United States Science Advisory Board EPA-SAB-RAC-ADV-98-001
Environmental Washington DC August 1998
Protection Agency
&EPA AN SAB ADVISORY:
ENVIRONMENTAL
RADIATION AMBIENT
MONITORING SYSTEM
(ERAMS) II
AN ADVISORY BY THE
RADIATION ADVISORY
COMMITTEE
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August 28, 1998
EPA-SAB-RAC-ADV-98-001
Honorable Carol M. Browner
Administrator
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
Re: Radiation Advisory Committee (RAC) Second Advisory on
Environmental Radiation Ambient Monitoring System
(ERAMS)
Dear Ms. Browner:
The Office of Radiation and Indoor Air (ORIA) requested that the Radiation
Advisory Committee (RAC) of the Science Advisory Board (SAB) provide advice on
technical issues pertinent to the proposed reconfiguration of the Environmental
Radiation Ambient Monitoring System (ERAMS). This Advisory is the second part of
the evaluation of ERAMS performed by the RAC in response to ORIA's request. The
first Advisory (ERAMS I) was submitted to the Administrator in April 1996.
The RAC met in Washington, DC on November 19 and 20, 1997, and again on
March 3, 1998 for presentations and discussions in regard to the second Advisory
(ERAMS II). ORIA provided the RAC with supporting materials for review prior to the
RAC meeting including a document titled Reconfiguration Design for the Environmental
Radiation Ambient Monitoring System which was prepared by ORIA's National Air and
Radiation Environmental Laboratory (NAREL) and which described, in detail, the
design for reconfiguring the ERAMS.
We compliment the ERAMS staff for the quality of its laboratory effort in
preparing the proposed reconfiguration as well as the draft document and its
presentations at the meeting. The RAC found the NAREL document to be a well-
organized, well-written and well thought-out high-level planning document. The
focused and succinct discussion in the document provided an excellent framework on
which the RAC could base its observations and recommendations. We also wish to
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take this opportunity to recognize and thank Dr. Janet Johnson of the SAB's RAC for
coordinating this review by the Committee.
The specific charge to the RAC for the second Advisory (ERAMS II) was to
assess the proposals for reconfiguring the ERAMS program and respond to the
following three questions:
1) Will the proposed reconfiguration of the current ERAMS system enable it to
meet the system's three basic objectives more effectively and efficiently as
described in the document titled "Reconfiguration Design for the Environmental
Radiation Ambient Monitoring System?
Response: The RAC believes that the reconfigured ERAMS can meet its three
basic objectives of 1) providing data for nuclear emergency response
assessments, 2) providing data on ambient levels of radiation in the environment
for baseline and trend analysis, and 3) informing the general public and public
officials about levels of radiation in the environment. The detailed advice given
in the Advisory is intended to enhance the ability of ERAMS to meet the stated
objectives.
2) Are the criteria used for matrix selection, determination of sampling locations
and sampling frequency, and other network features appropriate given the
reconfigured ERAMS stated mission and objectives? Are there other criteria that
should be considered?
Response: The RAC found that the criteria for selection of matrices to be
analyzed and sampling locations were generally appropriate but that some
elements of the system could be improved. The Advisory describes in detail
some of the improvements that could be made in the system including a clearer
description of the rationale for the number, distribution, and specific location of
sampling sites in the context of the ERAMS mission and objectives.
3) Will the proposed changes to the system's current data dissemination and data
evaluation practices increase the data's usefulness to governmental agencies,
the scientific community, and the public? Are there any other interpretation
issues and/or practices that should be addressed?
Response: The reconfigured ERAMS includes provisions for data dissemination
which will increase the visibility of the data to the public as well as governmental
agencies and the scientific community. However, the RAC believes that more
can be done to fulfill the ERAMS objective of "informing the general public and
public officials about levels of radiation in the environment" and enhancing the
quality of the data.
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4) Other Issues: The RAC strongly supports NAREL's concept of a National
Environmental Radiation Data Center (NERDC) and recommends that NAREL
prepare a proposal to develop such a center in phases, with specific actions
corresponding to different funding scenarios, similar to the approach used for the
ERAMS reconfiguration plan.
In general, the RAC found that the proposed reconfiguration is appropriate and
Committee recommendations, in most cases, call for elaborations at a greater level of
detail than was provided in the reviewed document. The RAC notes that NAREL was
quite responsive to the recommendations made by this committee as part of the
ERAMS I review.
We would like to again commend the NAREL for the quality of the reconfigur-
ation proposal. The RAC appreciates the opportunity to provide this Advisory to you
and hopes that the recommendations contained in it will enable EPA to enhance the
ERAMS program and ensure its essential service to the public. We look forward to the
response to the recommendations presented in this Advisory, and in particular to the
items raised in this letter to you.
Sincerely,
Dr. Joan M. Daisey, Chair Dr. Stephen L. Brown, Chair
Science Advisory Board Radiation Advisory Committee
Science Advisory Board
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NOTICE
This report has been written as a part of the activities of the Science Advisory
Board, a public advisory group providing extramural scientific information and advice to
the Administrator and other officials of the Environmental Protection Agency. The
Board is structured to provide a balanced, expert assessment of scientific matters
related to problems facing the Agency. This report has not been reviewed for approval
by the Agency; hence, the comments of this report do not necessarily reflect the views
and policies of the Environmental Protection Agency or of other Federal Agencies. Any
mention of trade names or commercial products does not constitute endorsement or
recommendation for use.
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ABSTRACT
The EPA Science Advisory Board's (SAB) Radiation Advisory Committee (RAC)
reviewed technical aspects of the draft document titled Reconfiguration Design for the
Environmental Radiation Ambient Monitoring System (ERAMS). The reviewed
document was developed by the staff of the Office of Radiation and Indoor Air (ORIA),
with lead responsibility by the staff of the National Air and Radiation Environmental
Laboratory (NAREL), Office of Air and Radiation (OAR), Montgomery, Alabama. The
charge to the RAC for this advisory was to assess the Agency's proposals for
reconfiguring the ERAMS program and to respond to specific questions related to the
effort regarding the reconfiguration design, the criteria used for matrix selection,
determination of sampling locations and frequency, other network features, whether
proposed changes will increase overall system usefulness to all the parties, and
whether there are other issues or practices that should be addressed.
The RAC found that the proposed reconfiguration is an appropriate, well
organized, well-written, and well thought-out planning document. The Committee
recommendations call for elaborations at a greater level of detail, a more effective
statement of the mission and objectives, improvements needed to guide emergency
response actions, better elaboration on use of radiation data from other routine
monitoring networks, improvements in the rationale and approach to sampling choices,
such as use of a Data Quality Objective (DQO) rationale in determining such factors as
the number, locations and frequency of sampling locations, as well as periodic re-
evaluation of design.
Key Words: Monitoring, Ambient Monitoring, Environmental Radiation Monitoring,
Radionuclide Fallout, Radiological Monitoring
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U.S. ENVIRONMENTAL PROTECTION AGENCY
SCIENCE ADVISORY BOARD
RADIATION ADVISORY COMMITTEE (RAC)
Chair
Dr. Stephen L. Brown, Director, Risks of Radiation and Chemical Compounds, Oakland, CA
Members
Dr. William Bair, (Retired) Former Manager, Life Sciences Center, Battelle Pacific Northwest
Laboratory, Richland, WA
Dr. June Fabryka-Martin, Staff Scientist, Chemical Science and Technology Division, Los
Alamos National Laboratory, Los Alamos, NM
Dr. Thomas F. Gesell, Professor of Health Physics and Director, Technical Safety Office,
Idaho State University, Pocatello, ID
Dr. F. Owen Hoffman, President, SENES Oak Ridge, Inc., Center for Risk Analysis, Oak
Ridge, TN
Dr. Janet Johnson, Senior Radiation Scientist, Shepherd Miller, Inc., Fort Collins, CO
Dr. Ellen Mangione, M.D., M.P.H., Director, Disease Control and Environmental Epidemiology
Division, Colorado Department of Health, Denver, CO
Dr. Paul J. Merges, Chief, Bureau of Pesticides and Radiation, Division of Solid and
Hazardous Materials, New York State Department of Environmental Conservation,
Albany, NY
Dr. John W. Poston, Sr., Professor and Head, Department of Nuclear Engineering, Texas
A&M University, College Station, TX
Dr. Genevieve S. Roessler, Radiation Consultant, Elysian, MN
Dr. James E. Watson, Jr., Professor, Department of Environmental Sciences and
Engineering, University of North Carolina at Chapel Hill, NC
Consultants
Dr. Bernd Kahn, Professor, School of Nuclear Engineering and Health Physics, and Director,
Environmental Resources Center, Georgia Institute of Technology, Atlanta, GA
Science Advisory Board Staff
Dr. K. Jack Kooyoomjian, Designated Federal Official, U.S. EPA, Science Advisory Board
(1400), 401 M Street, SW, Washington, DC 20460
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Mrs. Diana L. Pozun, Management Assistant, U.S. EPA, Science Advisory Board (1400), 401
M Street, SW, Washington, DC 20460
TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY 1
2.0 INTRODUCTION 7
2.1 Background 7
2.2 ERAMS II Charge to the Committee 8
3.0 RESPONSE TO CHARGE 10
3.1 Mission Statement 10
3.2 Charge #1 11
3.2.1 Nuclear Accident Scenarios 12
3.2.2 Ambient Radiation Level Data Collection 13
3.2.2.1 Surface and Ground Water 13
3.2.2.2 Drinking Water 13
3.2.2.3 Selection of Specific Radionuclides for Analysis .... 14
3.2.3 Public Information 15
3.3 Charge #2 15
3.3.1 Determination of Sampling Locations 15
3.3.1.1 Number of Sampling Locations 15
3.3.1.2 Site-Specific Locations 16
3.3.1.3 Site Characterization 17
3.3.2 Sampling Frequency 17
3.3.3 Matrix Selection 18
3.3.3.2 Precipitation Sampling 19
3.3.3.3 Air Sampling 19
3.3.3.4 Environmental Gamma Radiation Measurement .... 20
3.3.4 Resource Priorities 20
3.4 Charge #3 20
3.4.1 Data Quality Objectives (DQO) 21
3.4.2 Lower Detection Limits 21
3.4.3 Uncertainty Estimates 22
3.4.4 Dose Levels 22
3.4.5 Statistical Analyses and Trend Evaluation 22
3.4.6 Trend Evaluation 23
3.4.7 Dissemination of ERAMS Data 23
3.4.8 Cooperative Sampling Efforts 25
3.4.9 International Cooperation 25
IV
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4D ATHCNVD/E 25
41 RittCaGrtF 25
4.2 Standard Procedures for Environmental Sampling 26
4.3 Periodic Reviews 27
4.3.1 ERAMS Design Flexibility 27
4.4 Process for Implementing Reconfigured ERAMS 27
4.5 Prioritization Based on Available Funding 28
4.6 Termination of NRC Monitoring Contracts with States 28
REFERENCES R-1
APPENDIX A - GLOSSARY A-1
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1.0 EXECUTIVE SUMMARY
1.1 Background and Introduction
The Office of Radiation and Indoor Air (ORIA) requested that the Radiation
Advisory Committee (RAC) of the Science Advisory Board (SAB) provide advice on
technical issues pertinent to the proposed reconfiguration of the Environmental
Radiation Ambient Monitoring System (ERAMS). This Advisory is the second part of
the evaluation of ERAMS performed by the RAC in response to ORIA's request. Our
first Advisory (ERAMS I) was submitted to the Administrator in April 1996 (SAB, 1996).
As we noted in the ERAMS I Advisory, the Agency may ask for an Advisory when
it is in the midst of an extensive, complex project that would benefit from an objective
evaluation of its work. The purpose of the Advisory is to provide suggestions for
refinement that would assist in meeting the intent of the project and the goals of the
Agency. An SAB Advisory is similar to a Review in that it is a written report to the
Administrator.
ERAMS is comprised of monitoring stations across the United States, laboratory
capability for analyzing samples generated from the monitoring stations, and a system
for storing and disseminating data generated by the network. ORIA is responsible for
the system, which is managed by ORIA's National Air and Radiation Environmental
Laboratory (NAREL). ERAMS was established by the EPA in 1973 to consolidate
existing radiation monitoring networks into one system. ERAMS monitoring stations are
operated by volunteers in all 50 states and the American Territories. The volunteers
are often employees of state or local government agencies. NAREL analyzes
samples collected from the monitoring stations and publishes the data in a quarterly
journal, Environmental Radiation Data. NAREL is also responsible for providing
supplies and information to the station volunteers. ERAMS has operated with the same
mission, guidelines, and structure since 1973. In early 1995, ORIA decided to perform
a thorough evaluation of ERAMS to determine whether its objectives are still relevant to
the mission of EPA and whether the program was meeting its objectives.
In our first ERAMS Advisory (ERAMS I), we concluded that an ERAMS mission
statement was needed and that the objectives of ERAMS should support the mission.
The Advisory also noted that "A critical component in determining the objectives is
defining the uses for the ERAMS data." The RAC suggested that the ERAMS mission
should include the following components:
a) to gather independent, reliable baseline data on environmental levels of
natural and anthropogenic radiation and radionuclides, with data capable
of revealing trends;
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b) to gather data that help the assessment of population exposures/doses;
c) to monitor radionuclides released into the environment during radiological
emergencies; and
d) to inform the public and public officials about levels of radiation in the
environment.
In addition, the first Advisory contained an overarching recommendation that the
Agency should do more to interpret the data generated from the present ERAMS or a
reconfigured ERAMS. Detailed responses to the specific charge to the RAC are
contained in the April 5, 1996 Advisory (SAB, 1996).
The RAC met in Washington, DC on November 19 and 20, 1997 and again on
March 3, 1998 for presentations and discussions in regard to the second Advisory
(ERAMS II). ORIA provided the RAC with supporting materials for review prior to the
RAC meeting, including a document titled Reconfiguration Design for the Environmental
Radiation Ambient Monitoring System (NAREL, 1997) which described, in detail, the
design for reconfiguring the ERAMS.
1.2 Overview of Findings and Recommendations
The charge to the RAC for the second Advisory was to assess the proposals for
reconfiguring the ERAMS program and respond to three specific questions that are
elaborated upon below.
The RAC compliments the ERAMS staff for the quality of their effort in preparing
the proposed reconfiguration as well as the draft document and its presentations at the
meeting. The RAC found the NAREL document to be a well-organized, well-written,
and well thought-out high-level planning document. The focused and succinct
discussion in the document provided an excellent framework on which the RAC could
base its observations and recommendations.
In general, the RAC found that the proposed reconfiguration is appropriate.
Committee recommendations, in most cases, call for elaborations at a greater level of
detail than was provided in the reviewed document. The RAC notes that NAREL was
responsive to the recommendations made by the Committee as part of the ERAMS I
review.
1.2.1 Charge Question #1: Meeting ERAMS Objectives
Charge Question #1: Will the proposed reconfiguration of the current ERAMS
system enable it to meet the system's three basic objectives more effectively and
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efficiently as described in the document titled "Reconfiguration Design for the
Environmental Radiation Ambient Monitoring System?"
The RAC believes that the reconfigured ERAMS can meet its three basic
objectives of a) providing data for nuclear emergency response assessments; b)
providing data on ambient levels of radiation in the environment for baseline and trend
analysis; and c) informing the general public and public officials about levels of radiation
in the environment. The detailed advice given in the Advisory is intended to enhance
the ability of ERAMS to meet the stated objectives.
a) The ERAMS Mission Statement incorporates the elements suggested by
the RAC in the ERAMS I Advisory but the mission and its objectives can
be stated more effectively;
b) The RAC believes that NAREL can do a better job of showing how
ERAMS data could be used to guide emergency response actions by
describing potential accident scenarios, citing previous experience with
nuclear accidents;
c) NAREL should evaluate the applicability of radionuclide data collected by
the United States Geological Survey (USGS) and other governmental
agencies to meet the ERAMS objectives;
d) Sampling sites for drinking water should be selected based on the size of
the population served, to address the objectives of evaluating ambient
radiological conditions and informing the public. However, preference
should be given to surface water supplies, which are more likely to be
affected by a nuclear emergency than ground water supplies;
e) The criteria for the selection of radionuclides for analysis and the required
detection levels should include, explicitly, the potential of the radionuclide
to contribute significantly to population dose; and
f) The ERAMS mission statement and objectives should be supplemented
with an explicit statement describing what this monitoring system is not
intended to do as well as providing reasons that such objectives would be
infeasible or inappropriate.
1.2.2 Charge Question #2: Establishing Sampling Criteria
Charge Question #2: Are the criteria used for matrix selection, determination of
sampling locations and sampling frequency, and other network features
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appropriate given the reconfigured ERAMS stated mission and objectives? Are
there other criteria that should be considered?
The RAC found that the criteria for selection of matrices to be analyzed and
sampling locations were generally appropriate but that some elements of the system
can be improved. The Advisory describes in detail changes and clarifications that could
be made in the system to enhance its ability to meet ERAMS objectives.
a) NAREL needs to establish a technical basis for evaluating the suitability
of its proposed number and distribution of sampling sites and a more
explicit rationale for its selection of specific sampling locations;
b) Information should be compiled in a report on the relevant characteristics
of each sampling site;
c) The sampling frequencies for the various media should be determined
based on technical considerations and be sufficient to ensure that the
volunteers who collect the samples maintain their competence;
d) Precipitation sampling should be evaluated based on its utility in meeting
the ERAMS objectives and the potential for diverting those resources to
increasing sampling of drinking water;
e) NAREL should thoroughly review the performance requirements for air
particulate samplers and include these requirements in the specifications
submitted to commercial vendors;
f) NAREL should consider adding gross alpha analysis to the air particulate
sampling program;
g) NAREL should evaluate the technical basis for the proposed number of
real-time gamma radiation monitoring stations in comparison with other
strategies for assessing ambient gamma radiation levels;
h) Periodic re-evaluation, based on findings, should be built into ERAMS so
that the system can respond to new challenges and can either terminate,
or place on a less frequent schedule, the monitoring for radionuclides
whose levels have been well defined; and
i) NAREL should work to ensure that there is a proper balance in the budget
between capital acquisition and the needs of operations and
maintenance.
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1.2.3 Charge Question #3: Ensuring the Usefulness of the Data
Charge Question #3: Will the proposed changes to the system's current data
dissemination and data evaluation practices increase the data's usefulness to
governmental agencies, the scientific community and the public? Are there any
other interpretation issues and/or practices that should be addressed?
The reconfigured ERAMS includes provisions for data dissemination that will
increase the visibility of the data to the public as well as governmental agencies and the
scientific community. However, the RAC believes that more can be done to fulfill the
ERAMS objective of "informing the general public and public officials about levels of
radiation in the environment" and enhancing the quality of the data.
a) NAREL should use the Data Quality Objective (DQO) approach
systematically in the design of its reconfigured ERAMS, including all
aspects of sample analysis, such as analytical detection limits,
uncertainties, quality control measures, and action levels;
b) The RAC strongly supports the proposal to obtain analyses of samples
using more sensitive techniques periodically and encourages the use of
the Currie method for estimating minimum detectable activities;
c) All ERAMS data should be reported with uncertainty limits;
d) NAREL should calculate dose levels from concentration data where
feasible to lend perspective to the monitoring results;
e) Statistical summaries and analyses should be designed to address
ERAMS objectives;
f) NAREL should analyze the monitoring results for trends on a sampling
site basis. Data can then be grouped on a logical basis to improve
robustness;
g) NAREL should enhance its public outreach by active participation in
professional societies, further indexing its web pages in internet search
engines, and providing links to the web sites of other agencies with
radiological monitoring programs;
h) NAREL should investigate the cost-effectiveness of sharing samples with
other EPA monitoring programs; and
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i) NAREL should develop close working relationships with other North
American countries, especially Canada and Mexico, seeking to develop
environmental radiological profiles and trends.
1.3 Additional Advice
In addition to responding to the charge, the RAC Advisory includes several other
recommendations that it believes would strengthen the ERAMS program.
a) The RAC strongly supports the concept of periodic reviews of ERAMS to
assess what aspects need enhancement and what aspects may not be
cost-effective;
b) The time-scale and process for implementing the reconfigured ERAMS
should be defined in detail;
c) NAREL should define an ideal monitoring system and then compare each
system proposed under the different funding levels described in the
reconfiguration document to this "state-of-the-art" system;
d) EPA should be establishing and promoting standard procedures for
environmental sampling and analyses in the ERAMS program
(recognizing that the Multi-Agency Radiation Laboratory Analytical
Procedures protocols, which are currently being formulated, will provide
consensus guidance for federal agencies); and
e) The RAC strongly supports NAREL's concept of a National Environmental
Radiation Data Center (NERDC) and recommends that NAREL prepare a
proposal to develop such a center in phases, with specific actions
corresponding to different funding scenarios, similar to the approach used
for the ERAMS reconfiguration plan.
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2.0 INTRODUCTION
2.1 Background
The Environmental Radiation Ambient Monitoring System (ERAMS) comprises
monitoring stations across the United States, laboratory capability for analyzing
samples generated from the monitoring stations, and a system for storing and
disseminating data generated by the network. The Office of Radiation and Indoor Air
(ORIA) is responsible for the system which is managed by ORIA's National Air and
Radiation Environmental Laboratory (NAREL). ERAMS was established by the EPA in
1973 to consolidate existing radiation monitoring networks into one system. ERAMS
monitoring stations are operated by volunteers in all 50 states and the American
Territories. The volunteers are provided by state or local government agencies.
NAREL analyzes samples collected from the monitoring stations and publishes the data
in a quarterly journal, Environmental Radiation Data. NAREL is also responsible for
providing supplies and information to the monitoring station operators.
ERAMS has operated with the same mission, guidelines, and structure since
1973. In early 1995, ORIA decided to perform a thorough evaluation of ERAMS to
determine whether its objectives were still relevant to the mission of EPA and whether
the program was meeting these objectives. To that end, ORIA requested advice from
the RAC during the on-going reconfiguration process.
The first RAC ERAMS Advisory, ERAMS I, (SAB, 1996) concluded that an
ERAMS mission statement was needed and that the objectives of ERAMS should
support the mission. The Advisory also noted that "A critical component in determining
the objectives is defining the uses for the ERAMS data." The RAC suggested that the
ERAMS mission should include the following components:
a) to gather independent, reliable baseline data on environmental levels of
natural and anthropogenic radiation and radionuclides, with the data
capable of revealing trends;
b) to gather data that help the assessment of population exposures/doses;
c) to monitor radionuclides released into the environment during radiological
emergencies; and
d) to inform the public and public officials about levels of radiation in the
environment.
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In addition, the first Advisory contained an overarching recommendation that the
Agency do more to interpret the data generated from the present ERAMS or a
reconfigured ERAMS. Detailed responses to the specific charge to the RAC are
contained in its April 5, 1996 Advisory (SAB, 1996).
NAREL subsequently prepared a document presenting a design for
reconfiguring ERAMS, Reconfiguration Design for the Environmental Radiation Ambient
Monitoring System (NAREL, 1997). This document describes the reconfiguration of
ERAMS as follows:
"The assessment of ERAMS focussed on the examination of a number of
fundamental questions including: Is there a need for a national environmental
radiation monitoring system? If there are needs for such a system, what are
they? How would the radiation monitoring system promote the protection of
public health and the environment? How would data generated from such a
monitoring system be used and who would use the data? To answer these
questions and to ensure a thorough assessment of ERAMS, ORIA utilized inputs
from a number of sources including a national survey of ERAMS data recipients,
a review of ERAMS data requests, and a contractor-performed evaluation of
ERAMS. The process utilized in developing the network design presented in this
document was to take the inputs from the various sources and starting
essentially from "ground zero", design a national radiation monitoring system.
The mission statement and objectives were developed using the various inputs
and the working components of the system such as media to be sampled,
sampling locations and frequency, sampling equipment and protocols, and
analytical protocols were designed to ensure that the system objectives would be
met".
The RAC has reviewed this document and discussed the proposed
reconfiguration with Agency staff. This Advisory (ERAMS II) is the second phase of the
RAC response to ORIA's request for advice regarding the on-going reconfiguration
plans.
2.2 ERAMS II Charge to the Committee
The charge to the RAC for the second phase of the evaluation is to provide
responses to the following questions:
a) Will the proposed reconfiguration of the current ERAMS system enable it
to meet the system's three basic objectives more effectively and efficiently
as described in the attached document ["Reconfiguration Design for the
Environmental Radiation Ambient Monitoring System (NAREL, 1997)]?
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b) Are the criteria used for matrix selection, determination of sampling
locations and sampling frequency, and other network features appropriate
given the reconfigured ERAMS stated mission and objectives? Are there
other criteria that should be considered?
c) Will the proposed changes to the system's current data dissemination and
data evaluation practices increase the data's usefulness to governmental
agencies, the scientific community and the public? Are there any other
interpretation issues and/or practices that should be addressed?
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3.0 RESPONSE TO CHARGE
The ERAMS staff is to be complimented for the quality of its effort in developing
the proposed reconfiguration plan as well as preparing the draft document and
presentations at the meeting. It is clear that the Agency has done a substantial amount
of work in reconfiguring ERAMS.
The RAC found the NAREL document, Reconfiguration Design for the
Environmental Radiation Ambient Monitoring System to be a well-organized, well-
written, and well thought-out high-level planning document. The focused and succinct
discussion in the NAREL document provided an excellent framework on which the RAC
could base its observations and recommendations. In general, the RAC found that the
proposed reconfiguration is on the right track and Committee recommendations are in
most cases elaborations at a greater level of detail than provided in the reviewed
document. The RAC notes that NAREL was quite responsive to the recommendations
made by this Committee as part of the ERAMS I review (SAB, 1996).
3.1 Mission Statement
The ERAMS mission, as stated in the Reconfiguration document, is:
"to monitor environmental radioactivity in the United States and its Territories in
order to provide high quality data for assessing public exposure and
environmental impacts resulting from nuclear emergencies and to provide
baseline data during routine conditions."
Advice: The ERAMS Mission Statement incorporates the elements suggested by the
RAC in the ERAMS I Advisory (SAB, 1996) but the mission and its objectives could be
stated more effectively.
Although evaluation of the Mission Statement was not specifically included in the
charge to the RAC, it is an integral part of the reconfiguration and is relevant to each of
the three areas defined by ORIA in the charge. The Mission Statement, as described
in the November 1997 ERAMS Reconfiguration document, incorporates the elements
suggested by the RAC in the ERAMS I Advisory. However, the RAC suggests that the
Mission Statement be strengthened. The RAC believes that the ERAMS mission is to
provide the United States Government with the capability to assess on a regional basis,
the radiation doses to the public and the environmental consequences of exposures to
naturally occurring radionuclides as well as to radionuclides released into the
environment by human activities. This assessment is to be accomplished by:
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a) developing and operating an environmental radioactivity monitoring
program encompassing the US and its territories;
b) developing baseline and real time radioactivity and public dose data
capable of revealing trends;
c) having in place a functioning radioactivity monitoring network that would
operate routinely but also be responsive during emergency conditions,
both immediate and long term; and
d) developing and operating a program for communicating radiological
information to the public and governmental officials routinely and during
emergencies.
Advice: The ERAMS mission statement and objectives should be supplemented with
an explicit statement describing what this monitoring system is not intended to do as
well as providing reasons that such objectives would be infeasible or inappropriate.
Examples of issues that ERAMS is not designed or intended to address are: a)
providing site monitoring of potential radiation sources; b) providing data for site-
specific assessments of radiological doses; c) monitoring radiation along transport
routes for radioactive shipments, or d) providing an early warning system for nuclear
accidents. Such a statement would minimize ambiguity for the States, other
government agencies, and the public as to who has responsibility for the various
functions.
In addition, the relationship of ERAMS to and its role in U. S. nuclear emergency
responses should be clarified. The Reconfiguration document suggests its role is to
evaluate only long-term effects rather than the immediate impact on the radiation
environment (page 12, lines 2-3).
3.2 Charge #1: Meeting ERAMS Objectives
the proposed reconfiguration of the current ERAMS system enable it to meet
the system's three basic objectives more effectively and efficiently as described in the
attached document ("Reconfiguration Design for the Environmental Radiation Ambient
Monitoring System," NAREL report dated November 19-20, 1997)7
Response: The RAC believes that the proposed reconfigured ERAMS would be
capable of meeting its three basic objectives of: a) providing data for nuclear
emergency response assessments; b) providing data on ambient levels of radiation in
the environment for baseline and trend analysis; and c) informing the general public
and public officials about levels of radiation in the environment. However, the RAC
11
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recommends some improvements to specific aspects of the program, as described
below.
3.2.1 Nuclear Accident Scenarios
Advice: The RAG believes that NAREL could do even better in showing how ERAMS
data could be used to guide emergency response actions by describing potential
accident scenarios, citing previous experience with nuclear accidents.
ERAMS will not draw much support from the public or decision makers if its
primary role is perceived as one of gathering data of scientific interest. The potential
utility of the data for taking action in the event of an emergency needs to be
emphasized in greater detail, recognizing that ERAMS is not intended to be an early
warning system.
NAREL's discussion of ERAMS objective #1 should include a description of
realistic potential nuclear accident scenarios, making reference to historical incidents
or present day activities such as: Chernobyl, above ground or vented nuclear weapons
tests, reentry of radionuclide thermal generators in spacecraft, Three-Mile Island (TMI),
foreign intrusions, and interstate radioactive shipments to nuclear-waste disposal sites.
Experience with nuclear accidents should be used to present arguments for or
against existing or proposed monitoring patterns. For example, an article in Health
Physics concerning the radiation dose to the US population from Chernobyl fallout
calculated with ERAMS data (Broadway, 1988), stated that most of the dose to adults
was from 137Cs via food other than milk. The doses had to be inferred by use of a
food/milk ratio obtained from other sources. Although the RAC agrees that food
monitoring presents problems and is certainly not cost-effective, this situation should
nonetheless be addressed. NAREL should clarify or document what provisions exist
for standby capability for collecting and analyzing specific food items (e.g., grains,
vegetables), or typical diets in the event of an emergency or to establish baseline
levels.
Also, based on Chernobyl fallout experience, there should be an evaluation of
the utility of precipitation and airborne particle collection as indicators of radiation dose
to the population in the event of an accident. The TMI experience should be used to
evaluate the usefulness of a network as an early indicator of the potential effects of a
nuclear accident. NAREL should consider how dense a network of sampling stations
would have been optimal for this accident.
EPA should position the ERAMS program to assure environmental radiological
monitoring of US surface waters in the event that a major international incident should
occur.
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3.2.2 Ambient Radiation Level Data Collection
The second objective of the reconfigured ERAMS is to provide data on ambient
levels of radiation in the environment for baseline and trend analysis. The ability of the
program to meet this objective is dependent on the types of media collected and
analyses performed. The reconfigured ERAMS provides for sampling surface and
ground water, milk, air, precipitation, and drinking water. The following sections
address specific elements of the ambient radiation level and radioactivity concentration
data collection.
3.2.2.1 Surface and Ground Water
Advice: Before making the decision to end ERAMS monitoring of surface water,
NAREL should evaluate the utility of data collected by the United States Geological
Survey (USGS) in meeting the ERAMS objectives.
The USGS program of measuring radioactivity in surface water, other than
drinking water, was stated to be part of the justification for ending ERAMS monitoring of
surface water. NAREL should provide a written evaluation of the extent to which the
USGS sampling locations, frequencies and analyzed nuclides meet ERAMS objectives.
This evaluation should cover the following aspects: a) identify explicitly the criteria
used by the USGS for its sampling site selection, b) estimate the population coverage
of these sites, c) confirm, to the extent possible, whether the USGS program will
continue in its present form; and d) find out in what time frame and through what
channels the USGS data are made available to the public and public officials. The
ERAMS reports should note the availability of radiological analyses of surface water
from the USGS and provide proper references thereto.
3.2.2.2 Drinking Water
Advice: Sampling sites for drinking water should be selected based on the size of the
population served in order to address the objectives of evaluating ambient radiological
conditions and informing the public. However, preference should be given to surface
water supplies because these are more likely to be affected by a nuclear emergency
than ground water supplies.
The first and second of the three objectives of the new ERAMS are to: a) provide
data for nuclear emergency response assessments; and b) provide data on ambient
levels of radiation in the environment for baseline and trend analysis. It would seem
reasonable, in selecting sampling media and sites for the second objective, to consider
the first objective. That is, establish a baseline and determine any trends in media and
at sites that would be expected to be influenced by nuclear emergencies. To this end
sampling air, milk, and drinking water derived from surface water is appropriate, but
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sampling drinking water derived from ground water is of little utility for assessing
nuclear emergencies. Most ground water would not be affected by nuclear
emergencies in the short term, when nuclear emergency response assessments are
needed, and may never be affected. However, for drinking water sampling locations
selected to address ERAMS objective #3 (informing the public about levels of radiation
in the environment), the RAC agrees that the size of the population served by a given
system—regardless of whether the source is surface water or ground water—is the
most appropriate criterion for selecting a drinking water sampling location.
The RAC recommends that: a) sampling sites for drinking water be biased
toward population centers that derive their drinking water from surface sources; and b)
for population centers that derive drinking water from both surface and ground sources,
that effort be made to obtain samples from a point in the system where all or at least
some of the water is from surface sources. This approach would help ensure that any
effects on the drinking water supplies from nuclear emergencies would be detected and
factored appropriately into the emergency response assessments.
3.2.2.3 Selection of Specific Radionuclides for Analysis
Advice: The criteria for selection of radionuclides for analysis and the required
detection levels should include, explicitly, the potential of the radionuclide to contribute
significantly to population dose.
Before implementing the reconfiguration plan, NAREL should use available
information to describe, by radionuclide, what is known and what must be measured in
the future. Some radionuclides, such as 90Sr and isotopes of U and Pu, are currently
detectable at levels that are low and changing very slowly, so that once-yearly national
coverage is sufficient. Other radionuclides are generally not detectable by NAREL's
present analytical techniques (137Cs and 3H), but would be detected if measured at 10-
times lower detection limits. NAREL needs to decide if the lower detection levels are
worth the added cost. At the few locations where these radionuclides are detected,
continued monitoring is worth-while. Documentation of the ERAMS reconfiguration
should be more transparent with respect to selection and exclusion of specific nuclides
from its monitoring program. For example, short-lived radionuclides such as1311 are not
in the category of defining the background conditions but may be present downstream
from medical facilities and thus become part of "background" relative to releases from
nuclear accidents. Another radionuclide (85 Kr) has been dropped from ERAMS but
should be reconsidered in the context of emergency response capability. Other
radionuclides that have not been monitored (222Rn, 210Pb, 129I, 147Nd, 152Eu) should also
be considered for future monitoring to meet the objectives of the ERAMS program since
they may contribute significantly to population dose under normal or accident
conditions. The reason for excluding these nuclides from routine monitoring should be
stated explicitly.
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An additional criterion should be explicitly added to those listed for the selection
of a given radionuclide for analysis (see p. 29 of the draft document): "identified as a
nuclide with the potential to pose a significant contribution to population dose, based
on pathway modeling (or a surrogate for such a nuclide)." This criterion is included in
the draft NAREL report rather obliquely, as a radionuclide of "concern to the system
client." The explicit addition of this criterion merely reiterates a later statement in the
text (p. 31), that "Priority will be given to radionuclides that are significant contributors
to dose and those that are short-lived."
3.2.3 Public Information
The third objective of the reconfigured ERAMS is to inform the general public
about levels of radiation in the environment. Dose assessment may be performed to
enhance the effectiveness of ERAMS in meeting that objective.
(The ability of the reconfigured ERAMS to inform the public effectively regarding
ambient radiation levels is covered in more detail in Section 3.4 of this Advisory.)
3.3 Charge #2: Establishing Sampling Criteria
Are the criteria used for matrix selection, determination of sampling locations,
and sampling frequency and other network features appropriate, given the reconfigured
ERAMS stated mission and objectives? Are there other criteria that should be
considered?
Response: The RAC found the criteria for selection of matrices to be analyzed and
sampling locations were generally appropriate but that some elements of the system
could be improved. Determination of the number of sampling stations needed to meet
the objectives of ERAMS and the selection of monitoring locations should be based on
technical considerations to the extent feasible. The RAC is concerned that the sampling
frequency specified in the reconfiguration plans may not be sufficient to maintain an
adequate level of sampling team proficiency.
3.3.1 Determination of Sampling Locations.
3.3.1.1 Number of Sampling Locations
Advice: NAREL needs to establish a technical basis for evaluating the suitability of its
proposed number and distribution of sampling sites.
The ERAMS program should cover the continental USA (including Alaska), and
non-continental areas. Non-continental areas are defined in other EPA programs to
include the State of Hawaii, Virgin Islands, Guam, American Samoa, Commonwealth of
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Puerto Rico, and the Northern Mariana Islands. This coverage would be consistent
with the ERAMS mission "to monitor environmental radioactivity in the United States
and its Territories..."
3.3.1.2 Site-Specific Locations.
Advice: NAREL should provide a more explicit rationale for its selection of specific
sampling locations.
Justification for sampling locations in the reconfigured ERAMS is incomplete.
For each of the sampling and monitoring categories, ERAMs should present a
sensitivity analysis, for example in the form of a plot of fraction of population or
geographic coverage vs. number of optimally placed sites. This would indicate whether
there are break points beyond which only minor benefits would accrue from large
expenditures, and how funds could be apportioned to maximize the geographic or
population coverage.
The maps in the reconfiguration document show large regions without a single
monitoring station. This imbalance in national geographical distribution should be
redressed. In addition, it may be desirable to give every state the opportunity to be
included in each network, so that the citizens of each state can relate to results
pertinent to them. In designing the ERAMS network, consideration should be given to
the sampling networks of other organizations such as the Environmental Measurements
Laboratory (EML). Other sampling networks include the Los Alamos National
Laboratory (LANL)/Environmental Protection Agency (EPA) and the Department of
Energy's (DOE's) precipitation monitoring. Predominant global weather patterns
should also be taken into account in selecting ERAMS monitoring locations.
Placement of the few border locations for gamma-ray monitoring is undoubtedly
guided by convenience, but seems arbitrary when viewed on the map, and certainly
unlikely to permit reaching any systematic conclusions. ERAMS staff needs to specify
their purpose and use some algorithm (e.g., for plume width) to determine the number
required to meet the specified needs. If hundreds of stations are needed, one, two, or
three would be useless.
Once a general location has been established for a sampling site, criteria for
evaluating the suitability of a specific location for the sampling station should be
explicitly stated. In its present form, the review document gives the impression that
undue reliance has been given to operator convenience rather than scientific criteria for
siting the stations. An example of a site-specific criterion would be the specification of
a minimal acceptable distance from buildings for air and precipitation collectors.
However, since the stations are operated largely by volunteers, it should be
acknowledged that the convenience factor cannot be ignored in sampling site selection.
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3.3.1.3 Site Characterization
Advice: Background information on the relevant characteristics of each sampling site
should be compiled in a report or web-accessible data base and made readily available
to users of the data.
Examples of standard information that would be useful to include in a sampling-
site report are as follows:
a) For all sampling sites: longitude, latitude, elevation, objective of sampling
site (e.g., monitoring potential point source, border station, global fallout),
type of land use surrounding site;
b) Air and precipitation sampling sites: wind rose, population within specified
distances of the site, site sketch;
c) Milk sampling sites: wind rose, location and size of population served by
milk suppliers in the area; and
d) Drinking water: type of source (river/stream, reservoir, ground water well,
mixture), population served by this particular source, location of sample,
and collection site (if different from location of water supply).
3.3.2 Sampling Frequency
Advice: The sampling frequencies for the various media should be determined based
on technical considerations and be sufficient to ensure that the volunteers collecting
the samples retain their competence.
The reconfigured ERAMS calls for sampling some media on a semi-annual
basis. Considering the mission of ERAMS as defined in the draft document and the
expected budget limitations, the proposed reduced sampling schedule seems
reasonable and probably necessary. However, maintaining a high level of consistency
and quality of samples when these are only collected twice per year by volunteers will
require a special effort and even then may not achieve the state of readiness described
on page 12, lines 12-13 of the NAREL document (NAREL, 1997).
NAREL should consider increasing the sampling frequency for precipitation,
milk, and drinking water samples and archiving those that are not analyzed
immediately. Archived samples would have a limited storage time, e.g., not to exceed a
year, or to be held until analytical results are available for the next regularly scheduled
collection. (Obviously, the archived samples could not be analyzed for short-lived
radionuclides, so some information would be irretrievably lost.) Analyses of the
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archived samples would only be conducted if the more recent results showed a
significant change relative to the previous results. This increased sampling would also
keep the sample collectors "up to speed and at the ready" as well as have samples
available in the event of a sudden emergency.
For those media to be sampled twice per year, as specified in the
reconfiguration document, NAREL should consider establishing a two-tiered system of
sampling frequencies for each location and type of media, with more frequent sampling
being conducted when a trend is apparent or suggested by the data, when an
anomalous result has been confirmed, and when elevated concentrations have been
observed in another sample from the same location but in a different medium or for a
different radionuclide. Implementing such a recommendation would require the
establishment of an action level for each category, e.g., based on dose levels
corresponding to a particular concentration or trends. It would also require the
establishment of "stopping rules," defining in advance how long the increased
frequency of sampling should be in effect.
The crucial point regarding frequency is not only how often a location should be
monitored to avoid missing an increased level of a particular radionuclide, but also how
often a sample should be collected so that sampling staff retains its competence. This
question needs to be addressed directly, rather than arbitrarily answering it "twice
yearly." The experience with reliability of quarterly collections should be reviewed. If it
has not already been done, collection reliability should be checked in the field.
Methods of providing guidance and remote prompting for once-yearly collections
should be considered.
A sound rationale should also underlie the basis for establishing the timing of
sample collection for samples collected only twice a year. Staggering the analytical
schedule, as suggested in the reconfiguration document, does not appear to have a
sound technical basis and may be inappropriate for some media. Factors that affect
radiological levels in a given media (such as milk) should be identified in order to
evaluate whether the timing of sample collection is optimized to address ERAMS
objectives. Seasonal effects and coordination with other sampling locations may also
be relevant considerations.
In addition to sampling frequency and timing, the sampling periods for collecting
airborne particles, precipitation, and drinking water should be clearly defined.
However, the RAC recognizes that these issues may be addressed in the ERAMS
sampling manual.
3.3.3 Matrix Selection
3.3.3.1 Surface Water Sampling
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Surface water sampling issues are addressed in Sections 3.2.2.1 and 3.2.2.2.
3.3.3.2 Precipitation Sampling
Advice: Precipitation sampling should be evaluated for its utility in meeting the
ERAMS objectives as compared to the benefits of diverting those resources to
enhancing drinking water sampling.
NAREL should clarify how data on radionuclides in precipitation would be useful
in nuclear emergency response assessments or later dose assessments. Precipitation
has been demonstrated to be an effective indicator of ground deposition from localized
fallout, (e.g., releases from the Hanford Reservation in the 1940s, the Nuclear Test Site
in the 1950s, fallout from Chinese testing of nuclear devices in the 1970s and 1980s,
and the Chernobyl reactor accident in 1986). Rainfall is the main vector for
radionuclides moving from air to the ground. However, NAREL should evaluate the
utility of precipitation data against the advantages of diverting those resources into
taking more drinking water samples, especially from surface water systems. If NAREL
believes that precipitation data are useful, this could be made clearer by implementing
the suggestion for a written plan on how, and within what time frame(s), dose
assessments would be conducted, based on ERAMS data (Section 3.4.4).
3.3.3.3 Air Sampling
Advice: NAREL should thoroughly review the performance requirements for air
particulate samplers and include these requirements in the specifications submitted to
commercial vendors.
NAREL should be cautious in acquiring commercial samplers. Based on the
personal experience of members of the RAC, they should not be viewed as a panacea.
Commercial samplers are not necessarily reliable nor is their performance always up to
the standards specified by the manufacturer. NAREL should consult with the
individuals responsible for air particulate monitoring at nuclear facilities to obtain
practical evaluations of sampler performance.
NAREL should institute a periodic sampler testing program to measure reliability.
Advice: NAREL should consider adding gross alpha analysis to the air particulate
sampling program.
The Committee was somewhat surprised that no gross alpha analysis is
contemplated for the air particulate matter sampling program. The RAC acknowledges
the difficulties in detecting short-range alpha particles emitted from solid media;
however, some additional sample preparation steps may permit such analyses at
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modest additional cost. Although an argument can be made that this measurement is
not quantitative due to variable impaction in the filter and self absorption in the mass of
material collected on the filter, it is still a reasonable qualitative indicator. In systems
with which the RAC has had experience, significant differences between gross alpha
results in the general environment and those near an elemental phosphorus plant,
which emits natural 210Po, were routinely noted (US AEC, 1974). In addition,
considering the concern over the 238Pu radioisotope thermal generators (RTGs) such as
those launched recently in the Cassini spacecraft, a gross alpha capability for nuclear
emergency response assessments and a baseline would seem to be timely.
3.3.3.4 Environmental Gamma Radiation Measurement
Advice: NAREL should evaluate the technical basis for the number of real-time
gamma radiation monitoring stations proposed in comparison with other strategies for
assessing ambient gamma radiation levels.
Although the Committee supports the intent of the real-time gamma radiation
monitoring plan, it is concerned that the number of stations proposed may not be
sufficient to provide much useful information. A plume from a radionuclide-releasing
event could well miss all of the stations on its first pass, especially if it originated inside
the U.S. The Committee is well aware that such stations would be expensive and that
even the optimistic budget cannot provide for many real-time gamma monitors. NAREL
should improve its technical justification for the number of stations requested or
consider using the proposed budget for more useful strategies. NAREL should also
consider reinstituting the environmental thermoluminescent dosimeter (TLD) system, or
implementing a state-of-the-art TLD or Electret lonization Chamber (EIC) system
(Kotrappa, 1992) to supplement the planned pressurized ionization chamber (PIC)
network. These integrating systems are cost-effective and can be operated at locations
without electrical power.
3.3.4 Resource Priorities
Advice: NAREL should work to ensure that there is a proper balance in the budget
between capital acquisition and the needs of operations and maintenance.
In a recent visit to Los Alamos, a member of the RAC noted that several of the
Neighborhood Environmental Watch Network (NEWNET) stations had not operated
properly for periods of time and was told that there were insufficient resources to keep
them repaired and calibrated. The resources required for acquisition and maintenance
of expensive monitoring stations for ERAMS should be carefully considered by NAREL,
particularly in regard to new air samplers and PICs.
3.4 Charge #3: Ensuring the Usefulness of the Data
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Will the proposed changes to the system's current data dissemination and data
evaluation practices increase the data's usefulness to governmental agencies, the
scientific community, and the public? Are there any other interpretation issues and/or
practices that should be addressed?
Response: The reconfigured ERAMS includes provisions for data dissemination that
will increase the visibility of the data to the public as well as governmental agencies
and the scientific community. However, the RAC believes that more can be done to
fulfill the ERAMS objective of "informing the general public and public officials about
levels of radiation in the environment" and enhancing the quality of the data.
3.4.1 Data Quality Objectives (DQO).
Advice: NAREL should use the DQO approach systematically and up-front in the
design of its reconfigured ERAMS, including all aspects of sample analysis, such as
analytical detection limits, uncertainties, quality control measures, and action levels.
DQO are mentioned briefly on pages 42 and 44 of the NAREL document
(NAREL, 1997) document. Implementing this advice probably involves a
reorganization of the format of the reviewed document, with little change to its content.
3.4.2 Lower Detection Limits.
Advice: The RAC strongly supports the proposal to analyze samples periodically
using more sensitive techniques and encourages the use of the Currie method for
estimating minimum detectable activities.
More sensitive analytical techniques, as described on page 33 of the
reconfiguration document (NAREL, 1997), would serve several purposes:
a) They would provide greater confidence in results reported at or near the
detection limits of less-sensitive techniques;
b) They would permit the calculation of background doses to serve as a
basis against which to compare any increased dose resulting from a
nuclear event. When the reported exposure or concentration is zero, then
the implied background dose is also zero (although, of course, such is not
really the case). Consequently, if a nuclear event gave rise to detectable
radioactivity, then the entire dose would be attributed to the event since
the apparent background dose was zero. This conclusion could be quite
misleading if the true background was only slightly below the detection
limit, while the radioactivity resulting from the event was only slightly
above it; and
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c) Non-zero data are necessary in order to identify trends.
ERAMS should use the Currie method (Currie, 1968) for estimating minimum
detectable activities and concentrations instead of using 3 standard deviations as was
done in the sample Environmental Data Reports 74 and 75 (EDR) (NAREL, 1994a;
1994b) provided to the RAC. (Based on information received from NAREL, the Currie
method has been implemented since publication of Volume 75 of EDR.)
3.4.3 Uncertainty Estimates
Advice: All ERAMS data should be reported with uncertainty limits.
Some, but not all, categories of data are already reported with uncertainty limits
in the ERAMS' quarterly journal, Environmental Radiation Data. A statement should be
published together with each data set as to any other significant sources of uncertainty,
in addition to analytical counting statistics, that would not be reflected in the reported
uncertainty limits.
3.4.4 Dose Levels
Advice: NAREL should calculate dose levels from concentration data to lend
perspective to the monitoring results.
Reporting dose levels calculated from radionuclide concentrations resulting from
release events is important because the estimated dose places a specific radionuclide
measurement in perspective. On the other hand, the dose can vary widely because of
assumptions made concerning intake pathways and amounts, and target populations.
Hence, the assumptions underlying the dose calculations should be clearly stated.
It is assumed that doses would not be assessed for individuals in the population
but rather for specific segments of the population. These segments should be
identified. A written plan should be developed to describe how, and within what time
frame(s), dose assessments would be conducted, based on ERAMS data. To the
extent feasible, NAREL should consider reporting approximate dose levels
corresponding to its current and extended detection limits. Underlying assumptions for
these dose levels should also be clearly stated.
3.4.5 Statistical Analyses and Trend Evaluation
Advice: Statistical summaries and analyses should be designed to address ERAMS
objectives.
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NAREL should develop a proposed set of statistical parameters and specific
hypotheses to be tested and should prepare a draft report for peer review, applying
these statistical tools to its current data base. Some suggestions are:
a) provide statistical summaries on a regional, as well as national, scale;
b) provide statistical summaries on a seasonal, as well as annual, scale
since seasonal variations would occur for radionuclides with a significant
inventory in the stratosphere because of an annual spring breakthrough
to the troposphere; and
c) compare U.S. situation to worldwide trends.
3.4.6 Trend Evaluation
Advice: NAREL should analyze the monitoring results for trends on a sampling site
basis. Data can then be grouped on a logical basis to improve robustness.
The RAC encourages NAREL to develop trend analyses of the laboratory
analyses and resultant data they publish. These trend analyses should be reported in
a format readily understandable to the general public. A good example of this
approach is the Indicators of Stress and diagrams used in the Report Highlights,
STATE OF THE GREAT LAKES - 1997 (SOLEC, 1997a), prepared from information
gathered for and discussed during the November 1996 State of the Lakes Ecosystem
Conference (SOLEC, 1996; SOLEC, 1997a; 1997b).
In its discussions with the RAC, NAREL proposed to evaluate trends by
aggregating data nationally and examining the changes over time. While national
aggregation of data will probably work for nuclides such as 90 Sr in milk, it could
obscure regional differences in other cases. It may be better to examine trends on a
sample site basis and then aggregate data that exhibit similar trends, thus improving
robustness. Aggregating data with different trends could simply obscure possibly
meaningful local or regional trends. However, the data need to be grouped on a logical
basis in order to have sufficient power to detect trends. Trend analysis may also be
useful in determining when the frequency of monitoring for radionuclides whose levels
have been well defined should be reduced as discussed in Section 3.3.2., as well as
providing design flexibility as discussed in Section 4.3.1.
3.4.7 Dissemination of ERAMS Data and Public Outreach
The RAC strongly supports all efforts to disseminate the ERAMS data and to
design documents to meet the needs of a wider audience, especially by electronic
means such as the Internet.
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Advice: NAREL should enhance its public outreach by active participation in
professional societies, further indexing its web pages in Internet search engines, and
providing links to the web sites of other agencies with radiological monitoring programs.
NAREL has, laudably, included plans for enhancing the utility of ERAMS
products to outside users, e.g., by improving the formatting and content of the
Environmental Radiation Data (ERD) reports and placing data on the Internet. NAREL
should consider establishing a map-based database accessible on the Internet that
guides the user in accessing the radiation data available for the geographic area of
interest. The environmental database established and maintained by the National
Atmospheric Deposition Program/National Trends Network (NADP/NTN) is a good
example of such a map-based system. More public outreach may still be necessary.
The ERD page on the Internet showed only 243 visits through mid April 1998, many of
which may be from people who already knew about the database. NAREL may need to
make itself better known by further indexing its pages in search engines and publicizing
via the Health Physics Society, the American Nuclear Society, and other organizations
and journals featuring interests in environmental radiation data. The RAC recommends
that NAREL personnel become more active in professional societies in order to build a
stronger user constituency, to serve as a vehicle for data dissemination, and to
increase interaction between NAREL staff and environmental radiation professionals.
NAREL/ERAMS reports should discuss the relationship of ERAMS to the
radiological monitoring programs of other Federal Agencies (USGS, Department of
Defense, Department of Energy, Nuclear Regulatory Commission, Department of
Agriculture, and US Customs). The ERAMS web site should provide links to the web
sites of those agencies for access to their information.
While the above recommendations may help in disseminating the information to
a larger audience, it is somewhat unrealistic to expect much broadly based enthusiasm
for the ERAMS program data unless there is an event resulting in release of
radionuclides. NAREL should develop a plan to publicize the availability of its data and
of its interpretation of those data when a nuclear event occurs. The data should be
publicized even if the event does not result in measurable increases in activity
concentrations in environmental media or increases in direct gamma radiation levels.
As U.S. citizens, we should be pleased to live in an area for which ERAMS
reports have shown that our environmental exposure to anthropogenic sources of
radiation is practically nil. However, this finding should not lead to a sense of
complacency and a concomitant reduction in EPA's commitment to continued operation
of ERAMS. The RAC commends NAREL for its proposed approach for maintaining and
continually improving the baseline data provided by ERAMS. In addition, the RAC
recommends that the "good news" generated by the ERAMS program deserves greater
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visibility with the public, with public officials, and with scientists who may not be familiar
with the scope and breadth of the data or of the program. Such enhanced visibility can
be achieved through better interactions with radiation protection societies and other
societies such as the American Nuclear Society. An outreach program to make the
public aware of this excellent program could include presentations to local groups such
as Lions and Rotary clubs, Chambers of Commerce, the League of Women Voters,
schools, and other community organizations.
3.4.8 Cooperative Sampling Efforts
Advice: NAREL should investigate the cost-effectiveness of sharing samples with other
EPA monitoring programs.
The samples that NAREL collects may well contain non-radioactive substances
of interest to other parts of the Agency. If sample collection is a significant part of the
sampling and analysis cost for those other programs, sharing the samples may
increase the value of the ERAMS program to the nation. Conversely, samples from
other parts of the Agency might expand ERAMS coverage if analytical cost is not
dominant. The Committee recognizes that NAREL is aware of these possibilities and
intends to pursue them. Somewhat more specificity is desirable in the plan.
3.4.9 International Cooperation
Advice: EPA/NAREL should develop close working relationships with other North
American countries, especially Canada and Mexico, seeking to develop environmental
radiological profiles and trends.
These relationships would be consistent with the nation's international
environmental commitments, such as those discussed in the SOLEC '96 report (SOLEC
1997a; 1997b).
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4.0 ADDITIONAL ADVICE
The following comments and recommendations are not directly related to the
three elements of the charge to the RAC. They have been included here to provide
additional information that the RAC believes would strengthen the ERAMS program.
4.1 Radiation Data Center
Advice: The RAC strongly supports NAREL's concept of a National Environmental
Radiation Data Center (NERDC) and recommends that NAREL prepare a proposal to
develop such a center in phases, with specific actions corresponding to different
funding scenarios, similar to the approach used for the ERAMS reconfiguration plan.
The proposed incorporation of data from the States, Department of Energy
(DOE), U.S. Nuclear Regulatory Commission (NRC), and other agencies into the
ERAMS data base is excellent. However, the process for building, maintaining, and
sharing this database needs to be established. In order to assess the comparability of
radiation data from different sources and to minimize the potential for misusing data, a
critical task for the data center to undertake will be documentation of the data
objectives, sample collection and analytical protocols, and quality controls used by
other agencies. NAREL may want to consider bringing this topic before the RAC for a
consultation or advisory.
The RAC suggests that the NERDC could be started with real-time PIC data.
These data are already available electronically from many sources, and there should
be little issue of data comparability because calibration of these instruments is a
relatively straightforward process.
ERAMS documentation should include a summary of other radiation monitoring
systems around the world. ERAMS has been very useful in documenting the extent of
radiological fallout related to accidents. The system was "booted up" as a result of
information first obtained from systems in Europe. Therefore, there is a clear and very
useful relationship between ERAMS and other systems.
4.2 Standard Procedures for Environmental Sampling
Advice: EPA should establish and promote standard procedures for environmental
sampling and analyses in the ERAMS program.
EPA should establish and promote standard procedures for environmental
sampling and analyses in the ERAMS program, recognizing that the Multi-Agency
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Radiation Laboratory Analytical Procedures (MARLAP), which is currently being
formulated, will provide consensus guidance for federal agencies.
4.3 Periodic Reviews
Advice: The RAG strongly supports the concept of periodic reviews of ERAMS to
assess what aspects may need enhancement and what aspects may not be cost-
effective.
These future reviews of ERAMS should start from a zero base program, as is
being done currently, and consider options relative to an ideal radiological
environmental monitoring/surveillance program.
4.3.1 ERAMS Design Flexibility
Advice: Periodic reevaluation of the design should be built into ERAMS so that the
system can respond to new challenges, improvements in analytical technology, and
changes in population distribution, and can terminate, or place on a less frequent
schedule, the monitoring for radionuclides whose levels have been sufficiently well
defined and that show no temporal trends.
The NAREL plan generally provides a good rationale for its design choices. The
plan would be further improved if it also discussed "stopping rules." These are
statements of conditions under which NAREL might consider discontinuing or reducing
the frequency of collection of samples for a certain matrix or medium, discontinuing
analysis for a specific radionuclide, or abandoning a station.
The stopping rules could be based on failure to detect an analyte over a period
of time, levels routinely well below any risk-based action level, or stability of results
(indicating that little new information is being generated). Any resources freed through
these decisions could then be diverted to more productive activities. It must be noted,
however, that most of the anthropogenic radionuclides will be below detection limits of
standard methods under normal circumstances. There is nothing wrong with
measuring a long string of high quality "zeros" in media and at locations that would be
affected by an accident, should one occur. The readiness capability could be impaired
or lost if sample collection and analyses were stopped. It is reasonable, however, to
consider rules for increasing and decreasing the frequency of sample collection and
analyses, putting certain functions on standby, restarting, and shifting emphasis.
4.4 Process for Implementing Reconfigured ERAMS
Advice: The time scale and process for implementing the reconfigured ERAMS should
be described in greater detail.
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. If budgetary constraints force a reduction in sampling frequency to the extent
that ERAMS can no longer meet its basic objectives, then NAREL should describe how
that data gap will be addressed.
4.5 Prioritization Based on Available Funding
Advice: NAREL should define a "state-of-the-art" monitoring system and then compare
each system proposed under the different funding levels described in the
reconfiguration document (NAREL, 1997) to this system.
The reconfiguration plans include prioritization according to the available
funding: zero additional resources, some additional resources, and optimized additional
resources. The RAC suggests that NAREL develop and verbalize a "grand view" of
what could constitute a "state-of-the-art" monitoring system, and then compare each
system envisioned by the different funding levels to this ideal system.
ORIA should also evaluate the cost-benefit aspects of aerial gamma radiation
surveys. If this activity is deemed to be consistent with the ERAMS mission, its cost-
effectiveness should be evaluated in the context of available resources and other
activities necessary to meet the ERAMS objectives.
4.6 Termination of NRC Monitoring Contracts with States
Advice: The NRG has terminated contracts with 34 states for radiation monitoring
around nuclear facilities. NAREL should evaluate the effect this loss of funding for
state programs might have on the ERAMS sample collection networks that are staffed
by state employees.
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REFERENCES CITED
Broadway, J. A., J. M. Smith, D. L. Norwood, and C. R. Porter. 1988. Estimates of
radiation dose and health risks to the United States population following the
Chernobyl nuclear plant accident. Health Physics 55, No. 3. p. 533.
Currie, L. A. 1968. Limits for qualitative detection and quantitative determination. Anal.
Chem. 40. .p. 586.
Kotrappa, P., T. Brubaker, J. C. Dempsey, and L. R. Stieff. 1992. Electret ion chamber
system for measurement of environmental radon and environmental gamma
radiation. Rad. Prot. Dos. 45 (1-4 Supp). P 107.
NAREL. 1994a. Environmental Radiation Data Report 74: April-June 1993, U.S. EPA,
ORIA, NAREL, EPA 402-R-93-093, August 1994.
NAREL. 1994b. Environmental Radiation Data Report 75: July-September 1993, U.S.
EPA, ORIA, NAREL, EPA 402-R-93-094, August 1994.
NAREL. 1997. National Air and Radiation Environmental Laboratory (NAREL).
Reconfiguration Design for The Environmental Radiation Ambient Monitoring
System. United States Environmental Protection Agency (U.S. EPA), Office of
Radiation and Indoor Air (ORIA). November.
SAB. 1996. Advisory on Environmental Radiation Ambient Monitoring System (ERAMS),
U.S. EPA, Science Advisory Board (SAB), Radiation Advisory Committee (RAC),
Washington, DC EPA-SAB-RAC-ADV-96-003, April.
SOLEC. 1997a. State of the Lakes Environmental Conference (SOLEC), Environment
Canada and U.S. EPA, State of the Great Lakes: 1997a - Report Highlights,
Environment Canada and U.S. Environmental Protection Agency, 21 pages.
SOLEC. 1997b. State of the Lakes Environmental Conference (SOLEC), Environment
Canada and U.S. EPA,State of the Great Lakes: 1997b - The Year of the
Nearshore, Environment Canada (ISBN 0-662-26003-1; Catalogue N. En. 40-11/35-
1997E), U.S. Environmental Protection Agency (EPA 905-R-97-013), 76 pages.
U.S. AEC. 1974. United States Atomic Energy Commission (U.S. AEC), Idaho National
Engineering Laboratory 1973 Environmental Monitoring Program Report, Idaho
Operations Office, United States Atomic Energy Commission, Idaho Falls, Idaho.
R-1
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APPENDIX A - GLOSSARY OF TERMS AND ACRONYMS
AEC
Ci
137Cs
DOE
DQO
EDR
EIC
EML
EPA
152Eu
ERAMS
ERAMSI
ERAMS II
ERD
3H
129i
131i
85K|.
LANL
MARLAP
MARSSIM
NADP/NTN
NAREL
147Nd
NERDC
NEWNET
NRC
ORIA
210pb
Po
PIC
Pu
RAC
222Rn
RTGs
SAB
SOLEC
90S|.
TLD
TMI
U
US
USA
USCG
USGS
- Atomic Energy Commission (U.S. AEC)
- Curie (unit of radioactivity)
- Cesium 137, a radioactive isotope of cesium
- Department of Energy (U.S. DOE)
- Data Quality Objectives
- Environmental Data Reports
- Electret jonization Chamber
- Environmental Measurements Laboratory
- U.S. Environmental Protection Agency (U.S. EPA)
- Europium-152, a radioactive isotope of europium
- Environmental Radiation Ambient Monitoring System
- First ERAMS (D Advisory by the U.S. EPA/SAB/RAC
- Second ERAMS (N)Advisory by the U.S. EPA/SAB/RAC
- Environmental Radiation Data
- IHydrogen-3 (tritium), a radioactive isotope of hydrogen
- lodine-129, a radioactive isotope of iodine
- lodine-131, a radioactive isotope of iodine
- Krypton-85, a radioactive isotope of krypton
- Los Alamos Rational Laboratory
- Multi-Agency Radiation Laboratory Analytical Procedures (Manual)
- Multi-Agency Radiation Survey and Site Investigation Manual
- .National Atmospheric Deposition Program/l\|ational Trends l\[etwork
- .National Air and Radiation Environmental Laboratory (U.S. EPA)
- .Neodymium -147, a radioactive isotope of neodymium
- .National Environmental Radiation Data Center
- .Neighborhood Environmental Watch Network
- U.S. l\[uclear Regulatory Commission (U.S. NRC)
- Office of Radiation and indoor Air (U.S. EPA)
- Lead-210, a radioactive isotope of lead
- Polonium, as an element (Po), or as an isotope (e.g., 210Po, 214Po)
- Pressurized jonization Chamber
- Plutonium, as an element (Pu) or as an isotope (e.g., 239Pu, 240Pu)
- Radiation Advisory Committee (U.S. EPA/SAB/RAC)
- Radon, as an element (Rn), or as an isotope (e.g., Radon-222)
- Radioisotope Thermal Generators
- Science Advisory Board (U.S. EPA/SAB)
- State of the (Great) Lakes Environmental Conference
- Strontium-90, a radioactive isotope of strontium
- Thermoluminescent Dosimeter
- Three-Mile island (Nuclear Generating Station)
- .Uranium, as an element (U), or as an isotope (e.g., 234U, 235U, 238U)
- .United States
- .United States of America
- .United States Coast Guard
- .United States Geological Survey
A-1
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USSR - IJnion of Soviet Socialist Republics
A-2
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