office, Health Physics Division, Environmental
Branch. Long-Term Hydrologic Monitoring Program Amchitka Island, Alaska. Las Vegas,
NY: US. Department of Energy, Nevada Operations Office; NYO-242; 1982.
US. Environmental Protection Agency, Office of Radiation and Indoor Air. Amchitka, Alaska
Long Term Hydrologic Monitoring Plan. Las Vegas, NV: US. Environmental Protection
Agency, Radiation and Indoor Environments National Laboratory. Submitted to US. Department
of Energy April, 1997.
11
-------
GLOSSARY OF TERMS
Background Radiation
The radiation in man's environment, including cosmic rays and radiation from naturally-
occurring and man-made radioactive elements, both outside and inside the bodies of humans and
animals. The usually quoted average individual exposure from background radiation is 125
millirem per year in mid-latitudes at sea level.
Curie (Ci)
The basic unit used to describe the rate of radioactive disintegration. The curie is equal to 37
billion disintegrations per second, which is the equivalent of 1 gram of radium. Named for Marie
and Pierre Curie who discovered radium in 1898. One microcurie (Ilei) is 0.000001 Ci.
Isotope
Atoms of the same element with different numbers of neutrons in the nuclei. Thus 12C, BC, and
14e are isotopes of the element carbon, the numbers denoting the approximate atomic weights.
Isotopes have very nearly the same chemical properties, but have different physical properties
(for example 12C and Be are stable, 14e is radioactive).
Enrichment Method
A method of electrolytic concentration that increases the sensitivity of the analysis of tritium in
water. This method can be used for samples containing less than 800 pCiIL of tritium..
Minimum Detectable Concentration (MDC)
The smallest amount of radioactivity that can be reliably detected with a probability of Type I
and Type IT errors at 5 percent each (DOE 1981).
Tritium
A radioactive isotope of hydrogen that decays by beta emission. Its half-life is about 12.5 years.
Type I Error
The statistical error of accepting the presence of radioactivity when none is present. Sometimes
called alpha error.
Type II Error
The statistical error of failing to recognize the presence of radioactivity when it is present.
Sometimes called beta error.
12
-------
APPENDIX A
Standard Operating Procedures for the Center for Radioanalysis & Quality Assurance
RQA-302
RQA-602
RQA-603
RQA-604
RQA-606
Standard Operating Procedure of Gamma-Ray Detector Systems.
Tritium Enrichment Procedure.
Standard Operating Procedure for 89Sr and 90Sr in Water, Air Filters and Milk.
Standard Operating Procedure of Convention Tritium in Water.
Analysis of Plutonium, Uranium, and Thorium in Environmental Samples by
Alpha Spectroscopy.
13
-------
APPENDIX B
Summary of Analytical Procedures
Type of
Analysis
Analytical
Equipment
Counting Analytical
Period (Min) Procedures
Sample
Size
Approximate
Detection Limie
HpGe
Gammab
HpGe detector
calibrated at 0.5 keV/
channel (0.04 to 2 MeV
range) individual detector.
Efficiencies ranging from
15 to 35%.
100
Radionuclide concen-
tration quantified from
gamma spectral data by
online computer program.
3.5L
Varies with radionuclides.
3H
Automatic liquid
scintillation counter
300
Sample prepared by
distillation.
5 to 10 mL
300 to 700pCi/L
3H+ Automatic liquid
Enrichment scintillation counter
(LTHMP
samples)
a The detection limit is defined as the smallest amount of radioactivity that can be reliably detected, i.e.,
probability of Type I and Type II error at 5 percent each (DOE 1981).
b Gamma spectrometry using a high purity intrinsic germanium (HpGe) detector.
300
Sample concentrated by
electrolysis followed by
distillation.
250 mL
5 pCi/L
Geometry*
Matrix
Volume
Isotope
Typical MDA Values for Gamma Spectroscopy
(100 minute count time)
Marinelli Model
Water Density
3.5 Liter Units
MDA Isotope
Ru-106
Sn-113
Sb-125
1-131
Ba-133
Cs-134
Cs-137
Ce-l44
Eu-152
Ra-226
U-235
Am-241
4.56E+Ol
4.92E+Ol
5.88E+Ol
4.55E+Ol
9.65E+00
4.71E+00
1.07E+0 1
5.38E+00
1.24E+Ol
5.64E+00
9.06E+00
430G
1.0 glrnl
pCi/L
MDA
4.76E+Ol
8.32E+00
1.65E+0 1
8.28E+00
9. 16E+00
6. 12E+00
6.43E+00
7 .59E+0 1
2.86E+Ol
1.5 8E+0 1
1.01E+02
6.60E+Ol
Be-7
K-40
Cr-51
Mn-54
Co-57
Co-58
Fe-59
Co-60
Zn-65
Nb-95
Zr-95
Disclaimer
The MDA's provided are for background matrix samples presumed to contain no known analytes and no decay time.
All MDA's provided here are for one specific *Germanium detector and the geometry of interest. The MDA's in no
way should be used as a source of reference for determing MDA's for any other type of detector. All gamma
spectroscopy MDA's will vary with different types of shielding, geometries, counting times and decay time of
sample.
14
------- |