United States
Environmental Protection
Agency
Office of Radiation and
Indoor Air
Washington, DC 20460
EPA
January 1999
EPA-402-R-98-OI3
&EPA Offsite Environmental
Monitoring Report
Radiation Monitoring Around
United States Nuclear Test
Areas, Calendar Year 1997
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Offsite Environmental Monitoring Report:
Radiation Monitoring Around United States
Nuclear Test Areas, Calendar Year 1997
Contributors:
Max G. Davis, Richard D. Flotard, Chris A. Fontana,
Polly A. Hennessey, Herb K. Maunu, Terry L. Mouck,
Anita A. Mullen, Mark D. Sells, the Center for Radioanalysis &
Quality Assurance, and the Radiation and Indoor Environments National
Laboratory
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
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Notice
The U.S. Environmental Protection Agency (EPA), through the Office of Air and Radiation (OAR), Radiation
and Indoor Environments National Laboratory (R&IE) Las Vegas, NV, performed the work described with
funding received from the U.S. Department of Energy under interagency agreement number RW89937611 -
01 (EPA)/DE-AI08-96NV11969(DOE). EPA funded the publication of this report. It has been subjected to
the Agency's peer review and has been approved as an EPA publication. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
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Abstract
This report describes the Offsite Radiological Environmental Monitoring Program (OREMP) conducted during
1997 by the U. S. Environmental Protection Agency's (EPAs), Radiation and Indoor Environments National
Laboratory, Las Vegas, Nevada. This laboratory operated an environmental radiation monitoring program in
the region surrounding the Nevada Test Site (NTS) and at former test sites in Alaska, Colorado, Mississippi,
Nevada, and New Mexico. The surveillance program is designed to measure levels and trends of radioactivity,
if present, in the environment surrounding testing areas to ascertain whether current radiation levels and
associated doses to the general public are in compliance with existing radiation protection standards. The
surveillance program additionally has the responsibility to take action to protect the health and well being of the
public in the event of any accidental release of radioactive contaminants. Offsite levels of radiation and
radioactivity are assessed by sampling and analyzing milk, water, and air; by deploying and reading
thermoluminescent dosimeters (TLDs); and using pressurized ionization chambers (PICs) to measure ambient
gamma exposure rates with a sensitivity capable of detecting low level exposures not detected by other
monitoring methods.
No nuclear weapons testing was conducted in 1997 due to the continuing nuclear test moratorium. During this
period, R&IE personnel also maintained readiness capability to provide direct monitoring support if testing were
to be resumed by participating in exercises and subcritical.
Comparison of the measurements and sample analysis results with background levels and with appropriate
standards and regulations indicated that there was no airborne radioactivity from diffusion or resuspension
detected by the various EPA monitoring networks surrounding the NTS. There was no indication of potential
migration of radioactivity to the offsite area through groundwater and no radiation exposure above natural
background was received by the offsite population. All evaluated data were consistent with previous data
history. Using the EPAs CAP88-PC model and NTS radionuclide emissions and environmental monitoring data,
the calculated effective dose equivalent (EDE) to the maximally exposed individual offsite would have been
about 0.11 mrem. This value is less than two percent of the Federal dose limit prescribed for radionuclide air
emissions. The dose received from natural background radiation was about 144 mrem.
The offsite Environmental Monitoring Report: Radiation Monitoring Around United States Nuclear Test Areas,
Calendar Year 1994 and 1995 was not and may not be published. Please refer to the 1994 and 1995 Nevada
Test Site Annual Site Environmental Report, for data covering that time period.
iii
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This page is left blank intentionally
iv
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Contents
Notice jj
Abstract \\\
Figures viii
Tables jx
Abbreviations, Acronyms, Units of Measure, and Conversions x
Acknowledgements xii
SECTION 1
1.0 Introduction 1
1.1 Program Summary and Conclusions 1
1.1.1 Thermoluminescent Dosimetry Program 1
1.1.2 Pressurized Ion Chamber 2
1.1.3 Air Surveillance Network 2
1.1.4 Milk 2
1.1.5 Long-Term Hydrological Monitoring Program 2
1.1.5.1 Nevada Test Site Monitoring 2
1.1.5.2 Offsite Monitoring in the Vicinity of the Nevada Test Site 2
1.1.5.3 LTHMP at Off-NTS Nuclear Device Test Locations 2
1.1.6 Dose Assessment 3
1.1.7 Hazardous Spill Center „ 3
1.2 Offsite Monitoring 3
1.3 Offsite Radiological Quality Assurance 3
1.4 Nonradiological Monitoring 4
SECTION 2
2.0 Description of the Nevada Test Site 5
2.1 Location 5
2.2 Climate 5
2.3 Hydrology 7
2.4 Regional Land Use 7
2.5 Population Distribution 10
SECTION 3
3.0 External Ambient Gamma Monitoring 11
3.1 Thermoluminescent Dosimetry Network 11
3.1.1 Design 11
3.1.2 Results of TLD Monitoring 11
3.1.3 Quality Assurance/Quality Control 13
3.1.4 Data Management 14
3.2 Pressurized Ion Chambers 14
3.2.1 -Network Design 14
3.2.2 Procedures 14
3.2.3 Results 16
3.2.4 Quality Assurance/Quality Control 16
3.3 Comparison of TLD Results to PIC Measurements 16
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Contents (continued)
SECTION 4
4.0 Atmospheric Monitoring 21
4.1 Air Surveillance Network 21
4.1.1 Design 21
4.1.2 Procedures 21
4.1.3 Results 23
4.1.4 Quality Assurance/Quality Control 23
SECTION 5
5.0 Milk 27
5.1 Milk Surveillance Network 27
5.1.1 Design 27
5.1.2 Procedures 27
5.1.3 Results 27
5.1.4 Quality Assurance/Quality Control 27
SECTION 6
6.0 Long-Term Hydrological Monitoring Program 30
6.1 Network Design 30
6.1.1 Sampling Locations 31
6.1.2 Sampling and Analysis Procedures 31
6.1.3 Quality Assurance/Quality Control Samples 32
6.1.4 Data Management and Analysis 32
6.2 Nevada Test Site Monitoring 33
6.3 Offsite Monitoring in the Vicinity of the Nevada Test Site 33
6.4 Hydrological Monitoring at Other Locations 33
6.4.1 Project FAULTLESS, Nevada 36
6.4.2 Project SHOAL, Nevada 36
6.4.3 Project RULISON, Colorado 36
6.4.4 Project RIO BLANCO, Colorado 40
6.4.5 Project GNOME, New Mexico 40
6.4.6 Project GASBUGGY, New Mexico 40
6.4.7 Project DRIBBLE, Mississippi 43
6.4.8 Amchitka Island, Alaska 48
6.5 SUMMARY \[ 43
SECTION 7
7.0 Dose Assessment 73
7.1 Estimated Dose from Nevada Test Site Activity Data 73
7.2 Estimated Dose from Offsite Radiological Safety Program Monitoring Network
Data 74
7.3 Dose from Background Radiation 75
7.4 Summary 75
VI
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Contents (continued)
SECTION 8
8.0 Training Program 79
8.1 Emergency Response Training Program 79
8.2 Hazardous Materials Spill Center Support 80
SECTION 9
9.0 Sample Analysis Procedures 81
SECTION 10
10.0 Quality Assurance 83
10.1 Policy 83
10.2 Data Quality Objectives 83
10.2.1 Representativeness, Comparability, and Completeness Objective 83
10.2.2 Precision and Accuracy Objectives of Radioanalytical Analyses 84
10.2.3 Quality of Dose Estimates 84
10.3 Data Validation 84
10.4 Quality Assessment of 1997 Data 85
10.4.1 Completeness 86
10.4.2 Precision 87
10.4.3 Accuracy 88
10.4.4 Comparability 89
10.4.5 Representativeness 89
References 95
Glossary of Terms 96
Appendix (LD Calculations) 98
vii
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Figures
Figure 2.1 Location of the Nevada Test Site 6
Figure 2.2 Ground water flow systems around the Nevada Test Site 8
Figure 2.3 General land use within 180 miles (300 km) of the Nevada Test Site 9
Figure 3.1 Location of TLD Fixed Stations and Personnel Monitoring Participants 12
Figure 3.2 Community Technical Liaison Program (CTLP) and PIC station locations 15
Figure 3.3 Monthly averages from each PIC Network station, 1997 17
Figure 4.1 Air Surveillance Network stations, 1997 22
Figure 5.1 Milk Surveillance Network stations, 1997 28
Figure 6.1 LTHMP sampling sites around the United States 30
Figure 6.2 Wells on the Nevada Test Site included in the LTHMP, 1997 34
Figure 6.3 Wells outside the Nevada Test Site included in the LTHMP, 1997 35
Figure 6.4 LTHMP sampling locations for Project FAULTLESS, 1997 37
Figure 6.5 LTHMP sampling locations for Project SHOAL, 1997 38
Figure 6.6 LTHMP sampling locations for Project RULISON, 1997 39
Figure 6.7 LTHMP sampling locations for Project RIO BLANCO, 1997 41
Figure 6.8 LTHMP sampling locations for Project GNOME, 1997 42
Figure 6.9 LTHMP sampling locations for Project GASBUGGY, 1997 44
Figure 6.10 LTHMP sampling locations for Project DRIBBLE near ground zero, 1997 45
Figure 6.11 LTHMP sampling locations for Project DRIBBLE towns and residences, 1997 46
Figure 6.12 Tritium result trends in Baxterville, MS, public drinking water supply, 1997 47
Figure 6.13 Tritium results in Well HM-S, Salmon Site, Project DRIBBLE, 1997 47
Figure 6.14 Amchitka Island and background sampling location for the LTHMP 49
Figure 6.15 LTHMP sampling locations for Projects MILROW and LONGSHOT 50
Figure 6.16 LTHMP sampling locations for
Project CANNIKIN 51
VIM
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Tables
2.1 Characteristics of Climatic Types in Nevada (from Houghton et al., 1975) 7
3.1 Environmental Thermoluminescent Dosimetry Results, 1997 18
3.2 Personnel Thermoluminescent Dosimetry Results, 1997 19
3.3 Summary of Weekly Gamma Exposure Rates as Measured by Pressurized Ion
Chambers, 1997 20
4.1 Gross Beta Results for the Offsite Air Surveillance Network, 1997 24
4.2 Gross Alpha Results for the Offsite Air Surveillance, 1997 25
4.3 Offsite High-Volume Airborne Plutonium Concentrations, 1997 26
5.1 Offsite Milk Surveillance 90Sr Results, 1997 29
5.2 Summary of Radionuclides Detected in Milk Samples 29
6.1 Locations with Detectable Tritium and Man-Made Radioactivity in 1997 53
6.2 Summary of EPA Analytical Procedures, 1997 54
6.3 Typical MDA Values for Gamma Spectroscopy 54
6.4 LTHMP Summary of Tritium Results for Nevada Test Site Network, 1997 55
6.5 LTHMP Summary of Tritium Results for Wells near the Nevada Test Site, 1997 56
6.6 Analysis Results for Water Samples Collected in May 1997 (RULISON) 58
6.7 Analysis Results for Water Samples Collected in May 1997 (RIO BLANCO) 59
6.8 Analysis Results for Water Samples Collected in February 1997 (FAULTLESS) 60
6.9 Analysis Results for Water Samples Collected in February 1997 (SHOAL) 60
6.10 Analysis Results for Water Samples Collected in May 1997 (GASBUGGY) 61
6.11 Analysis Results for Water Samples Collected in June 1997 (GNOME) 62
6.12 Tritium Results for Water Samples Collected in April 1997 (SALMON) 63
6.13 Sampling Locations Established at the LONG SHOT Site 70
6.14 Sampling Locations Established at the MILROW Site 71
6.15 Sampling Locations Established at the CANNIKIN Site 72
6.16 Sampling Locations Established to Provide Background Data for (Amchitka) 72
7.1 NTS Radionuclide Emissions, 1997 76
7.2 Summary of Effective Dose Equivalents from NTS Operations, 1997 77
7.3 Monitoring Networks Data used in Dose Calculations, 1997 77
7.4 Radionuclide Emissions on the NTS, 1997 78
8.1 Co-instructed Training Courses, 1997 79
8.2 Emergency Response Classes Attended, 1997 80
9.1 Summary of Analytical Procedures 81
10.1 Data Completeness of Offsite Radiological Safety Program Networks 86
10.2 Precision Estimates for Duplicate Sampling, 1997 88
10.3 Accuracy of Analysis from RADQA Performance Evaluation Study, 1997 91
10.4 Comparability of Analysis from RADQA Performance Evaluation Study, 1997 92
10.5 Accuracy of Analysis from DOE/EML Performance Evaluation Studies 93
10.6 Accuracy of Analysis from DOE/MAPEP PE Studies 94
IX
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Abbreviations, Acronyms, Units of Measure, and
Conversions
ABBREVIATIONS and ACRONYMS
AEC -- Atomic Energy Commission MQO
ALARA - As Low as Reasonably Achievable MSL
ALI - Annual Limit on Intake MSN
ASN - Air Surveillance Network NCRP
ANSI -- American National Standards
Institute NIST
ARL/SORD - Air Resources Laboratory Special
Operations and Research Division NPDWR -
BOC - Bureau of Census
CEDE - committed effective dose NPS
equivalent NTS
CFR - Code of Federal Regulations NVLAP
CG -- Concentration Guide
CP-1 - Control Point One OREMP -
CTLP -- Community Technical Liaison
Program PHS
DAC - Derived Air Concentration PIC
DCG - Derived Concentration Guide QA
DOE -- U.S. Department of Energy QC
DOELAP - Department of Energy, ORIA
Laboratory Accreditation Program RAWS -
DQO - data quality objective
DRI - Desert Research Institute RCRA
ECF - Element Correction Factor
EDE - Effective Dose Equivalent R&IE
EPA - U.S. Environmental Protection
Agency
FDA -- Food and Drug Administration RWMS
GOES - Geostationary Operational
Environmental Satellite S.D.
GZ - Ground Zero SGZ
HMC - Hazardous Materials Center SOP
HTO - Tritiated Water STDMS -
HpGe - High purity germanium
lAGs -- Interagency Agreements TLD
ICRP - International Commission on USGS -
Radiological Protection WSNSO -
LTHMP - Long-Term Hydrological
Monitoring Program
MAPEP -- Mixed Analyte Performance
Evaluation Program
MDC -- minimum detectable concentration
MEI -- maximally exposed individual
measurement quality objective
mean sea level
Milk Surveillance Network
National Council on Radiation
Protection and Measurements
National Institute of Standards
and Technology
National Primary Drinking
Water Regulation
National Park Service
Nevada Test Site
National Voluntary Laboratory
Accreditation Program
Offsite Radiological Environmental
Monitoring Program
U.S. Public Health Service
pressurized ion chamber
quality assurance
quality control
Office of Radiation and Indoor Air
Remote Automatic Weather
Station
Resource Conservation and
Recovery Act
Radiation and Indoor
Environments National Laboratory-
Las Vegas
Radioactive Waste Management
Site
standard deviation
Surface Ground Zero
standard operating procedure
Sample Tracking Data
Management System
thermoluminescent dosimetry
U.S. Geological Survey
Weather Service Nuclear Support
Office
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Abbreviations, Acronyms, Units of Measure, and
Conversions (continued)
UNITS OF MEASURE
Bq - Becquerel, one disintegration per mo
second mR
C — coulomb mrem
°C - degrees centigrade mSv
Ci -- Curie pCi
cm - centimeter, 1/100 meter qt
eV - electron volt R
°F -- degrees Fahrenheit rad
g - gram rem
hr -- hour
keV - one thousand electron volts Sv
kg -- kilogram, 1000 grams wk
km -- kilometer, 1000 meters yr
L -- liter uCi
m - meter uR
MeV - one million electron volts %
mg - milligram, 10"3 gram ±
min - minute <
ml_ - milliliter, 10"3 liter =
- month
- milliroentgen, 10"3 roentgen
- millirem, 10"3 rem
- millisievert, 10"3 sievert
- picocurie, 10~12 curie
-- quarter
-- roentgen
- unit of absorbed dose, 100 ergs/g
-- dose equivalent, the rad adjusted
for biological effect
- sievert, equivalent to 100 rem
-- week
-- year
- microcurie, 10~6 curie
- microroentgen, 10~6 roentgen
-- percent
-- plus or minus
-- less than
-- equal to
-- approximately equal to
-- greater than
PREFIXES CONVERSIONS
a atto =
f femto =
p pico =
n nano =
u micro =
m milli =
k kilo
IO-IB
10'15
10-12
ID'9
10'6
io-3
103
Multiply by
Concentrations
uCi/mL 109
uCi/mL 1012
SI Units
rad
rem
pCi
mR/yr
10-2
10'2
3.7 x10'2
2.6 x10'7
To Obtain
pCi/L
pCi/m3
Gray (Gy=1 Joule/kg)
Sievert (Sv)
Becquerel (Bq)
Coulomb (C)/kg-yr
XI
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Acknowledgements
External peer review was provided by Steven G. Oberg, PhD, Director, Environmental Health & Safety,
University of Nevada, Reno, Nevada. Internal reviewers, in addition to the authors, included Jerry Martin
and James Benetti, U.S. Environmental Protection Agency (Las Vegas, Nevada). The contributions of these
reviewers in production of this final version of the 1997 annual report are gratefully acknowledged. Also,
the authors would like to thank Dr. Stuart C. Black for providing the offsite dose calculations.
The authors would like to thank Jed Harrison for his advice and assistance in the coordination and
preparation of this report. We also want to thank the staff of the ORIA Radiation and Indoor Environments
National Laboratory-Las Vegas for collecting samples, maintaining equipment, interfacing with offsite
residents, and for analyzing the samples.
The skill, dedication, and perseverance of Terry L. Mouck in text processing and graphics support were
crucial to the production of this report.
XII
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1.0 Introduction
The U.S. Atomic Energy Commission (AEC) used
the Nevada Test Site (NTS), between January
1951 and January 1975, for conducting nuclear
weapons tests, nuclear rocket engine development,
nuclear medicine studies, and for other nuclear and
nonnuclearexperiments. Beginning in mid-January
1975, these activities became the responsibility of
the U.S. Energy Research and Development
Administration. Two years later this organization
was merged with other energy-related agencies to
form the U.S. Department of Energy (DOE).
Atmospheric weapons tests were conducted peri-
odically at the NTS from January 1951 through
October 1958, followed by a test moratorium which
was in effect until September 1961. Since then all
nuclear detonations at the NTS have been con-
ducted underground, with the expectation of con-
tainment, except the above-ground and shallow
underground tests of Operation Sunbeam and
cratering experiments conducted under the Plow-
share program between 1962 and 1968. In late
1992 a nuclear explosives test moratorium brought
an end to nuclear weapons testing and only simu-
lated readiness tests were conducted in 1997.
Prior to 1954, an offsite radiation surveillance
program was performed by personnel from the Los
Alamos Scientific Laboratory and the U.S. Army.
Beginning in 1954, and continuing through 1970,
this program was conducted by the U.S. Public
Health Service (PHS). When the U.S. Environ-
mental Protection Agency (EPA) was formed in
December 1970, certain radiation responsibilities
from several Federal agencies were transferred to
it, including the Offsite Radiological Environmental
Monitoring Program (OREMP) of the PHS. From
1970 to 1995, the EPA Environmental Monitoring
Systems Laboratory-Las Vegas (EMSL-LV) con-
ducted the OREMP, both in Nevada and at other
U.S. nuclear test sites, under interagency agree-
ments (lAGs) with the DOE or its predecessor
agencies. Since that time, EPA's Office of Radia-
tion and Indoor Air, Radiation and Indoor Environ-
ments National Laboratory-Las Vegas (R&IE) has
conducted a scaled down OREMP
In 1997, the four major objectives of the OREMP
were:
• Assuring the health and safety of the
people living near the NTS.
• Measuring and documenting levels and
trends of environmental radiation or radio-
active contaminants in the vicinity of past
atomic testing areas.
• Maintaining readiness to resume nuclear
testing at some future date.
• Obtain data of suitable quality to be used
by DOE in demonstrations of compliance
with applicable radiation protection stand-
ards, guidelines and regulations.
Offsite levels of radiation and radioactivity are
assessed by gamma-ray measurements using
pressurized ion chambers (PICs) and thermolumi-
nescent dosimeters (TLDs); and by sampling air,
water, and milk. Although in years prior to 1996,
extensive sampling of wildlife on and off the NTS,
vegetation sampling from offsite residents gardens
and soil sampling and insitu soil measurements
were conducted, cut backs in funding and primarily
background results lead to the cessation of these
programs. It is felt that occasional future sampling
of these media is warranted as weathering of past
fallout may change the biological uptake of these
radionuclides.
1.1 Program Summary and
Conclusions
The primary functions of the OREMP are to conduct
routine environmental monitoring for radioactive
materials in areas potentially impacted by nuclear
tests and, when necessary, to implement actions to
protect the public from radiation exposure. Com-
ponents of the OREMP include surveillance net-
works for air, and milk, exposure monitoring by
thermoluminescentdosimetry, and pressurized ion
chambers, and long-term hydrological monitoring
of wells and surface waters. In 1997, data from all
networks and monitoring activities indicated no
radiation directly attributable to current activities
conducted at the NTS. Therefore, protective
actions were not required. The following sections
summarize the OREMP activities for 1997.
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1.1.1 Thermoluminescent
Dosimetry Program
In 1997, external exposure was monitored by a
network of thermoluminescent dosimeters (TLDs)
at 39 fixed locations surrounding the NTS and by
TLDs worn by 18 offsite residents. No net expo-
sures were related to NTS activities. Neither
administrative, ALARA, nor regulatory investigation
limits were exceeded for any individual or fixed
location cumulative exposure. The range of expo-
sures was similar to those observed in other areas
of the United States and were slightly lower than
those of the past.
No radioactivity attributable to current NTS opera-
tions was detected by any of the monitoring net-
works. However, based on the releases reported
by NTS users, atmospheric dispersion model
calculations (CAP88-PC) (EPA 1992) indicated
that the maximum potential effective dose equiva-
lent to any offsite individual would have been 0.11
mrem (1.1 x 10"3 mSv), and the dose to the popula-
tion within 80 kilometers of the emission sites would
have been 0.34 person-rem (3.4 x 10"3 person-Sv).
The hypothetical person receiving this dose was
also exposed to 144 mrem from normal back-
ground radiation. Details of this program may be
found in Section 3 of this Report.
1.1.2 Pressurized Ion Chamber
Network
The Pressurized lonization Chamber (PIC) network
measures ambient gamma radiation exposure rates
on a near real-time basis. The 26 PICs deployed
around the NTS in 1997 showed no unexplained
deviations from background levels. These back-
ground exposures, ranging from 71 to 156 mR/yr
are within the U.S. background range and are
consistent with previous years' trends. Details of
this program may be found in Section 3 of this
Report.
1.1.3 Air Surveillance Network
In 1997, the Air Surveillance Network (ASN) in-
cluded 20 continuously operating sampling stations
at locations surrounding the NTS. In the majority of
cases, no gamma emitting radionuclides were
detected by gamma spectrometry (i.e., the results
were gamma-spectrum negligible). Naturally
occurring 7Be was the only radionuclide occasion-
ally detected. As in previous years, the majority of
the gross beta results exceeded the minimum
detectable concentration (MDC). Analysis of air
samples for gross alpha showed results to be either
below or very slightly above (i.e. statistically
indistinguishable from) the MDC. The isotopes
239+240pu were consjstently detected at all six of the
sampling sites. Details of the Atmospheric Monitor-
ing program may be found in Section 4 of this
Report.
1.1.4 Milk
Milk samples were collected from 10 Milk Surveil-
lance Network (MSN) stations in 1997. The aver-
age total potassium concentration derived from 40K
was consistent with results obtained in previous
years. No man-made gamma-emitting
radionuclides were detected in any of the milk
samples. Results of analyses for 89Sr and ^Sr were
similar to those obtained in previous years. Neither
increasing nor decreasing trends were evident.
Detailed discussion of the collection and analysis of
milk may be found in Section 5 of this report.
1.1.5 Long-Term Hydrological
Monitoring Program
1.1.5.1 Nevada Test Site
Monitoring
Twenty-two wells on the NTS or immediately
outside its borders on federally owned land were
sampled. All samples collected during 1997 were
analyzed for gamma-emitting radionuclides by
gamma spectrometry and for tritium by the conven-
tional and/or the enrichment method. No gamma-
emitting radionuclides were detected. The highest
tritium level, detected in a non-potable sample from
Well UE-5n (6.0 x 10" pCi/L), was less than 70% of
the derived concentration guide for tritium. There
were no indications that migration from any test
cavity is affecting any domestic water supply.
Six of the wells sampled yielded tritium results
greater than the MDC. The trend in tritium concen-
tration in samples from Test Well B (see Table 6.4
page 65) is typical of a well with decreasing tritium.
1.1.5.2 Offsite Monitoring in the Vicinity
of the Nevada Test Site
These sampling locations represent drinking water
sources for rural residents and for communities in
the area. Sampling locations include 12 wells, nine
springs, and a surface water site. All the locations
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are sampled quarterly or semiannually. Gamma
spectrometric analysis is completed on all samples.
No man-made gamma-emitting radionuclides were
detected. Tritium analysis is performed on a
semiannual basis.
None of the 1997, samples analyzed for tritium
using the conventional method had results above
the MDC. Three that were analyzed for tritium by
the enrichment method showed detectable activity.
Adaven Spring and Lake Mead showed detectable
tritium activity while the sample from the low-level
waste site south of Beatty had barely detectable
activity.
1.1.5.3 LTHMP at Off-NTS Nuclear
Device Test Locations
Annual sampling of surface and ground waters is
conducted at Projects SHOAL and FAULTLESS
sites in Nevada, Projects GASBUGGYand GNOME
sites in New Mexico, Projects RULISON and RIO
BLANCO sites in Colorado, and the Project DRIB-
BLE site in Mississippi. Sampling is normally
conducted in odd numbered years on Amchitka
Island, Alaska, at the Projects CANNIKIN,
LONGSHOT, and MILROW. Water from well
EPNG 10-36 at Project GASBUGGY contained
tritium at a concentration of 122 ± 5.9 pCi/L. The
mechanism and route of migration from the Project
GASBUGGY cavity is not currently known.
Details of the on-site, near NTS, and off-NTS
hydrological monitoring programs may be found in
Section 6 of this Report.
1.1.6 Dose Assessment
The extensive offsite environmental surveillance
system detailed in this report measured no radia-
tion exposures that could be attributed to recent
NTS activities. The potential Effective Dose Equiv-
alent (EDE) to the maximally exposed offsite
resident was calculated to be 0.015 mrem, using
certain assumptions as all data were not available
due to a decrease of funding. Calculation with the
EPA CAP88-PC model, using estimated or calcu-
lated effluents from the NTS, resulted in a maxi-
mum dose of 0.089 mrem (8.9 X 10"4 mSv) to a
hypothetical resident of Springdale, NV located 14
km (nine mi) west of the NTS boundary. Based on
monitoring network data, this dose is calculated to
be 0.015 mrem. This EDE is about 5 percent of the
dose obtained using the CAP88-PC model. The
calculated population dose (collective effective
dose equivalent (CEDE)) to the approximately
32,210 residents living within 80 km (50 mi) from
each of the NTS airborne emission sources was
0.26 person-rem (2.6 X 10"3 person-Sv). Back-
ground radiation yielded a CEDE of 3,064 person-
rem(30.6 person-Sv). Details of the dose assess-
ment calculations may be found in Section 7 of this
Report.
1.1.7 Hazardous Spill Center
During 1997, EPA participated on the control board
for two experiments, each consisting of a series of
spill tests: (1) Remote Sensor Test Range - Lynx
Episode using 28 materials, and (2) Effluent Track-
ing Experiment using ten materials. The amounts
used in the tests were so small that boundary
monitoring was not necessary.
Detailed discussion of R&IE-LV activities in support
of this facility may be found in Section 8 of this
Report.
1.2 Offsite Monitoring
Under the terms of an Interagency Agreement
between DOE and EPA, the EPA R&IE conducts
the Offsite Radiological Environmental Monitoring
Program (OREMP) in the areas surrounding the
NTS. The largest component of R&IE's program is
routine monitoring of potential human exposure
pathways. Another component is public informa-
tion.
As a result of the continuing moratorium on nuclear
weapons testing, only two subcritical experiments
were conducted in 1997. For each one, R&IE-LV
senior personnel served on the Test Controller's
Scientific Advisory Panel and on the EPA offsite
radiological safety staff. No radioactive materials
were released to the ambient environment as a
result of these two experiments. Routine offsite
environmental radiation monitoring continued
throughout 1997, as in past years.
Public information presentations provide a forum
for increasing public awareness of NTS activities,
disseminating radiation monitoring results, and
addressing concerns of residents related to
environmental radiation and possible health effects.
Community Technical Liaison Program (CTLP)
stations have been established in prominent loca-
tions in a number of offsite communities. The
CTLP stations contain samplers for several of the
monitoring networks and are managed by local
-------
residents. DOE and DRI are cooperators with EPA
in the CTLP. The CTLP is discussed in Section 3.
Environmental monitoring networks, described in
the following subsections, measure radioactivity in
air, milk, and ground water. These networks
monitor the major potential pathways of
radionuclide transfer to man via inhalation, submer-
sion, and ingestion. Gamma radiation levels are
continuously monitored at selected locations using
Reuter-Stokes pressurized ion chambers (PICs)
and Panasonic TLDs. Atmospheric monitoring
equipment includes both high- and low volume air
samplers. Milk is sampled and analyzed annually.
Ground water on and in the vicinity of the NTS is
monitored in the Long-Term Hydrological Monitor-
ing Program (LTHMP). Data from these monitoring
networks are used to calculate an annual exposure
dose to the offsite residents, as described in Sec-
tion 7.
1.3 Offsite Radiological
Quality Assurance
The policy of the EPA requires participation in a
centrally managed QA program by all EPA organi-
zational units involved in environmental data
collection. The QA program developed by the
R&IE for the Offsite Radiological Environmental
Monitoring Program (OREMP) meets all require-
ments of EPA policy, and also includes applicable
elements of the Department of Energy QA require-
ments and regulations. The OREMP QA program
defines data quality objectives (DQOs), which are
statements of the quality of data a decision maker
needs to ensure that a decision based on those
data is defensible. Achieved data quality may then
be evaluated against these DQOs.
In addition, R&IE meets the EPA policy which
states that all decisions which are dependent on
environmental data must be supported by data of
known quality. EPA policy requires participation in
a centrally managed Quality Assurance Program by
all EPA elements as well as those monitoring and
measurement efforts supported or mandated by
contracts, regulations, or other formalized agree-
ments. The R&IE QA policies and requirements
are summarized in the "Quality Management Plan"
(EPA/R&IE1996).
1.4 Nonradiological
Monitoring
R&IE also provides support for the HAZMAT Spill
Center( HSC) located at Frenchman Flat in Area 5
of the NTS. The HSC was designed for safe
research on the handling, shipping, and storage of
liquified gaseous fuels and other hazardous liquids.
The R&IE provides a chemist to participate in
meetings of the Advisory Panel which reviews and
approves all programs prior to testing and main-
tains readiness for monitoring emissions at the
boundary of the NTS.
For those tests requiring monitoring, the R&IE
personnel deploy air sampling sensors to detect
any offsite releases. In 1997, at the HSC, two
series of tests, involving 38 chemicals, were
conducted. None of the tests generated enough
airborne contaminants to be detected at the NTS
boundary during or after the tests.
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2.0 Description of the Nevada Test Site
The NTS, located in southern Nevada, was the
primary location for testing of nuclear explosives in
the continental U.S. from 1951 until the present
moratorium began. Historical testing has included
(1) atmospheric testing in the 1950s and early
1960s, (2) underground testing in drilled vertical
holes and horizontal tunnels, (3) earth-cratering
experiments, and (4) open-air nuclear reactor and
engine testing. No nuclear tests were conducted in
1997. Limited non-nuclear testing has included
controlled spills of hazardous material at the
HAZMAT Spill Center. Low-level radioactive and
mixed waste disposal and storage facilities for
defense waste are also operated on the NTS.
The NTS environment is characterized by desert
valley and Great Basin mountain terrain and topog-
raphy, with a climate, flora, and fauna typical of the
southern Great Basin deserts. Restricted access
and extended wind transport times are notable
features of the remote location of the NTS and
adjacent U.S. Air Force lands. Also characteristic
of this area are the great depths to slow-moving
groundwaters and little or no surface water. These
features afford protection to the inhabitants of the
surrounding area from potential radiation expo-
sures as a result of releases of radioactivity or other
contaminants from operations on the NTS. Popula-
tion density within 150 km of the NTS is only 0.5
persons per square kilometer versus approximately
29 persons per square kilometer in the 48 contigu-
ous states. The predominant land use surrounding
the NTS is open range for livestock grazing with
scattered mining and recreational areas.
The EPA's Radiation and Indoor Environments
National Laboratory in Las Vegas, Nevada, con-
ducts hydrological studies at eight U.S. nuclear
testing sites in other states and two off the NTS in
Nevada. The last test conducted at any of these
sites was in 1973 (Project RIO BLANCO in Colo-
rado).
2.1 Location
The NTS is located in Nye County, Nevada, with its
southeast corner about 54 miles (90 km) northwest
of Las Vegas (Figure 2.1). It occupies an area of
about 1,350 square miles (3,750 square km), varies
from 28 to 35 miles (46 to 58 km) in width (east-
west) and from 49 to 55 miles (82 to 92 km) in
length (north-south). This area consists of large
basins or flats about 2,970 to 3,900 feet (900 to
1,200 m) above mean sea level (MSL) surrounded
by mountain ranges rising from 5,940 to 7,590 feet
(1,800 to 2,300 m) above mean sea level (MSL).
The NTS is surrounded on three sides by exclusion
areas, collectively named the Nellis Air Force Base
Range Complex, which provides a buffer zone
between the test areas and privately owned lands.
This buffer zone varies from 14 to 62 miles (24 to
104 km) between the test area and land that is
open to the public.
2.2 Climate
The climate of the NTS and surrounding area is
variable, due to its wide range in altitude and its
rugged terrain. Most of Nevada has a semi-arid
climate characterized as mid-latitude steppe.
Throughout the year, water is insufficient to support
the growth of common food crops without irrigation.
Climate may be classified by the types of vegeta-
tion indigenous to an area. According to Nevada
Weather and Climate (Houghton et al., 1975), this
method of classification developed by Koppen is
further subdivided on the basis of "...seasonal
distribution of rainfall and the degree of summer
heat or winter cold." Table 2.1 summarizes the
characteristics of climatic types for Nevada.
According to Quiring (1968), the NTS average
annual precipitation ranges from about 4 inches (10
cm) at the lower elevations to around 10 inches (25
cm) at the higher elevations. During the winter
months, the plateaus may be snow-covered for a
period of several days or weeks. Snow is uncom-
mon on the flats. Temperatures vary considerably
with elevation, slope, and local air currents. The
average daily temperature ranges at the lower
altitudes are around 25 to 50°F (-4 to 10°C) in
January and 55 to 95°F (13 to 35°C) in July, with
extremes of -15T (-26°C) and 120°F (49 °C).
Corresponding temperatures on the plateaus are
25 to 35°F (-4 to 2°C) in January and 65 to SOT (18
to 27 °C) in July with extremes of -SOT (-34°C) and
115T(46°C).
-------
NB-US
AF8
RANGE
'.COMPLEX
100
50 100 150
Scale in Kilometers
Figure 2.1 Location of the Nevada Test Site.
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Table 2.1 Characteristics of Climatic Types in Nevada (from Houghton et al. 1975)
Climate Type
Alpine tundra
Humid continental
Subhumid continental
Mid-latitude steppe
Mid-latitude desert
Low-latitude desert
Temperature
°F
Winter Summer
Oto15
(-18 to -9)
10 to 30
10 to 30
20 to 40
(-7 to 4)
20 to 40
(-7 to 4)
40 to 50
(4 to 10)
40 to 50
(4 to 10)
50 to 70
(10 to 21)
50 to 70
(10to21)
65 to 80
(18 to 27)
65 to 80
(18 to 27)
80 to 90
(27 to 32)
Annual
Precipitation
inches
(cm)
Total*
15 to 45
(38 to 11 4)
25 to 45
(64 to 11 4)
12 to 25
(30 to 64)
16to15
(15 to 38)
3 to 8
(8 to 20)
2 to 10
(5 to 25)
Snowfall
Medium to
heavy
Heavy
Moderate
Light to
moderate
Light
Negligible
Percent
Dominant of
Vegetation Area
Alpine meadows
Pine-fir forest
Pine or scrub
woodland
Sagebrush,
grass, scrub
Greasewood,
shadscale
Creosote bush
-
1
15
57
20
7
* Limits of annual precipitation overlap because of variations in temperature which affect the water balance.
The wind direction, as measured on a 98 ft (30 m)
tower at an observation station approximately 7
miles (11 km) north-northwest of CP-1, is predomi-
nantly northerly except during the months of May
through August when winds from the southwest
predominate (Quiring, 1968). Because of the
prevalent mountain/valley winds in the basins,
south to southwest winds predominate during
daylight hours of most months. During the winter
months, southerly winds predominate slightly over
northerly winds for a few hours during the warmest
part of the day. These wind patterns may be quite
different at other locations on the NTS because of
local terrain effects and differences in elevation.
2.3 Hydrology
Two major hydrologic systems shown in Figure 2.2
exist on the NTS (U.S. Energy Research and
Development Administration, 1977). Ground water
in the northwestern part of the NTS (the Pahute
Mesa area) flows at a rate of 6.6 to 600 feet (2 to
180 m) per year to the south and southwest toward
the Ash Meadows discharge area in the Amargosa
Desert. Ground water to the east of the NTS
moves from north to south at a rate of not less than
6.6 feet (2 m) nor greater than 730 feet (220 m) per
year. Carbon-14 analyses of this eastern ground
water indicate that the lower velocity is nearer the
true value. At Mercury Valley in the extreme south-
ern part of the NTS, the eastern ground water flow
shifts to the southwest, toward the Ash Meadows
discharge area.
2.4 Regional Land Use
Figure 2.3 is a map of the off-NTS area showing a
wide variety of land uses, such as mining, camping,
fishing, and hunting within a 180-mile (300 km)
radius of the NTS operations control center at CP-1
(the location of CP-1 is shown on Figure 2.2). West
of the NTS, elevations range from 280 feet (85 m)
below MSL in Death Valley to 14,600 feet (4,420 m)
above MSL in the Sierra Nevada. Portions of two
major agricultural valleys (the Owens and San
Joaquin) are included. The areas south of the NTS
are more uniform since the Mojave Desert ecosys-
tem (mid-latitude desert) comprises most of this
portion of Nevada, California, and Arizona. The
areas east of the NTS are primarily mid-latitude
-------
Pahute Mesa
Ground Water
System
Ash Meadows
Ground Water System
Flow Direction
Ground Water
System Boundaries
Silent Canyon
Caldera
Timber Mountain
Caldera
Scale In Miles
10 20
10 20 30 40
Scale in Kilometers
LOCATION MAP
Figure 2.2 Ground water flow systems around the Nevada Test Site.
8
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A. Camping &
Recreational
Areas
D Hunting
• Fishing
O Mines
A Oil Fields
Lake Havasu
Scale in Miles
50
100
50 100 150
Scale in Kilometers
Figure 2.3. General land use within 180 miles (300 km) of the Nevada Test Site.
9
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steppe with some of the older river valleys, such as
the Virgin River Valley and the Moapa Valley,
supporting irrigation for small-scale but intensive
farming of a variety of crops. Grazing is also
common in this area, particularly to the northeast.
The area north of the NTS is also mid-latitude
steppe, where the major agricultural activity is
grazing of cattle and sheep. Minor agriculture,
primarily the growing of alfalfa hay, is found in this
portion of Nevada within 180 miles (300 km) of the
CP-1. Many of the residents have access to locally
grown fruits and vegetables.
Recreational areas lie in all directions around the
NTS and are used for such activities as hunting,
fishing, and camping. In general, the camping and
fishing sites to the northwest, north, and northeast
of the NTS are closed during winter months.
Camping and fishing locations to the southeast,
south, and southwest are utilized throughout the
year. The peak of the hunting season is from
September through January.
2.5 Population Distribution
The population of counties surrounding the NTS
based on the 1990 Bureau of Census (BOC) count
(DOC, 1990) is still fairly accurate although growth
has occurred in all parts of the state. Excluding
Clark County, which has grown tremendously since
the 1990 census and is the major population
center (approximately 1,000,000 in 1997), the
population density within a 90-mi (150-km) radius
of the NTS is about 0.9 persons per square mile
(0.5 persons per square kilometer). For compari-
son, the population density of the 48 contiguous
states was 76 persons per square mile (29 persons
per square kilometer) (DOC, 1990). The estimated
average population density for Nevada in 1990 was
10.9 persons per square mile (3.1 persons per
square kilometer) (DOC, 1986).
The offsite area within 48 miles (80 km) of CP-1
(the primary area in which the dose commitment
must be determined for the purpose of this report)
is predominantly rural. Several small communities
are located in the area, the largest being in Pah-
rump Valley. Pahrump, a growing rural community
with a population of about 23,000 (Pahrump Times)
in 1996, is located 48 miles (80 km) south of CP-1.
The small residential community of Crystal, Ne-
vada, also located in the Pahrump Valley, is several
miles north of the town of Pahrump (Figure 2.2).
The Amargosa farm area, which has a population
of about 950, is located 30 miles (50 km) southwest
of CP-1. The largest town in the near offsite area
is Beatty, which has a population of about 1,500
and is located approximately 39 miles (65 km) to
the west of CP-1.
The Mojave Desert of California, which includes
Death Valley National Monument, lies along the
southwestern border of Nevada. The National Park
Service (NPS) estimated that the population within
the Monument boundaries ranges from a minimum
of 200 permanent residents during the summer
months to as many as 5,000 tourists, including
campers, on any particular day during the major
holiday periods in the winter months, and as many
as 30,000 during "Death Valley Days" in November
(NPS, 1990). The largest populated area is the
Ridgecrest, California area, which has a population
of 27,725 and is located 114 miles (190 km) south-
west of the NTS. The next largest town is Barstow,
California, located 159 miles (265 km) south-south-
west of the NTS, with a 1990 population of 21,472.
The Owens Valley, where numerous small towns
are located, lies 30 miles (50 km) west of Death
Valley. The largest town in the Owens Valley is
Bishop, California, located 135 miles (225 km)
west-northwest of the NTS, with a population of
3,475 (DOC, 1990).
The extreme southwestern region of Utah is more
developed than the adjacent part of Nevada. The
largest community is St. George, located 132 miles
(220 km) east of the NTS, with a 1997 population
estimated at 40,000. The next largest town, Cedar
City, with a population of over 18,000, is located
168 miles (280 km) east-northeast of the NTS. The
extreme northwestern region of Arizona is mostly
range land except for that portion in the Lake Mead
National Recreation Area. In addition, several
small communities lie along the Colorado River.
The largest towns in the area are Bullhead City, 99
miles (165 km) south-southeast of the NTS, with a
1990 population of 21,951 and Kingman, located
168 miles (280 km) southeast of the NTS, with a
population of 12,722 (DOC, 1990).
10
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3.0 External Ambient Gamma Monitoring
External ambient gamma radiation is measured by
the Thermoluminescent Dosimetry (TLD) Network
as well as the Pressurized Ion Chamber (PIC)
Network. The primary function of the two networks
is to detect changes in ambient gamma radiation.
In the absence of nuclear testing, ambient gamma
radiation rates naturally differ among locations
since rates vary with altitude (cosmic radiation) and
with radioactivity in the soil (terrestrial radiation).
Ambient gamma radiation will also vary slightly at a
location due to changes in weather patterns and
other factors.
3.1 Thermoluminescent
Dosimetry Network
Offsite fixed environmental TLD locations surround-
ing the Nevada Test Site (NTS) were selected to
detect and monitor trends in total ambient gamma
radiation levels and in response to stakeholder
concerns. Residents in communities near the NTS
continue to express concerns about radiation expo-
sure due to previous, current and proposed activi-
ties at the NTS. Use of TLDs offsite is an effective
method of addressing these concerns.
There is a difference between fixed environmental
dosimeter exposure levels and personnel dosime-
ter exposure levels worn in the same city or town
due to the fact that "background" ambient gamma
radiation levels vary significantly even within a city
or town.
3.1.1 Design
The current EPA TLD program utilizes the Panaso-
nic Model UD-802 TLD for personnel monitoring
and the UD-814 TLD for environmental monitoring.
Each dosimeter is read using the Panasonic Model
UD-710A automatic dosimeter reader.
The UD-802 TLD incorporates two elements of
Li2B4O7:Cu and two elements of CaSO4: Tm phos-
phors. The phosphors are behind approximately
17, 300, 300, and 1000 mg/cm2 of attenuation,
respectively. With the use of different phosphors
and filtrations, a dose algorithm can be applied to
ratios of the different element responses. This
process defines the radiation type and energy and
provides a mechanism for assessing an absorbed
dose equivalent.
Environmental monitoring is accomplished using
the UD-814 TLD, which is made up of one element
of Li2B4O7:Cu and three elements of CaSO4:Tm.
The CaSO4:Tm elements are behind approximately
1000 mg/cm2 attenuation. An average of the
corrected values for elements two through four
gives the total exposure for each TLD. Two UD-
814 TLDs are deployed at each station per moni-
toring period.
In general terms, TLDs operate by trapping elec-
trons at an elevated energy state. After the collec-
tion period, each TLD element is heated. When
heat is applied to the phosphor, the trapped elec-
trons are released and the energy differences
between the initial energies of the electrons and the
energies at the elevated state are given off in the
form of photons. These photons are then collected
using a photomultiplier tube. The number of pho-
tons emitted, and the resulting electrical signal, is
proportional to the initial deposited energy.
New computers and software were installed to
increase report options, and further hardware
upgrades were completed in 1997. Full implemen-
tation of the new computers and software will be
completed by calender year 1998.
3.1.2 Results of TLD Monitoring
ENVIRONMENTAL DATA:
In 1997, the TLD program consisted of 39 fixed
environmental monitoring stations and 18 offsite
personnel. Figure 3.1 shows the fixed environmen-
tal TLD monitoring stations and the location of
personnel monitoring participants. Total annual
exposures were calculated by dividing each quar-
terly result by the number of days representing
each deployment period. The quarterly daily rates
were averaged to obtain an annual daily average.
If a deployment period overlapped the beginning or
end of the year a daily rate was calculated, for that
deployment period, and multiplied by the number of
days that fell within 1997. The total average daily
rate was then multiplied by 365.25 to determine the
total annual exposure for each station.
There were 39 offsite environmental stations
monitored using TLDs. Figure 3.1 shows current
fixed environmental monitoring locations. Total
annual exposure for 1997 ranged from 61 mR (0.61
mSv) peryearat Pahrump, Nevada, to 161 mR (1.6
mSv) per year at Blue Jay, Nevada, with a mean
11
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r,..
N
Offsite Dosimetry Locations
A. Stations (39)
• Personnel (18)
50 100 150
Scale In KilomM«i
Figure 3.1 Location of TLD Fixed Stations and Personnel Monitoring Participants -1997
12
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annual exposure of 99 mR (0.99 mSv) per year for
all operating locations. The next highest annual
exposure was 130 mR (1.3 mSv) peryear at Queen
was City Summit, Nevada. See Table 3.1 for 1997
results. These results are consistent with those for
1996.
PERSONNEL DATA:
Eighteen offsite residents, managers, and
alternates for the CTLP, were issued TLDs to
monitor their annual dose equivalent. Locations of
personnel monitoring participants are also shown in
Figure 3.1 Annual whole body dose equivalents
ranged from a low of 74 mrem (0.74 mSv) to a high
of 147 mrem (1.5 mSv) with a mean of 96 mrem
(0.96 mSv) for all monitored personnel during 1997.
See Table 3.2 for 1997 results. These results are
similar to those for 1996.
3.1.3 Quality Assurance/
Quality Control
TLDs are sent to a National Institute of Standards
and Technology (NIST) laboratory for necessary
irradiations to assure acceptable quality. A TLD
irradiator manufactured by Williston-Elin (WE)
housing a nominal 1.8 Ci 137Cs source. This
irradiator provides for automated irradiations of the
TLDs. The WE irradiator provided data is plotted as
a control chart. Panasonic UD-802 dosimeters
exposed by the NIST traceable laboratory
irradiators are used to calibrate the TLD readers
and to verify TLD reader linearity. Control dosime-
ters of the same type as field dosimeters (UD-802
or UD-814) are exposed and read together with the
field dosimeters. This provides daily on-line pro-
cess quality control checks in the form of irradiated
controls.
• For each read-out three irradiated control TLDs
are included that have been exposed to a
nominal 200 mR. After the irradiated controls
have been read, the ratio of recorded exposure
to delivered exposure is calculated and re-
corded for each of the four elements of the
dosimeter. This ratio is applied to all raw
element readings from field and unirradiated
control dosimeters to automatically compen-
sate for reader variations.
• Prior to being placed in service, element cor-
rection factors are determined for all dosime-
ters. Whenever a dosimeter is read, the mean
of the three most recent correction factor deter-
minations is applied to each element to com-
pensate for normal variability (caused primarily
by the TLD manufacturing process) in individ-
ual dosimeter response.
• In addition to irradiated control dosimeters,
each group of TLDs is accompanied by three
unirradiated control dosimeters during deploy-
ment and during return. These unirradiated
controls are evaluated at the dosimetry labora-
tory to ensure that the TLDs did not receive any
excess dose while either in transit or storage.
The exposure received while either in storage
or transit is typically negligible and thus is not
subtracted.
• An assessment of TLD data quality is based on
the assumption that exposures measured at a
fixed location will remain substantially constant
over an extended period of time. A number of
factors will combine to affect the certainty of
measurements. The total uncertainty of the
reported exposures is a combination of random
and systematic components. The random
component is primarily the statistical uncer-
tainty in the reading of the TLD elements them-
selves. Based on repeated known exposures,
this random uncertainty for the calcium sulfate
elements used to determine exposure to fixed
environmental stations is estimated to be
approximately ± 3 to 5%. There are also sev-
eral systematic components of exposure uncer-
tainty, including energy-directional response,
fading, calibration, and exposures received
while in storage. These uncertainties are
estimated according to established statistical
methods for propagation of uncertainty.
• Accuracy and reproducibility of TLD processing
of personnel dosimeters has been evaluated
via the Department of Energy Laboratory
Accreditation Program (DOELAP). This pro-
cess concluded that procedures and practices
utilized by the EPA R&IE-LV TLD Laboratory
comply with standards published by the Depart-
ment of Energy. This evaluation includes three
rounds of blind performance testing over the
range of 50 mrem to 500 rem and a compre-
hensive onsite assessment by DOELAP site
assessors.
• The DOELAP accreditation process requires a
determination of the lower limit of detectability
and verification that the TLD readers exhibit
linear performance over the range included in
the performance testing program. The lower
limit of detectability (LD) for the R&IE-LV TLD
Laboratory is 10 mrem. This LD is an industry
standard. DOELAP accreditation will be
supplanted by the National Voluntary Labora-
13
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tory Accreditation Program (NVLAP) by CY
1998.
3.1.4 Data Management
During 1997, the TLD data base resides on a
Digital Equipment Corporation MicroVAX II directly
connected to the two Panasonic TLD readers.
Samples are tracked using field data cards and an
issue data base tracking system incorporated into
the reader control software. Two major software
packages are utilized by the TLD network. The
first, a proprietary package written and supported
by International Science Associates, controls the
TLD readers, tracks dosimeter performance, com-
pletes necessary calculations to determine ab-
sorbed dose equivalent, performs automated
QA/QC functions, and generates raw data files and
reports. The second software package, locally
developed, maintains privacy act information and
the identifying data, generates reports in a number
of predefined formats, and provides archival stor-
age of TLD results.
3.2 Pressurized Ion Chambers
The Pressurized Ion Chamber (PIC) Network
continuously measures ambient gamma radiation
exposure rates, and because of its sensitivity, may
detect low-level exposures not detected by other
monitoring methods. The primary function of the
PIC network is to detect changes in ambient
gamma radiation due to anthropogenic activities.
In the absence of anthropogenic activities, ambient
gamma radiation rates naturally differ among
locations as rates vary with altitude (cosmic radia-
tion) and with radioactivity in the soil (terrestrial
radiation). Ambient gamma radiation also varies
slightly within a location due to weather patterns,
i.e., snow changes the amount of radon-thoron
released by the soil and detected by the PICs.
3.2.1 Network Design
There are 26 PICs located in communities around the
NTS and one in Mississippi, which provide near real-
time estimates of gamma exposure rates. The
locations of the PICs for stations around the NTS are
shown in Figure 3.2.
Because of the successful experience with the
Citizen's Monitoring Program during the purging of
the Three Mile Island containment in 1980, the
Community Radiation Monitoring Program (CRMP)
was begun. Because of reductions in the scope of
monitoring, the CRMP was changed to the CTLP.
It now consists of stations located in the states of
Nevada and Utah. In 1997, there were 15 stations
located in these two states. The CTLP is a
cooperative project of the DOE, EPA, and DRI.
The DOE/NV sponsors the program. The EPA
provides technical and scientific direction, main-
tains the instrumentation and sampling equipment,
analyzes the collected samples, and interprets and
reports the data. The DRI administers the program
by hiring the local station managers and alternates,
securing rights-of-way, providing utilities, and
performing additional quality assurance checks of
the data. Shown in Figure 3.2 are the locations of
the CTLP stations.
Each station is operated by a local resident. In
most cases, this resident is a high-school science
teacher. Samples are analyzed at the R&IE Labo-
ratory. Thirteen of the 15 CTLP stations have a low
volume air sampler, a tritium and noble gas sam-
pler on standby, and a TLD. The two stations
recently set up have no tritium or noble gas sam-
pler. In addition, a PIC and recorder for immediate
readout of external gamma exposure and a record-
ing barograph are located at the station. All of the
equipment is mounted on a stand at a prominent
location in each community. Residents may visit
the stations and if interested, they can check the
data. Also, computer-generated reports of the PIC
data are issued monthly by EPA for each station.
3.2.2 Procedures
The PIC Network utilizes Reuter-Stokes models
1011,1012, and 1013 PICs. The PIC is a spherical
shell filled with argon gas to a pressure 25 times
that of atmospheric. In the center of the chamber
is a spherical electrode with a charge opposite to
the outer shell. When gamma radiation penetrates
the sphere, ionization of the gas occurs and the
ions are collected by the center electrode. The
electrical current generated is measured, and the
intensity of the radiation field is determined from the
magnitude of this current.
Data are currently recorded on magnetized re-
corder tapes, memory data cartridges, and strip
chart recorders. Previously, data collection was
performed by satellite telemetry for immediate
access to the PIC data. In October 1997, the
funding for support and maintenance of the Los
Alamos National Laboratory (LANL) satellite telem-
etry system, which allowed EPA access to near
14
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V r a Uhaldes
»,»
\Goldfield • \ NELUS" S Rachel Rn"
RANGE
Medlm'sRn.
iPio
• Ca nte
• Alamo
Delta*
• Milford
• Cedar City
• St. George
iiri
ARIZONA
Furnace Creek! >• C Overtonfi,
Amargosa Center -/^ Indian Springs
Pahrunip 9 fLAKE MEAD
\ Las •
V Vegas
^> •^Boulder City
V Henderson
\ i
\ i
Community Technical Liaison Program (CTLP) (17)
Other PIC Locations) (9)
Scale in Miles
50
50 100 150
Scale in Kilometers
Figure 3.2 Community Technical Liaison Program (CTLP) and PIC station locations -1997
15
-------
real-time data, was discontinued. Currently, the
PICs are visited weekly at the stations immediately
adjacent to the NTS and monthly at the other
stations to retrieve data. EPA stations in Boulder
City, Henderson, Las Vegas, and Mississippi,
display gamma and meteorological data near real-
time on the LANL NEWNET web page which is
updated every 24 hours.
The PIC data are recorded on magnetic tapes at 24
of the 27 EPA stations and on magnetic cards for
the other three EPA stations. Currently, the PICs
are visited weekly at the stations immediately
adjacent to the NTS and monthly at other stations
to retrieve data. The data are useful for investigat-
ing anomalies. Anomalies are recorded in smaller
increments of time (5-minute averages). The PICs
also contain a liquid crystal display, permitting
interested persons to monitor current readings.
The data are evaluated by R&IE-LV personnel.
Trends and anomalies are investigated and equip-
ment problems are identified and referred to field
personnel for correction. Monthly averages are
stored in Lotus files on a personal computer.
These monthly averages are compiled from the 4-
hour averages from the telemetry data, when
available, and from the 5-minute averages from the
magnetic tapes or cards when the telemetry data
are unavailable. Computer-generated reports of
the PIC monthly average data are issued monthly
for posting at each station. These reports indicate
the current month's average gamma exposure rate,
the previous month's averages, and the maximum
and minimum background levels in the U.S.
3.2.3 Results
Table 3.3 contains the number of monthly averages
available from each station and the maximum,
minimum, mean, standard deviation, and median of
the monthly averages. The mean ranged from 8.1
uR/hr at Pahrump, Nevada, to 17.7 uR/hr at Milford,
Utah, or annual exposures from 71 to 155 mR (18
to 40 uC/kg). The table shows the total mR/yr
(calculation based on the mean of the monthly
averages) and the average gamma exposure rate
for each station. Background levels of environmen-
tal gamma exposure rates in the U.S. (from the
combined effects of terrestrial and cosmic sources)
vary between 49 and 247 mR/yr (13 to 64 uC/kg-yr)
(BEIR III, 1980). The annual exposure levels
observed at each PIC station are well within these
U.S. background levels. Figure 3.3 shows the
distribution of the monthly data from each PIC
station. The horizontal lines extend from the mean
value (*) to the minimum and maximum values.
The vertical lines are the approximate U. S. back-
ground range.
The data from the Milford, Stone Cabin Ranch,
and Tonopah stations show the greatest range
and the most variability. All of these data are
within a few tenths uR/hr from those of last year.
3.2.4 Quality Assurance/Quality
Control
General QA/QC guidelines for the PICs follow the
Quality Management Plan referenced on page 66
and are summarized as follows:
• Procedures for the operation, mainte-
nance, and calibration, of PIC equip-
ment and the data review, statistical
analysis and records are documented in
approved SOPs.
• Radiation monitoring specialists place a
radioactive source of a known activity on
the PICs monthly to check the perfor-
mance of the units.
• Source check calibration and
background exposure rate data are
evaluated monthly and compared to
historical values.
• Data not transmitted via the telemetry
system due to equipment failure are
retrieved by reading mag tapes.
A data quality assessment of the PIC data is given
in Section 10, Quality Assurance.
3.3 Comparison of TLD Results
to PIC Measurements
When calculated TLD exposures are compared
with results obtained from collocated PICs, a
uniform under-response of TLDs was noted. This
difference, is attributed primarily to the differing
energy response of the two systems. The PICs
have a greater sensitivity to lower energy gamma
radiation than the TLDs and hence will normally
record a higher apparent exposure. There are
three primary factors: 1) PICs are more sensitive to
lower energy gamma radiation than are the TLDs.
2) The PIC units are calibrated against 60Co, while
the TDLs are calibrated using 137Cs. 3) The PIC is
an exposure rate measuring device, while the TLD
is an integrating dosimeter.
16
-------
Alamo,
Amargosa Ctr.,
Beatty,
Boulder City,
Caliente,
Cedar City,
Complex 1,
Delta,
Furnace Creek,
Goldfield,
Henderson,
Indian Springs,
c
.2 Las Vegas,
CO
g Medlin's Ranch,
Milford,
Nyala,
Overton,
Pahrump,
Pioche,
Rachel,
St. George,
Stone Cabin Ranch,
Terrell's Ranch,
Tonopah,
Twin Springs,
Uhalde's Ranch,
Average Gamma Exposure Rate (uR/hr)
(
NV
NV
NV
NV
NV
NV
NV
UT
CA
NV
NV
NV
NV
NV
UT
NV
NV
NV
NV
NV
UT
NV
NV
NV
NV
NV
5 5 10 15 20 25 30
-
-
-
-
-
I I I I
!-• 1
LA 1
h»H
r-»— 1
^^^^^^J
l^^F^t
1^H^^__I
^^^^^"t
1 * 1
M>-H
1— »H
H» 1
(-• — 1
!-• 1
H — 1
• 1
(-•— 1
^ 1
Natural Background ranges from about 4 to 28 uR/hr in the U.S.
Figure 3.3 Shows the maximum, minimum and the mean from PIC Network station 1997
17
-------
Table 3.1 Environmental Thermoluminescent Dosimetry Results, 1997
Daily Exposure (mR) Total (mR) Percent
Station Name Min Max Mean Exposure Complete
Alamo, NV 0.23 0.25 0.24 113 100
Amargosa Center, NV 0.20 0.23 0.21 76 75
Beatty, NV 0.30 0.32 0.31 112 100
Blue Jay, NV 0.32 0.46 0.36 161 100
Boulder City, NV 0.23 0.26 0.24 86 100
Caliente, NV 0.26 0.28 0.27 97 100
Cedar City, UT 0.19 0.21 0.20 72 100
Complex I, NV 0.29 0.30 0.29 107 100
Coyote Summit, NV 0.33 0.35 0.34 122 100
Delta, UT 0.22 0.33 0.25 87 100
Ely, NV 0.20 0.20 0.20 72 100
Furnace Creek, CA 0.20 0.21 0.21 75 100
Goldfield, NV 0.26 0.28 0.27 99 100
Groom Lake, NV 0.24 0.26 0.25 91 100
Henderson (CCSN), NV 0.23 0.28 0.25 90 100
Hiko, NV 0.19 0.22 0.20 72 100
Indian Springs, NV 0.20 0.21 0.21 74 50
Las Vegas UNLV, NV 0.13 0.20 0.17 81 100
Lund, NV 0.27 0.29 0.28 100 100
Lund, UT 0.29 0.32 0.30 111 100
Medlin's Ranch, NV 0.29 0.31 0.30 111 100
Mesquite, NV 0.19 0.21 0.20 72 100
Milford, UT 0.23 0.33 0.30 112 100
Moapa, NV 0.22 0.24 0.24 86 100
Nyala, NV 0.23 0.25 0.24 109 100
Overton, NV 0.19 0.20 0.20 71 100
Pahrump, NV 0.16 0.18 0.17 61 100
Pioche, NV 0.23 0.25 0.24 85 100
Queen City Summit, NV 0.33 0.38 0.36 130 100
Rachel, NV 0.30 0.32 0.31 113 100
Sarcobatus Flats, NV 0.20 0.35 0.30 121 100
St. George, UT 0.17 0.19 0.18 64 100
Stone Cabin, NV 0.29 0.33 0.31 114 100
Sunnyside, NV 0.17 0.24 0.19 69 100
Tonopah Test Range, NV 0.33 0.37 0.34 125 100
Tonopah, NV 0.32 0.35 0.33 120 100
Twin Springs, NV 0.31 0.33 0.32 116 100
Uhalde's Ranch, NV 0.30 0.31 0.31 111 100
Warm Springs #1, NV 0.27 0.29 0.28 103 100
18
-------
Table 3.2 Personnel Thermoluminescent Dosimetry Results, 1997
Location
022 Alamo, NV
028
042
293
344
345
346
347
348
427
592
593
595
596
607
608
610
621
Beatty, NV
Tonopah, NV
Pioche, NV
Delta, UT
Delta, UT
Milford, UT
Milford, UT
Overton, NV
Alamo, NV
Rachel, NV
Cedar City, UT
Las Vegas, NV
Las Vegas, NV
Tonopah, NV
Logandale, NV
Caliente, NV
Indian Springs, NV
Number Daily Deep Dose
of Days Exposure (mrem)
Worn Min Max Mean
358 0.21
300
357
357
301
301
317
317
300
336
298
358
328
328
335
300
357
358
0.37
0.25
0.22
0.21
0.27
0.24
0.28
0.20
0.20
0.21
0.26
0.20
0.17
0.26
0.17
0.27
0.20
0.25
0.46
0.36
0.27
0.23
0.31
0.31
0.30
0.27
0.30
0.35
0.35
0.27
0.25
0.41
0.26
0.40
0.21
0.22
0.41
0.32
0.24
0.22
0.28
0.28
0.30
0.22
0.25
0.28
0.31
0.23
0.23
0.33
0.21
0.31
0.20
Total
Annual
Exposure
83
147
116
86
80
103
103
108
82
95
103
113
84
84
120
79
112
74
Percent
Complete
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
19
-------
Table 3.3 Summary of Gamma Exposure Rates as Measured by Pressurized Ion Chambers -
1997
Gamma Exposure Rate (uR/hr)
Number of
Davs Station
Station
Alamo, NV
Amargosa Center, NV
Beatty, NV
Boulder City, NV
Caliente, NV
Cedar City, UT
Complex I, NV
Delta, UT
Furnace Creek, CA
Goldfield, NV
Henderson, NV
Indian Springs, NV
Las Vegas, NV
Medlin's Ranch, NV
Milford, UT
Nyala, NV
Overton, NV
Pahrump, NV
Pioche, NV
Rachel, NV
St. George, UT
Stone Cabin Ranch, NV
Terrell's Ranch, NV
Tonopah, NV
Twin Springs, NV
Uhalde's Ranch, NV
Reported
364
365
334
70
304
335
365
303
297
359
286
356
294
365
304
304
334
358
364
350
360
328
365
358
364
304
Maximum
15.0
14.0
19.0
12.3
16.0
12.6
18.9
12.9
11.0
17.1
19.0
14.0
12.7
18.7
19.0
17.0
12.0
10.6
13.9
19.0
10.0
20.0
19.0
19.3
20.0
19.0
Minimum
11.9
10.0
15.3
10.6
13.0
9.0
14.0
10.5
8.6
14.0
12.0
10.7
8.3
15.0
16.3
11.0
9.0
7.0
10.9
15.2
7.8
15.4
15.0
16.5
15.0
12.8
Standard
Deviation
0.25
0.76
0.24
0.27
0.28
0.47
0.43
0.35
0.28
0.34
0.42
0.32
0.27
0.38
0.50
0.38
0.27
0.18
0.27
1.37
0.16
0.43
0.29
0.45
0.47
0.84
Median
12.8
11.0
12.8
11.4
14.2
10.5
15.3
11.9
9.7
15.3
13.7
11.5
10.2
16.4
17.6
12.3
10.1
8.0
11.9
16.4
8.3
17.0
16.0
17.6
16.4
17.4
mR/vr
111
97
143
99
125
91
134
103
86
135
119
101
89
143
155
108
88
71
105
145
73
150
141
154
146
149
Mean
fuR/hrt
12.7
11.1
16.3
11.3
14.3
10.4
15.3
11.8
9.8
15.4
13.6
11.5
10.2
16.4
17.7
12.3
10.0
8.1
12.0
16.5
8.2
17.1
16.1
17.6
16.6
17.0
Note: Multiply uR/hr by 2.6 x 10"10 to obtain C • kg'1 • hr1
20
-------
4.0 Atmospheric Monitoring
The inhalation of radioactive airborne particles can
be a major pathway for human exposure to radia-
tion. The atmospheric monitoring networks are
designed to detect environmental radiation from
NTS and non-NTS activities. Data from atmo-
spheric monitoring can determine the concentration
and source of airborne radioactivity and can project
the fallout patterns and durations of exposure to
man. The only atmospheric monitoring network still
operating is the Air Surveillance Network (ASN).
The ASN was designed to monitor the areas within
350 kilometers (220 miles) of the NTS.
Most of the data collected from the ASN fall below
the minimum detectable concentration (MDC).
Averages of data presented in this chapter were
calculated including measured results below MDCs.
All of the data collected from the atmospheric
monitoring network reside on a VAX computer in
the Sample Tracking Data Management System
(STDMS).
4.1 Air Surveillance Network
4.1.1 Design
During calendaryear (CY)1997, the ASN consisted
of 20 continuously operating sampling stations.
High-volume air samplers were operational at six of
the stations. The current network is shown in
Figure 4.1.
Each station is equipped with a low-volume air
sampler to collect particulate radionuclides on fiber
filters and gaseous radioiodines in charcoal car-
tridges. The filters and charcoal cartridges receive
complete analyses at the R&IE-LV Radioanalysis
Laboratory. Duplicate air samples are collected
from two ASN stations each week. The duplicate
samplers operate at randomly selected stations
continuously for three months and are then moved
to a new location.
Six of the air sampling stations are equipped with
high-volume air samplers that collect particulate
radionuclides on glass fiber filters. The filters are
analyzed by gamma spectrometry in the R&IE-LV
Radioanalysis Laboratory. The filters are then
composited by month and analyzed for plutonium
isotopes by wet chemistry methods. One duplicate
high-volume sampler is co-located at a randomly
selected high-volume sampling station and is
moved to a new location at the beginning of each
quarter. Duplicate samples are collected and
analyzed by the same methods as the routine
samples.
4.1.2 Procedures
Low-volume samplers collect airborne particulates
at each ASN station. The samples are collected as
air is drawn through 5 cm (2.1 in) diameter, glass-
fiber filters (prefliters) at a flow rate of about 100 m3
(2800 ft3) per day. Activated charcoal cartridges are
placed directly behind the filters to collect gaseous
radioiodines. Filters and cartridges are exchanged
after sampler operation periods of about one week
(approximately 560 m3 or 20,000 ft3). High-volume
(hi-vol) samplers are located at selected stations
within the ASN. The hi-vol samplers collect air-
borne particulates as air is drawn through an eight
inch by ten inch glass fiber filter at a rate of about
2000m3 (58,000 ft3) per day. The hi-vol filters are
collected monthly with a total volume of approxi-
mately 60,000 m3 (1,700,000 ft3).
Duplicate air samples are obtained weekly from
selected stations. Two low-volume air samplers
and one high-volume air sampler, which are identi-
cal to the ASN station samplers, are rotated be-
tween ASN stations quarterly. The results of the
duplicate field sample analyses are given in Chap-
ter 8 as part of the data quality assessment.
Prefilters and charcoal cartridges from low-volume
samplers, and high-volume filters are initially
analyzed by high resolution gamma spectrometry.
The low-volume prefilters are then analyzed for
gross alpha and gross beta activity. Analysis is
performed 7 to 14 days after sample collection to
allow time for the decay of naturally occurring
radon-thoron daughter products. Gross alpha/beta
analysis is used to detect trends in atmospheric
radioactivity since it is more sensitive than gamma
spectrometry for this purpose. High-volume filters
are submitted for wet chemistry analysis for pluto-
nium isotopes upon completion of gamma spec-
trometry. Additional information on the analytical
procedures is provided in Chapter 10.
21
-------
NEVADA
PYRAMID
I LAKE
i.
' N, Tonopal
VQoldfield
T*
Stone
Cabin Rn.
t
•
Sunnyside
N
•
Pioche
Alamo
r -u YMMk/arsa' n—
Beattyf
^
Amagosi
Valley \ - ^ Overton^
V Indian Springs
V •Pahrump
V Las
\ Vegas»|Hende7son&
\ "Boulder City
V -
\!
UTAH
Delta i
Milford
• Cedar City
St George
ARIZONA
LAKEMEAD
% Routine Air Sampling Stations (20)
(Low Volume)
El Routine Air Hi-Low Volume Air Samplers (6)
Scale in Miles
50
50 100 150
Scale in Kilometers
Figure 4.1 Air Surveillance Network stations -1997
22
-------
4.1.3 Results
The ASN measures the major radionuclides which
could potentially be emitted from activities on the
NTS. Data from the ASN represents the inhalation
pathway component of radiation exposure to the
general public.
Gamma spectrometry was performed on all sam-
ples from the ASN high and low-volume air sam-
plers. The majority of the samples were gamma-
spectrum negligible (i.e., no gamma-emitting
radionuclides detected). Naturally occurring 7Be,
was detected occasionally by the low-volume
network of samplers. It was detected consistently
by the high-volume sample method with average
annual activity of 1.5 x 10"13 uCi/mL, slightly less
than the onsite average.
As in previous years, the gross beta results from
the low-volume sampling network consistently
exceeded the analysis minimum detectable con-
centration (MDC). The annual average gross beta
activity was (1.5 ± 2.2 x 10"4 Bq/m3), somewhat
lower than the results for the onsite network.
Summary gross beta results for the ASN are shown
in Table 4.1.
Gross alpha analysis was performed on all low-
volume network samples. The average annual
gross alpha activity was 2.0 x 10~15 uCi/mL (73
uBq/m3), slightly higher than the onsite results.
Summary results for the ASN are shown in Table
4.2.
During 1997, high-volume samples were collected
monthly and analyzed for plutonium isotopes. Due
to a low limit of detection for high-volume sampling
and analysis methods, environmental levels of
239+24opu were consistently detected at all six of the
sampling sites. Sixty-six samples were analyzed
during the calendar year of which 52 were above
the MDC for 239+24°pu and 13 were above the MDC
for 238Pu. The average annual activity was 0.18 x
10'18 uCi/mL (7 nBq/m3) for Z38Pu and 4.2 x 10'18
uCi/mL (0.16 uBq/m3) for239+240Pu, about one-fourth
the onsite activity. Plutonium results for the high-
volume air sampling network are presented in
Table 4.3.
4.1.4 Quality Assurance/
Quality Control
General QA/QC guidelines for the ASN are as
follows:
• All field sampling and laboratory instru-
ments are calibrated and the date of cali-
bration is marked on a decal affixed to
the equipment.
• A file of calibration records, control
charts, and log books is maintained.
• Unique sample numbers are assigned.
• The laboratory supervisor approves all
analytical results before they are entered
into the permanent data base.
• Files of QA data, which includes raw
analytical data, intermediate calculations,
and review reports are maintained.
• Blanks are analyzed to verify the ab-
sence of method interferences. These
may be caused by contaminants in sol-
vents, and reagents, on glassware, or
introduced by sample processing.
• Analytical accuracy is estimated with perfor-
mance evaluation samples. Forthe gamma
analysis of fiber filters, spiked samples
should be within ±10% of the known value.
Gross beta analysis should be within ± 20%.
Plutonium analysis of internal spikes should
produce results within ± 20% of the known
value.
• The combined error due to both sampling
and analytical technique is estimated by
using replicates.
• An estimate of bias (the difference between
the value obtained and the true or reference
value) is determined by participating in
intercomparison studies.
Further discussion of the QA program and the data
quality assessment is given in Chapter 10.
23
-------
Table 4.1 Gross Beta Results for the Offsite Air Surveillance Network -1997
Gross Beta Concentration (1C)'14 uCi/mL F0.37 mBa/m31)
Sampling Location
Alamo, NV
Amargosa C.C., NV
Beatty, NV
Boulder City, NV
Clark Station, NV
Goldfield, NV
Henderson, NV
Indian Springs, NV
Las Vegas, NV
Overton, NV
Pahrump, NV
Pioche, NV
Rachel, NV
Sunnyside, NV
Tonopah, NV
Twin Springs, NV
Cedar City, UT
Delta, UT
Milford, UT
St. George, UT
Mean MDC = 2.43 x 1CT15 //Ci/mL
Number
52
50
52
23
52
52
51
51
51
51
50
50
51
35
51
52
52
52
47
21
Maximum
6.9
2.7
3.1
3.0
2.6
2.4
3.0
3.1
3.0
3.5
2.4
2.4
4.2
2.6
3.1
5.3
2.3
3.8
3.0
3.7
Minimum
0.46
0.20
0.51
0.13
0.10
0.20
0.39
0.27
0.00
0.65
0.47
0.08
0.36
0.63
0.28
0.41
0.48
0.69
0.21
0.91
Arithmetic
Mean
1.5
1.5
1.5
1.8
1.3
1.4
1.5
1.4
1.4
1.7
1.4
1.4
1.5
1.3
1.3
1.6
1.4
1.6
1.6
2.2
Standard
Deviation
0.85
0.52
0.50
0.71
0.47
0.51
0.52
0.54
0.60
0.57
0.40
0.51
0.60
0.42
0.48
0.78
0.45
0.72
0.56
0.71
Std.Dev of Mean MDC = 3.89 x 10"16 ,uCi/mL
24
-------
Table 4.2 Gross Alpha Results for the Offsite Air Surveillance Network - 1997
Concentration (10'15 ^Ci/mL [37/^Bq/m3])
Sampling Location
Alamo, NV
Amargosa C.C., NV
Beatty, NV
Boulder City, NV
Clark Station, NV
Goldfield, NV
Henderson, NV
Indian Springs, NV
Las Vegas, NV
Overton, NV
Pahrump, NV
Pioche, NV
Rachel, NV
Sunnyside, NV
Tonopah, NV
Twin Springs, NV
Cedar City, UT
Delta, UT
Milford, UT
St. George, UT
Number
52
50
52
23
52
52
51
51
51
51
50
50
51
35
51
52
52
52
47
21
Maximum
5.3
5.9
5.4
6.6
4.3
6.8
6.3
3.4
4.4
6.0
3.6
3.3
7.3
4.3
4.1
12
4.8
5.5
3.8
6.6
Minimum
0.0
-0.1
0.3
0.3
0.9
0.3
-0.6
0.2
0.1
0.2
-0.4
0.2
0.2
-0.2
0.0
-0.4
0.7
0.3
0.3
0.7
Arithmetic
Mean
2.2
1.8
2.4
2.7
2.4
2.2
2.0
1.3
2.0
1.8
1.6
1.4
2.9
1.3
1.8
2.5
2.4
1.2
1.5
2.5
Standard
Deviation
1.2
1.3
1.3
1.5
0.88
1.4
1.4
0.73
0.95
1.3
0.93
0.72
1.6
0.91
1.0
1.8
0.98
0.93
0.78
1.5
Mean MDC = 7.5 x 10'18 //Ci/mL
Std.Dev of Mean MDC = 2.3 x 10'16
25
-------
Table 4.3 Offsite High-Volume Airborne Plutonium Concentrations - 1997
238Pu Concentration (10'18 uCi/mL)
Composite
Sampling Location
Alamo, NV
Amargosa C.C., NV
Goldfield, NV
Las Vegas, NV
Rachel, NV
Tonopah, NV
Mean MDC = 0.51 x10'18
Number Maximum
12
11
9
12
12
10
,Ci/mL
0.34
0.74
0.28
0.24
1.8
0.49
Minimum
-0.10
0.00
-0.17
-0.24
-0.16
0.00
Std.Dev
Arithmetic
Mean
0.04
0.14
0.12
-0.01
0.64
0.13
of Mean MDC
Standard
Deviation
0.09
0.21
0.08
0.07
0.67
0.14
= 0.39x10'1
%DCG'a)
(b)
(b)
(b)
(b)
0.03
(b)
8 AiCi/mL
(a) Derived Concentration Guide; Established by DOE Order as 2 x 10"15 /^Ci/mL
(b) Not applicable, result
Note: To convert //Ci/mL
Composite
Sampling Location
Alamo, NV
Amargosa C.C., NV
Goldfield, NV
Las Vegas, NV
Rachel, NV
Tonopah, NV
Mean MDC = 0.35 x 10'18
less than
to Bq/m3
MDC
multiply by 3.7 x
239+240pu
Number Maximum
12
11
9
12
12
10
4.3
8.0
5.0
1.5
77
2.3
1010(e.g.,
[0.64x10'18]x
[37x109] =
24 nBq/m3).
Concentration (10'18 uCi/mL)
Minimum
0.00
0.21
0.17
-0.19
0.49
0.25
Arithmetic
Mean
1.1
1.5
1.3
0.56
18
0.91
MCi/mL Std.Dev of Mean MDC =
Standard
Deviation %DCG (a)
1.1
2.2
1.4
0.36
25
0.60
= 0.24x10-18
0.06
0.08
0.06
0.03
0.90
0.05
//Ci/mL
(a) Derived Concentration Guide; Established by DOE Order as 3 x 10'15
(b) Not applicable, result less than MDC
Note: To convert ^Ci/mL to Bq/m3 multiply by 3.7 x 1010 (e.g., [1.1 x 10'18] x [37 x 109] = 41 nBq/m3).
26
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5.0 Milk
Ingestion is one of the critical exposure pathways
for radionuclides to humans. Food crops may
absorb radionuclides from the soil in which they are
grown. Radionuclides may be found on the surface
of fruits, vegetables, or food crops. The source of
these radionuclides may be atmospheric
deposition, resuspension, or adhering particles of
soil. Weather patterns, especially precipitation, can
affect soil inventories of radionuclides. Grazing
animals ingest radionuclides which may have been
deposited on forage grasses and, while grazing,
ingest soil which could contain radionuclides.
These radionuclides may be transferred to milk.
5.1 Milk Surveillance Network
Milk is an important source for evaluating
potential human exposures to radioactive
material. It is one of the most universally
consumed foodstuffs and certain radionuclides
are readily traceable through the chain from feed
or forage to the consumer. This is particularly true
of radioiodine isotopes which, when consumed by
children, can cause significant impairment of
thyroid function. Because dairy animals consume
vegetation representing a large area of ground
cover and because many radionuclides are trans-
ferred to milk, analysis of milk samples may yield
information on the deposition of small amounts of
radionuclides over a relatively large area. The
samples collected in July are from animals
consuming local feed. Accordingly, milk is
monitored by R&IE-LV through the Milk
Surveillance Network (MSN).
5.1.1 Design
The MSN includes commercial dairies and family-
owned milk cows and goats representing the major
milksheds within 186 mi (300 km) of the NTS.
During 1997, two sampling locations were
deleted and one was added. The David Hafen
Dairy, Ivins, UT, was sold and Frances Jones,
Inyokern, CA, moved. Both were deleted from
the MSN. The Bunker Dairy, Bunkerville, NV,
was added to the list. The ten locations
comprising the MSN for 1997 are shown in
Figure 5.1.
5.1.2 Procedures
Raw milk was collected in 3.8-L (1-gal)
cubitainers from each MSN location in July and
preserved with formaldehyde. This network was
designed to monitor areas adjacent to the NTS,
which could be affected by a release of activity,
as well as from areas unlikely to be so affected.
All milk samples are analyzed by high-resolution
gamma-ray spectroscopy to detect gamma-ray
emitting radionuclides. These samples are also
analyzed for 89Sr and 90Sr by radiochemical
separation and beta counting (see Table 5.1).
5.1.3 Results
The average total potassium concentration derived
from naturally occurring 40K activity was 1.5 g/L for
samples analyzed by gamma spectrometry. All MSN
milk samples were analyzed for 89Sr and ^Sr, and the
results are similar to those obtained in previous
years. Only Rockview Dairies, Inc., located in
Moapa, Nevada had a 90Sr, result above the MDC
(1.9 ±0.44 pCi/L). The MSN network average values
are shown in Table 5.2 for 89Sr and 90Sr.
In conclusion, the MSN data is consistent with
previous years and is not indicative of increasing or
decreasing trends. No radioactivity directly related
to current NTS activities was evident.
5.1.4 Quality Assurance/Control
General QA/QC guidelines for the MSN are as
follows:
• Proceduresfortheoperation, maintenance
and calibration of laboratory counting
equipment, the control and statistical
analysis of the samples and the data
review and records are documented in
approved SOPs.
• External and internal comparison studies
were performed and field and internal
duplicate samples were obtained for
precision and accuracy assessments.
• Analytical results are reviewed for
completeness and comparability.
• Trends are identified and potential risks to
humans and the environment are
determined based on the data. The data
quality assessment is given in Chapter 10.
27
-------
1 i ,
1 NEVADA 1 UTAH '
/^.
i
i
j
j
•
i
i
i
i
ill PYRAMID
\
Austin •
fcjLrV
Tviv
• Young Rn.H
S, 0 Duckwater
V • Bradshaw Rn.
0
fc
F
0
?-A
\ \
o** *_
^^ ^k
"* ^*. Karen Epperlv
^ Tonopah^*
S AFB1"18 1 June G°X Rn' •
V J RANGE N| •
>, f COMPLEX ^ ( ^L_
N \ / ^^HB^I^ «
V ^x_ // >
*» ^ rafEvsBfl \ /// Mesqui
Ponderosa Dairy #14"yL|iJ|[I!L //f^ r/ Moapa
Aimrnnrn Vnllrfl JfcM^K. 9
% Rockview /
^ Dairies f
Pahrump 0 V/
Pahrump Dairy • /^S^k
V |
\ 1
i \ \
T N •
N« Hinkley V
• Desert View Dairy
Scale in Miles
50 100
I i
^ 1—1
==:r^^^ 1
50 100 150
Scale in Kilometers
|
*-» >• i O6Q3T wily
wall T6 ^ _. . ,
• Brent Jones
Dairy
te
• Bunker Dairy ARIZONA
i
1EAD
\f*
• Milk
Sampling
Locations(IO)
• Nearest Town
NOTE: When
sampling location
occurred in city or
town, the sampling
location symbol was
used for showing
both town and
sampling location.
Figure 5.1 Milk Surveillance Network stations -1997
28
-------
Table 5.1 Offsite Milk Surveillance 90Sr Results -1997
-Sr Concentration (10'1°
Sampling Location
Hinkley, CA
Desert View Dairy
Amargosa Valley, NV
Ponderosa Dairy #141
Austin, NV
Young's Ranch
Bunkerville, NV
Bunker Dairy
Caliente, NV
June Cox Ranch
Duckwater, NV
Bradshaw's Ranch
Moapa, NV
Rockview Dairies
Pahrump, NV
Pahrump Dairy
Tonopah, NV
Karen Epperly
Cedar City, UT
Brent Jones Dairy
* Result greater than MDC.
Number
1
1
1
1
1
1
1
1
1
1
Mean
7.8
5.7
10.0
0.38
3.9
6.9
19*
6.4
5.0
5.0
Table 5.2 Summary of Radionuclides Detected in Milk Samples
Milk Surveillance Network
No. of samples with results > MDC
(Network average concentration in pCi/L)
3H
90
Sr
1997
Not analyzed
Not analyzed
1 (0.70)
1996
Not analyzed
0(0.01)
0(0.63)
1995
0(37)
0(0.03)
0(0.61)
29
-------
6.0 Long-Term Hydrological Monitoring Program
One of the concerns of underground nuclear
weapons testing is the possibility of radionuclide
contamination of groundwaters. Since 1973,
underground nuclear weapons tests were
conducted only on the Nevada Test Site (NTS), but
between 1961 and 1973, eleven tests were
conducted in eight other locations in the United
States. The initial ground and surface water
monitoring program was established by the U.S.
Public Health Service (USPHS) in the early 1950s.
Pretest and post-test monitoring forthe locations off
the NTS was conducted by the USPHS, the U.S.
Geological Survey (USGS), and Teledyne Isotopes,
Inc. In 1972, the Long-Term Hydrological
Monitoring Program (LTHMP) was established by
the Nevada Operations Office (NVO) of the Atomic
Energy Commission (AEC), a predecessor agency
to DOE. Through an interagency agreement
between AEC (later DOE) and EPA, responsibility
for operation of the LTHMP was assigned to the
U.S. EPA's Radiation and Indoor Environments
National Laboratory formerly the Environmental
Monitoring Systems Laboratory in Las Vegas,
Nevada (EMSL-LV). The LTHMP is only one
component of the total surface and ground water
monitoring program conducted under the auspices
of DOE/NV.
The LTHMP conducts routine monitoring of specific
wells on the NTS and of wells, springs, and surface
waters in the offsite area around the NTS. In
addition, sampling for the LTHMP is conducted at
other locations in the U.S. where nuclear weapons
tests have been conducted. These locations
include sites in Nevada, Colorado, New Mexico,
Mississippi, and Alaska.
6.1 Network Design
The LTHMP was instituted because AEC (later
DOE/NV) acknowledged its responsibility for
obtaining and for disseminating data acquired from
all locations where nuclear devices have been
tested. The three objectives originally established
for the LTHMP were to:
• Assure public safety.
RioBlanco Site
Rulison Site
Shoal Site
Faultless Site
Nevada Test
Site
Gasbuggy Site
Long Shot Site
Milrow Site
Cannikin Site
Figure 6.1 LTHMP sampling sites around the United States.
30
-------
• Inform the public, news media, and
scientific community about any radiologi-
cal contamination.
• Document compliance with existing fed-
eral, state, and local antipollution
requirements.
Another objective which has been incorporated into
the LTHMP is to, where possible, detect trends in
radionuclide activities which may be indicative of
migration from test cavities.
The primary radionuclide analyzed in the LTHMP is
tritium. As a product of nuclear weapons testing,
high levels of tritium are found in test cavities.
Because tritium can be incorporated into water
molecules, it is expected to be the first radionuclide
to migrate from a test cavity. Therefore, tritium
serves as an indicator of radionuclide migration.
Atmospheric tritium may also be deposited into
water, primarily by precipitation. Tritium from this
source is primarily found in surface waters, surficial
aquifers, and springs closely connected to surficial
aquifers.
6.1.1 Sampling Locations
In order to meet the objective of ensuring public
safety, R&IE-LV monitors drinking water supply
wells and springs around the NTS and in the
vicinity of surface ground zero (SGZ) at the other
locations. The majority of these sampling sites are
privately owned and participation in the LTHMP is
voluntary. Municipal drinking water supplies are
also represented.. Regardless of the number of
individuals served by a particular water supply, the
National Primary Drinking Water Regulation1
(NPDWR) pertaining to radioactivity is used as the
compliance standard.2
All of the nuclear weapons tested at locations other
than the NTS were emplaced at depths of greater
than 1200 feet. Nuclear weapons tested on the
NTS are also emplaced at great depths, with the
exception of some shallow underground tests
conducted in the early 1960s. The drinking water
supply wells tap shallow aquifers and,
consequently, do not represent groundwater in the
geologic strata containing the test cavities. There-
fore, wherever possible, deep wells are included in
the monitoring program. These wells include some
which were drilled soon after a nuclear test
specifically to monitor activities in or near the test
cavity and others which can be considered only as
"targets of opportunity;" e.g., existing wells for
which sampling permission has been obtained.
Most of the deep wells tap non-potable water
sources. Monitoring design standards, such as
those in the Resource Conservation and Recovery
Act (RCRA), did not become available until long
after the LTHMP deep wells had been drilled. Cost
has delayed emplacement of new wells, although
a program to drill more than 90 new wells on the
NTS was initiated in 1990. The sampling locations
not associated with the NTS are defined by DOE as
inactive hazardous waste sites and are exempt
from the RCRA monitoring design requirements.
Table 6.1 is a listing of routine sampling locations,
on and offsite, where well water samples contained
tritium concentrations greater than 0.2 percent of
the National Primary Drinking Water Standards.
6.1.2 Sampling and Analysis
Procedures
The procedures for the analysis of samples
collected for this report were described by Johns, et
al. (1979) and are summarized in Table 6.2 (see
Table 6.3 for Typical MDA Values for Gamma
Spectroscopy). These procedures include gamma
spectral analysis and radiochemical analysis for
tritium. The procedures were based on standard
methodology. Two methods for tritium analysis
were performed: conventional and electrolytic
enrichment. The samples are initially analyzed by
the conventional method. If the tritium result is less
than 700 pCi/L, selected samples are analyzed by
the electrolytic enrichment method which lowers the
minimum detectable concentration (MDC) from
approximately 300 pCi/L to 5 pCi/L. An upper level
of 700 pCi/L has been established for use of the
tritium enrichment method. Sample cross
contamination becomes a problem at higher
ranges.
For wells with operating pumps, the samples are
collected at the nearest convenient outlet. If the
well has no pump, a truck-mounted sampling unit is
used. With this unit it is possible to collect three-
liter samples from wells as deep as 1,800 meters
(5,900 ft). At the normal sample collection sites,
the pH, conductivity, water temperature, and
sampling depth are measured and recorded when
the sample is collected.
The first time samples are collected from a well, 3H,
89'90Sr, 238.239+24°pu, and uranium isotopes are deter-
mined. At least one of the one gallon samples from
each site is analyzed by gamma spectrometry. In
late 1995, because there was no indication of
migration and because of funding cutbacks, it was
31
-------
decided that only 25% of tritium samples collected
would be analyzed by the enrichment method.
Sampling locations in a position to show migration
are usually selected.
6.1.3 Quality Assurance/Quality
Control Samples
Sample collection and analysis procedures are
described in standard operating procedures
(SOPs). Data base management and data analysis
activities are described in the Quality Assurance
Program Plan (EPA, QAPP 1992).
• Use of standardized procedures ensures
comparability of operations and data
among monitoring locations and across
temporal intervals.
• Annual data quality assessments of
precision, accuracy, and comparability are
based on the results of quality
assurance/quality control samples. The
data quality assessment results for 1997
are given in Section 7.0.
• Overall system precision is estimated from
the results of field duplicates. A field
duplicate is a second sample collected
from a sampling location immediately
following collection of the routine sample
using identical procedures.
• Field duplicates are collected from
sampling locations on the NTS and in the
vicinity of the NTS according to a schedule
established by the LTHMP Technical
Leader. Generally, all samples from the
other locations are collected in duplicate;
the second sample may be used as a
duplicate or may be used as a
replacement for the routine sample, if
necessary.
• Accuracy is estimated from results of
intercomparison study samples. These
intercomparison study samples are spiked
samples (i.e., a water sample to which a
known amount a of particular radio-
nuclide(s) has been added).
• Intercomparison study programs managed
by R&IE-LV and DOE's Environmental
Monitoring Laboratory (EML) both include
water matrix samples. The R&IE-LV
intercomparison study samples are also
used as an estimate of comparability.
Generally, sixty to more than 300
laboratories participate in a given
intercomparison study. Results for each
laboratory are reported, as are pooled
results (mean, standard deviation).
• Comparison of the R&IE-LV Radioanalysis
Laboratory results to the mean for all
laboratories provides an estimate of the
comparability of results.
In addition to the above described QA/QC samples
which are used in annual data quality assessments,
the Radioanalysis Laboratory employs a number of
internal QC samples and procedures to ensure
data quality on a day-to-day basis. Internal QC
samples include blanks, regularcalibrations, matrix
spike samples, and duplicate analyses (gamma
spectroscopy only). If results of these internal QC
samples fall outside prescribed control limits,
analysis is stopped until the cause of the discrepant
data is found and resolved and corrective actions
are implemented.
6.1.4 Data Management and
Analysis
Bar code labels are prepared prior to each
sampling excursion, based on the sampling
schedule prepared by the LTHMP Technical
Leader. Upon receipt of samples in Sample
Control, the bar code label is read and the
information transferred into the Sample Tracking
Data Management System (STDMS), along with
information from the field data card.
Analysis data are entered into STDMS after they
have been generated and reviewed by the analyst
and Group Leader. Special software written in
Fortran (referred to as "Chemistry Programs") is
used for a majority of the radiochemical data
reduction. The Chemistry Programs are used for
calculating final data such as activity per unit
volume, MDC, and 2-sigma error terms. All hand-
entered data are checked for transcription errors.
Once data is entered and checked, they are
transferred from a "review" data base to a
permanent data base, where further changes may
be made only by authorized personnel.
Periodically, the assigned media expert reviews the
data base and checks for completeness of sample
collection, transcription errors, completion of
sample analysis and QA/QC samples, and
accuracy of information input. All discrepancies are
resolved and corrected. Once the data base is
complete for a given location, time series plots are
32
-------
generated. Data review of the LTHMP is held with
DOE and Desert Research Institute (DPI) hydrology
personnel. The time series plots which indicated
consistent data trends are included as figures in the
subsections which follow. The filled circles on the
time series plots represent the result values, the
error bars indicate ± one standard deviation of the
result, and the (x) represents the MDC value.
6.2 Nevada Test Site
Monitoring
The present sample locations on the NTS, or
immediately outside its borders on federally owned
land are shown in Figure 6.2. All sampling
locations are selected by DOE and primarily
represent potable water supplies. In 1995,
sampling on the NTS was modified so that EPA
only samples wells without pumps and, for Quality
Assurance purposes, collects samples from some
of the potable wells sampled by Bechtel Nevada.
A total of 22 wells was sampled.
All samples were analyzed by gamma spectrometry
and for tritium. No gamma-emitting radionuclides
were detected in any of the NTS samples collected
in 1997. Summary results of tritium analyses are
given in Table 6.4. The highest average tritium
activity was 6.0 x 104 pCi/L (2.2 kBq/L) in a sample
from Well UE-5n. This activity is less than 70
percent of the DCG for tritium established in DOE
Order 5400.5 for comparison with the dose limit (4
mrem) in the National Primary Drinking Water
Regulations. Six of the wells sampled yielded
tritium results greater than the minimum detectable
concentration (MDC). Well UE-7ns was routinely
sampled between 1978 and 1987 and sampling
began again in 1992. An increasing trend in tritium
activity was evident at the time sampling ceased in
1987.
6.3 Offsite Monitoring In The
Vicinity Of The Nevada
Test Site
The monitoring sites in the area around the NTS
are shown in Figure 6.3. Most of the sampling
locations represent drinking water sources for rural
residents or public drinking water supplies for the
communities in the area. The sampling locations
include 12 wells, nine springs, and a surface water
site. All of the locations are sampled quarterly or
semiannually.
Gamma spectrometric analyses are performed
on the samples when collected. No man-made
gamma-emitting radionuclides were detected in
any sample. Tritium analyses are performed on
a semiannual basis. Adaven Spring and Lake
Mead showed detectable tritium activity while the
sample from the low-level waste site south of
Beatty had barely detectable activity. All results
for this project for 1997 are shown in Table 6.5.
6.4 Hydrological Monitoring At
Other United States
Nuclear Device Testing
Locations
In addition to the groundwater monitoring
conducted on and in the vicinity of the NTS,
monitoring is conducted under the LTHMP at sites
of past nuclear device testing in other parts of the
United States to ensure the safety of public drinking
water supplies and, where suitable sampling points
are available, to monitor any migration of
radionuclides from the test cavity. Annual sampling
of surface and ground waters is conducted at the
Projects SHOAL and FAULTLESS sites in Nevada,
the Projects GASBUGGY and GNOME sites in New
Mexico, the Projects RULISON and RIO BLANCO
sites in Colorado, and the Project DRIBBLE site in
Mississippi. Sampling is normally conducted in odd
numbered years on Amchitka Island, Alaska, at the
sites of Projects CANNIKIN, LONG SHOT, and
MILROW.
The sampling procedure is the same as that used
for sites on the NTS and offsite areas (described in
Section 6.1.2), with the exception that two 3.8-L
samples are collected in cubitainers. The second
sample serves as a backup or as a duplicate
sample.
Because of the variability noted in past years in
samples obtained from the shallow monitoring wells
near Project DRIBBLE ground zero (GZ), the
sampling procedure was modified several years
ago. A second sample is taken after pumping for a
specified period of time or after the well has been
pumped dry and permitted to recharge. These
second samples may be more representative of
formation water, whereas the first samples may be
more indicative of recent area rainfall.
33
-------
Well P.M.
Exploratory
#1
WellUE-19c ™
GSTeV
Well D }. „
J/^.__ 7
, /•! 3!"
I 29
Water Well J-13
Well Arrn^
#1
= Water Sampling Location
Well U3cn#-5
..aterWellC
Well C-1
Water Well #4
^i
Well UE-5N
'ell UE-Sc
III
Well 5B
Well 5C
Well Army #6A
Figure 6.2 Wells on the NTS Included in the LTHMP -1997
34
-------
V
Sharp's Ranch
Adaven Springs
Twin Springs Rn.
Tonopah City
Well
I Klondike
'c'' ^x-. ^
Weir 6 * ^? *' V
' ^ "*•
•* v '„ , 1
V ^ NELLIS AFB
11^1-L.IO MHD
RANGE COMPLEX
B
N
I Penoyer Culinary Well
• Crystal Springs
• Alamo
City Well 4
V
^»v Goss Springs
\ Coffers 11S/48-1dd
BeattyWell12S/47E-7dbdB •
*
%^B U.S. Ecology
Amargosa Valley
Well15S/50E-18cdc Fairbanks
•> • Springs
V
•
Furnace Creek
Supply Well #6
-
Crystal Pool
\ • Spring 17S/50E-14cac
*VHWell18S/51IE-7db
~*.
• Indian Springs
Sewer Co. Well 1
X
V
V
V
V
\
I = Water Sampling Location
Scale in Miles
0 10 20 30 40
0 10 20 30 40 50 60
Scale in Kilometers
LOCATION MAP
NEV.
TEST
SITE&
NELLIS
AFB RANGE
COMPLEX
Figure 6.3 Wells Outside the NTS Included in the LTHMP -1997
35
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6.4.1 Project FAULTLESS
Project FAULTLESS was a "calibration test"
conducted on January 19, 1968, in a sparsely
populated area near Blue Jay Maintenance Station,
Nevada. The test had a yield of less than 1 Mt and
was designed to test the behavior of seismic waves
and to determine the usefulness of the site for high-
yield tests. The emplacement depth was 975 m
(3,199 ft). A surface crater was created, but as an
irregular block along local faults rather than as a
saucer-shaped depression. The area is charac-
terized by basin and range topography, with
alluvium overlying tuffaceous sediments. The
working point of the test was in tuff. The
groundwater flow is generally from the highlands to
the valley and through the valley to Twin Springs
Ranch and Railroad Valley (Chapman and Hokett,
1991).
Sampling was conducted on February 26,1997, at
locations shown in Figure 6.4. Routine sampling
locations include one spring and five wells of
varying depths. All routine samples were collected.
At least two wells (HTH-1 and HTH-2) are
positioned to intercept migration from the test
cavity, should it occur (Chapman and Hokett,
1991). All samples yielded negligible gamma
activity.
Gamma-ray spectral analysis results indicated that
no man-made gamma emitting radionuclides were
present in any sample above the MDC. Tritium
concentrations were less than the MDC. These
results are all consistent with results obtained in
previous years. The results for tritium indicate that,
to date, migration into the sampled wells has not
taken place and no event-related radioactivity has
entered area drinking water supplies.
6.4.2 Project SHOAL
Project SHOAL, a 12-kt test emplaced at 365 m
(1,198 ft), was conducted on October 26, 1963, in
a sparsely populated area near Frenchman Station,
Nevada. The test, part of the Vela Uniform
Program, was designed to investigate detection of
a nuclear detonation in an active earthquake zone.
The working point was in granite and no surface
crater was created. An effluent was released
during drillback but was detected onsite only and
consisted of 110 Ci of 131Xe and 133Xe, and less
than LOCiof 131I.
Samples were collected on February 24 and 25,
1997. The sampling locations are shown in Figure
6.5. Only nine of the ten routine wells were
sampled. Spring Windmill, and Smith and James
spring have been deleted. In 1997, four new wells
were added to the LTHMP at this site which are
positioned near ground zero. Well HC-3 was dry
and will have to be reworked. It will be sampled in
1998. At least one location, Well HS-1, should
intercept radioactivity migrating from the test cavity,
should it occur (Chapman and Hokett, 1991).
Gamma-ray spectral analysis results indicated that
no man-made gamma-emitting radionuclides were
present in any samples above the MDC. One of
the new wells, HC-4 drilled in 1996, had a tritium
concentration of 8.63 x 102 ± 158 pCi/L (321 ± 6
Bq/L). Tritium concentration at all the other
locations were below the MDC.
6.4.3 Project RULISON
Co-sponsored by the AEC and Austral Oil
Company under the Plowshare Program, Project
RULISON was designed to stimulate natural gas
recovery in the Mesa Verde formation. The test,
conducted near Grand Valley, Colorado, on
September 10, 1969, consisted of a 40-kt nuclear
explosive emplaced at a depth of 2,568 m (8,425
ft). Production testing began in 1970 and was
completed in April 1971. Cleanup was initiated in
1972 and the wells were plugged in 1976. Some
surface contamination resulted from
decontamination of drilling equipment and fallout
from gas flaring. Contaminated soil was removed
during the cleanup operations.
Sampling was conducted May 6, 1997, with
collection of samples from all sampling locations in
the area of Grand Valley and Rulison, Colorado.
Routine sampling locations are shown in Figure
6.6, and include five local ranches, five sites in the
vicinity of SGZ, including one test well, a surface-
discharge spring and a surface sampling location
on Battlement Creek. Seven new monitoring wells
were completed at the RULISON Site in 1995.
Wells RU-1 and RU-2 were added to the LTHMP in
1997, as part of the Remedial Investigation and
Feasibility Study.
Tritium has never been observed in measurable
concentrations in the Grand Valley City Springs. All
of the remaining sampling sites show detectable
levels of tritium, which have generally exhibited a
stable or decreasing trend over the last two
decades. The range of tritium activity in 1997 was
36
-------
HTH2
HTH1
X '
x' '
s
Hot Creek
Ranch
Six-Mile Well
!
N
Blue Jay
Maintenance
Station
SiteC
Complex
Surface Ground Zero
Water Sampling Locations
5 10
Scale in Kilometers
NYE
COUNTY
LOCATION MAP
Figure 6.4 LTHMP Sampling Locations for Project FAULTLESS -1997
37
-------
Fallon
HS-1
CHURCHILL COUNTY
^M ^H ^H ^M MK ^H ^M •
MINERAL COUNTY
I
N
Surface Ground Zero
Water Sampling Locations
LOCATION MAP
Scale in Miles
5 10
0 5 10 15
Scale in Kilometers
CHURCHILL
COUNTY
Figure 6.5 LTHMP Sampling Locations for Project SHOAL -1997
38
-------
Rothgery
Ranch
Grand Valley
City Springs
«_.,_ , »,„,,„,, m*rU fli _ y* Tim Jacobs Ranch
Grand Valley ^^ "^P- •*• —• — — — •*
I \ • Hayward Ranch
m I M\ Battlement Creek
•^ •
Gardner CER x
Ranch Test Well
Potter Ranch
Rulison
N
Surface Ground Zero
Water Sampling Locations
Scale in Miles
0 5
0 8
Scale in Kilometers
LOCATION MAP
GARFIELD
COUNTY
Figure 6.6 LTHMP Sampling Locations for Project RULISON -1997
39
-------
from 42 ± 5 pCi/L (2 ± 0.2 Bq/L) at Well Ru-1, to
104 ± 5.9 pCi/L (4 ± 0.2 Bq/L) at Lee Hayward
Ranch. All values were less than 1 percent of the
DCG. The detectable tritium activities were
probably a result of the high natural background in
the area. This was supported by the DRI analysis,
which indicated that most of the sampling locations
were shallow, drawing water from the surficial
aquifer which was unlikely to become contaminated
by any radionuclides arising from the Project
RULISON cavity (Chapman and Hokett, 1991).
Gamma-ray spectral analysis results indicated that
man-made gamma-emitting radionuclides were not
detectable.
6.4.4 Project RIO BLANCO
Like Project RULISON, Project RIO BLANCO was
a joint government-industry test designed to
stimulate natural gas flow and was conducted
under the Plowshare Program. The test was
conducted on May 17,1973, at a location between
Rifle and Meeker, Colorado. Three explosives with
a total yield of 90 kt were emplaced at 1780-, 1920-
, and 2040-m (5838-, 6229-, and 6689-ft) depths in
the Ft. Union and Mesa Verde formations.
Production testing continued to 1976 when cleanup
and restoration activities were completed. Tritiated
water produced during testing was injected to 1710
m (5610 ft) in a nearby gas well.
Samples were collected May 7 and 8, 1997, from
the sampling sites shown in Figure 6.7. Only 13 of
the 14 routine wells were sampled. No sample was
collected from CER #4 which was in accessible due
to heavy rainfall. The routine sampling locations
included three springs and six wells. Three of the
wells are located near the cavity and at least two of
the wells (Wells RB-D-01 and RB-D-03) were
suitable for monitoring possible migration of
radioactivity from the cavity.
No radioactive materials attributable to the RIO
BLANCO test were detected in samples collected
in the offsite areas during May 1997. The range of
tritium activity, using the enrichment method, was
from 36 ± 5.2 (1 ± 0.2 Bq/L) at the B-1 Equity Camp
to 25 ± 3.7 (1 ±0.1 Bq/L) at Fawn Creek, 8,400 ft
downstream. The tritium concentrations are well
below 20,000 pCi/L level defined in the EPA
National Primary Drinking Water Regulations (40
C.F.R. 141). All samples were analyzed for
presence of gamma-ray emitting radionuclides, and
none were detected.
6.4.5 Project GNOME
Project GNOME, conducted on December 10,
1961, near Carlsbad, New Mexico, was a
multipurpose test performed in a salt formation. A
slightly more than 3-kt nuclear explosive was
emplaced at 371 m (1217 ft) depth in the Salado
salt formation. Radioactive gases were
unexpectedly vented during the test. The USGS
conducted a tracer study in 1963, involving injection
of 20 Ci 3H, 10 Ci 137Cs, 10 Ci 90Sr, and 4Ci 131I
(740,370,370 and 150 GBq, respectively) into Well
USGS-8 and pumping water from Well USGS-4.
During cleanup activities in 1968-69, contaminated
material was placed in the test cavity access well.
More material was slurried into the cavity and drifts
in 1979.
Sampling at Project GNOME was conducted June
25 through 27, 1997. The routine sampling sites,
depicted in Figure 6.8, include nine monitoring
wells in the vicinity of GZ and the municipal
supplies at Loving and Carlsbad, New Mexico.
Tritium results greater than the MDC were detected
in water samples from six of the twelve sampling
locations in the immediate vicinity of GZ. Tritium
activities in Wells DD-1, LRL-7, USGS-4, and
USGS-8 ranged from 6.16 x 107 to 103 pCi/L (2.29
x 10s to 91 Bq/L). Well DD-1 collects water from
the test cavity; Well LRL-7 collects water from a
side drift; and Wells USGS-4 and -8 were used in
the radionuclide tracer study conducted by the
USGS. None of these wells are sources of potable
water.
In addition to tritium, 137Cs and 90Sr concentrations
were observed in samples from Wells DD-1, LRL-7,
and USGS-8 and 90Sr activity was detected in Well
USGS-4 as in previous years. No tritium was
detected in the remaining sampling locations,
including Well USGS-1, which the DRI analysis
(Chapman and Hokett, 1991) indicated is
positioned to detect any migration of radioactivity
from the cavity. All other tritium results were below
the MDC.
6.4.6 Project GASBUGGY
Project GASBUGGY was a Plowshare Program test
co-sponsored by the U.S. Government and El Paso
Natural Gas. Conducted near Farmington, New
Mexico, on December 10, 1967, the test was
designed to stimulate a low productivity natural gas
reservoir. A nuclear explosive with a 29-kt yield
was emplaced at a depth of 1,290 m (4,240 ft).
40
-------
Johnson
Artesian Well
awn Cr. No. 1
B-1 .Equity
Camp
Brennan
Windmill
Fawn Cr.8400'
Downstream
Fawn Cr.500' Downstream
RB-D-
RB-D-03 >3
RG
Fawn Cr.500'
Upstream
Fawn Cr. 6&
Upstream
Fawn Cr. No. 3
Scale in Kilometers
RIO BLANCO COUNTY
GARFIELD COUNTY
LOCAT ON MAP
Surface Ground Zero
Water Sampling Locations
D Not Sampled This Year
RIO BLANCO
COUNTY
Figure 6.7 LTHMP Sampling Locations for Project RIO BLANCO -1997
41
-------
Carlsbad
Carlsbad
City |
Well?
obley
Ranch
USGS Wells
PHSWellQ
PHSWelMO
Loving City
Well 2
PHS Well 6 •
• PHS Well 8
ii
N
Surface Ground Zero
Water Sampling Locations
EDDY
-A COUNTY
0 5 10 15
Scale in Kilometers
LOCATION MAP
Figure 6.8 LTHMP Sampling Locations for Project GNOME -1997
42
-------
Production testing was completed in 1976 and
restoration activities were completed in July 1978.
The principal aquifers near the test site are the Ojo
Alamo sandstone, an aquifercontaining nonpotable
water located above the test cavity and the San
Jose formation and Nacimiento formation, both
surficial aquifers containing potable water. The
flow regime of the San Juan Basin is not well
known, although it is likely that the Ojo Alamo
sandstone discharges to the San Juan River 50 mi
northwest of the GASBUGGY site. Hydrologic
gradients in the vicinity are downward, but upward
gas migration is possible (Chapman and Hokett,
1991).
Sampling at GASBUGGY was conducted during
May 10 through 12, 1997. Only twelve samples
were collected at the designated sampling locations
shown in Figure 6.9. The Bixler Ranch well has
been sealed up and Well 28.3.33.233 south had
the pumps removed and no samples could be
obtained.
The three springs sampling sites yielded tritium
activities of 26 ± 4.3 pCi/L for Bubbling Springs, 43
± 4.0 pCi/L for Cedar Springs, and 54 ± 6.2 pCi/L
for Cave Springs (0.96, 1.6, and 2.0 Bq/L,
respectively), which were less than 0.2 percent of
the DCG and similar to the range seen in previous
years. Tritium samples from the three shallow
wells were all below the average MDC.
Well EPNG 10-36, a gas well located 132 m (435 ft)
northwest of the test cavity, with a sampling depth
of approximately 1,100 m (3,600 ft), has yielded
detectable tritium activities since 1984. The sample
collected in May 1997 contained tritium at a
concentration of 120 ± 6 pCi/L (4.8 Bq/L). The
migration mechanism and route is not currently
known, although an analysis by DRI indicated two
feasible routes, one through the Printed Cliffs
sandstones and the other one through the Ojo
Alamo sandstone, one of the principal aquifers in
the region. In either case, fractures extending from
the cavity may be the primary or a contributing
mechanism.
All gamma-ray spectral analysis results indicated
that no man-made gamma-emitting radionuclides
were present in any offsite samples. Tritium
concentrations of water samples collected onsite
and offsite are consistent with those of past studies
at the GASBUGGY site.
6.4.7 Project DRIBBLE
Project DRIBBLE was comprised of two nuclear
and two gas explosive tests, conducted in the
SALMON test site area of Mississippi under the
Vela Uniform Program. The purpose of Project
DRIBBLE was to study the effects of decoupling on
seismic signals produced by nuclear explosives
tests. The first test, SALMON, was a nuclear
device with a yield of about 5 kt, detonated on
October 22, 1964, at a depth of 826 m (2,710 ft).
This test created the cavity used for the subsequent
tests, including STERLING, a nuclear test
conducted on December 3, 1966, with a yield of
380 tons, and the two gas explosions, DIODE
TUBE (on February 2, 1969) and HUMID WATER
(on April 19, 1970). The ground surface and
shallow groundwater aquifers were contaminated
by disposal of drilling muds and fluids in surface
pits. The radioactive contamination was primarily
limited to the unsaturated zone and upper,
nonpotable aquifers. Shallow wells, labeled HMH
wells on Figure 6.10, have been added to the area
near surface GZ to monitor this contamination. In
addition to the monitoring wells near GZ, extensive
sampling of water wells is conducted in the nearby
offsite area as shown in Figure 6.11.
Because of the variability noted in past years in
samples from the shallow monitoring wells near
Project DRIBBLE (SALMON) ground zero (GZ),
the sampling procedure was modified several
years ago. A second sample is taken after
pumping for a specified period of time or after the
well has been pumped dry and permitted to
recharge. These second samples may be
representative of formation water, whereas the
first samples may be more indicative of recent
rainfall.
Sampling on and in the vicinity of the DRIBBLE
site was conducted between April 20 through 24,
1997. The radioactive contamination was
primarily limited to the unsaturated zone and
upper, nonpotable aquifers near surface ground
zero (SGZ).
Long-term decreasing trends in tritium
concentrations are evident for those locations that
had detectable tritium activity at the beginning of
the LTHMP, such as in the samples from Well
HMH-5 depicted in Figure 6.12 and Well HM-S
shown in Figure 6.13. Due to the high rainfall in the
area, the normal sampling procedure is modified for
the shallow onsite wells as described above. Of
the 45 locations sampled from 42 ± 5 pCi/L
43
-------
To Blanco &
Gobernador.NM
Bubbling
Springs
EPNG Well 10-36
Cedar Springs
Cave Springs ^
Arnold Ranch Spring
Arnold Ranch Well
To Gobernador, NM
N
h
To Dulce, NM
(J7,
• Pond N. of
Well 30.3.32.343N
Well 30.3.32.343N
La Jara Creek
Pf
To Cuga, NM
LOCATION MAP
Surface Ground Zero
Water Sampling Locations
Scale in Miles
0 5
0 8
Scale in Kilometers
RIO
ARRIBA
COUNTY
Figure 6.9 LTHMP Sampling Locations for Project GASBUGGY -1997
44
-------
Decontamination
Pad
t*M
\ • • Hunting Tatum
\ Half Moon Club Well
Pond West of GZ
•*\
\
SWAMP
HMH-10
HalfMoorU,
Creek Overflow
ISA1-2-H
MH-1
M-2B
BHMH-11
Surface Ground Zero
Water Sampling Locations
New Wells Added in 1997
0 100 200 300 400 500
Scale in Meters
Figure 6.10 LTHMP Sampling Locations for Project DRIBBLE, Near Ground Zero -1997
45
-------
I B. Dennis
I M. Dennis
I Columbia City Little Creek #1-j
Well 64B Lee Anderson -\
Gil Ray's Crawfish Pond
Lower Little Creek #2
i—Willie Burge
I r~Joe Burge
Salt Dome Timber Co.
A.C.
Mills
Roy Mills
Howard
Smith Pond-
Lee L. Saul
P.T. Lee
R.H. Anderson
E.Cox
W.H. Noble Jr
Arleene Anderson
Noble's Pond
B. Hibley D, Napien*
if
Andersonls.Ppnd.^
B.R. Anderson!
Purvis City Well
***
G. Ray
Dennis
Saucier Jr.
Tatum Hunting Club
Steve Cockerham
Ray Daniels •_ R.L. Anderson Sr.
Daniel's Fish1* R.L. Anderson Jr.
Pond Well #2
Ola Saul
Ray Hartfield
Baxterville
City Well
Lumberton
City Well 2
Surface Ground Zero
Water Sampling Locations
Tatum Dome Test Area
Scale in Miles
1 2
01234
Scale in Kilometers
Figure 6.11 LTHMP sampling Locations for Project DRIBBLE, towns and residences -1997
46
-------
12
10
+ Measured
— Predicted by 3H decay
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
Calendar Year
Figure 6.12 Tritium results in Well HMH-5, SALMON Site, Project DRIBBLE -1997
,-^
s!
40
30
20
10
•f-
-|- Measured
— Predicted by 3H decay
-I- -t-
T +
i i
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
Calendar Year
Figure 6.13 Tritium Results in Well HM-S, SALMON Site, Project DRIBBLE - 1997
47
-------
onsite, 20 sites sampled twice (pre-and post-
pumping), eight yielded tritium activities greater
than the MDC in either the first or second
sample. Of these, eight yielded results higher
than normal background (approximately 60 pCi/L
[2.2 Bq/L]) as shown in Table 6.12. The locations
where the highest tritium activities were
measured generally correspond to areas of
known contamination. Decreasing trends are
evident for the wells where high tritium activities
have been found, such as Well HM-S depicted in
Figure 6.13. No tritium concentrations above
normal background values were detected in any
offsite samples. Man-made gamma-ray emitting
radionuclides were not detected in any sample
collected in this study. Six of the previously
sampled locations regularly have tritium values
above those expected in surface water samples;
of the 15 new wells, tritium values ranged from
3.45 x 104 to 14 ± 3.2 pCi/L (1.28 X 10 3 to 0.5 ±
0.2 Bq/L). Only one well was above the MDC in
the 36 samples collected from the offsite
sampling locations, tritium activity ranged from
less than the MDC to 26 pCi/L (1 Bq/L), 0.01
percent of the DCG. These results do not
exceed the natural tritium activity expected in rain
water in this area, activities were measured
generally correspond to areas of known
contamination. Decreasing trends are evident for
the wells where high tritium activities have been
found, such as Well HM-S depicted in Figure 6.13.
No tritium concentrations above normal
background values were detected in any offsite
samples. Man-made gamma-ray emitting
radionuclides were not detected in any sample
collected in this study.
Results of sampling related to Project DRIBBLE are
discussed in greater detail in the Onsite and Offsite
Environmental Monitoring Report, "Radiation
Monitoring around SALMON Test Site," Lamar
County, Mississippi, April 1997 (Davis 1997,
available from R&IE-LV).
6.4.8 AMCHITKA ISLAND, ALASKA
Three nuclear weapons tests were conducted on
Amchitka Island in the Aleutian Island chain on
Alaska. Project LONG SHOT, conducted on
October 29, 1965, was an 85-kt test under the
Vela Uniform Program, designed to investigate
seismic phenomena. 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.
Project CANNIKIN, conducted on November 6,
1971, was a proof test of the Spartan antibalistic
missile warhead with less than a 5-Mt yield.
Project LONG SHOT resulted in some surface
contamination, even though the chimney did not
extend to the surface.
Amchitka Island is composed of several hundred
feet of permeable tundra overlaying tertiary
volcanics. The groundwater 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 LONG SHOT and
CANNIKIN to the Bering Sea (Chapman and
Hokett, 1991).
Sampling was conducted June 3 through 17,
1997. 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. Background sampling locations are
shown in Figure 6.14, Projects LONG SHOT and
MILROW in Figure 6.16, and for Project
CANNIKIN in Figure 6.15.
All gamma-ray spectral analysis results indicated that
no man-made gamma-emitting radionuclides were
present in any samples collected onsite. 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. Water
samples collected onsite are consistent with those of
past studies atthe three sites, MILROW, CANNIKIN,
and LONG SHOT. Results are discussed in greater
detail in Amchitka Alaska Special Sampling Report
(Faller 1997 available from R&IE, LV).
6.5 Summary
None of the domestic water supplies monitored in
the LTHMP in 1997 yielded tritium activities of any
health concern. The greatest tritium activity mea-
sured in any water body which has potential to be
a drinking water supply was less than one percent
of the limit prescribed by the NPDWRs. In general,
surface water and spring samples yielded tritium
48
-------
Tx - Site Spring
Tx - Site Water
Tank
BERING
SEA
CQNSTANTINE
HARBOR
PACIFIC
OCEAN
Surface Ground Zero
Water Sampling
Locations
Pump Hous
Duck Cove Cre
Milro
Scale in Miles
5 10
BASE CAMP
AREA
0 5 10
Scale in Kilometers
Water Sampling
Locations
Runway
South Hanger
Maintenance
Building
OCEAN
amiiimiiiiiiiiiiiiH in iiiiui HIM iTiniiiminiiiiiinniiniiniiiiniiiiiiiinniiniiiiiimiiimiiiiiiinniiiiiiiiiiiiiiiiiiiiiiiiiiiiniiiiiiiiiiiinniiiiiiiiiiiiiiiiiiiiiiiiiiiifE
Figure 6.14 Amchitka Island and background sampling location for the LTHMP
49
-------
Surface Ground Zero
D Water Sampling Locations
Figure 6.15 LTHMP sampling locations for Project CANNIKIN
50
-------
Scale in Feet
600 1200
200 400
Scale in Meters
LINEAR
FRACTURE
Surface Ground Zero
Clevenger
Creek
Water Sampling
Locations
MILROW
LONG SHOT
Long Shot
PondS
Surface Ground
Zero
Water Sampling
Locations
Long Shot
Pond 2
.- .
East
Long Shot
Long Shot
Pondl
Well GZ-2
Well EPA-1
Figure 6.16 LTHMP sampling locations for Projects MILROW and LONGSHOT
51
-------
activities greater than those observed in shallow In most cases, monitoring wells also yielded no
domestic wells in the same area. This is probably radionuclide activity above the MDC. Exceptions
due to scavenging of atmospheric tritium by include wells into test cavities, wells monitoring
precipitation. Where suitable monitoring wells known areas of contamination, and one well at
exist, there were no indications that migration from GASBUGGY. Known areas of contamination exist
any test cavity is affecting any domestic water at Project GNOME where USGS conducted a tracer
supply. study experiment, some areas onsite at Project
DRIBBLE, and a few surface areas near Project
LONG SHOT. The 1997 results for these
monitoring wells are consistent with decreasing
trends observed over time.
1. The NPDWR states that the sum of all beta/gamma emitter concentrations in drinking water cannot
lead to a dose exceeding 4 mrem/year, assuming a person were to drink two liters per day for a year (40
CFR 141). Assuming tritium to be the only radioactive contaminant yields a maximum allowable
concentration of 2 x 104 pCi/L.
2. The NPDWR applies only to public systems with at least 15 hookups or 25 users. Although many of
the drinking water supplies monitored in the LTHMP serve fewer users and are therefore exempt, the
regulations provide a frame of reference for any observed radionuclide activity.
52
-------
Table 6.1 Locations with Detectable Tritium and Man-Made Radioactivity in 1997 (a)
Concentration
Sampling Location Radionuclide x 10'9uCi/mL
NTS Onsite Network
WellPM-1 3H 175
Well UE-5n 3H 66,000*
Well UE-6d 3H 500
Well UE-7ns 3H 500
WellUE-18t 3H 200
Project DRIBBLE, Mississippi (B)
Well HMH-1 3H 2,000
Well HMH-2 3H 290
WellHMH-4 3H 130
Well HMH-5 3H 870
Well HMH-9 3H 130
WellHMH-10 3H 150
Well HM-L 3H 950
Well HM-S 3H 3,400
Half Moon Creek Overflow 3H 190
REECo Pit B 3H 590
REECo Pit C 3H 340
SA1-1-H 3H 34,000
SA1-2-H 3H 3,190
SA1-3-H 3H 890
SA1-4-H 3H 340
SA1-5-H 3H 1,270
Project GNOME, New Mexico
WellDD-1 3H 6.1 x 107
90Sr 13,100
137Cs 6.8 x105
Well LRL-7 3H 5,800
90Sr 2.5
137Cs 160
Well USGS-4 3H 73,800
90Sr 4,700
137Cs <5.0
Well USGS-8 3H 68,000
90Sr 4,500
137Cs 99
(a) Only 3H concentrations greater than 0.2 percent of the 4 mrem DCG are shown {i.e., greater than
1.6 x 10'7 uCi/mL [160 pCi/L (6 Bq/L)]}. Detectable levels of other radioisotopes are also shown.
* Highest analytical result for Well UE-5n in 1997.
53
-------
Table 6.2 Summary of EPA Analytical Procedures -1997
Type of Analytical Counting
Analysis Equipment Period (Min)
HpGe HpGe detector 100
Gamma(b> calibrated at 0.5 keV/
channel (0.04 to 2
MeV range) individual
detector efficiencies
ranging from 15 to
35 percent.
3H Automatic liquid 300
scintillation counter.
3H+ Automatic liquid 300
Enrichment scintillation counter.
Analytical
Procedures
Radionuclide concen-
tration quantified from
gamma spectral data
by online computer
program.
Sample prepared by
distillation.
Sample concentrated
by electrolysis followed
by distillation.
Sample
Size
3.5 L
Approximate
Detection Limit'3'
Varies with radio-
nuclides and detector
used, see Table 6.3
below.
5-1 OmL 300 to 700 pCi/L
250 ml_ 5 pCi/L
(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.
Table 6.3 Typical MDA Values for Gamma Spectroscopy
All MDA values are computed for a water matrix sample (1.0 g/ml density) in a 3.5 L Marinelli beaker geometry,
counted for 100 minutes on a Canbarra model 430G HpGe detector.
Isotope
MDA (pCi/L)
Isotope
MDA (pCi/L
Be-7
K-40
Cr-51
Mn-54
Co-57
Co-58
Fe-59
Co-60
Zn-65
Nb-95
Zr-95
45.6
49.2
58.8
45.5
9.65
4.71
10.7
5.38
12.4
5.64
9.06
Ru-106
Sn-113
Sb-125
1-131
Ba-133
Cs-134
Cs-137
Ce-144
Eu-152
Ra-226
U-235
Am-241
47.6
8.32
16.5
8.28
9.16
6.12
6.43
75.9
28.6
15.8
101
66.0
Disclaimer
The MDAs provided are for background matrix samples presumed to contain no known analytes and no
decay time. All MDAs provided here are for one specific high purity Germanium detector and the
geometry of interest. The MDAs in no way should be used as a source of reference for determining
MDAs for any other type of detector. All gamma spectroscopy MDAs will vary with different types of
shielding, geometries, counting times, and decay time of sample.
54
-------
Table 6.4 Long-Term Hydrological Monitoring Program Summary of Tritium Results for
Nevada Test Site Network, 1997
Tritium Concentration (pCi/L)
Arithmetic
Number
1
1
2
1
1
1
2
2
2
2
2
1
1
2
1
2
1
1
1
1
1
1
Maximum
—
31
—
—
—
140
66000
540
77
530
—
—
3.7
—
19
—
—
—
—
—
—
Minimum
—
26
—
—
—
-77
54000
510
-51
310
—
—
-2.9
—
-26
—
—
—
—
—
—
Mean
46
3.0
29
0.46
180
180
32
60000
520
13
420
66
58
0.4
210
-4
19
-3.1
-3.0
-100
6.8
-12
1 Sigma
2.2
1.6
2.4
1.7
70
70
70
400
6.6
68
100
70
69
2.2
70
95
69
1.8
1.6
65
1.8
69
Mean
as %DCG
0.05
NA(b)
0.03
NA
NA
NA
NA
67
0.58
NA
0.47
NA
NA
NA
NA
NA
NA
NA
NA
NA
<0.01
NA
Mean
MDC
5.6
5.3
4.9
5.6
230
230
220
230
5.5
230
230
230
230
5.2
230
220
230
6.0
5.8
220
4.2
230
Location
Test Well B
Test Well D
Test Well F
Well C-1
Well HTH-1
Well PM-1
WellUE-1c
Well UE-5n
Well UE-6d
Well UE-6e
Well UE-7ns
Well UE-16d
Well UE-16f
WellUE-18r
WellUE-18t
Well 1 Army
Well 2
Well 4
Well5B
Well 5C
Well 6A Army
WellS
(a) DCG Derived Concentration Guide; established by DOE Order as 90,000 pCi/L for
water.
(b) NA Not applicable; percent of concentration guide is not applicable as the tritium result
is less than the MDC or the water is known to be nonpotable.
55
-------
Table 6.5 Long-Term Hydrological Monitoring Program Summary of Tritium Results for Wells
near the NTS -1997
Tritium Concentration (pCi/L)
Location
Adaven
Adaven Spring
Alamo
Well 4 City
Ash Meadows
Crystal Pool
Fairbanks Spring
17S-50E-14cac
Well 18S-51E-7db
Beatty
Low Level Waste Site
Tolicha Peak
11S-48E-1dd Coffer's
12S-47E-7dbdCity
Number
of Samples'3' Max.
2 28
2 110
1
1
3
1
2
1
1
1
1
1
3
1
3
1
3
1
1
Younghans Ranch House Well 3
Boulder City
Lake Mead Intake 1
Clark Station
TTR Well 6 2
Goldfield
Klondike #2 Well 2
Hiko
Crystal Springs
Indian Springs
Sewer Co. Well 1
Air Force Well 2
Lathrop Wells
15S-50E-18cdcCity
2.9
0.33
190
110
150
190
56
39
Min. Mean
19
0
-2.9
-1.1
0
0
38
-77
39
-38
22
55
-2.3
39
-0.3
150
-0.8
0.8
0
1.0
39
6.2
94
-2.8
57
-0.6
110
-1.0
0
59
40
48
0.5
-1.7
0
0
2.6
0
-0.08
0
%of
1 s.d. DCG
1.7
67
3.0
68
1.9
67
1.7
1.8
68
1.4
68
0.02
(c)
(c)
(c)
(c)
(c)
(c)
(c)
(c)
(c)
(c)
1.8 <0.01
65
1.6
66
1.6
67
2.2
68
67
(c)
(c)
(c)
(c)
(c)
(c)
(c)
(c)
1.8 0.04
67
140
3.1
68
68
1.3
68
1.2
68
(c)
(c)
(c)
(c)
(c)
(c)
(c)
(c)
(c)
Mean
MDC
5.1
220
10
220
6.3
210
5.8
5.8
220
4.3
220
5.9
220
5.4
220
5.4
220
7.5
220
220
4.9
220
220
10
220
220
4.3
220
4.0
220
(a) For each sample: 1st row is from enrichment analysis, 2nd row from conventional analysis.
(b) Derived Concentration Guide (DCG) established by DOE Order as 90,000 pCi/L.
(c) Not applicable. Percent of concentration guide is not applicable because the result is less
than the MDC or the water is known to be nonpotable.
56
-------
Table 6.5 (Long-Term Hydrological Monitoring Program Summary of Tritium Results for
Wells near the NTS -1997, con't.)
Tritii im finnrpntration
Location
Nyala
Sharp's Ranch
Oasis Valley
Goss Springs
Rachel
Penoyer Culinary
Tonopah
City Well
Warm Springs
Twin Springs Ranch
Number
of Samples'3' Max. Min.
1
1
DRY
1
3
Mean
2.0
0
% of Mean
1 s.d. DCG MDC
3.2
68
470
56
0.6
320
1.3
67
(c)
(c)
(c)
(c)
10
220
1
3
2
—
150
39
—
56
-19
1.2
95
10
1.4
67
66
(c)
(c)
(c)
4.8
210
220
4.3
220
(a) For each sample: 1st row is from enrichment analysis, 2nd row from conventional analysis.
(b) DCG - Derived Concentration Guide. Established by DOE Order as 90,000 pCi/L.
(c) Not applicable because the result is less than the MDC or the water is known to be
nonpotable.
57
-------
Table 6.6 Analysis Results for Water Samples Collected in May 1997.
RULISON Site
Sample
Location
Battlement
Creek
City Springs
Albert Gardner
CER Test Well
Lee Hayward
Rn.
Potter Ranch
Wayne & Debra
Rothgery
Tim Jacobs
Spring 300 yds
N. of GZ
Well RU-1
Well RU-2
Collection
Date
5/07/97
5/06/97
5/06/97
5/06/97
5/06/97
5/06/97
5/06/97
5/06/97
5/06/97
5/06/97
5/06/97
Enriched Tritium
pCi/L±2SD (MDC)
36 ± 4 (5.0)
55 ± 5 (5.7)
100 ±6 (6.8)
30 ± 4 (5.3)
42 ± 5 (6.9)
33 ± 4 (5.3)
Tritium
pCi/L ± 2 SD (MDC)
-------
Table 6.7 Analysis Results for Water Samples Collected in May 1997.
RIO BLANCO Site
Sample
Location
B-1 Equity Camp
Brennan Windmill
CER #1 Black
Sulpher
CER #4 Black
Sulpher
Fawn Creek #1
Fawn Creek #3
Fawn Creek 500'
Upstream
Fawn Creek 6800'
Upstream
Fawn Creek 500'
Downstream
Fawn Creek 8400'
Downstream
Johnson Artesian
Well
Well RB-D-01
Well RB-D-03
Well RB-S-03
Collection
Date
5/08/97
5/07/97
5/08/97
5/08/97
5/07/97
5/07/97
5/07/97
5/07/97
5/07/97
5/07/97
5/07/97
5/08/97
5/07/97
5/08/97
Enriched Tritium
pCi/L±2SD (MDC)
36 ± 5 (7.4)
-------
Table 6.8 Analysis Results for Water Samples Collected in February 1997.
FAULTLESS Site
Sample
Location
Hot Creek Ranch
Spring
Blue Jay Maint
Station
Well HTH-1
Well HTH-2
Site C Base
Camp
Six Mile
Collection
Date
2/26/97
2/26/97
2/26/97
2/26/97
2/26/97
2/26/97
Enriched Tritium
pCi/L±2SD (MDC)
-------
Table 6.10 Analysis Results for Water Samples Collected in May 1997.
GASBUGGY Site
Sample
Location
Arnold Ranch
Spring
Arnold Ranch Well
Bixler Ranch
Bubbling Springs
Cave Springs
Cedar Springs
La Jara Creek
Lower Burro
Canyon
Pond N. of Well
30.3.32.343
Well EPNG-1 0-36
JicarillaWell 1
Well 28.3.33.233
(South)
Well 30.3.32.343
(North)
Windmill #2
Collection
Date
5/09/97
5/10/97
5/10/97
5/10/97
5/10/97
5/10/97
5/10/97
5/11/97
5/12/97
5/10/97
5/11/97
5/10/97
5/12/97
5/12/97
Enriched Tritium
pCi/L±2SD (MDC)
-------
Table 6.11 Tritium Results for Water Samples Collected in June 1997.
GNOME Site
Sample
Location
Well 7 City
Well 2 City
PHS6
PHS8
PHS9
PHS10
USGS Well 1
USGS Well 4
Well USGS 8
J. Mobley Ranch
Well DD-1
LRL-7
Collection
Date
6/26/97
6/26/97
6/26/97
6/26/97
6/26/97
6/26/97
6/27/97
6/25/96
6/26/97
6/26/97
6/27/97
6/15/96
Enriched Tritium
pCi/L ± 2 SD (MDC)
5.7 ± 3.0 (5.3)
-------
Table 6.12 Tritium Results for Water Samples Collected in April 1997.
Collection Enriched Gamma
Sample Date Tritium Tritium
Location 1997 pCi/L±2SD (MDC) pCi/L±2SD (MDC) Comments
Baxterville, MS
Anderson, Billy Ray
Anderson Pond
Steve Cockerham
Anderson, Robert Harvey
Anderson, Robert Lowell, Jr.
Anderson, Robert Lee
Anderson, Tony
Burge, Joe
Daniels, Webster, Jr.
Daniels - Well #2 Fish Pond
Half Moon Creek Pre
Post
Half Moon Creek Pre
Overflow Post
Post Dup
Hibley, Billy
Napier, Denice
Lee, P.T.
Little Creek #1
Lower Little Creek #2
Mills, Roy
4-22
4-22
4-24
4-23
4-21
4-21
4-22
4-21
4-23
4-23
4-20
4-22
4-20
4-22
4-22
4-21
4-22
4-21
4-21
4-21
4-21
55 ± 142 M (232)
11 ±3.4 (5.2)
-23 ± 141 (4.5)
199 ±6.4 (5.7)
188 ±6.9 (6.5)
-23 ± 141 > NO gamma radionuclides detected above MDC
ND Non-detected, represents 137Cs (pCi/L)
63
-------
Table 6.12 Tritium Results for Water Samples Collected in April 1997 (Continued).
Collection Enriched Gamma
Sample Date Tritium Tritium Spectrometry (b)
Location 1997 pCi/L ± 2 SD (MDC) pCi/L ± 2 SD (MDC) Comments (MDC)
Baxterville, MS (Cont)
Nobles Pond
Noble, W.H., Jr.
Pond West of GZ Pre
Post
REECo Pit Drainage-A
REECo Pit Drainage-B
REECo Pit Drainage-C
REECo Pit Drainage-C Dup
Salt Dome Hunting Club
Salt Dome Timber Co.
Saucier, Dennis
Well Ascot 2
Baxterville Well City
Well E-7
Well HM-1 Pre
lst30Min
2nd 30 Min
Post
WellHM-2A Pre
1st 30 Min
2nd 30 Min
Post
4-21
4-25
4-20 0.12±3.7(a) (6.0)
4-21 13 ±3.3 (5.0)
4-21
4-21 594 ± 9.6 (6.4)
4-21 317 ±6.6 (5.1)
4-21 344 ± 7.7 (6.2)
4-23 17 ±3.4 (5.1)
4-22
4-21
4-23 26 ±4.1 (6.0)
4-22 17+4.0 (6.1)
4-21 3.5±3.7(a) (6.0)
4-21 16 + 3.8 (5.7)
4-21
4-21
4-21 -l.l+3.1(a) (5.1)
4-21 -l.l±2.8(a) (4.7)
4-21
4-21
4-22 -1.4 + 3.0(a) (4.9)
-23 ± 141 (a) (232) ND (5.0)
-23 ± 141 (a) (232) ND (4.9)
ND (6.0)
ND (5.9)
Not sampled
ND (5.0)
16 ± 141 (a) (232) ND (4.8)
16 ± 141 (a) (232) ND (4.9)
ND (5.0)
ND (4.6)
ND (4.9)
-23±141(a) (232) ND (5.0)
-23±141(a) (232) ND (5.0)
ND (5.0)
ND (5.0)
-23 ± 141 (a) (232) ND (5.0)
16 + 141 (a) (232) ND (4.8)
ND (4.8)
(a) Indicates results are less than MDC
-------
Table 6.12 Tritium Results for Water Samples Collected in April 1997 (Continued).
Collection Enriched Gamma
Sample Date Tritium Tritium Spectrometry (b)
Location 1997 pCi/L ± 2 SD (MDC) pCi/L ± 2 SD (MDC) Comments (MDC)
BaxtervUle, MS (cont.)
Well HM-2B
Well HM-3
Well HM-L
Well HM-L2
Well HM-S
WellHMH-1
Well HMH-2
Well HMH-3
Pre
lst30Min
2nd 30 Min
Post
Pre
1st 30 Min
2nd 30 Min
3rd 30 Min
Post
Pre
1st 30 Min
2nd 30 Min
3rd 30 Min
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Dup
4-21 -0.96 ± 3.0 (a) (5.0)
4-21
4-21
4-21 2.2 ± 3.2 (a) (5.2)
4-21 2.0±3.3(a) (5.3)
4-21
4-21
4-21
4-21 2.4±3.0(a) (4.9)
4-21
4-21
4-21
4-21
4-21
4-22
4-22
4-20
4-21
4-20
4-21
4-20 224 ±5.7 (4.5)
4-21 291 ±6.3 (5.1)
4-20 14 ±3. 3 (5.0)
4-21 12 ±3.3 (5.1)
4-21 14 ±3.3 (5.1)
-63 ± 140 (a)
-23 ± 141
-------
Table 6.12 Tritium Results for Water Samples Collected in April 1 997 (Continued).
Collection Enriched Gamma
Sample Date Tritium Tritium Spectrometry (b)
Location 1997 pCi/L ± 2 SD (MDC) pCi/L ± 2 SD (MDC) Comments (MDC)
Baxterville, MS
Well HMH-4
Well HMH-5
Well HMH-6
Well HMH-7
Well HMH-8
Well HMH-9
WellHMH-10
WellHMH-11
WellHMH-12
WellHMH-13
Well HMH-14
WellHMH-15
(cont.)
Pre
Post
Pre
Dup
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
4-20
4-21
4-20
4-21
4-21
4-20
4-21
4-20
4-21
4-20
4-21
4-20
4-21
4-20 113+4.6 (4.6)
4-21 157 ±5.0 (5.0)
4-20 55 ± 3.7 (4.5)
4-21 106 ±4.5 (5.0)
4-20
4-21
4-20
4-21
4-20
4-21
4-20
4-21
133 ± 143 (a)
-63 ± 140 (a)
407 ± 148
251 ± 146
877 ± 152
55 ± 142 (a)
-63 ± 140 (a)
133 ± 143 (a)
-63 ± 140 (a)
55 ± 142 (a)
-63 ± 140 (a)
-23 ± 141 (a)
-23 ± 141 (a)
-23 ± 141
-------
Table 6.12 Tritium Results for Water Samples Collected in April 1997 (Continued).
Collection Enriched Gamma
SamPle Date Tritium Tritium Spectrometry (W
location 1997 pCi/L ± 2 SD (MDC) pCi/L ± 2 SD (MDC) Comments (MDC)
Baxterville, MS (cont.)
Well HMH-16 Pre
Post
SA1-1H
SA1-2H
SA1-3H
SA1-4H
SA1-5H
SA1-6H
SA1-7H
SA3-1M
SA3-3M
SA3-4H
SA4-1M
SA5-1M
SA5-2M
SA5-3M
SA3-4H
Well HT-2C
4-20 55 ± 142 (a) (232)
4-21 55 ± 142 (a) (232)
4-23 34500 ±447 (232)
4-23 3190+191 (232)
4-23
4-23 343 ± 7.0 (5.5)
4-23 1270+163 (232)
4-23 157 ± 5.0 (4.4)
4-23 33 ± 3.7 (5.2)
4-24 9 ± 3.3 (5.2)
4-22 15 + 3.5 (5.4)
4-23 25 + 5.8 (8.8)
4-22 4.8 ± 3.4 (5.4)
4-22 15 + 4.0 (6.2)
4-22 20 ± 3.8 (5.7)
4-22 14 + 3.2 (4.8)
4-23 22 ± 4.9 (7.5)
4-23 0.30 ± 2.9 (a) (4.7)
ND
ND
ND
No Sample,
Lost in Lab
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
(4.9)
(5.0)
(5.0)
(4.9)
(5.0)
(4.9)
(4.8)
(5.0)
(4.8)
(4.9)
(3.6)
(4.6)
(4.7)
(3.1)
(5.0)
(5.0)
(a) Indicates results are less than MDC
(b) No gamma radionuclides detected above MDC
ND Non -detected, MDC for gamma represents 137Cs (pCi/L)
67
-------
Table 6. 12 Tritium Results for Water Samples Collected in April 1997 (Continued).
Collection Enriched Gamma
Sample Date Tritium Tritium Spectrometry (b)
Location 1997 pCi/L ± 2 SD (MDC) pCi/L ± 2 SD (MDC) Comments (MDC)
Baxterville, MS (cont.)
Well HT-4
Well HT-5
Columbia, MS
Dennis, Buddy
Dennis, Marvin
Well 64B City
Lumberton, MS
Anderson, Arleene
Anderson, Lee L.
Ron Boren Crawfish
Pond
Hartfield, Ray
Powell, Shannon
Rogers, Robert
Ladner, Rushing,
Debra
Saul O/A
4-24 1.6±3.2(a) (5.2)
4-24 0.59 ± 3.4 (a) (5.6)
4-22 -23 ± 141
-------
Table 6.12 Tritium Results for Water Samples Collected in April 1997 (Continued).
Collection Enriched Gamma
SamPle Date Tritium Tritium Spectrometry (b)
location 1997 pCi/L ± 2 SD (MDC) pCi/L ± 2 SD (MDC) Comments (MDC)
Lumberton, MS (cont.)
Smith, Howard Pond 4-22
Thompson, Roswell 4-21
Well 2 City 4-22
Burge, Wilbe 4-21
City Supply Purvis 4-22
Ron Boren House Well
Rain Sample IT Compound 4-22
16±141(a) (232)
-23 ±141(a) (232)
1.7±3.4
-------
Table 6.13 Sampling Locations Established at the Long Shot Site
Wells
WL-1
WL-2
GZ-1*
GZ-2
EPA-1
Surface Locations
Reed Pond
Mud Pit No. 1
Mud Pit No. 2
Mud Pit No. 3
Stream East of Long Shot
Long Shot Pond No. 1
Long Shot Pond No. 2
Long Shot Pond No. 3
pCi/L
Tritium
12
41
938
48
12
2-sigma
3
4
152
4
4
MDA
5
5
223
5
6
15
83
113
157
110
13
13
19
4
4
5
5
5
3
3
3
6
5
5
5
5
5
5
5
* Conventional analysis
70
-------
Table 6.14 Sampling Locations Established at the Milrow Site
Tundra Holes
W-2
W-3
W-4
W-5
W-6
W-7
W-8
W-9
W-10
W-ll
W-12
W-13
W-14
W-15
W-16
W-17
W-18
W-19
Surface Locations
Heart Lake
Duck Cove Creek
Clevenger Creek
pCi/L
Tritium
8
0
18
2-sigma
136
4
4
MDA
223*
6
6
Not Sampled - well dry
Not Sampled - well dry
12
0.5
3
3.5
5
5.8
Not Sampled well head under water
0.3
5.1
3.5
3.5
5.8
5.6
Not Sampled - well head under water
20
13
2.3
13
4
3
3.5
4
6
5
5.6
6
Not Sampled - well head under water
21
4
6
Not Sampled - well head under water
0.0
5.4
23
4.8
3.5
4
7.9
5.6
6
* Insufficient sample for enrichment, conventional screening only.
71
-------
Table 6.15 Sampling Locations Established at the Cannikin Site
Wells
HTH-3
Surface Locations
Cannikin Lake, north end
Cannikin Lake, south end
Ice Box Lake
Pit south of Cannikin GZ
DK-45 Lake
White Alice Creek
pCi/L
Tritium
19
2-sigma
3
MDA
5
15
13
16
9.1
14
13
3
3
4
3.4
4
4
5
5
6
5.3
6
6
Table 6.15 Sampling Locations Established to Provide Background Data.
Wells
Army Well No. 1
Army Well No. 2
Army Well No. 3
Army Well No. 4
Exploratory Hole D
Exploratory Hole E
Surface Locations
Jones Lake
Constantine Spring
Clevenger Lake
TX Site Spring
Precipitation
pCi/L
Tritium
15
9
2-sigma
5
3.2
MDA
8
5
Not Collected - well blocked
9.4
2.5
3.8
Not Collected - well blocked
Not Collected - well blocked
12
32
19
13
3
5
4
3
5
7
5
5
None Collected
72
-------
7.0 Dose Assessment
There are four sources of possible radiation
exposure to the population of Nevada, which were
monitored by EPA's offsite monitoring networks
during 1997. The pathways are:
• Background radiation due to natural sourc-
es such as cosmic radiation, natural radio-
activity in soil, and 7Be in air, and 3H in
water.
• Worldwide distributions of man-made
radioactivity, such as 90Sr in milk, 85Kr in
air, and plutonium in soil.
• Operational releases of radioactivity from
the NTS, including those from drill-back
and purging activities when they occur.
• Radioactivity that was accumulated in
migratory game animals during their
residence on the NTS.
7.1 Estimated Dose From
Nevada Test Site Activity
Data
The potential EDE to the offsite population due to
NTS activities is estimated annually. Two methods
are used to estimate the EDE to residents in the
offsite area in order to determine the community
potentially most impacted by airborne releases of
radioactivity from the NTS. In the first method,
effluent release estimates, based on monitoring
data or calculated resuspension of deposited
radioactivity, and meteorological data are used as
inputs to EPA's CAP88-PC model by Bechtel NV,
which then produces estimated EDEs. The second
method entails using data from the Offsite
Radiological Environmental Monitoring Program
(OREMP) with documented assumptions and
conversion factors to calculate the committed
effective dose equivalent (CEDE). The latter
method provides an estimate of the EDE to a
hypothetical individual continuously present
outdoors at the location of interest that includes
both NTS emissions and worldwide fallout. In
addition, a collective EDE is calculated by Bechtel
NV, the first method for the total offsite population
residing within 80 km (50 mi) of each of the NTS
emission sources. Background radiation
measurements are used to provide a comparison
with the calculated EDEs. In the absence of
detectable releases of radiation from the NTS, the
Pressurized Ion Chamber (PIC) network provides a
measurement of background gamma radiation in
the offsite area.
The extensive offsite environmental surveillance
system operated around the NTS by EPA R&IE-LV
measured no radiation exposures attributed to
recent NTS operations. However, using onsite
emission measurements, as provided by U.S.
Department of Energy (DOE) and calculated
resuspension data as input to the EPA's CAP88-PC
model, a potential effective dose equivalent (EDE)
to the maximally exposed individual (MEI) was
calculated to be 0.089 mrem (8.9 x 10'4 mSv) to a
hypothetical resident of Springdale, NV, located 58
km (36 mi) west-northwest of Control Point 1 (CP-
1), on the NTS. The calculated population dose
(collective EDE) to the approximately 32,210
residents living within 80 km (50 mi) from each of
the NTS airborne emission sources was 0.26
person-rem (2.6 x 10"3 person-Sv). Monitoring
network data indicated a 1997 exposure to the MEI
of 144 mrem (1.44 mSv) from normal background
radiation. The calculated dose to this individual
from worldwide distributions of radioactivity as
measured from surveillance networks was 0.015
mrem (1.5 x 10"4 mSv). These maximum dose
estimates, excluding background, are less than one
percent of the most restrictive standard.
Onsite source emission measurements, as
provided by DOE, are listed in Table 7.1, and
include tritium, radioactive noble gases, and
plutonium. These are estimates of releases made
at the point of origin. Meteorological data collected
by the Air Resources Laboratory Special
Operations and Research Division, (ARL/SORD)
were used by Bechtel NV, to construct wind roses
and stability arrays for the following areas:
Mercury, Area 12, Area 20, Yucca Flat, and the
Radioactive Waste Management Site (RWMS) in
Area 5. A calculation of estimated dose from NTS
effluents was performed by Bechtel NV, using
EPA's CAP88-PC model (EPA 1992). The results
of the model indicated that the hypothetical
individual with the maximum calculated dose from
airborne NTS radioactivity would reside at
Springdale, Nevada, 58 km (36 mi) west-northwest
of CP-1. The maximum dose to that individual
would have been 0.1 mrem (1 x 10"3 mSv). For
73
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comparison, data from the PIC monitoring network
indicated a 1997 dose of 144 mrem (1.44 mSv)
from background gamma radiation occurring in that
area. The population living within a radius of 80 km
(50 mi) from the airborne sources on the NTS was
estimated to be 32,210 individuals, based on 1995
population data. The collective population dose
within 80 km (50 mi) from each of these sources
was calculated to be 0.3 person-rem (3 x 10~3
person-Sv). Activity concentrations in airthat would
cause these calculated doses are much higherthan
actually detected by the offsite monitoring network.
For example, 0.088 mrem of the calculated EDE to
the MEI is due to plutonium. The annual average
plutonium concentration in air that would cause this
EDE is 3.4 x 10~17 uCi/mL This is about 20 times
the annual average plutonium in air measured in
Goldfield (nearest community) of 0.14 x 10~17
uCi/mL (Chapter 4, Table 4.3). Table 7.2
summarizes the annual contributions to the EDEs
due to 1997 NTS operations as calculated by use
of CAP88-PC and the radionuclides listed in Table
7.1.
Input data for the CAP88-PC model included
meteorological data from ARL/SORD and effluent
release data calculated from monitoring results and
from resuspension estimates. These release data
are known to be estimates and the meteorological
data are mesoscale; e.g., representative of an area
approximately 40 km (25 mi) or less around the
point of collection. However, these data are
considered sufficient for model input, primarily
because the model itself is not designed for
complex terrain such as that on and around the
NTS. Errors introduced by the use of the effluent
and meteorological data are small compared to the
errors inherent in the model. The model results are
considered overestimates of the dose to offsite
residents. This has been confirmed by comparison
with the offsite monitoring results.
7.2 Estimated Dose From
OREMP Monitoring
Network Data
Potential CEDEs to individuals may be estimated
from the concentrations of radioactivity, as
measured by the EPA monitoring networks during
1997. Actual results obtained in analysis are used;
the majority of which are less than the reported
minimum detectable concentration (MDC). No
krypton or tritium in air data were collected offsite,
so the onsite krypton for this year, and an average
value for the previous year's offsite tritium were
used. No vegetable or animal samples were
collected in 1997, so calculations for these intakes
were not done.
Data quality objectives for precision and accuracy
are, by necessity, less stringent for values near the
MDC, so confidence intervals around the input data
are broad. The concentrations of radioactivity
detected by the monitoring networks and used in
the calculation of potential CEDEs are shown in
Table 7.3.
The concentrations given in Table 7.3 are
expressed in terms of activity per unit volume.
These concentrations are converted to a dose by
using the assumptions and dose conversion factors
described below. The dose conversion factors
assume continuous presence at a fixed location
and no loss of radioactivity in storage or handling of
ingested materials.
• Adult respiration rate = 8,400 m3/yr (2.3 x 104
L/day[ICRP1975]).
• Milk intake for a 10-year old child = 164 L/yr
(ICRP1975).
• Water consumption for adult-reference man
= 2 L/day (approximately 1,900 mL/day [ICRP
1975]).
The EDE conversion factors are derived from
EPA-520/1-88-020 (Federal Guidance Report No.
11). Those used here are:
• 3H: 6.4 x 10~8 mrem/pCi (ingestion or
inhalation).
• 7Be 2.6 x 10~7 mrem/pCi
(inhalation).
• 90Sr: 1.4 x 10'4 mrem/pCi (ingestion).
• 85Kr: 1.5x10-5mrem/yr/pCi/m3
(submersion).
9 23B,239+240p...
3.7 x 10~4 mrem/pCi (ingestion).
3.1 x 10"1 mrem/pCi (inhalation).
The algorithm for the dose calculation is:
• (concentration) x (assumption in volume/unit
time) x (CEDE conversion factors) = CEDE
74
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As an example calculation, the following is the
result of breathing tritium in air concentration of 0.2
pCi/m3:
• (2 x 10 "1 pCi/m3) x (8400 m3/yr) x (6.4 x 10'8
mrem/pCi) = 1.1 x 10'" mrem/yr
However, in calculating the inhalation CEDE from
3H, the value is increased by 50 percent to account
for absorption through the skin (ICRP, 1975). The
total dose in one year, therefore, is 1.1 x 10"" x 1.5
= 1.6 x 10"4 mrem/ yr. Dose calculations from
OREMP data are summarized in Table 7.3.
The individual CEDEs, from the various pathways,
added together give a total of 0.015 mrem/yr. Total
EDEs can be calculated based on different
combinations of data. If the interest was in just one
area, for example, the concentrations from those
stations closest to that area could be substituted
into the equations used here.
In 1997, because of budget cuts and the standby
status of nuclear device testing, samples of game
animals and garden vegetables were not collected.
Also, the noble gas and tritium sampling network
was discontinued in the offsite locations, and the air
sampling network was reduced. In order to
calculate an EDE for a resident of Springdale, the
MEI from the CAP88-PC operation, it is necessary
to make some assumptions. The NTS average
krypton-85 concentration is representative of
statewide levels; tritium in air does not change
significantly from year to year; and, because
Goldfield has the nearest air samplerto Springdale,
its plutonium concentration is used to calculate the
EDE.
7.3 Dose from Background
Radiation
In addition to external radiation exposure due to
cosmic rays and gamma radiation from naturally
occurring radionuclides in soil (e.g., 40K, U, and Th
and their progeny), there is a contribution from 7Be
that is formed in the atmosphere by cosmic ray
interactions with oxygen and nitrogen. The annual
average 7Be concentration measured by the offsite
surveillance network was 0.12 pCi/m3. With a dose
conversion factor for inhalation of 2.6 x 10"7
mrem/pCi, and a breathing volume of 8,400 m3/yr,
this equates to a dose of 2.6 x 10'4 mrem as
calculated in Table 7.3. This is a negligible quantity
when compared with the PIC network
measurements that vary from 73 to 144 mR/year,
depending on location.
7.4 Summary
The offsite environmental surveillance system
operated around the NTS by EPA's R&IE-LV
detected no radiological exposures that could be
attributed to recent NTS operations, but a
calculated EDE of 0.015 mrem can be obtained, if
certain assumptions are made, as shown in Table
7.2. Calculation with the CAP88-PC model, using
estimated or calculated effluents from the NTS
during 1997, resulted in a maximum dose of 0.089
mrem (8.9 x 10"3 mSv) to a hypothetical resident of
Springdale, Nevada, 14 km (9 mi) west of the NTS
boundary. Based on monitoring network data, this
dose is calculated to be 0.005 mrem. This latter
EDE is about 5 percent of the dose obtained from
CAP88-PC calculation. This maximum dose
estimate is less than one percent of the
International Commission on Radiological
Protection (ICRP) recommendation that an annual
EDE for the general public not exceed 100 mrem/yr
(ICRP 1985). The calculated population dose
(collective EDE) to the approximately 32,210
residents living within 80 km (50 mi) of each of the
NTS airborne emission sources was 0.26
person-rem (2.6 x 10"3 person-Sv). Background
radiation yielded a CEDE of 3,064 person-rem
(30.6 person-Sv).
Data from the PIC gamma monitoring indicated a
1997 dose of 144 mrem from background gamma
radiation measured in the Springdale area. The
CEDE calculated from the monitoring networks or
the model, as discussed above, is a negligible
amount by comparison. The uncertainty (2o) for
the PIC measurement at the 144 mrem exposure
level is approximately five percent. Extrapolating to
the calculated annual exposure at Springdale,
Nevada, yields a total uncertainty of approximately
7 mrem which is greater than either of the
calculated EDEs. Because the estimated dose
from NTS activities is less than 1 mrem (the lowest
level for which Data Quality Objectives (DQOs) are
defined, as given in Chapter 10) no conclusions
can be made regarding the achieved data quality
as compared to the DQOs for this insignificant
dose.
75
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CD
Table 7.1 NTS Radionuclide Emissions -1997
Onsite Liquid Discharges
Containment
Ponds
Area 12, E Tunnel
Area 20, Well ER-20-5
Area 20, Well ER-20-6
TOTAL
Airborne Effluent Releases
Facility Name
(Airborne Releases)
Areas 3 and 9(c)
Area 5, RWMS(d)
Atlas Facility(d)
SEDAN Craterw
Other Areas'0'
TOTAL
-H
1.6 x101
3.7x10°
5.5 x101
7.5 x 10'
2.4 x 10"'
1.1 x10'1
1.4x102
14x101
Curies(a>
90 O r 137/"» o
—£L —OS
1.5x10'5 1.7x10;
1.5 x 105
1.7x 1Q-3
Curies(a)
1.5x10'
1.5xlO-6
239+240pu
0.036
0.24
0.28
(a) Multiply by 3.7 x 1010 to obtain Bq. Calculated releases from laboratory spills and losses are included in Table 7.4.
(b) In the form of tritiated water vapor, primarily HTO.
(c) Resuspension from known surface deposits.
(d) Calculated from air sampler data.
3.4 x 10'5
3.4x105
-------
Table 7.2 Summary of Effective Dose Equivalents from NTS Operations -1997
Dose
Location
NESHAP(C)
Standard
Percentage
of NESHAP
Background
Percentage of
Background
Maximum EDE at
NTS Boundary'8'
0.12 mrem
(1.2x10'3mSv)
Site boundary 40 km
WNW of NTS CP-1
10 mrem peryr
(0.1 mSv peryr)
1.2
144 mrem
(1.44 mSv)
0.08
Maximum EDE to
an Individual^
0.11 mrem
(1.1 x10'3mSv)
Springdale, NV 58 km
WNW of NTS CP-1
10 mrem peryr
(0.1 mSv per yr)
0.89
144 mrem
(1.44mSv)
0.06
Collective EDE to
Population within 80 km
of the NTS Sources
0.34 person-rem
(3.4 x 10"3person-Sv)
32,210 people within
80 km of NTS Sources
3064 person-rem
(30.6 person-Sv)
0.008
(a) The maximum boundary dose is to a hypothetical Individual who remains in the open continuously during
the year at the NTS boundary located 40 km (25 mi) west-northwest from CP-1.
(b) The maximum individual dose is to a person outside the NTS boundary at a residence where the highest
dose-rate occurs as calculated by CAP88-PC (Version 1.0) using NTS effluents listed in Table 6.1 and
assuming all tritiated water input to the Area 12 containment ponds was evaporated.
(c) National Emission Standards for Hazardous Air Pollutants.
Table 7.3 Monitoring Networks Data used in Dose Calculations -1997
Medium Radionuclide Concentration MrenrAYear Comment
Meat
Milk
Drinking Water
Vegetables
Air
9oSr
3H
3H
3H
7Be
85Kr
239+240 p..
TOTAL (Air = 4.2x
(a) Units are pCi/L
(hi Units are oCi/m
10'3, Liquids = 1.'
and Bq/L.
3 and Ba/m3.
0.7 (a)
(0.023)
0
18(a)
(0.07)
0.2 (b)
(0.007)
0.12*'
(0.0044)
27.0 (b)
(0.93)
1.3x 10-6(b)
(4.8 x 1Q-8)
1 x10'3)= 1.5x
1.1 x10'2
0
8.4 x10'5
1.6x10'4
2.6 x10"4
4.1 x1Q-4
3.4 x10'3
10"2 mrem/yr
Not collected this year
Concentration is the average
of all network results
Not Analyzed
Concentration is the average
from wells in the area
Not collected this year
Concentration is average
network result (1994 data)
Annual average for
Goldfield, Nevada
NTS network average
Annual average for Goldfield
77
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Table 7.4 Radionuclide Emissions on the NTS - 1997(a)
Radionuclide Half-life (year) Quantity Released (Ci)(b)
Airborne Releases:
3H 12.35 (c)140
239+24opu 24065. (c)0.28
Containment Ponds:
3H 12.35 (d)20
238Pu 87.743 1.5 X1CT6
239+240Pu 24065. 3.4 x10-5
90Sr 29. 1.5 x10-6
137Cs 30.17 1.7 x10'3
(a) Assumes worst-case point and diffuse source releases.
(b) Multiply by 37 to obtain Gbq.
(c) Includes calculated data from air sampling results, postulated loss of laboratory standards, and
calculated resuspension of surface deposits.
(d) This amount is assumed to evaporate to become an airborne release.
78
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8.0 Training Program
Proper and efficient performance of radiological
health functions by qualified personnel is required
to ensure protection from radiological hazards. The
purpose of the training program is to provide well-
trained, qualified personnel to safely and efficiently
perform their assigned duties at a predetermined
level of expertise.
8.1 Emergency Response
Training Program
Emergency response training is essential to
maintain a cadre of personnel who are qualified to
perform approved radiological health and field
monitoring practices. The training program
includes: tracking training requirements;
maintaining training records; developing in-house
training; and documenting personnel qualifications
and accomplishments. Systematic determination of
job functions promotes consistent training activities
and develops or improves knowledge, skills and
abilities that can be utilized in the work
environment.
In 1997, the EPA ORIA/R&IE National Laboratory
in Las Vegas (R&IE-LV) supported DOE by
instructing or co-instructing radiological training
courses for state and local emergency responders
nationwide. One such program is the
Transportation Emergency Training for Radiological
Assistance (TETRA); another is the Federal
Radiological Monitoring and Assessment Center
(FRMAC). TETRA training includes railway
simulated accidents known as TETRA/RAIL; an
intensive course in radiological emergency
response called Radiological Emergency
Operations (REO) at the Nevada Test Site (NTS);
and Radiological Emergency Response for Local
Responders (RETLR). FRMAC training is given at
drills and exercises in the form of classroom and
hands-on training followed by a drill or exercise
involving field monitoring practical experience
simulating an actual emergency response scenario.
In addition, R&IE-LV supports other emergency
response needs. Several personnel are trained in
the Radiological Assistance Program (RAP).
Radiation field monitors are required to complete
an initial 40 hr. Hazardous Waste Site Operations
and Emergency Response (HAZWOPER) (29 CFR
1910.120) with 8 hour annual refreshers course
and complete a RAP training class, plus maintain
respirator fit qualification to be on the RAP team.
Table 8.1 Co-instructed Training Courses -1997
Course Name Location Dates
REO NTS, NV February 3 - 6
REO NTS, NV March 3 - 6
EPA Co-instructors Provided
(9)
(9)
79
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Table 8.2 Emergency Response Classes Attended -1997
Course Name
8-hr. HAZWOPER
Refresher
FRMAC/Emergency
Response Readiness
Training - Digit Pace II
and Cassini
Digit Pace Il/Cassini
follow-up training
Digit Pace II
Cassini Field Team
Leader Training
Location
Las Vegas, NV
Las Vegas, NV
Las Vegas, NV
Kirtland AFB
Albuquerque, NM
Las Vegas, NV
Dates
On an availability basis; self-paced,
Computer-based training with exam.
April 21
April 28
May 19-22
August 25
Radiation Monitoring
Support Pre/Post Cassini
Launch
NASA, Cape Canaveral, FL October 13-17
8.2 Hazardous Materials Spill
Center Support
The Hazardous Materials Spill Center (formerly the
Liquified Gaseous Fuels Spill Test Facility) is
located at Frenchman Flat in Area 5 of the Nevada
Test Site. Originally completed in 1986, the
HAZMAT Spill Center was designed for safety
research on the handling, shipping, and storage of
liquified gaseous fuels and other hazardous liquids.
Early research was aimed at understanding the
physics of spill dispersion, spill effects mitigation,
and clean-up technology. More recently the Center
has been used by industry for conducting tests on
protective clothing, to give hands-on spill mitigation
experience to industrial emergency response
workers, and to test a variety of sensors designed
to detect airborne hazardous materials.
Organizations conducting tests range from the
Federal government, and corporations, to foreign
governments working in co-operation with the U.S.
Government. The facility is completely supported
by user fees paid by the organizations conducting
the tests.
The HAZMAT Spill Center has the advantages of
being located far from populated areas, inside of a
secure facility, and subjected to well characterized
and predictable meteorological conditions. The
EPA provides a chemist to participate in meetings
of the Advisory Panel which reviews and approves
all programs prior to testing and maintains a
readiness for monitoring emissions at the boundary
of the NTS. Recent spills have involved such small
amounts of material that monitoring at the boundary
was not justified. Dispersion models show that
even a catastrophic release of the entire supply of
the test materials would not be measurable at the
test site boundary.
80
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9.0 Sample Analysis Procedures
The procedures for analyzing samples collected for this report are described in Radiochemical and Analytical
Procedures for Analysis of Environmental Samples (Johns, 1979) and are summarized below and (see Table
6.2 page 52). These include gamma analysis, gross beta on air filters, strontium, tritium, and plutonium
analyses. These procedures outline standard methods used to perform given analytical procedures.
Table 9.1 Summary of Analytical Procedures
Type of Analytical Counting Analytical
Analysis Equipment Period (min) Procedures
HpGe
Gamma"
Gross alpha
and beta on
air filters
es.9osr
3H
HpGe 60 - Air charcoal
detector- cartridges and
calibrated at individual air
0.5 keV/ filters.
channel 1 00 - milk, water,
(0.04 to 2 suspended solids.
meV range)
individual
detector
efficiencies
ranging from
15 to 35%.
Low-level end 30
windows, gas
flow pro-
portional
counter with a
5-cm diameter
window.
Low 50
background
thin-window,
gas-flow,
proportional
counter.
Automatic 1 50 - 300
liquid
scintillation
counter
with output
printer.
Radionuclide concen-
tration quantified from
gamma spectral data
by online computer
program.
Samples are
counted after decay
of naturally occurring
radionuclides.
Chemical separation
by ion exchange.
Separated sample
counted succes-
sively; activity calcu-
lated by simulta-
neous solution of
equations.
Sample prepared by
distillation.
Sample Approximate
Size Detection Limif'0
1.0L&3.5L Cs-1 37, routine
routine liquids. liquids; 5 x 10"9 uCi/mL
560 m3 - low- (1 .8 x 1 Q-1 Bq/L). Also
volume air see Table 6.3, page 52.
filters.
1 0,000 m3 - Low-volume air filters:
high-volume air 5x1 0"'4 uCi/mL
filters. (LSxIO-'Bq/m3),
High-volume air filters;
5x10-16uCi/mL
(1.8x10-5Bq/m3).
560 m3 alpha: 8.0 x 10'16 uCi/mL
(3.0x10'5Bq/m3)
beta: 2.5 x 10'15 uCi/mL
(9.25x10'5Bq/m3)
1 .0 L - milk 89Sr: 5 x 1 0'9 uCi/mL
or water. (1.85x10'1 Bq/L)
""Sri 2x10'9uCi/mL
(7.4 X10'2 Bq/L)
4 to 1 0 mL for 300 to 700 pCi/mL
water. (ir26Bq/L)c
Continued
81
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Table 9.1 (Summary of Analytical Procedures, cont.)
Type of
Analysis
3H Enrichment
(LTHMP
samples)
zswawMOpu
Analytical Counting
Equipment Period (min)
Automatic 300
liquid
scintillation
counter
with output
printer.
Alpha 1 ,000
spectrometer
with silicon
surface
barrier
detectors
operated in
vacuum
chambers.
Analytical
Procedures
Sample concen-
trated by electrolysis
followed by
distillation.
Water sample, or
acid-digested filter
separated by ion
exchange and electro-
plated on stainless
steel planchet.
Sample
Size
250 mL -
water.
1 .0 L - water.
5,000 to
10,000 m3 -air.
Approximate
Detection Limit"
IQxIO-'pCi/mL
(3.7x10'' Bq/L)
23flPu: 0.08x10'9
uCi/mL (2.9 x 10"3
Bq/L).
239+240 pu- Q Q4
x10-9uCi/mL(1.5x
10-3 Bq/L) -water.
23aPu: 5x10'17
(1.9X10"6
239+240 py.
10x10'17|jCi/mL-
air filters.
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 (DOE81).
Gamma spectrometry using a high purity intrinsic germanium (HpGe) detector.
Depending on sample type.
82
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10.0 Quality Assurance
10.1 Policy
One of the major goals of the EPA is to ensure that
all agency decisions which are dependent on
environmental data are supported by data of known
quality. EPA Order 5360.1, "Policy and Program
Requirements to Implement the Quality Assurance
Program" requires participation in a QA Program by
all EPA organizational units involved in
environmental data collection. This policy further
requires participation in a centrally managed QA
Program by all EPA Laboratories, Program Offices,
Regional Offices, and those monitoring and mea-
surement efforts supported or mandated through
contracts, regulations, or other formalized agree-
ments.
The QA policies and requirements of EPA's R&IE-
LV are summarized in the Quality Management
Plan (R&IE, 1997). Policies and requirements
specific to the OREMP are documented in the
Quality Assurance Program Plan for the Nuclear
Radiation Assessment Division Offsite Radiation
Safety Program (EPA, 1992, under revision). The
requirements of these documents establish a
framework for consistency in the continuing appli-
cation of quality assurance standards and
procedures in support of the OREMP.
Administrative and technical procedures based on
these QA requirements are maintained in
appropriate manuals or are described in SOPs. It
is R&IE policy that personnel adhere to the require-
ments of the QA Plan and all SOPs applicable to
their duties to ensure that all environmental radia-
tion monitoring data collected by R&IE in support of
the OREMP are of adequate quality and properly
documented for use by the DOE, EPA, and other
interested parties.
10.2 Data Quality Objectives
Data quality objectives (DQOs) are statements of
the quality of data a decision maker needs to
ensure that a decision based on that data is
defensible. Data quality objectives are defined in
terms of representativeness, comparability, com-
pleteness, precision, and accuracy. Representa-
tiveness and comparability are generally qualitative
assessments while completeness, precision, and
accuracy may be quantitatively assessed. In the
OREMP, representativeness, comparability, and
completeness objectives are defined for each
monitoring network. Precision and accuracy are
defined for each analysis type or radionuclide.
Achieved data quality is monitored continuously
through internal QC checks and procedures. In
addition to the internal QC procedures, R&IE
participates in external intercomparison programs.
One such intercomparison program is managed
and operated by a group within EPA/CRD-LV.
These external performance audits are conducted
as described in and according to the schedule con-
tained in "Environmental Radioactivity Laboratory
Intercomparison Studies Program" (EPA, 1992a).
The analytical laboratory also participates in the
DOE Environmental Measurements Laboratory
(EML) Quality Assurance Program in which real or
synthetic environmental samples that have been
prepared and thoroughly analyzed are distributed to
participating laboratories. The R&IE laboratory also
began participation in the DOE Mixed Analyte
Performance Evaluation Program (MAPEP) during
1996. External Dosimetry is accredited every two
years. In 1996 the program was accredited under
the Department of Energy Accreditation Program
(DOELAP). Accreditation includes performance
testing as well as an on-site assessment. The
R&IE External Dosimetry Program is currently
seeking National Voluntary Laboratory
Accreditation Program (NVLAP) accreditation,
which will also include performance testing and an
on-site assessment.
10.2.1 Representativeness, Compa-
rability, and Completeness
Objectives
Representativeness is defined as "the degree to
which the data accurately and precisely represent
a characteristic of a parameter, variation of a
property, a process characteristic, or an operation
condition" (Stanley and Verner, 1985). In the
OREMP, representativeness may be considered to
be the degree to which the collected samples
represent the radionuclide activity concentrations in
the offsite environment. Collection of samples
representative of pathways to human exposure as
well as direct measurement of offsite resident
exposure through the TLD monitoring programs
provides assurance of the representativeness of
the calculated exposures.
83
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Comparability is defined as "the confidence with
which one data set can be compared to another"
(Stanley and Verner, 1985). Comparability of data
is assured by use of SOPs for sample collection,
handling, and analysis; use of standard reporting
units; and use of standardized procedures for data
analysis and interpretation. In addition, another
aspect of comparability is examined through long-
term comparison and trend analysis of various
radionuclide activity concentrations, and TLD, and
PIC data. Use of SOPs, maintained under a
document control system, is an important compo-
nent of comparability, ensuring that all personnel
conform to a unified, consistent set of procedures.
Completeness is defined as "a measure of the
amount of data collected from a measurement
process compared to the amount that was expect-
ed to be obtained under the conditions of measure-
ment" (Stanley and Verner, 1985). Data may be
lost due to instrument malfunction, sample destruc-
tion, loss in shipping or analysis, analytical error, or
unavailability of samples. Additional data values
may be deleted due to unacceptable precision,
accuracy, or detection limit or as the result of
application of statistical outlier tests. The com-
pleteness objective for all networks except the
LTHMP is 90%. The completeness objective for
the LTHMP is 80%; a lower objective has been
established because dry wells oraccess restrictions
occasionally preclude sample collection.
10.2.2 Precision and Accuracy
Objectives of Radioanalytical
Analyses
Measurements of sample volumes should be
accurate to ± 5% for aqueous samples (water and
milk) and to ± 10% for air and soil samples. The
sensitivity of radiochemical and gamma spectro-
metric analyses must allow no more than a 5% risk
of either a false negative or false positive value.
Precision to a 95% confidence interval, monitored
through analysis of duplicate and blind samples,
must be within ±10% for activities greater than 10
times the minimum detectable concentration (MDC)
and ± 30% for activities greater than the MDC but
less than 10 times the MDC. There are no preci-
sion requirements for activity concentrations below
the MDC, which by definition cannot be distin-
guished from background at the 95% confidence
level. Control limits for accuracy, monitored with
matrix spike samples, are required to be no greater
than ± 20% for all gross alpha, gross beta, and
gamma spectrometric analyses, depending upon
the media type.
At concentrations greater than 10 times the MDC,
precision is required to be within ± 10% for:
• Conventional Tritium Analyses
• Uranium
• Thorium (all media)
• Strontium
and within ± 20% for:
• Enriched Tritium Analyses
• Strontium (in milk)
• Plutonium.
At concentrations less than 10 times the MDC, both
precision and accuracy are expressed in absolute
units, not to exceed 30% of the MDC for all
analyses and all media types.
10.2.3 Quality of Dose Estimates
The allowable uncertainty of the effective dose
equivalent to any human receptor is ± 0.1 mrem
annually. This uncertainty objective is based solely
upon the precision and accuracy of the data
produced from the surveillance networks and
parameter uncertainties does not apply to
uncertainties in the model used, effluent release
data received from DOE, or dose conversion
factors. Generally, effective dose equivalents must
have an accuracy (bias) of no greater than 50% for
annual doses greater than or equal to 1 mrem but
less than 5 mrem and no greater than 10% for
annual doses greater than or equal to 5 mrem.
10.3 Data Validation
Data validation is defined as "A systematic process
for reviewing a body of data against a set of criteria
to provide assurance that the data are adequate for
their intended use." Data validation consists of
data editing, screening, checking, auditing,
verification, certification, and review (Stanley et al;
1983). Data validation procedures are documented
in SOPs. All data are reviewed and checked at
various steps in the collection, analysis, and
reporting processes.
The first level of data review consists of sample
tracking; e.g., that all samples planned to be
collected are collected or reasons for noncollection
are documented; that all collected samples are
delivered to Sample Control and are entered into
84
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the appropriate data base management system;
and that all entered information is accurate. Next,
analytical data are reviewed by the analyst and by
the laboratory supervisor. Checks at this stage
include verifying that all samples received from
Sample Control have been analyzed or reasons for
nonanalysis have been documented; that data are
"reasonable" (e.g., within expected range), and that
instrumentation operational checks indicate the
analysis instrument is within permissible tolerances.
Discrepancies indicating collection instrument
malfunction are reported to the R&IE Center for
Environmental Restoration and Emergency
Response (CERMER). Analytical discrepancies
are resolved; individual samples or sample batches
may be reanalyzed if required.
Raw data are reviewed by a designated media
expert. A number of checks are made at this level,
including:
1. Completeness - all samples scheduled to
be collected have, in fact, been collected
and analyzed or the data base contains
documentation explaining the reasons for
noncollection or nonanalysis.
2. Transcription errors - checks are made of
all manually entered information to ensure
that the information contained in the data
base is accurate.
3. Quality control data - field and analytical
duplicate, audit sample, and matrix blank
data are checked to ensure that the col-
lection and analytical processes are within
specified QC tolerances.
4. Analysis schedules - lists of samples
awaiting analysis are generated and
checked against normal analysis sched-
ules to identify backlogs in analysis or
data entry.
5. Unidentified malfunctions - sample results
and diagnostic graphics of sample results
are reviewed for reasonableness. Condi-
tions indicative of instrument malfunction
are reported to CERMER/CRQA.
Once the data base has been validated, the data
are compared to the DQOs. Completeness,
accuracy, and precision statistics are calculated.
The achieved quality of the data is reported at least
annually. If data fail to meet one or more of the
established DQOs, the data may still be used in
data analysis; however, the data and any inter-
pretive results are to be qualified.
All sample results exceeding the natural back-
ground activity range are investigated. If data are
found to be associated with a non-environmental
condition, such as a check of the instrument using
a calibration source, the data are flagged and are
not included in calculations. Only data verified to
be associated with a non-environmental condition
are flagged; all other data are used in calculation of
averages and other statistics, even if the condition
is traced to a source other than the NTS (for
example, higher-than-normal activities were ob-
served for several radionuclides following the
Chernobyl accident). When activities exceeding
the expected range are observed for one network,
the data for the other networks at the same location
are checked. For example, higher-than-normal-
range PIC values are compared to data obtained by
the air or TLD samplers at the same location.
Data are also compared to previous years' data for
the same location using trend analysis techniques.
Other statistical procedures may be employed as
warranted to permit interpretation of current data as
compared to past data. Trend analysis is made
possible due to the length of the sampling history,
which in some cases is 30 years or longer.
Data from the offsite networks are used, along with
NTS source emission estimates prepared by DOE,
to calculate or estimate annual committed effective
dose equivalents to offsite residents. Surveillance
network data are the primary tools for the dose
calculations. Additionally, EPA'sCAP88-PC model
(EPA, 1992) is used with local meteorological data
to predict doses to offsite residents from NTS
source term estimates. An assessment of the
uncertainty of the dose estimate is made and
reported with the estimate.
10.4 Quality Assessment Of 1997
Data
Data quality assessment is associated with the
regular QA and QC practices within the radio-
analytical laboratory. The analytical QC plan,
documented in SOPs, describes specific proce-
dures used to demonstrate that data are within
prescribed requirements for accuracy and preci-
sion. Duplicate samples are collected or prepared
and analyzed in the exact manner as the regular
samples for that particular type of analysis. Data
obtained from duplicate analyses are used for
determining the degree of precision for each
85
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Table 10.1 Data Completeness of Offsite Radiological Safety Program Networks
Network
LTHMP(a)
Low-volume Air
High-volume Air
Milk Surveillance
PIC
Environmental TLD
Personnel TLD
Number of
Sampling
Locations
381
20
6
10
26
-------
goats that can provide milk only when the animal is
lactating.
One hundred percent of the total possible number
of samples were collected from ten locations (see
Figure 5.1). Annual means for these locations,
individually, cannot be considered to be represent-
ative of the year. However, milk collected in July is
representative of cows grazing on pasture or fed
green chop which represent the typical food chain
for those areas. The David Hafen Dairy, in Ivins,
UT was sold and Frances Jones, Inyokern, CA,
moved. Both were deleted from the MSN. The
Bunker Dairy, Bunkerville, NV, was added to the
list.
The achieved completeness of over 93 percent for
the PIC Network exceeded the DQO of 90 percent.
This completeness value represents satellite
telemetry data and magnetic tapes or card media,
which is used for reporting purposes. Gaps in the
satellite transmissions are filled by data from the
magnetic tape or card media. The redundant data
systems used in the PIC Network (i.e., magnetic
tape or card data acquisition systems) are
responsible for high rates of recovery of the
collected data, and are stored electronically for
reference.
10.4.2 Precision
Precision is monitored through analysis of duplicate
samples. Field duplicates (i.e., a second sample
collected at the same place and time and under the
same conditions as the routine sample) are
collected in the ASN, LTHMP, and MSN. For the
ASN, a duplicate sampler is collocated with the
routine sampler at randomly selected sites for a
period of three months to provide the field
duplicate. A total of two samplers are used for low
volume sample duplicates and one sampler is used
for a duplicate high volume sample. The duplicate
samplers are moved to randomly selected sampling
sites throughout the year. Approximately ten
percent of samples submitted to the laboratory are
analyzed twice for intralaboratory comparison
whenever possible. In lieu of field duplicates,
precision for the PICs is determined by the variance
of measurements over a specific time interval when
only background activities are being measured.
Precision may also be determined from repeated
analyses of routine or laboratory spiked samples.
The spiked QC samples are generally not blind to
the analyst; i.e., the analyst both recognizes the
sample as a QC sample and knows the expected
(theoretical) activity of the sample.
Precision is expressed as percent relative standard
deviation (%RSD), also known as coefficient of
variation, and is calculated by:
mean
The precision or %RSD (also called Coefficient of
Variation) is not reported for duplicate pairs in
which one or both results are less than the MDC of
the analysis. For most analyses, the Measurement
Quality Objectives (MQOs) for precision are defined
for two ranges: values greater than or equal to the
MDC but less than ten times the MDC and values
equal to or greater than ten times the MDC. The
%RSDs is partially dependent on statistical
counting uncertainty so it is expected to be more
variable for duplicate analyses of samples with low
activities.
From duplicate samples collected and analyzed
throughout the year, the %RSD was calculated for
various types of analyses and sampling media.
The results of these calculations are shown in
Table 10.2. Samples not meeting the precision
MQO were low activity, air particulate samples in
which 7Be was detected. The precision data for all
other analyses were well within their respective
MQOs. The R&IE data presented in Table 10.2
includes only those duplicate pairs that exceeded
the minimum detectable concentration (MDC).
One hundred forty-five low volume duplicate pairs
were analyzed for gross alpha and gross beta.
Field duplicates account for sixty-nine of the
samples and ninety-two were laboratory duplicates.
Eighty-four duplicate pairs exceeded the analysis
MDC for gross alpha. Twenty-six of these were
field duplicates and fifty-eight were laboratory
duplicates. Of the field duplicates, ten of the
twenty-six exceeded the MQO of 30 percent for
samples greater than MDC but less than ten times
MDC. One of the field duplicate samples exceeded
ten times the MDC and the RSD for that sample
was zero percent. Of the fifty-eight laboratory
duplicates, nineteen exceeded the MQO of thirty
percent. None of the laboratory duplicates were
greater than ten times the MDC. Sixty-seven of the
sixty-nine field duplicates exceeded the analysis
MDC for gross beta. Of these, three were greater
than ten times the MDC. The average RSD for the
pairs greater than ten times MDC was 13.2 percent,
exceeding the MQO of 10 percent for samples
87
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Table 10.2 Precision Estimates from Duplicate Sampling, 1997
Analysis Type
Gross Alpha
Gross Beta
Gamma Spectroscopy (low-vol 7Be)
Gamma Spectrometry (hi-vol 7Be)
Tritium in Water (enriched)
Tritium in Water (unenriched)
Number of duplicate
Analysis > MDC
84
145
14
11
12
2
Estimated Precision,
%RSD
28.5
18.0
36.2
46.8
7.9
26.2
greater than ten times MDC. All three samples had
RSDs of less than 15 percent.
The average RSD for the sixty-four pairs greater
than MDC but less than ten times MDC was 19.9
percent, well below the MQO of thirty percent for
the analysis.
Ten of the sixty-four samples exceeded the MQO.
Of ninety-two laboratory duplicate pairs, five were
greater than ten times the MDC. The average RSD
for these five samples was 3.5 percent with all
samples less than the MQO of 10 percent. Eighty-
four samples were greater than the MDC but less
than ten times MDC for the analysis. The average
RSD for this group of samples was 15.5 percent,
well below the MQO of 30 percent. Eight of the
samples exceeded the MQO value. Beryllium 7
(7Be) was detectable on 25 low volume duplicate
pairs. Eleven were field duplicates and 14 were
laboratory duplicates. The average RSD of 31.4
percent is above the precision MQO of 30 percent
for samples above MDC and less than ten times
MDC. Of the eleven field duplicates, the average
RSD was 29.8 percent which meets the MQO. The
average RSD forthe laboratory duplicates was 32.7
percent. Eight duplicate pairs from the field
samples and 11 of the duplicate pairs from the
laboratory samples were less than the MQO of 30
percent. High volume duplicate pairs where 7Be
was detected did not meet the MQO. The average
of 11 samples was 46.8 percent. Four of the
eleven samples met the MQO of 30 percent.
Forty-two duplicate pairs were analyzed for tritium
using the unenriched method. Of the 42 samples
analyzed, two were above the MDC for the
analysis. The average RSD for these two samples
was 26.2 percent which meets the MQO for this
type of analysis. Twenty-five samples were
analyzed for tritium using the enrichment method.
Five of the duplicate pairs were above ten times
MDC for the analysis with an average RSD of 7.1
percent, within the MQO of 10 percent for the
analysis. Seven duplicate pairs were greater than
MDC and less than ten times MDC, with RSD of 8.6
percent which is well within the MQO of 20 percent
for this type of analysis.
10.4.3 Accuracy
The accuracy of all analyses is controlled through
the use of NIST-traceable standards for instrument
calibrations. Internal checks of instrument
accuracy may be periodically performed, using
spiked matrix samples. These internal QC
procedures are the only control of accuracy for
Pressurized Ion Chambers. For spectroscopic and
radiochemical analyses, an independent
measurement of accuracy is provided by
participation in intercomparison studies using
samples of known activities. The EPA R&IE-LV
Radioanalysis Laboratory participates in three such
intercomparison studies.
In the EPA CRD/RADQA Intercomparison Study
program, samples of known activities of selected
radionuclides are sent to participating laboratories
on a set schedule throughout the year. Water, milk,
and air filters are used as the matrices for these
samples. Results from all participating laboratories
are compiled and statistics computed comparing
each laboratory's results to the known value and to
the mean of all laboratories. The comparison to the
known value provides an independent assessment
of accuracy for each participating laboratory.
Table 10.3 presents accuracy (referred to therein
as Percent Bias) results for these intercomparison
studies. Comparison of results among all partici-
pating laboratories provides a measure of compa-
88
-------
rability, discussed in Section 10.4.4. Approximately
70 to 290 laboratories participate in any given
intercomparison study. Accuracy, as percent
difference or percent bias is calculated by:
( C C ~\
%BIAS = -H *
100
Where:
%BIAS = Percent bias
Cm = Measured Sample Activity
Ca = Known Sample Activity
The other intercomparison studies in which the
EPA R&IE-LV Radioanalysis Laboratory
participates are the semiannual DOE QA Program
conducted by EML in New York, NY. and the DOE
Mixed Analyte Performance Evaluation Program
(MAPEP). Approximately 20 laboratories
participate in the EML performance evaluation
program. The MAPEP program evaluates the
performance of approximately forty laboratories.
Sample matrices for both of these programs include
water, air filters, vegetation, and soil. Results for
these performance audit samples are given in
Tables 10.5 and 10.6.
In addition to use of irradiated control samples in
the processing of TLDs, DOELAP and NVLAP both
monitor accuracy as part of their accreditation
program. As with the intercomparison studies,
samples of known activity are submitted as single
blind samples. The designation "single blind"
indicates the analyst recognizes the sample as
being other than a routine sample, but does not
know the concentration or activity contained in the
sample. Individual results are not provided to the
participant laboratories by DOELAP or NVLAP;
issuance of the accreditation certificate indicates
that acceptable accuracy reproducibility has been
achieved as part of the performance testing
process and that an onsite independent review has
indicated conformance with established
accreditation standards.
10.4.4 Comparability
The EPA Performance Evaluation Program pro-
vides results to each laboratory participating in
each study that includes a grand average for all
values, excluding outliers.
A normalized deviation statistic compares each
laboratory's result (mean of three replicates) to the
known value and to the grand average. If the value
of this statistic (in multiples of standard normal
deviate, unitless) lies between control limits of -3
and +3, the accuracy (deviation from known value)
or comparability (deviation from grand average) is
within normal statistical variation. Table 10.4
displays data from the 1997 intercomparison
studies for all variables measured. There were no
instances in which the EPA R&IE-LV Radioanalysis
Laboratory results deviated from the grand average
by more than three standard normal deviate units
during 1997. This indicates acceptable
comparability of the Radioanalysis Laboratory with
the 70 to 290 laboratories participating in the EPA
Intercomparison Study Program.
10.4.5 Representativeness
Representativeness cannot be evaluated quantita-
tively. Rather, it is a qualitative assessment of the
ability of the sample to model the objectives of the
program. The primary objective of the OREMP is
to protect the health and safety of the offsite resi-
dents. Therefore, the DQO of representativeness
is met if the samples are representative of the
radiation exposure of the resident population.
Monitoring stations are located in population
centers. Siting criteria specific to radiation sensors
are not available for many of the instruments used.
Existing siting criteria developed forother pollutants
are applied to the OREMP sensors as available.
For example, siting criteria for the placement of air
sampler inlets are contained in Prevention of
Significant Deterioration guidance documents
(EPA, 1976). Inlets for the air samplers at the
OREMP stations have been evaluated against
these criteria and, in most cases, meet the siting
requirements. Guidance or requirements for
handling, shipping, and storage of radioactivity
samples are followed in program operations and
documented in SOPs. Standard analytical method-
ology is used and guidance on the holding times for
samples, sample processing, and results
calculations are followed and documented in SOPs.
In the LTHMP, the primary objectives are protection
of drinking water supplies and monitoring of any
potential cavity migration. Sampling locations are
primary "targets of opportunity", i.e., the sampling
locations are primarily wells developed for
purposes other than radioactivity monitoring.
Guidance or requirements developed for Compre-
hensive Environmental Response, Compensation,
and Liability Act and Resource Conservation
Recovery Act regarding the number and location of
monitoring wells have not been applied to the
89
-------
LTHMP sampling sites. In spite of these limitations,
the samples are representative of the first objective,
protection of drinking water supplies. At all of the
LTHMP monitoring areas, on and around the NTS,
all potentially impacted drinking water supplies are
monitored, as are many supply sources with
virtually
no potential to be impacted by radioactivity
resulting from past or present nuclear weapons
testing. The sampling network at some locations is
not optimal for achieving the second objective,
monitoring of any migration of radionuclides from
the test cavities. An evaluation conducted by DRI
describes, in detail, the monitoring locations for
each LTHMP location and the strengths and
weaknesses of each monitoring network (Chapman
and Hokett, 1991). Corrective actions are
dependent upon DOE funding of new wells. This
evaluation is cited in the discussion of the LTHMP
data in Section 6.
90
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Table 10.3 Accuracy of Analysis from RADQA Performance Evaluation Study, 1997
Known Value EPA Average Percent
Nuclide Month (pCi/L) (pCi/U Bias
Water Performance Evaluation Studies
Alpha Jan 5.2 5.9 13.5
Alpha Apr 48 49.3 2.7
Alpha Jul 3.1 5.0 61.3
Alpha Oct 14.7 18.5 25.9
Alpha Oct 49.9 48.6 -2.6
Beta Jan 14.7 16.4 11.6
Beta Apr 102.1 101.6 -0.5
Beta Jul 15.1 17.4 15.2
Beta Oct 48.9 53.4 9.2
Beta Oct 143.4 145.7 1.6
3H Mar 7900 7590.3 -3.6
3H Aug 11011 11013 0.0
60Co Jun 18 18.3 1.7
60Co Nov 27 27 0
60Co Apr 21 21 0
60Co Oct 10 10 0
65Zn Jun 100 104 4
65Zn Nov 75 77.3 3.1
89Sr Jan 12 6.3 -47.5
90Sr Jul 44 39 -11.4
90Sr Jan 25 25 0
90Sr Jul 16 14.3 -10.6
131I Feb 86 88.7 3.1
131I Sep 10 10 0
133Ba Jun 25 24.3 -2.8
133Ba Nov 99 95.7 -3.3
134Cs Jun 22 20 -9.1
134Cs Nov 10 10 0
134Cs Apr 31 27.3 -11.9
137Cs Oct 41 36.3 -11.5
137Cs Jun 49 49.7 1.4
137Cs Apr 22 21.3 -3.2
137Cs Oct 34 34 0
U(Nat) Feb 27 26.2 -3.0
U(Nat) Jun 40.3 39.6 -1.7
U(Nat) Sep 5.1 5 -2
91
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Table 10.4 Comparability of Analysis from RADQA Performance Evaluation Study, 1997
Nuclide Month
Known
Value
(pCi/U
EPA
Average
fpCi/Ll
Grand
Average
(pCi/U
Expected
Precision
Normalized
Dev. of EPA
Average from
Grand Average
Normalized
Dev. of EPA
Average from
Known Value
Water Performance Evaluation Studies
Alpha
Alpha
Alpha
Alpha
Alpha
Beta
Beta
Beta
Beta
Beta
3H
3H
60Co
60Co
60Co
60Co
65Zn
65Zn
89Sr
89Sr
89Sr
89Sr
90Sr
90Sr
90Sr
90Sr
131|
131 1
133Ba
133Ba
134Cs
134Cs
134Cs
134Cs
137Cs
137Cs
137Cs
137Cs
y(Nat)
y(Nal)
y(Nat)
Jan
Jul
Oc
Apr
Oct
Jan
Jul
Oct
Apr
Oct
Mar
Aug
Jun
Nov
Apr
Oct
Jun
Nov
Jan
Jul
Apr
Oct
Jan
Jul
Apr
Oct
Feb
Sep
Jun
Nov
Jun
Nov
Apr
Oct
Jun
Nov
Apr
Oct
Feb
Jun
Sep
5.2
3.1
14.7
48
49.9
14.7
15.1
48.9
102.1
143.4
7900
11011
18
27
21
10
100
75
12
44
24
143.4
25
16
13
22
86
10
25
99
22
10
31
41
49
74
22
34
27
40.3
5.1
5.9
5
18.5
49.3
48.6
16.4
17.4
53.4
101.6
145.7
7590.3
11013
18.3
27
21
10
104
77.3
6.3
39
22
145.67
25
14.3
13
23.2
88.7
10
24.3
95.7
20
9
27.3
36.3
49.7
74
21.3
34
26.2
39.6
5
6
4.1
12.3
46.9
47.3
15.7
15.4
48.9
97.3
134.3
7730.3
10868.2
18.8
27.5
21.9
10.5
103.3
78.1
11.8
43.5
24.18
134.27
23.5
15.3
12.5
21.53
87.7
10.9
23.7
94.6
20.2
9.5
28.5
37.8
50
76.2
22.7
35.5
26.2
38.7
5
5
5
5
12
12.5
5
5
5
15.3
21.5
790
1101
5
5
5
5
10
8
5
5
5
21.5
5
5
5
5
9
6
5
10
5
5
5
5
5
5
5
5
3
4
3
•0.05
0.73
2.15
0.35
0.18
0.26
0.26
1.58
0.49
0.92
•0.31
0.23
•0.15
•0.19
•0.30
•0.30
0.12
•0.17
•1.89
•1.56
•0.75
0.92
0.51
•0.33
0.17
0.63
0.18
•0.26
0.21
0.19
•0.06
•0.18
-0.42
-0.52
•0.11
•0.75
•0.49
•0.52
0.03
0.36
•0.05
0.23
0.67
1.30
0.19
-0.18
0.59
0.59
1.57
-0.06
0.18
-0.68
0
0.1
0
0
0
0.69
0.51
-1.96
-1.73
-0.69
0.18
0
-0.58
0
0.46
0.51
0
-0.23
-0.58
-0.69
-0.35
-1.27
-1.62
0.23
0
-0.23
0
-0.44
-0.32
-0.08
92
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Table 10.5 Accuracy of Analysis from DOE/EML Performance Evaluation Studies
Percent
Nuclide Month EML Value EPA Value Bias
Air Intercomparison Studies
54Mn March 7.62 10.31 26.09
5?Co March 10.81 14.81 27.01
5?c° September 12.64 11.1 -13.87
6°c° March 5.01 6.71 25.34
6°Co September 10.73 9.4 -14.15
134Cs March 10.88 13.28 18.07
134Cs September 28.17 24 -17.38
137Cs March 8.7 10.55 17.54
137Cs September 7.31 6.3 -16.03
125Sb March 12.33 17.21 28.36
144Ce March 15.7 21.01 25.27
238Pu March 0.1 0.11 9.09
239Pu March 0.119 0.125 4.8
Soil Intercomparison Studies
238Pu March 134.93 128 -5.41
Vegetation Intercomparison Studies
239Pu March 1.94 2.02 3.86
Water Intercomparison Studies
3H March 250.3 258.27 3.09
3H September 115 126 8.73
54Mn March 20.85 25.84 19.31
60Co March 90.85 109.33 16.9
60Co September 23.3 23.8 2.10
137Cs September 66 67.2 10.57
137Cs March 69.78 83.31 16.34
137Cs September 34.3 35 2
90Sr March 23.2 22.23 -4.36
90Sr September 2.94 3.49 15.76
238Pu March 1.29 1.32 2.2
239Pu March 0.85 0.827 -2.78
234U March 0.54 0.629 14.15
238U March 0.55 0.615 10.57
93
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Table 10.6. Accuracy of Analysis from DOE/MAPEP PE Studies
Result Mean Std Bias
Nuclide (Ba/U Result Dev. [%] Flag
Water Sample 96-W4
238Pu 1.219 1.2 0.12 -4.02 A
239Pu 1.495 1.44 0.12 -11.71 A
90Sr 26.38 25.63 2.31 -2.90 A
Z34/233U 0.402 0.40 0.04 -5.47 A
23BU 0.417 0.41 0.03 -6.47 A
Soil Sample 97-S4
238Pu 26.86 24.7 266 -8.04 A
Flags:
A = Mean result is acceptable (Bias <= 20%)
94
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References
Bureau of the Census, 1990, Population Count
Pursuant to Public Law 94-171. Department of
Commerce, Washington, D.C. DOC90
Bureau of Census, 1986. 1986 Population and
1985 Per Capita Income Estimates for Counties
and Incorporated Places, Publication Number P-26.
U.S. Department of Commerce, Washington, D.C.
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95
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Glossary of Terms
Definitions of terms given here are modified from the U.S. Nuclear Regulatory Commission Glossary of
terms (NRC81).
alpha Positively charged moving particles curie (Ci)
particles (a) identical with the nuclei of helium
atoms. They penetrate tissues to
usually less than 0.1 mm (1/250 inch)
but create dense ionization and
heavy absorbed doses along these
short tracks.
background The radiation in man's natural envir-
radiation onment, including cosmic rays and dosimeter
radiation from the naturally radioac-
tive elements, both outside and in-
side the bodies of humans and ani-
mals. It is also called natural radia- duplicate
tion. The usually quoted average
individual exposure from background
radiation is 125 millirem per year in
midlatitudes at sea level.
becquerel A unit, in the International System
(Bq) of Units, of measurement of radio-
activity equal to one nuclear trans- half-life
formation per second.
beta A charged particle emitted from a
particle (0) nucleus during radioactive decay,
with a mass equal to 1/837 that of a
proton. A positively charged beta
particle is called a positron. Large ionization
amounts of beta radiation may cause
skin bums, and beta emitters are
harmful if they enter the body. Beta
particles are easily stopped by a thin
sheet of metal or plastic.
Committed The summation of Dose Equivalents
Effective to specific organs or tissues that ionization
Dose would be received from an intake of chamber
Equivalent radioactive material by an individual
during a 50-year period following the
intake, multiplied by the appropriate
weighting factor. isotope
cosmic Penetrating ionizing radiation, both
radiation particulate and electromagnetic,
originating in space. Secondary
cosmic rays, formed by interactions
in the earth's atmosphere, account
for about 45 to 50 millirem of the 125
millirem background radiation that an
average individual receives in a year.
The basic unit used to describe the
rate of radioactive disintegration.
The curie is equal to 37 billion disin-
tegrations per second, which is
approximately the rate of decay of 1
gram of radium; named for Marie
and Pierre Curie, who discovered
radium in 1898.
A portable instrument for measuring
and registering the total accumulated
dose of ionizing radiation.
A second aliquot of a sample which
is approximately equal in mass or
volume to the first aliquot and is ana-
lyzed for the sample parameters.
The laboratory performs duplicate
analyses to evaluate the precision of
an analysis.
The time in which half the atoms of a
particular radioactive substance dis-
integrate to another nuclear form.
Measured half-lives vary from mil-
lionths of a second to billions of
years. Also called physical half-life.
The process of creating ions
(charged particles) by adding one or
more electrons to, or removing one
or more electrons from, atoms or
molecules. High temperatures, elec-
trical discharges, nuclear radiation,
and X-rays can cause ionization.
An instrument that detects and mea-
sures ionizing radiation by measuring
the electrical current that flows when
radiation ionizes gas in a chamber.
One of two or more atoms with the
same number of protons, but differ-
ent numbers of neutrons in their
nuclei. Thus, 12C, 13C, and14 C are
isotopes of the element carbon, the
numbers denoting the approximate
atomic weights. Isotopes have very
nearly the same chemical properties,
but often different physical properties
(for example, 13C and 14C are radio-
active).
96
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matrix spike An aliquot of a sample which is
spiked with a known concentration of
the analyte of interest. The purpose
of analyzing this type of sample is to
evaluate the effect of the sample
matrix upon the analytical methodol-
ogy.
method blank A method blank is a volume of de-
mineralized water for liquid samples,
or an appropriate solid matrix for
soil/sediment samples, carried
through the entire analytical proce-
dure. The volume or weight of the
blank must be approximately equal
to the volume or weight of the sam-
ple processed. Analysis of the blank
verifies that method interferences
caused by contaminants in solvents,
reagents, on glassware, and other
sample processing hardware are
known and minimized.
minimum The smallest amount of radioactivity
detectable that can be reliably detected with a
concentration probability of Type I and Type II
(MDC) error at five percent each (DOE81).
millirem
(mrem)
milliroentgen
(mR)
personnel
monitoring
picocurie
(pCi)
A one-thousandth part of a rem.
(See rem.)
A one-thousandth part of a roent-
gen. (See roentgen.)
The determination of the degree of
radioactive contamination on individ-
uals using survey meters, or the
determination of radiation dosage
received by means of internal or
external dosimetry methods.
One trillionth part of a curie.
quality factor The factor by which the absorbed
dose is to be multiplied to obtain a
quantity that expresses, on a com-
mon scale for all ionizing radiations,
the biological damage to exposed
persons. It is used because some
types of radiation, such as alpha
particles, are more biologically dam-
aging than other types.
rad Acronym for radiation absorbed
dose. The basic unit of absorbed
dose of radiation. A dose of one rad
means the absorption of 100 ergs (a
small but measurable amount of
energy) per gram of absorbing mate-
rial.
radioisotope An unstable isotope of an element
that decays or disintegrates sponta-
neously, emitting radiation.
radionuclide A radioisotope.
rem Acronym for roentgen equivalent
man. The unit of dose of any ioniz-
ing radiation that produces the same
biological effect as a unit of absorbed
dose of ordinary X-rays. (See quality
factor.)
roentgen (R) A unit of exposure in air to ionizing
radiation. It is that amount in air of
gamma or X-rays required to pro-
duce ions carrying one electrostatic
unit of electrical charge in one cubic
centimeter of dry air under standard
conditions. Named after Wilhelm
Roentgen, German scientist who
discovered X-rays in 1895.
Sievert (Sv) A unit, in the International System of
Units (SI), of dose equivalent which
is equal to one joule per kilogram (1
Sv equals 100 rem).
terrestrial The portion of natural radiation
(background) that is emitted by natu-
rally occurring radiation radioactive
materials in the earth.
tritium A radioactive isotope of hydrogen
that decays by beta emission. It's
half-life is about 12.5 years.
97
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Appendix
(LD Calculations)
Determination of L-
Accomplished upon the addition of a new
dosimeter type to the program. Once
completed, this test is not normally repeated.
Two methods are acceptable for accomplishing
the task.
Method #1: At least 10 dosimeters for
irradiation per category, plus 10 dosimeters for
background evaluation, for each dosimeter
design, are selected from the routine
processed pool of dosimeters. The dosimeters
are placed in an unshielded environment for a
time sufficient to obtain an unirradiated
background signal typical for routine processed
dosimeters. At least 10 dosimeters are
irradiated for each category to a dose
significantly greater (e.g., 500 mrem) than the
estimated lower limit of detectability. Both the
irradiated and unirradiated dosimeters are
processed and evaluated. The following
quantities are calculated:
Xio
n ,-=i
\
1 "
VE
n-l i=
Where:
Xio
X,
Ho
H,
Sn
S, =
Unirradiated dosimeter values.
Irradiated dosimeter values.
Mean evaluated dose equivalent
values for unirradiated dosimeters.
Mean evaluated dose equivalent
values for irradiated dosimeters.
Associated standard deviation of
unirradiated dosimeters dose
equivalent values.
Associated standard deviation of
irradiated dosimeters dose equivalent
values.
• The dosimeter readings are processed through
the standard dose algorithms without truncation
or distortion (i.e., readings are not rounded to
zero). If a background is subtracted, negative
values are retained for the calculation of S0.
The algorithms for the calculation of shallow
and/or deep dose equivalent are used to
calculate H0 and H,, depending on the category
test specifications. The lower limit of detection,
LD is then calculated as follows:
i _
Method # 1 - Lower Limit of Detectability Determination
-— £
n-i i=i
1 n
f,—E
n i=i
Where:
t, =
H0 =
The t distribution for n - 1 degrees of
freedom and a p value of 0.95.
The average of the unirradiated
dosimeter values without subtracting a
background signal.
Method #2: If NAVLAP performance testing
was completed within six months of this study,
then the values of B and S may be used to
calculate [1.75 X S/(1 + B)] which may be used
in place of tpS/H, in the above equation. Only
one set of unirradiated dosimeters is required
to determine LD using this method.
98
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The above equation is based on the desire
to minimize both false negative and false
positive results. All values below the
detection threshold should be set to zero.
For example, tpS0 for p = 0.95 is an
estimate of the detection threshold allowing
5% false positive values. For the lower
limit of detection false negative values are
also minimized. For p = 0.95, the
probability of no more than 5% false
positive and false negative values provides
a lower limit of detection of:
tp DSD
= tp 0S0
Where:
Sn =
The standard deviation of unirradiated
dosimeters.
tpo and tpD depend on the number of
dosimeters used to estimate S0 and SD>
respectively.
The above equation is an estimate of the
relationship:
LD = Kp o0 + Kp OD
Where:
o0 and OD = The true standard deviations.
Kp - The abscissa of the standard normal
distribution below which the total
relative area under the curve is P.
The OD value is composed of the fluctuation of
the background {o0) and the fluctuation
inherent in the readout process. If o^ is the
relative standard deviation at high doses, then
and solving for LD
2
f °,Y
K'°° + K'TT\ "°
V i/
a.
v
'Tt
2
Using tp for Kp and S for o, the final equation in
Method #1 is obtained. If tpi0 is not equal to tpD,
the formula for LD is not exact, but should be a
close approximation of the lower limit of
detectability.
Lower Limit of Detectability Determination -
Two methods of calculation are considered
acceptable and are detailed in this document. This
Determination uses the data obtained from a 6-
month fade study conducted with both UD-802
(personnel) and UD-814 (environmental)
dosimeters. In each case, the following calculation
is accomplished to determine lower limit of
detectability:
2
1\ 2
s \
''H
1
1
t S,
p 1
1
r-
2
Where
LD
Lower limit of detectability.
tp = The t distribution for n - 1 degrees of
freedom and a p value of 0.95.
S0 = Associated standard deviation of
unirradiated dosimeterdose equivalent
values.
Si = Associated standard deviation of
irradiated dosimeter dose equivalent
values.
H0 = Mean evaluated dose equivalent
values for unirradiated dosimeters.
H'0 =
The average of the unirradiated dosimeter
values without subtracting a background signal.
H, = Mean evaluated dose equivalent
values for irradiated dosimeters.
LD = Calculation for Personnel dosimeters:
2 [2.262 x 0.583 + (2.262)
115.014V
' 174.05
3.425]
1 -
2.262 x 15.014
174.05
Method #2 - Lower Limit of Detectability Determination
99
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LD = 3.01 mR; (for UD 802s)
( 5 039 V
2 [2.571 x 0.983 + (2.571) 1.033]
, I 168.33 J
^c
2.571 x 5.039
168.33
LD = 5.10 mR; (for UD814s, CaSO4
elements only)
Similarly LD = 44.73 mR (for UD814s, Li2B4O7
elements only)
Where:
Tp = 12.706
S, = 19.315
S0 = 2.081
H0 = 4.5
H! = 163.300
100
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