&EPA
United States
Environmental Protection
Agency
Office of Radiation and Indoor Air
National Air and Radiation
Environmental Laboratory
EPA402-R-09-007
June 2009
www.epa.gov/narel
Radiological Laboratory Sample
Analysis Guide for Incidents
of National Significance -
Radionuclides in Air
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EPA 402- R-09-007
www.epa.gov
June 2009
Revision 0
Radiological Laboratory
Sample Analysis Guide for
Incidents of National Significance -
Radionuclides in Air
U.S. Environmental Protection Agency
Office of Air and Radiation
Office of Radiation and Indoor Air
National Air and Radiation Environmental Laboratory
Montgomery, AL 36115
Recycled/Recyclable
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This report was prepared for the National Air and Radiation Environmental Laboratory of the Office of Radiation
and Indoor Air, United States Environmental Protection Agency. It was prepared by Environmental Management
Support, Inc., of Silver Spring, Maryland, under contracts 68-W-03-038, work assignment 35, and EP-W-07-037,
work assignments B-33and 1-33, all managed by David Carman. Mention of trade names or specific applications
does not imply endorsement or acceptance by EPA.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Preface
The document describes the likely analytical decision paths that would be made by personnel at a
radioanalytical laboratory following a radiological or nuclear incident, such as that caused by a
terrorist attack. EPA's responsibilities, as outlined in the National Response Framework, include
response and recovery actions to detect and identify radioactive substances and to coordinate federal
radiological monitoring and assessment activities. This document was developed to provide guidance
to those radioanalytical laboratories that will support EPA's response and recovery actions following
a radiological or nuclear incident of national significance (INS).
The need to ensure adequate laboratory infrastructure to support response and recovery actions
following a major radiological incident has been recognized by a number of federal agencies. The
Integrated Consortium of Laboratory Networks (ICLN), created in 2005 by 10 federal agencies1,
consists of existing laboratory networks across the Federal Government. The ICLN is designed to
provide a national infrastructure with a coordinated and operational system of laboratory networks
that provide timely, high quality, and interpretable results for early detection and effective
consequence management of acts of terrorism and other events requiring an integrated laboratory
response. It also designates responsible federal agencies (RFAs) to provide laboratory support across
response phases for chemical, biological, and radiological agents. To meet its RFA responsibilities
for environmental samples, EPA has established the Environmental Response Laboratory Network
(ERLN) to address chemical, biological, and radiological threats. For radiological agents, EPA is the
RFA for monitoring, surveillance, and remediation, and will share responsibility for overall incident
response with the U.S. Department of Energy (DOE). As part of the ERLN, EPA's Office of
Radiation and Indoor Air is leading an initiative to ensure that sufficient environmental
radioanalytical capability and competency exists to carry out EPA's designated RFA responsibilities.
This document presents three radioanalytical scenarios, responding to two different public health
questions, that address the immediate need to determine the concentration of known or unknown
radionuclides in air particulate samples. The scenarios are based upon the radionuclides that probably
would be released by a radiological dispersal device into the atmosphere. The first analytical scenario
assesses whether air particulate samples indicate immediate threats to human health, at identified
Protective Action Guides doses, and warrant implementation of protective measures specific to
radiation concerns. The second assesses the radionuclide content of samples subsequent to the initial
response phase and assesses radionuclide concentrations down to the lowest risk levels.
The third situation assumes that the radioactive contaminants are known, and a shortened version
of the first two analytical scenarios is used to help expedite the analysis process. Use of established
analytical schemes will increase the laboratory efficiency so that large numbers of samples can be
analyzed in a timely manner. The use of the analytical schemes and the associated measurement
quality objectives also will ensure that the radioanalytical data produced will be of known quality
appropriate for the intended incident response decisions.
1 Departments of Agriculture, Commerce, Defense, Energy, Health and Human Services, Homeland Security, Interior,
Justice, and State, and the U.S. Environmental Protection Agency.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
As with any technical endeavor, actual radioanalytical projects may require particular methods or
techniques to meet specific measurement quality objectives. The document cannot address a
complete catalog of analytical methodologies or potential radionuclides. Radiochemical methods to
support response and recovery actions following a radiological or nuclear INS can be found in
Standardized Analytical Methods for Environmental Restoration Following Homeland Security
Events, Revision 4.0.
Detailed guidance on recommended radioanalytical practices may be found in the Multi-Agency
Radiological Laboratory Analytical Protocols Manual (MARLAP) referenced in this document.
Familiarity with Chapters 2 and 3 of MARLAP will be of significant benefit to the users of this
guide.
This document is one in a planned series designed to present radioanalytical laboratory personnel,
Incident Commanders (and their designees), and other field response personnel with key laboratory
operational considerations and likely radioanalytical requirements, decision paths, and default data
quality and measurement quality obj ectives for samples taken after a radiological or nuclear incident,
including incidents caused by a terrorist attack. Documents currently completed or in preparation
include:
• Radiological Laboratory Sample Analysis Guide for Incidents of National Significance -
Radionuclides in Water (EPA 402-R-07-007, January 2008)
• Radiological Laboratory Sample Analysis Guide for Incidents of National Significance -
Radionuclides in Air (EPA 402-R-09-007, June 2009)
• Radiological Laboratory Sample Screening Analysis Guide for Incidents of National
Significance (EPA 402-R-09-008, June 2009)
• Method Validation Guide for Qualifying Methods Used by Radiological Laboratories
Participating in Incident Response Activities (EPA 402-R-09-006, June 2009)
• Guide for Radiological Laboratories for the Identification, Preparation, and Implementation of
Core Operations for Radiological Incident Response (in preparation)
• Guide for Radiological Laboratories for the Control of Radioactive Contamination and
Radiation (in preparation)
• Radiological Laboratory Sample Analysis Guide for Incidents of National Significance -
Radionuclides in Soil (in preparation)
Comments on this document, or suggestions for future editions, should be addressed to:
Dr. John Griggs
U.S. Environmental Protection Agency
Office of Radiation and Indoor Air
National Air and Radiation Environmental Laboratory
540 South Morris Avenue
Montgomery, AL 36115-2601
(334) 270-3450
Griggs.John@epa.gov
11
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Acknowledgments
This manual was developed by the National Air and Radiation Environmental Laboratory (NAREL)
of EPA's Office of Radiation and Indoor Air (ORIA).
Dr. John Griggs served as project lead for this document. Several individuals provided valuable
support and input to this document throughout its development. Special acknowledgment and
appreciation are extended to Dr. Keith McCroan, ORIA/NAREL; Mr. Daniel Mackney for his
support in instrumental analysis, ORIA/NAREL; Ms. Lindsey Bender, ORIA/Radiation Protection
Division (RPD); Dr. Lowell Ralston and Mr. Edward Tupin, CHP, both of ORIA/RPD; Ms. Schatzi
Fitz-James, Office of Emergency Management, Homeland Security Laboratory Response Center;
and Mr. David Garman, ORIA/NAREL. We also wish to acknowledge the external peer reviews
conducted by Carolyn Wong, David Burns, and Sherrod Maxwell, whose thoughtful comments
contributed greatly to the understanding and quality of the report. Numerous other individuals both
inside and outside of EPA provided peer review of this document, and their suggestions contributed
greatly to the quality and consistency of the final document. Technical support was provided by Dr.
N. Jay Bassin, Dr. Anna Berne, Dr. Carl V. Gogolak, Dr. Robert Litman, Dr. David McCurdy, and
Mr. Robert Shannon of Environmental Management Support, Inc.
in
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Contents
Acronyms, Abbreviations, Units, and Symbols vii
Radiometric and General Unit Conversions ix
I. INTRODUCTION 1
A. Purpose and Objectives 2
B. Scope of Radiological Scenarios 3
C. Relationship of PAG, AAL, ADL, Risk Levels, and WMR 5
D. Analytical Response Time 8
E. Implementation 9
F. References 10
H. RADIONUCLIDES 13
HI. DISCUSSION 14
A. Sampling and Processing at the Laboratory 14
B. Discrete Radioactive Particles 17
C. Sampling for Iodine and Tritium 18
D. Crosswalk of Data Values 20
IV. SCENARIO 1 (Identifying Air Samples with Highest Activities) 21
Notes to Scenario 1: High-Flow Air Sampling 22
V. SCENARIO 2 (Priority to Air Samples with Highest Activities) 33
Notes to Scenario 2: Low-Flow Air Sampling 34
VI. SCENARIO 3 (Radionuclides in Air Particulate Samples Have Been Identified) 42
Notes for Scenario 3: Contaminating Radionuclides Known 43
APPENDIX I. Tables of Radioanalytical Parameters for Radionuclides of Concern 47
APPENDIX n. Example of High-Concentration Air Particulates (Radioanalytical Scenario 1) 53
Description 53
Event Sequence 53
Analysis Paths 53
APPENDIX IE. Example of Air Particulate Filters Contaminated at Less than 2 rem (Radioanalytical
Scenario 2) 58
Description 58
Event Sequence 58
Analysis Paths 58
APPENDIX IV. Example of Air Particulate Filters With Known Radiological Contaminants
(Radioanalytical Scenario 3) 63
iv
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Description 63
Event Sequence 63
Analysis Paths 63
APPENDIX V. Representative Analytical Processing Times 66
APPENDIX VI. Establishing DQOs and MQOs for Incident Response Analysis 70
APPENDIX VII. Glossary 82
Figures
Figure 1 - Air Sample Scenarios and Response Phases 4
Figure 2 - Air Scenario 1 Analytical Flow 21
Figure 3 - Air Scenario 2 Analytical Flow 33
Figure 4 - Air Scenario 3 Analytical Flow 42
Figure 5 - Approximate Timeframe for Radiochemical Analyses (Radioanalytical Scenario 1) 66
Figure 6 - Approximate Timeframe for Radiochemical Analyses (Radioanalytical Scenario 2) 67
Figure 7 - Approximate Timeframe for Radiochemical Analyses (Radioanalytical Scenario 3) 68
Figure 8 - A Decision Point in a Flowchart 70
Figure 9 - The Data Quality Objectives Process 71
Figure 10 -Example Illustrating Case (a). Baseline Condition (null hypothesis): Parameter Exceeds
the Analytical Action Level 74
Figure 11 -Example Illustrating Case (b). Baseline Condition (null hypothesis): Parameter Does Not
Exceed the Analytical Action Level 74
Tables
Table 1 - Analytical Response Responsibilities 4
Table 2 - Relationship Among Dose, AAL, ADL, and UMR 7
Table 3 - Radionuclides of Concern 13
Table 4 - Crosswalk of PAG, AAL, ADL, and UMR Values 20
Table 5 - Radionuclides with Low-Abundance Gamma Rays 32
Table 6 - Beta "Only" Emitters 32
Table 7A - Analytical Decision Levels (ADL) and Required Method Uncertainty Using Gross Alpha
Screening Methods 47
Table 7B - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty Using Gross Beta-Gamma Screening Methods 48
Table 7C - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty Using Alpha Radionuclide Specific Methods 49
Table 7D - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty Using Beta-Gamma Radionuclide-Specific Methods 50
Table 8A - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty at 10~4 and 10~6 Risk Using Alpha Radionuclide-Specific Methods 51
v
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Table 8B - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty at 1CT4 and 1CT6 Risk Using Beta-Gamma Radionuclide-Specific Methods .... 52
Table 9 - Air Monitoring: Air Filter Counting Times for Various PAGs and Sampling Rates and
Durations 69
Table 10A - The DQO Process Applied to a Decision Point 72
Table 10B - Possible Decision Errors 72
Table IOC - The DQO Process Applied to a Decision Point 73
Table 10D - Values of z;_a (or z^) for Some Commonly Used Values of a (or/?) 74
Table 11A - DQOs and MQOs for Radioanalytical Scenario 1. Laboratory Prioritization Decisions
Based on Screening 76
Table 1 IB - DQOs and MQOs for Scenario 1. Values Reported to the Incident Commander Based
on Radionuclide-Specific Measurements 77
Table 12A - DQOs and MQOs for Radioanalytical Scenario 2. Laboratory Prioritization Decisions
Based on Screening (Gross a, P, or y Measurements) and 131I 78
Table 12B - DQOs and MQOs for Scenario 2. Values Reported to the Incident Commander Based
on Radionuclide-Specific Measurements 79
Table 13 - DQOs and MQOs for Scenario 3 80
Table 14 - Estimated Counting Times for a Filter Sample Analyzed on a Gas Proportional Counter
To Reach an Alpha Detection Limit and a 10% Count Rate Uncertainty for Low- and High-
Volume Air Samples at 500-mrem AAL Values 81
VI
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Acronyms, Abbreviations, Units, and Symbols
(Excluding chemical symbols and formulas)
a alpha particle
a probability of a Type I decision error
AAL analytical action level
ADL analytical decision level
AL action level
AS alpha spectrometry
P beta particle
ft probability of a Type n decision error
Bq becquerel (1 dps)
CERCLA .... Comprehensive Environmental Response, Compensation, and Liability Act of 1980
("Superfund")
cfm cubic feet per minute
CFR Code of Federal Regulations
cm centimeter
COC chain of custody
cpm counts per minute
d day
DAC derived air concentration
DCF Dose Conversion Factor
DL discrimination limit
DOE United States Department of Energy
DP decay product(s)
dpm disintegration per minute
dps disintegration per second
DQO data quality objective
DRP discrete radioactive particle
e~ electron
Epmax maximum energy of the beta-particle emission
EDD electronic data deliverable
ERLN Environmental Response Laboratory Network
EPA United States Environmental Protection Agency
y gamma ray
g gram
Ge germanium [semiconductor]
GM Geiger-Muller [detector]
GP gas proportional
GPC gas proportional counting/counter
GS gamma spectrometry
Gy gray
h hour
H0 null hypothesis
Hj alternate hypothesis
HF hydrofluoric acid
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
HPGe high-purity germanium [detector]
1C Incident Commander
ICC Incident Command Center
ICLN Integrated Consortium of Laboratory Networks
ICRP International Commission on Radiological Protection
IND improvised nuclear device (i.e., a nuclear bomb)
INS incident of national significance
keV kilo (thousand) electron volts
L liter
LBGR lower bound of the gray region
LEPD low-energy photon detector
LS liquid scintillation
LSC liquid scintillation counter/counting
MARLAP .... Multi-Agency Radiological Laboratory Analytical Protocols Manual
MARSSEVI . . . Multi-Agency Radiation Survey and Site Investigation Manual
MeV mega (million) electron volts
mg milligram (1CT3 g)
mL milliliter(lCT3L)
mrem millirem (1CT3 rem)
ug microgram (1CT6 g)
MDC minimum detectable concentration
min minute
MQO measurement quality objective
Nal(Tl) thallium-activated sodium iodide detector
NORM naturally occurring radioactive materials
#V required relative method uncertainty
PAG protective action guide
pCi picocurie (1CT12 Ci)
QA quality assurance
QC quality control
rad radiation absorbed dose
ROD radiological dispersal device (i.e., "dirty bomb")
RDL required detection limit
REGe reverse electrode germanium [detector]
RFA responsible federal agency
rem roentgen equivalent man
s second
SI International System of Units
SOP standard operating procedure
Sv sievert
TAT turnaround time
TEDA triethylenediamine
TEDE total effective dose equivalent
UBGR upper bound of the gray region
MMR required method uncertainty
y year
Vlll
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Radiometric and General Unit Conversions
To Convert
years (y)
disintegrations
per second (dps)
Bq
Bq/kg
Bq/m3
Bq/m3
microcuries per
milliliter
(nCi/mL)
disintegrations
per minute (dpm)
cubic feet (ft3)
gallons (gal)
gray (Gy)
roentgen equiva-
lent man (rem)
To
seconds (s)
minutes (min)
hours (h)
days (d)
becquerels (Bq)
picocuries (pCi)
pCi/g
pCi/L
Bq/L
pCi/L
uCi
pCi
cubic meters
(m3)
liters (L)
rad
si evert (Sv)
Multiply by
3.16x 107
5.26 x 105
8.77 x 103
3.65 x 102
1
27.0
2.70 x 1Q-2
2.70 x 1Q-2
io-3
109
4.50 x 1Q-7
4.50 x 1Q-1
2.83xlO~2
3.78
IO2
io-2
To Convert
s
min
h
d
Bq
pCi
pCi/g
pCi/L
Bq/L
pCi/L
pCi
cubic meters
(m3)
liters
rad
Sv
To
y
dps
Bq
Bq/kg
Bq/m3
Bq/m3
uCi/mL
dpm
cubic
feet (ft3)
gallons
Gy
rem
Multiply by
3.17 x 1Q-8
1.90 x 10~6
1.14 x 1Q-4
2.74x ID'3
1
3.70 x 1Q-2
37.0
37.0
IO3
io-9
2.22
35.3
0.264
io-2
IO2
NOTE: Traditional units are used throughout this document instead of International System of Units
(SI) units. Protective Action Guides (PAGs) and their derived concentrations appear in official
documents in the traditional units and are in common usage. Conversion to SI units will be aided by
the unit conversions in this table. Conversions are exact to three significant figures, consistent with
their intended application.
IX
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
I. INTRODUCTION
This guide deals with the analysis of air samples that may have been contaminated as the result of
a radiological or nuclear event, such as a radiological dispersal device (RDD), improvised nuclear
device (IND), or an intentional release of radioactive materials into the atmosphere via mechanical
or other methods. In the event of a major incident that releases radioactive materials to the
environment, EPA will turn to selected radioanalytical laboratories to support its response and
recovery activities. In order to expedite sample analyses and data feedback, the laboratories will need
guidance on EPA's expectations.
A response to a radiation release to the environment likely will occur in three phases: "early,"
"intermediate," and "recovery." Each phase of an incident response will require different and distinct
radioanalytical resources to address the different consequences, management, priorities, and
requirements of each phase. Some of the more important radioanalytical laboratory responsibilities
germane to an incident response consist of:
• Radionuclide identification and quantification,
Sample load capability,
• Sample processing turnaround time,
Quality of analytical data, and
• Data transfer capability.
The early phase begins at the initial event and lasts for three or four days, during which data are
scarce and pre-planned dispersion models may be used when appliable. During this phase,
responders are primarily concerned about evacuating people, sheltering them in place, or restricting
exposure to ambient air and dust. The purpose of the actions and evaluations taken during the early
phase is to minimize exposure and to prevent acute health effects. The Protective Action Guides
(PAGs) for radiological emergencies recommend evacuation of a population if the projected short-
term total effective dose equivalent1 (TEDE) exceeds 1 rem.2 The nominal trigger for sheltering is
1-rem over four days (projected avoided inhalation dose). The radioanalytical resource requirements
(field or fixed laboratory) for this early phase may vary significantly depending on the time frame,
source-term nuclide (see glossary), and the extent of the contamination.
The intermediate phase begins when no more radiation releases are expected, and the source term
contamination radionuclides have been qualitatively identified. In this phase, radionuclide concentra-
tions, extent of the contaminated zone, and matrices (air, water, soil) required for analysis may not
be well defined. The radioanalytical resources needed will depend on the radionuclide analytical
action level (AAL) developed for the various media important to human exposure. The AAL may
change depending upon the stage of the event, the appropriate PAGs, or riskvalues. The radionuclide
AALs (derived concentrations) for different media types are based on the PAGs or risk values. For
1 The sum of the effective dose equivalent (for external exposure) and the committed effective dose equivalent (for
internal exposure). TEDE is expressed in units of sievert (Sv) or rem.
2 The common unit for the effective or "equivalent" dose of radiation received by a living organism, equal to the actual
dose (in rads) multiplied by a factor representing the danger of the radiation. "Rem" stands for "roentgen equivalent
man," meaning that it measures the biological effects of ionizing radiation in humans. One rem is equal to 0.01 Sv.
1
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
the intermediate phase, PAGs have been established to limit the projected radiation doses for
different exposure periods: not to exceed 2-rem TEDE over the first year, 500-mrem TEDE during
the second year, or 5 rem over the next 50 years (including the first and second years of the incident).
In addition, radionuclide concentration limits for food and water as regulated by the Food and Drug
Administration and EPA would be applicable.
The final, or "recovery," phase occurs as part of a radiological incident site-remediation effort.
During this phase, when site atmospheric characterization and remediation cleanup effectiveness are
determined, there is a potential for more extensive radiochemical analyses at the lowest radionuclide
concentrations. Airborne radionuclide concentrations therefore should be compared to derived air
concentrations (DACs) corresponding to 1CT4 and 1CT6 lifetime cancer morbidity risk factors for long-
term exposures.
During all phases of an incident response, radioanalytical resources are needed for identifying the
radionuclide source term and quantification of the radionuclides in a variety of sample media.
Additionally, gross screening of samples to prioritize sample processing or to obtain information
related to the general level of contamination in samples is also necessary. This guide has been
developed to provide the Incident Commander (1C)3 and the laboratories used during an incident with
a logical processing scheme to prioritize sample processing in relation to the radionuclide air
concentrations corresponding to established PAGs or risk levels.
A. Purpose and Objectives
This document is intended to assist those analytical laboratories that will be called upon to provide
rapid support to field personnel and decision makers following a radiological release to the
atmosphere. Because EPA recognizes that in the early and intermediate period following such a
release there may not be sufficient time for the Incident Command Center (ICC) to coordinate and
communicate complete measurement quality objectives and analytical priorities to the laboratory,
this document will enable laboratories to proceed with a consistent approach to developing and
reporting data suitable for the anticipated use.
The ultimate purpose of the screening process described in this guide is to ensure that laboratories
can adequately respond to the Incident Commander's requirements with timely analytical results so
that public health is protected. The recommendations in this guide are based upon EPA's PAGs and
risk factors for radionuclides in air.4 The PAGs and risk factors are converted to air concentrations
for individual radionuclides based on the decay particle, its energy, and inhalation/residence time
dose models for a standard person.
Analytical action levels (AALs) are derived radionuclide-specific activity concentrations in air that
correspond to specific EPA PAG dose limits or acceptable Agency risk levels. In this document,
EPA uses AALs to prioritize air filter samples for radiochemical analyses. Subsection C, on page
3 Throughout this guide, the term "Incident Commander" (or "1C") includes his or her designee.
4 Eckerman et al.(1999), EPA (2002), ICRP (1995, 1996)
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
5, describes the methods and assumptions EPA
uses to calculate AALs for the radionuclides
discussed in this document.
One of the key objectives in this document is
to explain the responsibilities indicated above
in terms of analytical processes. While the 1C
should provide the necessary information
(analytes, matrices, measurement quality
objectives) that define the scope of the
laboratory's processing requirements and
results, the laboratory should ensure that the
methods used have been validated and will
meet the desired measurement quality objec-
tives (MQOs) and the required turnaround
time. In the event that laboratories receive
samples without complete documentation or
direction, laboratories may follow the proce-
dures and examples in this document and be
confident that their analyses will provide
reasonable and consistent results.
This document is not meant to replace any
field monitoring decisions on sample prioriti-
zation. It is intended as a guide for how to
establish priorities for samples received at the
laboratory at different times throughout the
response, and it should provide to the 1C the
basis for understanding the nature and limita-
tions of the data received from the laboratories.
B. Scope of Radiological Scenarios
Radiological events can be subdivided into
three phases, which are generally defined in
this document as: early (onset of the event to
about day 4), intermediate (about day 4 to
about day 30), and recovery (beyond about day
30). This guide concentrates on the time from
the end of the early phase, through the
intermediate phase, and into the recovery
phase. During the early phase, analytical
priorities need to address the protection of the
public and field personnel due to potentially
high levels of radioactivity and to provide for
qualitative identification of radionuclides.
Action Levels: AALs and ADLs
This guide relies heavily on the use of the terms "analytical
action level" (AAL), "required method uncertainty" (MMR),
and "analytical decision level" (ADL) in characterizing the
desired levels of performance of analytical methods and the
radioanalytical results for use in decisions.
The term "analytical action level" (AAL) is used as a general
term denoting the radionuclide concentration at which action
must be taken by incident responders. The AAL will
correspond to aPAGvalue (short-term dose-based) orarisk-
based value (related to long-term health effects). Ideally, the
Incident Commander (1C) will provide the laboratory with
the dose- or concentration-based action level and the
acceptable decision error rates. If not, this guide provides
"default"values. For example, the air concentration of 226Ra
corresponding to the 500-mrem PAG is 1.8 pCi/m3. Tables
7A, 7B, 7C, and 7D show the AALs associated with the 2-
rem, 500-mrem, 10~4 risk and 10~6 risk values for selected
alpha, beta, and gamma-emitting radionuclides. Incident-
specific action levels different from the ones used in the
tables may be promulgated. In these cases, the corresponding
AALs canbe calculated as a linear function of either the 500-
mrem AALs or the 10"4 or 10^ risk values (see Scenario 3
for an example of an event-specific AAL calculated in this
manner).
The selection, validation, and execution of a particular
analytical method rely on the ability of that method to
produce a result with the specified uncertainty, WMR, at the
AAL. These conditions assure that the quality of the final
sample analysis data will be adequate for making critical
decisions. Whenever the reported sample activity or concen-
tration exceeds a pre-defined decision level (the ADL),
appropriate action is warranted. The derivation and use of
AAL, MMR, and ADL are discussed in detail throughout this
guide. While closely interrelated, it is important to note that
the use of AAL (and associated WMR) and ADL represent
distinct concepts; they may not be used interchangeably but
rather should be interpreted and applied according the
guidelines of this document.
The required method uncertainty and ADL will change
depending upon the acceptable decision error rate. Tables
provided in Appendix I list the AAL, ADL, and MMR values
for the radionuclides of concern. The tables present gross
screening and radionuclide-specific measurements for alpha
and beta/gamma-emitting radionuclides. Derivation of the
ADL values for each of these tables can be found in
Appendix VI. The listed AALs are applicable as default
values based on generic conversions of the dose level to
concentration in air for a specific radionuclide. The 1C may
provide incident-specific action levels or decision error rates
that would supersede these values. In this case, the laboratory
will need to develop new tables for all values, using the
process described in Appendix VI.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
During the intermediate phase, the radionuclides and matrices of concern are known qualitatively,
and the quantitative levels suitable for making decisions based on action levels need to be
determined rapidly. The time period of an incident where this document will find its greatest utility
is early in the intermediate phase through the end of the recovery phase. Laboratories performing
analyses must optimize sample processing and rapid delivery of sample results to permit assessment
in a timely manner of whether or not AALs have been exceeded. During the recovery phase, the
screening techniques used for samples will be less significant because the radionuclides from the
event are likely to have been characterized already. This is represented by the lower portions of the
flowcharts, which address analyses of specific radionuclides.
This document presents three analytical scenarios to aid laboratories in establishing priorities for
analyzing samples received during the response to a radiological release. The first two assume that
the radioactive material is unknown. Table 1 summarizes the relevant responsibilities of the 1C and
the laboratory manager during such a response, and Figure 1 depicts how they relate to the response
team's needs for sample prioritization.
TABLE 1 - Analytical Response Responsibilities
Reporting Turnaround
Information Sample Method DQOs/ (Results, Analyte Sampling Specs Hot Time Filter Procedure
Provided... Priority Uncertainty MQOs Anomalies) Selection (Time, Volume) Particles Compliance Media Selection
By: 1C 1C 1C Lab 1C* 1C Lab Lab 1C Lab
To: Lab Lab Lab 1C Lab Lab 1C 1C Lab 1C
'During the early phase, the laboratory will identify the radionuclides present. Once it is determined which radionuclides are present, the 1C may
decide analytical priorities.
Early Phase
Day 3 Following Event
Intermediate Phase
Weeks to Months Following Event
Recover
Unknown
radionuclides?
(Scenario 1)
Radionuclides characterized
(Radioanalytical Scenario 3)
Yes,
but priority set
low* by 1C
No, and
activity is
Low
Radio-
analytical
Scenario 3
Sample
priority based on
oncentration
Priority set
by 1C
Radioanalytical
Yes, and priority set
high* by 1C
Determination of
radionuclides < 1(H
risk level
Determination of
radionuclides >1(H risk level
Gross quantification
of activity at
2 rem and 500 mrem
"Note: "High" and "Low"
refer to processing
priorities, not activity
Figure 1 -Air Sample Scenarios and Response Phases
4
-------
Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
• In Radioanalytical Scenario 1, the identity of the radionuclides and potential concentrations are
unknown. This is most likely to occur during the early phase of the event. The laboratory's
priority is to identify all the radionuclides present and their air concentrations. Air particulate
samples (filters) and aerosol samples (canisters, see page 19), taken from an area in the vicinity
of the radiological event, are suspected to be highly contaminated with an unknown quantity of
yet unidentified radionuclides. The radionuclide identities and concentrations taken from various
analyses will be compared to the 2-rem and 500-mrem AAL values, giving priority to the highest
activity samples. MQOs for these AALs can be met with smaller volume air samples than
normal, allowing shorter sampling times.
• The second scenario (Radioanalytical Scenario 2) addresses the need to identify areas of
acceptable air quality and will occur later in the intermediate phase and into the recovery phase.
This scenario requires the laboratory to determine whether identified or partially identified
airborne radionuclide concentrations are above the 500-mrem AAL value or correspond to
concentrations in the 10~4 to 10~6 risk levels. Decisions regarding priority are based on EPA's
PAGs or risk factors. Samples with concentrations corresponding to the 10~4 and 10~6 risk-based
factors are of lower analytical priority at this time.
• Radioanalytical Scenario 3 is where the radionuclides have been identified, and this scenario
would normally occur during the intermediate/recovery phase. This scenario is focused on
assessing air-particulate filters that have concentrations below an associated 10~4 long-term risk
factor. So while Figure 1 depicts Scenario 3 occurring during the later intermediate phase,
Scenario 3 could occur earlier, in which case the laboratory need not waste analytical processing
time trying to identify which radionuclides are present. The flow focuses on establishing the
priority for processing samples based on the gross concentration screening values for the specific
radionuclides. Formal evaluation of other naturally occurring radionuclides may be necessary
when assessingthe long-term risks of the sampled aerosol. In the later phases, sample input from
Radioanalytical Scenario 1 or 2 flow schemes (as is the case for Scenario 2) is not anticipated.
These scenarios may be applicable in different phases of the event, although as was previously
indicated, Scenario 1 is usually the early phase, and Scenario 2 is the late-intermediate to recovery
phase. The flow charts (Figures 2-4) assume that the laboratory already has acquired or developed
the general guidance discussed for each scenario. However, laboratories should note that at any time
samples may be assigned a specific priority based on the status or phase of the incident.
Samples that may become evidence in a criminal investigation must be handled separately
(particularly with respect to chain of custody), and the laboratory should receive information form
the Incident Commander or lead law-enforcement agency on how to process these samples.
C. Relationship of PAG, AAL, ADL, Risk Levels, and UMR
PAGs reflect the limits of dose that are allowed to be received by individuals during different phases
of an incident. Because laboratories will determine sample concentrations in pCi/m3, AALs (see
Tables 7A-7D) are action levels expressed in units of pCi/m3 that equate to PAG annual dose limits
of 2 rem (first year) and 500 mrem (second year). These are based on:
-------
Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
• Maximum inhalation dose coefficients (DCFs) (in units of Sv/Bq) taken from ICRP
Publication 72 (ICRP 1996) or from Federal Guidance Report 13 CD Supplement (EPA
2002). From among the coefficients listed for each radionuclide for lung clearance
classifications of fast (F), medium (M), and slow (S), EPA chose the coefficient that gave
the largest or maximum committed effective dose per unit intake for the adult member of the
public. Dose coefficients in Sv/Bq were converted to units of mrem/pCi by multiplying by
a conversion factor of 3,700.
• An exposure duration of 1 year (365 days).
• An inhalation rate of 22.1 m3/d taken from ICRP Publication 66 (ICRP 1995) for an adult
member of the public.
Accordingly, PAG-derived AALs are calculated for each radionuclide according to the following
equation:
AAL (pCi/m3) = PAG / (DCF x 22.1 m3/d x 365 d/y)
For example, the AAL for 241Am corresponding to the 2000 mrem/y dose limit is calculated as:
AAL 241Am = 2000 mrem/y / (0.36 mrem/pCi x 22.1 m3/d x 365 d/y)
= 0.7 pCi/m3
Action levels can be either risk-based or dose-based. Risk-based AALs (Tables 8A and 8B) are
expressed in units of pCi/m3 that equate to EPA's acceptable lower and upper cancer risk levels for
cleanup, namely 1 in 1 million (lxlO~6) and 1 in 10,000 (lxlO~4). These are based on:
• Maximum inhalation risk coefficients (in units of Sv/Bq) taken from Federal Guidance
Report 13 (Eckerman et al., 1999) or from Federal Guidance Report 13 CD Supplement
(EPA 2002). From among the coefficients listed for each radionuclide for lung clearance
classifications of fast (F), medium (M), and slow (S), EPA chose the coefficient that gave
the largest or maximum lifetime, age-averaged, excess morbidity (total cancer) risk per unit
intake. Risk coefficients in Risk/Bq were converted to units of Risk/pCi by dividing by the
conversion factor of 27.027.
• An exposure duration of 1 year (365 days)
• An inhalation rate of 22.1 m3/y taken from ICRP Publication 66 (ICRP 1995) for an adult
member of the public.
Accordingly, risk-based AALs are calculated for each radionuclide according to the following
equation:
AAL (pCi/m3) = Risk Level / (Risk coeff. x 22.1 m3/d x 365 d/y)
For example, the AAL for 241Am corresponding to the 10~4 risk level is calculated as:
AAL241 Am = lxlO-4risk/(3.8xlO-8risk/pCi x 22.1 m3/d x 365 d/y)
= 0.33 pCi/m3.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Decisions related to the processing and prioritization of specific samples will be made by laboratory
personnel at the laboratory by comparing the results of radioanalytical measurements to "analytical
decision level" (ADL) concentrations. Whenever the measured analyte concentration equals or
exceeds the applicable ADL concentration, it will be concluded that the AAL (PAG or risk factor)
has been exceeded. The ADL concentrations are always less than the corresponding AAL values by
an interval calculated to provide statistical confidence when deciding whether the corresponding
AAL has or has not been exceeded. The magnitude of this interval corresponds to the maximum
uncertainty that would be consistent with acceptable decision error rates established during the data
quality objective (DQO)/MQO process.5 This uncertainty is referred to as the required method
uncertainty, UMR, and is defined in MARLAP.
MQOs are statements of performance objectives or requirements for selected method performance
characteristics. Method performance characteristics include the method uncertainty, the method's
detection capability, the method's quantification capability, the method's range, the method's
specificity, and the method's ruggedness. An example MQO for the method uncertainty at a specified
concentration, such as the action level, could be:
"A required method uncertainty for 226Ra of 2.1 pCi/m3 or less at the analytical action
level of 7.0 pCi/m3 for screening methods of analysis."
Table 2 provides examples of a dose and its corresponding AAL, ADL, and required method
uncertainty (z/MR) for 226Ra. Note that there are differences in these values not only based on the dose
or risk, but also on whether or not a screening instrument or radiochemical-specific methods are
used.
TABLE 2 - Relationship Among Dose, AAL, ADL, and «MR for 226Ra
Measurement Type
Screening7
Radionuclide-
Specific
Radionuclide-
Specific
Dose
(mrem) or
Risk-Based
Value
2,000
2,000
(at 10-4 risk)8
AAL6
(pCi/m3)
7.0
7.0
0.44
ADL*
(pCi/m3)
3.5
4.9
0.31
"MR
(pCi/m3)
2.1
0.88
0.055
*ADL values are calculated per equations in Appendix VI
5 Appendix VI provides the derivation and detailed discussion of MQOs, required method uncertainties, and ADLs.
6 See Tables 7A-7D for 2-rem and 500-mrem AALs and Tables 8A and 8B for risk-based AALs.
7 Tables 7A and 7B summarize default ADLs and MMR for gross screening measurements at 2 rem and 500 mrem. Tables
7C and 7D summarize default ADLs and MMR for radionuclide-specific measurements at 2 rem and 500 mrem.
8 Tables 8A and 8B summarize ADLs and WMR for radionuclide-specific measurements at 10"4 and KT6 risk levels.
7
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
The values in the tables in Appendix I are calculated based on tolerable Type I and Type n error rates
for each measurement type as described in Appendix VI.
Laboratories will perform both gross activity measurements and radionuclide-specific measurements
during an incident. Because different DQOs and MQOs are applicable to different types of measure-
ments, different u^ and the corresponding ADL values are provided for screening and radionuclide-
specific analyses. The values for WMR and corresponding ADL for screening and radionuclide-specific
determinations presented in Tables 7A-D, 8A, and 8B (Appendix I) provide laboratories with a
starting point for developing methods and systems for recovery activities. It is anticipated that
incident-specific DQOs and MQOs may be developed by the 1C and provided to the laboratory.
Once the radionuclides are identified, the focus of response activities will shift to assessment of
dispersion, habitability, and long-term health effects. This is the focus of the second scenario, and
again the laboratory's main job will be to prioritize the order of sample analysis based on activity.
It should be noted that, during the intermediate and recovery phases, resuspension of particulates
during remediation may cause airborne radionuclide concentrations to increase. Thus, one cannot
assume that all radionuclide concentrations on air particulate filters will decrease as the event
progresses. Continued sample screening will help provide the laboratory staff with accurate
information regarding activity on the filters.
The attached charts and accompanying numbered notes and data tables depict the anticipated
analytical flow that will assist the lab to respond rapidly and consistently. In keeping with concepts
of theMulti-Agency Radiological Laboratory Analytical Protocols Manual (MARL AP), this guide
does not specify analytical methods. A performance-based approach for the selection of appropriate
analytical methods by the laboratory will be used to achieve MQOs specified by this document and
incident responders.
The MQOs and any other analytical requirements serve as the basis for the laboratory's selection of
a method under a performance-based approach. The laboratory should have method validation and
performance data to demonstrate the method's ability to achieve the project-specific MQOs.
This document presents a default set of MQOs. Actual MQOs, however, always will depend upon
events and may need to be modified by incident responders and project planners to better address
a particular event. However, in order to have an analytical approach in place to address a variety of
incident scenarios, the identified decision points in the accompanying flow diagrams refer to the
default MQOs. The important MQO is the required method uncertainty at the AAL, which together
with the acceptable decision error rates, is used to establish the ADL. At most decision points in the
diagram, the decision is related to the ADL based on either PAG values or risk-based values.
D. Analytical Response Time
Decisions regarding the extent of air contamination will need to be made in a timely manner.
Approximate times required for laboratory processing of these samples and finalizing the sample
results are shown in Appendix V for each radioanalytical scenario. They identify the workflow for
making qualitative and quantitative measurements of high-activity contaminated air particulate
samples (Radioanalytical Scenario 1) and determine whether lower-concentration samples still
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
present longer-term risk (Radioanalytical Scenario 2). The information regarding sample radio-
activity measurements also needs to be communicated vigorously to the 1C so that decisions
regarding movement of population, sheltering, other protective actions, or additional sampling can
be assessed accurately.
E. Implementation
It may be necessary for laboratories to incorporate key aspects of this document into their standard
operating procedures (SOPs). For example, the gross screening process will require specific
standards and response factors for each of the instruments used by the laboratory. This could be a
departure from the laboratory's current screening practice because the activity levels, sample
geometries, and matrices may be significantly different from what the laboratory normally
experiences. Generally, it should be expected that higher activity tracers and QC standards may be
needed for the analysis of higher activity samples.
This guide focuses on the prioritization of sample analyses and some of the technical issues
encountered in performing analyses on air particulate samples received by the laboratory following
a radiological incident. The guidance on how to prepare and calibrate screening instruments for the
support of a radiological incident is outlined in Radiological Laboratory Sample Screening Analysis
Guide for Incidents of National Significance (EPA 402-R-09-007, June 2009). The guide describes
calibration and measurement techniques, instruments used for screening, and provides guidance on
interpretation of screening results.
Laboratories should become proficient with these procedures because they could be tasked to
respond to analytical requests in hours rather than weeks. Thus, laboratory personnel should become
familiar with the recommendations and procedures, and laboratories should conduct both training
and actual "drills" or exercises where analytical scenarios and samples are tested during a controlled
scenario. The frequency and depth of these exercises will be at the discretion of the laboratory
management.
Laboratory personnel also should be cross-trained in different areas of the incident response activities
listed belowto help ensure continuity of sample analysis throughout the duration of the response and
cleanup:
• Equipment calibration and QC checks
Sample receipt and log-in
• Sample tracking and storage
Screening
• Sample preparations
• Analytical separations
• Counting
• Contamination monitoring
• Report generation
• Data review
• Waste management
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
The scope of these activities may be different for incident response than for normal laboratory
operations. In order for the laboratories to be able to begin to process the samples promptly, certain
presumptive values are identified in the tables in this document for action levels, which may be
relied upon in the absence of explicit action levels received from the 1C. However, these values may
change based on the needs of the particular event. MQOs will be stipulated by the 1C and should be
communicated to the laboratory as early as possible so that analysis can meet project objectives.
For air monitoring, MQOs typically would be stated for analytical action levels. In most air
monitoring applications, it is impractical to specify an exact "standard" air volume that is passed
through an air particulate filter, or an iodine cartridge. The activity collected on an air filter (or
cartridge) will vary according to the sampling duration and flow rate. For operational practicality,
the analytical method and analysis time of the measurement should be adjusted to a "hypothetical
minimum" volume sampled so that the MQOs for an AAL can be met for all samples collected
(representing a batch) as long as the actual volume sampled for any sample is equal to or larger than
the "minimum" volume. The value of the "minimum volume" would be selected for a batch of
samples by evaluating the field sample submission form that contains the sample identifications and
corresponding total volumes sampled. For both gross screening and radionuclide-specific analyses,
most laboratories will standardize the counting time of a batch of samples to a single value, normally
the limiting counting time to meet the UUR at the AAL or a detection level. The flow diagram for
Scenario 1 (Figure 2) assumes a collected volume of 68 m3, but volumes may be in the range of 3
to 100 m3. The analytical decision paths in Figure 3 (Scenario 2), which are based on discriminating
500-mrem AAL samples fromlO~4 and 10~6 risk levels, assume a collected volume of 200 to 1,600
m3. Figure 4 (Scenario 3) outlines the flow path when the radionuclides are known.
Once the appropriate method and the appropriate volume have been selected, the laboratory can
select the proper counting time and other parameters to meet the MQOs in the most efficient manner.
Presumably, the volume provided by the 1C will exceed the minimum volume that a laboratory will
need when analyzing a batch of samples. It is also important for laboratories to be in contact with
the ICC regarding requirements for split samples and reserving aliquants of sample digestate for
additional analyses. This may require that more than the minimum volume is collected, that longer
counting times are specified, or that the laboratory has a procedure for splitting a sample before
starting analysis. The measurement uncertainty of the calculated air concentration from the sample
analyzed will be compared to the absolute and required relative method uncertainty.
Finally, it should be noted that laboratories that perform radiochemical analyses on a routine basis
only determine the total activity for a specific radionuclide and do not differentiate among different
chemical species that may be present. This requires a methodology that is not part of the normal
analytical processes for these laboratories.
F. References
Eckerman, K.F., Leggett R.W., Nelson, C.B., Puskin, J.S., and A.C.B Richardson. 1999. Cancer
Risk Coefficients for Environmental Exposure to Radionuclides. Federal Guidance Report
No. 13. EPA 402-R-99-001. Oak Ridge National Laboratory, Oak Ridge, Tennessee.
10
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
U.S. Environmental Protection Agency (EPA). 1992. Manual of Protective Action Guides and
Protective Actions for Nuclear Incidents. Washington, DC. EPA400-R-92-001, May. Available
at: www.epa.gov/radiation/rert/pags.htm.
U.S. Environmental Protection Agency (EPA). 1999. Cancer Risk Coefficients for Environmental
Exposure to Radionuclides. Federal Guidance Report No. 13. EPA402-R-99-001, September.
Available at: www.epa.gov/radiation/assessment/pubs.html.
U.S. Environmental Protection Agency (EPA). 2000. "Radionuclides Notice of Data Availability
Technical Support Document." Available at: www.epa.gov/safewater/rads/tsd.pdf.
U.S. Environmental Protection Agency (EPA). 2002. Federal Guidance Report 13 CD Supplement:
Cancer Risk Coefficients for Environmental Exposure to Radionuclides. Office of Air and
Radiation, Washington, DC. EPA402-C-99-001, Rev. 1, April 2002. Available atwww.epa.gov/
radiation.
U.S. Environmental Protection Agency (EPA). 2008a. Radiological Laboratory Sample Analysis
Guide for Incidents of National Significance-Radionuclides in Water. Revision 0. Office of Air
and Radiation, Washington, DC. EPA 402-R-07-007, January. Available at: www.epa.gov/
narel/recent_info.html.
U.S. Environmental Protection Agency (EPA). 2008b. Standardized Analytical Methods for
Environmental Restoration Following Homeland Security Events, Revision 4.0. Office of
Research and Development, Washington, DC. EPA/600/R-04/126D, September. Available at:
www.epa.gov/ordnhsrc/sam.html.
U.S. Environmental Protection Agency (EPA). 2009a. Method Validation Guide for Radiological
Laboratories Participating in Incident Response Activities. Revision 0. Office of Air and
Radiation, Washington, DC. EPA402-R-09-006, June. Available at: www.epa.gov/narel/recent_
info.html.
U.S. Environmental Protection Agency (EPA). 2009b. Radiological Laboratory Sample Screening
Analysis Guide for Incidents of National Significance. Revision 0. Office of Air and Radiation,
Washington, DC. EPA402-R-09-007, June. Available at: www.epa.gov/narel/recent_info.html.
U.S. Environmental Protection Agency (EPA). (In Preparation). Guide for Radiochemical
Laboratories for the Identification, Preparation, and Implementation of Core Operations for
Radiological Incident Response. Washington, DC.
U.S. Food and Drug Administration (FDA). 1998. "Accidental Radioactive Contamination of
Human Food and Animal Feeds: Recommendations for State and Local Agencies." 13 August.
Available at: www.fda.gov/cdrh/dmqrp/1071.pdf.
U.S. Department of Health, Education and Welfare (HEW). 1970. Radiological Health Handbook.,
p.123. Superintendent of Documents, Government Printing Office. 017-011-00043-0 GPO.
Available for purchase from http://catalog.gpo.gov/.
11
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
International Commission on Radiological Protection (ICRP). 1995. ICRP Publication 66: Human
Respiratory TractModel for Radiological Protection. International Commission on Radiological
Protection, Volume 24, Nos.1-3. Elsevier Science Ltd.
International Commission on Radiological Protection (ICRP). 1996. Publication 72: Age-dependent
Doses to Members of the Public from intake of Radionuclides: Part 5 Compilation of Ingestion
and Inhalation Dose Coefficients. International Commission on Radiological Protection, Volume
26, No.l. Elsevier Science, Ltd.
Multi-Agency RadiologicalLaboratory AnalyticalProtocols Manual(MARLAP) . 2004. EPA 402-
B-04-001A, July. Volume I, Chapters 3, 6, Volume II. Available at: www.epa.gov/radiation/
marlap.
Multi-Agency Radiation Survey and Site Investigation Manual, Revision 1 fMARSSEVIj. 2000.
NUREG-1575 Rev 1, EPA 402-R-97-016 Revl, DOE/EH-0624 Revl. August. Available at:
www.epa.gov/radiation/marssim/.
U.S. Nuclear Regulatory Commission (NRC). 1986. "Excessive Skin Exposures Due to
Contamination with Hot Particles," Information Notice 86-23.
U.S. Nuclear Regulatory Commission (NRC). 1987. "Control of Hot Particles at Nuclear Power
Plants," Information Notice 87-39.
U.S. Nuclear Regulatory Commission (NRC). 1998. "Protection Against Discrete Radioactive
Particle Exposures," Rulemaking Plan SECY 98-245. Accession number ML012140137.
Available at: www.nrc.gov/reading-rm/adams.html.
U.S. Nuclear Regulatory Commission (NRC). 1998. Minimum Detectable Concentrations with
Typical Radiation Survey Instruments for Various Contaminants and Field Conditions. NUREG-
1507. Office of Nuclear Regulatory Research, Washington, DC. Available at: http://techconf.
llnl.gov/radcri/1507.html.
12
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
II. RADIONUCLIDES
Table 3 lists some of the radionuclides that are believed to be accessible and possibly could be used
in a radiological dispersal device (RDD), or "dirty bomb," and the major (noninclusive) dose-related
radionuclides that might be formed from the detonation of an improvised nuclear device (IND).
These radionuclides are addressed in this report. In the case of an IND, numerous short- and long-
lived radionuclides will be present, requiring proper identification and quantification. Several of the
radionuclides on the list have progeny that will coexist with the parents. Thus, if 228Th were to be
found, 224Ra also would be present (although it is not listed). Several different radionuclides may be
present even if only one RDD is used.
TABLE 3 - Radionuclides of Concern
Alpha Emitters
Radionuclide
241Am
252Cf
242Cm
243Cm
244Cm
237Np
2iopo -
238Pu
239Pu
240pu
226Ra^
228Th
230Th
232Th
234U
235U
238U
U-Nat
Half-Life
432.6 y
2.64 y
163d
29.1 y
18.10y
2.14xl06y
138.4 d
87.7 y
2.41xl04y
6.56xl03y
1.60xl03y
1.912y
7.538xl04y
1.405xl010y
2.455xl05y
7.038xl08y
4.468xl09y
—
Emission
Type
0,7
a, y
a
a, y
a
a, y, x-ray
a
a
a
a
0,7
a, y
0,7
a
a
a, y
a
a
Beta/Gamma Emitters
Radionuclide
Ac-227T
Ce-141*
Ce-1441
Co-57*
Co-60*
Cs-134*
Cs-137§
H-3*
1-125*
I-129T
1-131*
IT- 192*
Mo-99T
P-32*
Pd-103*
Pu-241
Ra-228T
Ru-103T
Ru-106T
Se-75*
Sr-89*
Sr-90T
Tc-99*
Half-Life
21.77 y
32.51 d
284.9 d
271.7 d
5.271 y
2.065 y
30.07 y
12.32 y
59.40 d
1.57xl07y
8.021 d
73.83d
65.94 h
14.26 d
16.99 d
14.29 y
5.75y
39.26 d
373.6 d
119.8(1
50.53d
28.79 y
2.11xl05y
Emission
Type
P,y
P,y
P,y
8, y, x-ray
P,T
P,y
P,y
P only
8, y, x-ray
(3, y, x-ray
P,y
P,y
P,y
P only
P,y
a,P
P only
P,y
P only
e,y
P only
P only
P only
The half-lives of the nuclides are given in years (y), days (d) or hours (h)
* No radioactive progeny or progeny not analytically useful.
f Radioactive progeny with short half-lives, and the progeny may be used as part of the detection method for
the parent.
* Radioactive progeny not used for quantification, only screening.
§ Radioactive progeny used for quantification only, not screening.
13
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
III. DISCUSSION
In order to illustrate the typical decisions and actions to be taken by a laboratory for each scenario,
examples of the three scenarios using theoretical samples and measurement results are provided in
Appendices n, IE, and IV. These examples represent only three of many different possible
permutations, however, and should not be construed as limiting. Each example is keyed back to the
steps in its respective diagram and notes.
A. Sampling and Processing at the Laboratory
These scenarios assume that the time period from taking of sample to the actual beginning of the
analysis by the laboratory will be short (< 1-2 days). During the intermediate or recovery phases,
actual sampling duration can be up to one week, so that risk-based ADL concentrations of some
radionuclides can be achieved within a reasonable counttime (i.e., lower radionuclide concentrations
will require larger sample volume to achieve detectability). For the three scenarios discussed in this
guide, it is assumed that field personnel have performed some type of radiation screening survey of
the samples prior to sending them to the laboratory. If appropriate, field personnel may determine
which samples are to be submitted first to the laboratory based on these survey results. The
laboratory's surveys and analyses of the samples are not intended to confirm the field survey results,
but should be used by the laboratory to prioritize samples and determine the potential presence of
short-lived radionuclides.
In some instances, field monitoring results (measured with Nal(Tl), HPGe detectors, scintillation
detectors or proportional counters for field use) will provide information that may help establish the
radionuclides' identity or energy-specific information regarding the radionuclides involved in the
event. This will help the laboratory to expedite more accurate assessment of the concentration of
these radionuclides.
Only laboratories using validated radioanalytical methods (see Method Validation Guide, EPA
2009a, and MARLAP, Chapter 6) should be used in order to process samples in a timely and
effective manner. These laboratories will have the necessary radioanalytical capability and sample-
processing capacity to conduct the required gross screening and radionuclide-specific analyses
defined for the scenarios. This guide recommends the following analytical process flow:
1. General screening based on total radiation emitted from the sample.
2. Screening based on type of radiation emitted (i.e., alpha, beta, or gamma).
3. Radionuclide-specific analytical techniques applied after screening indicates the most significant
activities or when the radionuclide(s) have been identified.
This is the sequence used for screening in the flow diagrams for each scenario. Each decision point
in the flow diagram relates to an ADL that is part of the overall analytical process. Many of the flow
diagram boxes have numbers indicating the sequence of the analytical process. The boxes are color-
coded, indicating the most important flow path (red) to the least important (yellow) based on the time
requirements for returning the analytical results.
14
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Prior to starting the screening process, it is imperative that the laboratory have some specific
information about the air filters themselves and the sampling parameters:
• Volume of air sampled.
• Beginning and ending times of the sampling period.
• Type of filter medium.
• Percent area of the filter sent to the laboratory (e.g., if the filter was split or "punched" prior to
shipment to the laboratory).
• Contact activity or dose reading of the filter at the end of the sampling period.
This information must be communicated to the laboratory by the field sampling personnel in the
chain-of-custody form. There may be occasions where the entire filter is not sent to the laboratory,
or when the size of the filter sent to the laboratory does not match a calibrated detector geometry:
• When the entire filter is not to be sent to the laboratory, the air particulate filter may need to be
"field split" if there are different laboratories involved with the analytical process, and each one
has different radioanalytical capabilities (e.g., determination of 239Pu/240Pu ratio, or analysis for
a unique radionuclide like 241Am).
• When the size of the filter does not match a calibrated detector geometry, the laboratory may
have the analytical capability to perform the direct screening measurement on the filter.
However, if the detector geometry that is calibrated does not match the filter geometry, the filter
will need to be "punched" to accommodate this instance.
In both of these instances, it is imperative that the fraction of the sample used in the screening and
subsequent radionuclide-specific analyses be included in the final radionuclide concentration
calculations. For example, if a4"-diameter circle is cut from 8x12" filter (e.g., field split), the sample
results must be multiplied by 7.64 to correct for the activity on the whole filter. Another possibility
is that the field sample is a 4"-diameter filter and the laboratory must reduce the size to 2" diameter
(using a punch) to accommodate the laboratory's instrumentation. In this case, the final value would
be multiplied by 4. Other filter sizes that do not fit a laboratory counting geometry would need to be
corrected as appropriate.
It is likely that particulate matter collected on air filters following an INS will not be uniformly
distributed on that filter. Hot particles and inhomogeneous distributions are likely on the filter.
Therefore, the most representative sub-samples from a filter would be obtained by converting the
entire air particulate filter to a homogeneous form, such as a digestate, prior to sub-sampling. In
some cases, a portion of the filter should be retained for future use, or a filter may need to be
punched to create a reproducible geometry for rapid screening of the sample. A universally accepted
methodology for splitting or sub-dividing an air particulate filter does not exist. In cases where the
filter must be split prior to digestion, it is important that the laboratory has (and adheres to) written
guidance on how the sub-sampling is performed. For example, the guidance may stat to use a 10x
magnification and visually identify an area that visually appears uniform in particle deposition.9 Sub-
9 This is one of several options that potentially could be used. Another option might be to select a portion of the filter
that has a higher loading of the particulates containing the radionuclides. In this instance it may be anticipated that the
final result will be biased high if it is known that the particulates contain the radionuclide(s) of interest.
15
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
sampling will create bias in the analytical results, and subsequent results should be used with this
understanding. Once a filter has been sub-divided for screening (by cutting or punching out a
section), the remaining filter should be retained so that all sample constituents are included in the
final analysis.
The screening techniques outlined in the first steps of the flowcharts assume that the laboratory
maintains the necessary instrumentation and can perform the initial gross sample screening (at or
immediately subsequent to sample receipt) functions identified below:
• Micro-R meters for evaluating radiation exposures and doses on low-activity samples.
• Dose-rate meters capable of detecting gamma-beta exposures and doses.
• Hand-held gross alpha frisker for assessing the alpha count rate on sample contact.
• Probes that can be used to determine whether samples exceed the maximum dose rate that can
be handled or analyzed at the laboratory.
It is important to note that none of these screening instruments are suitable for all types of emissions.
It may take measurements from two or three different types of screening instruments to assess the
total potential activity present and only the combination of the results should be used to prioritize
the sample processing at the laboratory. Further discussion of some of the assessment of these
measurements may be found in Radiological Laboratory Sample Analysis Guide for Incidents of
National Significance - Gross Sample Screening Analysis (in preparation).
The laboratory also should have the instrumentation to perform gross radioactivity measurements
either before or after chemical separation (e.g., gas proportional or liquid scintillation counters) and
radionuclide-specific analyses (e.g., high-purity germanium detectors). Some of the radionuclides
listed in Table 3 (e.g., 103Pd) can be detected only with a specific type of gamma-ray detector because
of their low gamma-ray emission energy (60 keV is the usual lower limit of calibration for many
high-purity germanium [HPGe] detectors).
Each numbered box has an associated note that provides additional detail for that particular part of
the process. Clarification is also provided in these notes as to when parallel paths of analysis should
be followed to help expedite the processing of samples.
Appendix V (Table 9) contains generic assumptions that can help laboratory personnel in assessing
count times for screening samples for gross radioactivity. The information in the table may assist in
determining the approximate time it will take to achieve the required method uncertainty for the
decision points in the flow diagram for two different screening methodologies. Laboratories should
prepare their own spreadsheets, in advance of an event, using their preferred methodology.
Laboratories also should determine (in advance) whether their individual analytical protocols will
need to be revised to accommodate this process. The flow sheets used in this document that describe
the screening process use gas proportional counting for various air volumes collected and
instrument-count times. It is important to point out that the volume of air collected will most likely
be highly variable. Thus it is incumbent on the laboratory personnel to know that the count times on
each instrument are based on the total number of picocuries that may have been deposited.
16
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
The number of samples that will be analyzed and their level of radioactivity may be significantly
greater than samples routinely analyzed. Laboratories must also consider the following:
• Establishing separate procedures for sample handling and storage.
• Identifying protocols for personal protective equipment that are commensurate with the radio-
logical hazard.
• Additional protocols for personnel and sample radiation monitoring.
• Increasing the frequency of detector background analyses.
• Obtaining tracer solutions of higher activity.
• Increasing the frequency of QC checks.
• Adjusting the QC-check activity level to more closely align with the activity of the anticipated
samples.
• Increasing the frequency of contamination assessments (i.e., smears/swipes) on working surfaces
in the laboratory.
• Separating the storage location for high activity samples from personnel and instrumentation
(possibly with additional shielding).
• Monitoring dead time for individual samples.
• Revise automated count times based on achieving the required method uncertainties.
If laboratory protocols for routine situations cannot ensure that the MQOs for incident-specific
samples are achievable with the laboratory's SOPs, then a separate set of SOPs for incident response
sample conditions will need to be developed and validated. Further information on developing
incident-response laboratory operations may be found in EPA's Guide for Radiochemical Labora-
tories/or the Identification, Preparation, and Implementation of Core Operations for Radiological
Incident Response (in preparation).
B. Discrete Radioactive Particles
An important consideration for air particulate samples taken following a radiological or nuclear
event is the likelihood of encountering "hot" particles. The radioactive components used to make
an RDD, for example, likely would be from commercially available, solid materials. The conven-
tional explosive used to disperse the radioactive material would intermix radioactive fragments with
other debris, resulting in a distribution of particle sizes, all mixed together and trapped on an air
particulate filter according to the filter's characteristics. Hot particles, termed "discrete radioactive
particles" (DRPs), will be small, on the order of 1 mm or less. Discrete radioactive particles are
typically not evenly distributed on an air particulate filter, and their radiation emissions are not
uniform in all directions (anisotropic).
The radioactive sources/materials that may be potentially used in an RDD event emit alpha, beta, or
gamma radiation (see Table 3), and although highly radioactive, they may not be identified with field
equipment using conventional scanning techniques on field surfaces such as concrete or soil due to
their small size. This will present problems to the field sampling teams from certain perspectives:
• A hand-held field scanner may provide low activity or dose readings if it is not performed slowly
enough. This can lead to exposure to individuals because they think the air particulate sample
is not highly radioactive based on the area deposition surveys.
17
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
• It may cause them to classify an area under one category of contamination (when using only
scanning techniques on surfaces) when in fact it may have higher exposure concerns due to the
DRPs.
The laboratory will have similar issues to those of the field sampling team. When processing samples
that contain DRPs, the material may be relatively inert and not easily dissolved (192Ir is an example
of a material that would not be dissolved easily by traditional laboratory digestion techniques).
Laboratory personnel should be aware that significant information may be derived from solution
residues that contain radioactive materials (e.g., DRPs). These residues should undergo either fusion
or digestion with hydrofluoric acid (HF) to ensure that they are solubilized. HF may be better for
samples that only have alpha-emitting radionuclides because its use minimizes the addition of other
solid matter to the final counting form, which in turn minimizes sample self-absorption. Alternately,
the entire particulate filter may need to be analyzed directly, as a solid matrix (this may require
special processes). Great care should be used when deciding to sub-sample an air particulate filter
that may have DRPs. This type of material, by its nature, will result in non-uniform deposition on
the filter. Either the whole filter should be used, or an alternative means for identifying a
representative portion of the filter should be determined. In addition, because these recommendations
identify analytical priorities for samples based on their screening values, samples with DRPs could
get misclassified and put on a lower-priority track.
DRPs usually will have a high electrostatic charge due to their high specific activity. This
phenomenon has been observed at nuclear power plants that have had major fuel defects. The small
fuel fragments can be transported to various locations throughout the reactor coolant system. When
the system is opened for maintenance, and liquid, air, or swipe samples are obtained and the samples
allowed to dry out, the DRPs will "jump." This jumping phenomenon may occur with any highly
radioactive, micron-sized particles.
Finally, laboratory personnel also must be wary of dosimetry readings involving DRPs if they are
not experienced with personal frisking techniques. The personal dosimeter reading either will yield
a very high reading (if the DRPs are near or in contact with dosimeter) or a background reading (if
the DRPs are distant from the frisker or probe). The technique used in frisking should take into
account these concepts and should allow accurate assessment (assignment) of dose based on the
particle and its location.
C. Sampling for Iodine and Tritium
Air particulate filters are not acceptable methods for collecting samples containing radioiodines or
tritium, because of the volatility of these elements under environmental conditions. Therefore, during
the initial phase of an event, additional matrices described below may be presented to the laboratory
for analysis of these two radionuclides. If neither radioiodine nor tritium is present, these additional
sample matrices will not be necessary. Tritium is a radioactive form of hydrogen. If tritium is used
in an ROD, it will become exclusively associated with water (chemical formula, ^-O-3!!, tritiated
water) regardless of its initial chemical form. The sampling techniques used for normal water in a
vapor phase also can be used for tritiated water. The following list includes only some of the media
that the laboratory may receive if tritium-aerosol sampling is performed:
18
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
• Drierite®
• Molecular sieve
• Water (from an air bubbler collection method)
Sodium carbonate
• Ethylene glycol solution
Silica gel
These matrices would be preceded by the particulate air filter in the sample flow path so that
particulate matter is trapped only by the particulate filter. The above media cannot be prioritized for
analysis by the laboratory following receipt because neither field nor laboratory survey instruments
are effective at detecting tritium in these matrices. Thus, all sample media for tritium analysis would
need to follow a prioritization designated by the 1C. Samples should be appropriately packaged,
shipped, and handled to avoid inadvertent dilution with water or loss during processing. The most
effective methods of tritium separation from all other radionuclides are ion exchange (to remove all
other radionuclides), distillation, or freeze-drying (although other techniques can be successfully
employed).
Iodine, as compounds of inorganic iodide, is susceptible to oxidation to molecular iodine, I2. In this
case, iodine may not be captured effectively on a particulate filter. Iodine may also exist in the
atmosphere as an organically bound compound and would likewise not be captured effectively on
a particulate filter.
In order to accommodate the potentially different chemical forms of iodine that may be present,
different collection media may be required. Some techniques that have been used for field sampling
of volatile radioisotopes of iodine include:
• Charcoal or activated carbon cartridges (usually containing triethylenediamine, TED A)
• Molecular sieve (containing silver halide, also known as silver zeolite cartridges)
• Charcoal or activated carbon cartridge (containing silver halide)
• Water containing alkaline thiosulfate solution (from an air bubbler collection method)
The three radioisotopes of concern, 125/129/131i3 aii can be sampled effectively using these media as
long as the chemical form of the iodine is susceptible to air oxidation. If the iodine compound is
chemically stable with respect to oxidation, it may be possible to collect the material on the filter.
Organically bound iodine will be effectively removed from an aerosol using charcoal cartridges
containing TED A. Regardless of the media, potential radionuclides of concern that have short half-
lives, such as m I (t,/2 ~ 8 d) and 125I (t,/2 ~ 60 d), should be analyzed promptly upon receipt. For
example,1311 is easily detected, without any sample preparation, using gamma-ray spectrometry. The
detection of 125I can be done using a low-energy gamma-ray detector. Based on environmental
conditions, the sampling cartridges may be face- or fully loaded (see page 25).
Once the radionuclides have been identified, special measures will need to be taken to detect the
particular radionuclides resulting from this event. These will involve modification of scanning
techniques (both in the laboratory and in the field measurements), more frequent contamination-
control measures, and attention to the total particulate mass and moisture content of the samples. It
19
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
will also require that laboratory personnel be vigilant in the observation of residues in the sample
digestion processes.
D. Crosswalk of Data Values
The values corresponding to different terms referred to in this document are located in the tables
listed below:
TABLE 4 - Crosswalk of PAG, AAL, ADL, and «MR Values
Data or Value
2 -rem/5 0 0 -mrem
(Screening)Tables 7 A and 7B
2 -rem/5 0 0 -mrem
(Radionuclide-specific)Tables
7C and 7D
lO^risk—
10^ risk—
DQO and MQO
Derivations —
Estimated counting
timeTables 9 and 14
AAL
Tables 7A and 7B
Tables 7C and 7D
Tables 8A and 8B
Tables 8A and 8B
—
Tables 9 and 14
ADL
Tables 7A and 7B
Tables 7C and 7D
Tables 8A and 8B
Table 8A and 8B
Tables 11A, 11B,
12A, 12B and 13
"MR
Tables 7A and 7B
Tables 7C and 7D
Tables 8A and 8B
Table 8A and 8B
Tables 11A, 11B, 12A,
12B and 13
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
IV. SCENARIO 1 (Identifying Air Samples with Highest Activities)
1.Rapid lab scan
for P/Y and a
Air Filter Analysis — High Flow Sampler
Background Information
Unknown source
Priority to those samples with highest activities
Field sample volume collected 3-100 m3
Separate samples received from field for 3H and
iodine
Key
Highest priority
(> 2 rem)
Second priority
(> 500 mrem)
Lowest priority
(<500 mrem)
End result
See accompanying tables
for alpha and beta/gamma
concentrations, and
numbered notes
1c. Perform iodine
cartridge gamma
spectrometry for
1311 125| 129|
la.
Value for
gross a > Table 7A, Or
gross |3/Y > Table 7B
ADLs for 2-rem?
1b. Perform 3H
analysis on aerosol
sample
>2-rem ADL:
Report to 1C
< 500-mrem
ADL
13. Long gamma
spectrometry and gross
a/p count time
>500 mrem and
<2 rem ADL
14.
Any a, p, or Y
Result
Table 7A or 7B
500-mrem
ADL?
4. Dissolve filter
5. Reanalyze gross a/p
No
i
r
15. Follow Scenario
2
1
' 1
10. Gamma
Spectrometry
r
9. a emitters by
chemical separation
I
1
r
8. p emitters by
chemical separatiora •••
1
\ P/Y >2.5 7"
\ ? /
Yes|
7. Perform
total Sr analysis
17. Archive final
sample forms;
segregate from low
activity archived
samples
i
/Any ind
/ result > 1
12. Report i
L
Ifl/ Or Table'
^v Sum off
16. Reanalyze ]
] if possible; note discrepancy i
i ___'
Figure 2-AirScenario 1 Analytical Flow
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Notes to Scenario 1: High-Flow Air Sampling
Purpose: Priority to those samples with highest activities
Important Sampling Notes: Sample time will be short; sample volume will be small
In this scenario, prioritization of sample analyses in the laboratory is based on the observed
sample activity at the various steps in the analytical process. Samples with activity that exceed
the 2-rem ADLs will get the highest priority. Samples with activity less than the 2-rem ADLs but
more than the 500-mrem ADLs will get an intermediate priority, and samples with activity below
the 500-mrem ADLs will get the lowest priority. Samples may arrive over several days; those
with the highest priority (red flow path on this diagram) are always to be analyzed first. Only
after an analytical step or procedure has been completed for the highest-priority samples should
lower-priority samples be addressed. Lower-priority samples (those following the green and
yellow flow paths on this chart) may need to be stored for several days until analysis of the
highest-priority samples has been completed. Some of the information in Step 1 is the responsi-
bility of the field sampling team but is needed by the laboratory so that the final analytical result
can be calculated.
High-flow sampling rates are on the order of 30-50 fWmin (0.85-1.4 m3/min) with sample
volumes typically greater than 2x 103 ft3 (55 m3), but between 100 and 3.5x103 ft3 (between 3 and
100 m3) for a one-hour collection time. A one-hour nominal volume of-2.4 xlO3 ft3 (-68 m3)
taken through a 4" air filter is assumed for this scenario.
The laboratory will need to be notified by the sampling team if sampling was conducted in a
highly dusty environment (much greater than 100 ug/m3). If this is the case, the solids loading
(mg/cm2) on the filter will need to be assessed10 so that self-attenuation factors can be
determined, especially for alpha analysis. The charcoal cartridge will be downstream of the
parti culate filter. The flow-monitoring device should be placed downstream of the filter housing
but upstream of the pump, ensuring that the net flow through the media can be calculated
accurately.
Many of the flow diagram shapes are color-coded to reflect the highest-priority analytical flow
path (red), intermediate (next important) flow path (green), or the lowest-priority flow path
(yellow) based on the time needed to return the required analytical results to the 1C. The
accompanying numbered notes are color-coded in the same fashion, as are the examples in
Appendix II. It is highly advisable to study the flow paths in color, as a black-and-white printing
may be confusing or ambiguous.
Note also that as the sample screening and analysis progresses in the laboratory, there are
sequential decision steps to guide the sample to the correct priority path. For example, Diamond
14 in the preceding figure checks for gross alpha/beta on the filter using GPC or gamma analysis,
with longer count times to ensure that the sample activity is less than the 500-mrem AAL.
10 The sampling team needs to provide the laboratory with an unused paniculate air filter, so that a blank weight can be
determined. This would be used to assess the total paniculate loading on the filter so that self-attenuation factors can be
estimated.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
The laboratory instruments used might include a survey meter (with alpha and beta channels)
or a Geiger-Muller (GM) counter with appropriately calibrated beta and gamma detector
probes, or a micro-roentgen meter (gamma only). This step will be conducted in the
laboratory initially with the particulate filter in its container. The first measurement will be
for gross P/y to assess overall exposure and potential contamination. Once it has been
determined if any other precautions are necessary for direct measurement (e.g., fume hood,
protective breathing equipment, etc.), then the filter is removed from its container so that the
alpha measurement can be assessed more accurately. Unless the identity of the radionuclide
contaminant is known, the hand-held survey instrument should be calibrated using a standard
source (e.g., 241Am for a, 90Sr for P, or 137Cs for y) that will replicate the particulate filter
geometry.
Activity measurements of one type of radiation that are high due to the level of
contamination present may cause a measurable response with a different screening detector
although significant quantities of that radiation may not be present (e.g., crosstalk). For
example, a sample that is highly contaminated with 90Sr may appear to contain alpha activity
if beta emissions are misclassified as alpha emissions as a result of beta-to-alpha crosstalk.
A discussion of this type of instrument response is found in RadiologicalLaboratory Sample
Analysis Guide for Incidents of National Significance - Gross Sample Screening Analysis
(in preparation).
Important sampling information will be the start and stop times of the air sampler, total
volume sampled, and the time that survey-meter measurements of the filters were made.
Field staff may prioritize the samples being sent to laboratory based on their survey-meter
scans of the air filter samples. Field survey meters using gas proportional (GP) or GM
detectors should be able to detect the radioactivity collected in 68 m3 of air having a 2-rem
or 500-mrem AAL for most targeted p-emitting radionuclides (NRC, 1998).
During this sample processing phase, special precautions should be taken to avoid sample
cross-contamination as well as laboratory contamination from samples that may have loosely
held radioactive particulate matter.
Special precautions should be taken when performing initial scans to account for the
potential presence of DRPs, especially if the filter is large enough so that more than a single
reading is required. If "hot" particles are found, it is very important to communicate this
information immediately to field personnel. If DRPs are present, additional sample handling
controls may be necessary, such as:
• Establishing a "hot-particle" sample handling and storage area with step-off pads;
• Extra personal protective equipment for normally exposed body surfaces; and
• Single-sample handling until the sample digestion has started (to prevent cross-
contamination).
The MQOs at the 2-rem and 500-mrem AALs for required method uncertainty can be found in
Tables 7A and 7B.
23
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Laboratory personnel should be aware that when using the nominal volume for the sample
(68 m3), the 2-rem AAL concentrations correspond to a total activity of about 48 pCi for
alpha and 29,000 pCi for beta. Laboratories should have screening equipment that is capable
of detecting the range of activities at the 2-rem ADL total activity (for a 68 m3 sample) of 24
pCi for alpha emitters and 14,000 pCi for beta emitters.
If the gross screening value is less than the 2-rem ADL values listed in this diamond, the
sample reverts to a lower priority (green). The ADL values for alpha and beta are 0.35 and
210 pCi/m3, respectively. If sample screening measurements are less than these values when
the UMR is achieved, the sample is put on the lower-priority flow path. Otherwise, the sample
stays on the high-priority pathway.
Tritium assessment generally is not performed with screening equipment because of the low
energy of its emitted beta particle and the significant effects of non-radiological interferences
with its analysis. Sample volumes and times will usually be different for samples obtained
for tritium analysis (the volumes for tritium sampling routinely are lower). The media used
for trapping tritium are described in Section in. The laboratory must have a procedure in
place to handle the media used for trapping tritium, as each has separate retention factors and
potential diluents (water) that can alter the final tritium concentration. Screening
measurements on the aerosol's water fraction are made without removing interfering
radionuclides. This means that at this step in the process, tritium results are of screening
quality only. Inspection of liquid scintillation spectra may enable elimination of some
radionuclide interferences based on beta particle energy distributions.
The gross alpha/beta air filter and the gamma spectrometry on the iodine cartridge analyses
should be performed in parallel. Information from this gross screening may provide insight
into potential for interference with tritium analysis.
A simple distillation, collecting approximately 5 mL of liquid, may provide the most
effective removal of all interfering radionuclides from the collection media used for water.
Sample count times using liquid scintillation will be short in order to demonstrate that the
sample concentration exceeds the 2-rem ADL value of 1.3xl05 pCi/m3. The UMR value is
7.9xl04pCi/m3.
The laboratory should not make decisions regarding the priority for the corresponding
particulate filter or iodine cartridge based on the tritium analysis until Step 3b is completed.
Similar consideration for a standard source calibration (137Cs for y) and geometry should be
given to the cartridge used for iodine/noble gas sampling.
An iodine cartridge may be used in combination with a particle filter (the filter preceding the
radioiodine collection cartridge in the flow path) during the sample collection process. Thus,
the sample time and volume should be the same for these two separate collection media. At
the laboratory, the alpha-beta gross analysis of the particulate filter by gas proportional
counting (GPC) should be corrected for self attenuation if the mass of material collected on
the filter can be or has been determined.
24
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Gamma spectrometry of the cartridge is specifically for 131I (364.5 keV is the principal
gamma ray). Although the 129I or 125I may be present, their activities would need to be verified
in the longer gamma count intervals using a low-energy gamma-ray detector. It is likely that
an iodine cartridge will be "face-loaded."11 However, the laboratory must be able to confirm
this assumption. Laboratory counting techniques must be able to account for differences in
face or fully loaded cartridges. Cartridge orientation when counting, as well as proper
calibration for that geometry, must be ensured. Although possible, it is not likely to detect
131,129,125 j on ^g particulate filter.12 If iodine is present on the filter, the most likely form
would be an iodide salt. Additionally, because the energy of the 129I and 125I gamma rays are
-35 keV, the laboratory should ensure that a valid calibration curve exists at the energies of
these radionuclides and that they consider corrections for self attenuation of the gammas by
the sample matrix. If radioisotopes of iodine are present on both paniculate filter and
cartridge the sum of the two contributions (for the same radioisotope of iodine) must be
assessed versus the ADL for that radioisotope of iodine.
It is also possible that noble gasses, such as krypton and xenon (if present from a nuclear
detonation or power plant accident) or radon (and its decay products), would be captured on
the iodine cartridge. Thus, the gamma-ray energies from these radionuclides and their decay
products should be in the gamma-ray library. Count times should be 5 to 10 minutes.
Gamma-ray lines with net peak area uncertainties <50% (at the 1-sigma level) should be
positively identified and quantified to aid in direction of additional analyses. Significant
quantities of radon on the radioiodine collection cartridge should alert the laboratory to the
presence of unsupported progeny on the filter or cartridge that emit alpha, beta, or gamma
radiation. The gross alpha/beta air filter and the gamma spectrometry on the iodine cartridge
analyses should be performed in parallel.
The laboratory should not make decisions regarding the priority for the corresponding
particulate filter or tritium sample based on the iodine analysis.
The 2-rem UUR values for screening analysis for iodines are based upon the sum of iodine
activity from vapor trapped on a cartridge or any particulate caught on the filter upstream of
the iodine cartridge. The specific values for 125I, 129I, and 131I are presented in Table 7B.
Proceed with Step 3b.
Direct gross alpha/beta analysis of the particulate filters may be performed with a portable
or laboratory, low-background GPC unit. When making these measurements, consider the
levels of activity that were measured for each of the samples in Step 1 to avoid contaminating
low-level background detectors with samples that have very high activity.
1' This term describes the concentration of the radionuclides of interest in a thin slice of the entire cartridge width that
faces the inlet air flow. At low concentrations, this will usually be the case, but loading can be affected by humidity,
temperature, and presence of other gases that may be adsorbed by the cartridge. One technique that may avoid the issue
efface versus fully loaded is to "side count" the cartridge. The gamma spectrometry detector must be calibrated for this
special geometry.
12 For an event that involves a nuclear power plant release, there may be a significant amount of radioiodines on the
particulate filter. This depends on several factors including the chemical form of aerosols during the release.
25
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Special contamination-control procedures should be implemented when transferring filters
that may contain high activity in order to avoid contaminating areas that normally have low
background and contamination. Examples of such procedures include a separate enclosed
area for transferring a sample from one container to another, double containers, and thin
encapsulating film such as collodion on the filter surface.
Lab assessment of the total activity decay during transport can provide information regarding
the half-life of the principal radionuclides. The activity ratio of field to lab analysis for gross
P/y activity may be used to estimate the composite half-life of the radionuclides contained
in the sample to help resolve discrepancies between field versus laboratory gross-activity
measurements. For example, if a sample is received 24 hours post-incident and the laboratory
gross P activity is -20% of the field activity measurement, thoron (220Rn) decay products of
2i2pb/2i2Bi may be mvoivecj
If the laboratory finds that its receipt survey is significantly different from the field survey
of the sample, it may be important to know which reference radionuclide was used to
calibrate the field survey detector.
NOTE: Laboratory personnel also must know if the shipped sample is only part of a larger sample,
so that appropriate correction factors can be applied before reporting final results. For example,
if a 4"-diameter circle is cut from 8x12", or if a 4"-diameter filter is received and the laboratory
needs to reduce the size to 2" diameter, then the laboratory must calculate the appropriate
correction factor for the fraction of filter analyzed (see discussion of filter sizes on page 15).
The sample chain-of-custody form must specify if the field measurements were made on the
entire filter, or just the portion shipped, so that lab measurement can be compared with the
field measurements. This will assist in gaining insight into the quantity of short-lived
radionuclides that may be present (this will help in the gross activity assessment when
compared to the sum of individual radionuclides in Step 11). The field sample team should
have provided specific information regarding the composition of the filter medium (including
a blank sample) so that appropriate steps can be taken during the filter-digestion process.
Gamma spectrometry is performed on the entire filter sample initially to assess which gamma
emitters may be present. Although possible, it is not likely to detect 131> 129' 1251 on the
particulate filter. If iodine is present on the filter, the likely forms would be an iodide salt or
iodine trapped with particulate matter. Additionally, because the energy of the 129I and 125I
gamma rays are -35 keV, the laboratory should ensure that a valid calibration curve exists
at the energies of these radionuclides and that it considers corrections for self attenuation of
the gammas by the sample matrix. Count times will vary depending upon the sample size and
efficiency of the detector. However, count time should be at least 15 minutes (this helps to
ensure software routines have sufficient data to properly perform peak fitting algorithms).
The UUR values at the 2-rem and 500-mrem ADL for gross alpha are 0.21 and 0.052 pCi/m3
and that for the gross beta 130 and 33 pCi/m3, respectively (Tables 7A and 7B).
Initial assessment of the activity is made based on comparison with the 2-rem ADL values:
26
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
• The gross alpha-beta analysis of the filter (gross a > 0.35 and gross P > 210 pCi/m3), and
The short-count gamma spectrometry results (Step 2, y> 2-rem ADL values; see Table
7B).
If any 2-rem ADL is exceeded, notify the 1C immediately and indicate that these results are
based on screening methods and radionuclide-specific analyses have not yet been performed.
NOTE: If either the gross alpha or beta ADL (at 2-rem or 500-mrem) is exceeded, a second analysis
should be performed for gross alpha and beta after dissolution, for the ADL (alpha or beta) that
was exceeded (see Step 5a). See a more detailed explanation of this under "Additional Points" on
page 31.
Based on gamma spectrometry results, determine if the radionuclide used for gross beta
calibrations should be adjusted. For example, if gross beta was determined using a 90Sr/90Y
calibration source and the only radionuclide is 60Co, an adjustment in the attenuation factor
may be necessary (this could be made based on actual sample measurements or calibration
with the radionuclide source if available).
Determine if any individual gamma emitter exceeds its 2-rem ADL. Gamma-ray lines with
net peak area uncertainties (or as identified by the instrument manufacturer) below 50%
should be identified and quantified to aid in direction of additional analyses.
Review the original gross alpha/beta results based on the self-attenuation assessment above.
Determine if the gross alpha/beta ADL assessments have changed from the original
assessment made in Step 2.
The following analyses will have been completed:
Tritium-specific analysis from a separate sample (Step Ib), and
• Iodine-specific analysis from a cartridge (Step Ic).
The 1C should be notified immediately if any of the following 2-rem ADL values identified
in Tables 7A or 7B are exceeded :
• 3H
If not, a longer gamma count for the iodines and a longer liquid scintillation analysis for
tritium should be performed for Step 13 (to be conducted later). It is important to note that
this analysis flow path is only for tritium and iodines. The particulate filter associated with
the tritium and iodine analysis may remain on the high-priority flow path based on its
screening analysis completed in Steps 1 or 2. If radioiodines are detected on the cartridge,
a gamma count of the particulate filter should be performed to identify any additional
radioiodine contribution prior to assessing what AAL may have been exceeded.
27
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Once the a, P, and y analyses from Step 3 are complete, the entire filter sample should be
dissolved so that separate aliquants of the final digestate may be analyzed simultaneously for
specific a- and p-emitting radionuclides. A fusion technique that uses a low-temperature
flux, or an acid digestion that ensures a single, homogeneous phase should be applied.13 If
glass-fiber filters have been used, some form of fluoride treatment should be used to
eliminate silica precipitation later in the analytical process (for example, sodium fluoride
[NaF] fusion or hydrofluoric acid [HF] removal of silica are commonly used techniques). FTP
may be better for samples that only have alpha-emitting radionuclides because its use
minimizes the addition of other solid matter to the final counting form, which in turn
minimizes sample self-absorption. Note that any method used to dissolve the filter may
reduce or eliminate the activity of any volatile or semi-volatile radionuclides present on the
filter. Therefore, analyses for tritium and radioisotopes of iodine, phosphorus, and sulfur will
need to be performed in a manner that prevents their loss during sample preparation and
analysis.
Sufficient final volume of the digested sample should be saved for subsequent removal of
aliquants for specific alpha- and beta-emitting radionuclides. This should include an aliquant
that may need to be recounted by gamma spectrometry for a longer period of time (2-3
hours). Ensure that the calculation of the final activity of the sample corrects for that fraction
of the digested solution or filter actually used in the analysis.
If either the gross alpha or beta ADL determined in Step 3 was exceeded (2-rem or 500-
mrem values), a re-analysis should be performed for the corresponding ADL (a or P) that was
exceeded. Based on the screening analyses, it may be best to gamma-count the entire
digestate for a longer period of time (such that the WMR, see Table 7B, is achieved, e.g., 4-6
hours) before subdividing the digested sample for other individual analyses. Any gamma-
emitting radionuclide with a measured activity greater than its calculated critical level should
be included in the total gamma activity sum.
Calculate the total gamma activity per cubic meter in the samples as the sum of all gamma-
emitting radionuclides (Step 2) with measured activity greater than the critical level. If the
ratio of gross beta (from Step 5) and total gamma indicate a gross beta/gamma ratio > 2.5,
immediately start total strontium (89+90Sr) analysis. The alpha-spectrometric and beta-only
analyses always should be performed as soon as possible after the start of the Sr analysis,
regardless of the strontium results. If gross P/y ratio is < 2.5, perform Steps 8, 9 and 10 in
parallel. If P/y ratio is > 2.5, immediately start total strontium analysis (89+90Sr).
The strontium analysis should provide a rapid assessment of total radioactive strontium
(89+90Sr) in the sample. If total radiostrontium analysis indicates the presence of radiostron-
tium at greater than 0.71 x AAL for 90Sr (this represents the corresponding ADL for 2-rem or
500-mrem), the sample should be recounted 24 hours later to assess the distribution of the
two radiostrontium isotopes in the sample. Some beta measurement techniques may allow
for assessment of 89Sr and 90Sr, separately, based on the beta particle energy distribution.
13 This is particularly important if the presence of DRPs is known or suspected.
28
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Using input from the gross beta and gamma spectrometry measurements, begin pure beta-
specific analyses (plus 227Ac) based on the radionuclides identified in Table 3. This includes
analysis for 90Sr if not already started. The corresponding ADL and uUR values are found in
Table 7D.
Using input from the gross alpha and gamma spectrometry measurements, begin alpha-
specific analyses for the radionuclides identified in Table 3 .The corresponding ADL and WMR
values are found in Table 7C.
Conduct gamma spectrometry of sufficient time to meet the corresponding ADL and WMR
values that are found in Table 7D. All gamma-ray-emitting radionuclides that result in a
radionuclide activity above the critical level should be included with their associated
uncertainty on the final report to the 1C. This would make the 1C aware of other radionuclides
that may be present at lower concentration that may not be of dose consequence, but that may
affect remediation efforts. Any gamma-emitting radionuclide with a measured activity
greater than its calculated critical level should be included in the total gamma activity sum
and in the sum of the fractions (Stepl 1).
NOTES:
Steps 8, 9, and 10 should be performed in parallel. Although all the radionuclides listed in
Table 3 are possible contaminants, perform those analyses that are most probable based on
previous sample results and direction by the 1C.
Samples from the same event and area may be queued more accurately using the information
already obtained on the first batch of samples. For example, if 241Am is one of the known
contaminants, that analysis would be started first in Step 9.
As testing results become available, verify that data quality requirements have been met for
each of the analyses and take action promptly to address any deficiencies identified. This
includes any quality control sample requirement results (e.g., liquid scintillation counters
[LSCs]) imposed on the laboratory by the available proj ect plan documents or contract. Once
a final result is available, compare the individual radionuclide concentrations to the
individual ADL values listed in Tables 7C and 7D. When the high- and intermediate-priority
radionuclide-specific analyses are completed, verify that no major nuclide has been missed
and that data quality requirements have been met. This can be done by verifying that the sum
of the individual nuclide concentrations is approximately equivalent to the gross activity
concentration (a rule of thumb is within a range of about half to twice the gross value).
Activity concentrations due to decay products should be included in the verification.
NOTE: The sum of the fractions (individual beta/gamma radionuclide concentrations divided by
their respective 500-mrem AAL value—see Table 7B and "sum of the fractions" in the glossary)
of all radionuclide concentrations above their individual critical level is to be calculated. This
includes all naturally occurring radionuclides above their respective critical level even if the
naturals are not part of the event. If the summed value exceeds unity, then the 500-mrem AAL has
been exceeded, even though an individual radionuclide activity value does not exceed its respective
AAL. If all comparisons are satisfactory and data quality requirements have been met, report results
to the 1C. If there are outstanding data quality requirements or activity measurement issues, go to
Step 16.
29
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Report all final reviewed results to the 1C and provide electronic data deliverable (EDD).
Clearly identify any sample activity or concentration totals that do not compare favorably
with the original gross activity or concentration measurements.
13. On this lower-priority flow path, the gross screen of the samples has indicated lower activity.
The sample count time should be long enough so that the required method uncertainties for
1CT4 and 1CT6 risk factors listed in Tables 8A and 8B can be achieved. This will assist in
identifying the presence of lower activity radionuclides that may be present.
This count is performed to assess if the sample result is greater than the 500-mrem ADL as
indicated in Tables 7A and 7B for:
• Gross alpha
Gross beta
• Any beta-gamma emitter
If the sample result is less than the 500-mrem ADL, the sample is put on the low-priority
track (yellow, Step 14). If the sample result is greater than the 500-mrem ADL, the sample
goes to Step 4 for an intermediate priority.
The radioiodine collection matrix may be re-counted now for sufficient time to meet the
required measurement uncertainties identified in Table 8B, and should be counted on a
detector that is calibrated for gamma rays as low as 30 keV. Do not allow significant delay
in counting the iodine cartridge due to short half-life of 131I.
A longer gross a/P count of the filter is appropriate using GPC to assess if the sample activity
is between ADLs corresponding to the 500-mrem and 2-rem AAL values (use Tables 7A and
7B). The length of count will depend on the fraction of original sample which is being
analyzed.
If tritium was not initially identified above the 500-mrem AAL (Step 3b), a longer liquid
scintillation count at this time may be warranted to assess its presence at greater than ambient
levels.
14. If the gross alpha or gross beta results, or the longer gamma count results do not exceed the
500-mrem ADL for any radionuclide concentrations listed in Tables 7A and 7B, then go to
Step 15 (sample has not yet been dissolved). If the sample is greater than the 500-mrem
ADL, return sample processing to the analysis flow path, Steps 5-12, with a secondary
(green) priority.
15. Samples that have activities that are low enough to fall into this category should be preserved
(if needed) for analysis in the future (as directed by project management) using the scheme
outlined for Scenario 2 (specifically at Steps 13a or 13b).
16. Recount samples or re-analyze aliquants of the remaining solution after digestion to
determine if an interfering radionuclide or non-radioactive contaminant interfered with the
30
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
analysis. Determine if gross alpha/beta efficiency factors used for the gross activity
measurements (Step 5) should be updated to radionuclides now known to be present in the
sample. If no cause of the discrepancy can be determined, make note of the discrepancy in
the report to the 1C.
17. Archive final sample test sources that were counted and digested in Step 4. These samples
should be segregated from the lower activity samples, such as those that may have been
archived in Step 15 due to their difference in activity. Although a potential cross-contamina-
tion issue, it is also a personnel exposure issue.
Additional Points
Analysts should recognize that when performing gross a or gross P analysis directly on the air
particulate filters, the mass loading will have a significant effect on the reliability of the results when
they are compared to the total a or P analysis following radiochemical separations. Step 11 notes that
the analyst should compare the radiochemical specific analyses to the gross analyses and see whether
they are within a factor of two. If not, and if there are additional samples being analyzed that have
similar characteristics, a correction factor may need to be applied to the efficiency factor in the gross
analysis to adjust for sample interference with the gross measurement.
It is important to remember also that gross a or gross P analysis by evaporation, following sample
digestion (Step 4), will result in a significant loss of volatile radionuclides (such as technetium and
iodine).
Change in activity of samples from decay during transport may be significant depending upon the
radionuclide mix. If the time from completion of field sampling to sample receipt at a laboratory is
about 12 hours, any accumulated 222Rn progeny will have decayed to 210Pb (yielding negligible
activity due to its 22 y half-life). Any collected 220Rn progeny will be reduced by one-half (due to the
11-hour half-life of 212Pb). With an upper estimate of 3.5 pCi/m3, 220Rn surface concentration for
most sites, -210 pCi of 212Pb (ignoring decay while sampling) would be collected on the filter (for
a 60 m3 sample) and -100 pCi (220 dpm) would be present after the 12-hour delay to begin the
laboratory's gross beta analysis. The laboratory would calculate a gross beta concentration of-3.5
pCi/m3 (from 212Pb plus 212Bi and an additional contribution from 208T1 of about 36%) and -1.5
pCi/m3 gross alpha concentration from 212Po. Gamma-ray spectrometry may detect 212Pb, 212Bi and
208T1 at this concentration (depending upon total activity on particulate filter).
Gross alpha and beta radioactivity contributions to these analyses due to airborne dust (generally
-100 ug/m3) from typical soil concentrations of 238U, 232Th, or 40K will be negligible for a 1-hour
sampling duration using either a high- or low-volume sampler.
Certain a- and p-emitting radionuclides have very low abundance y rays. These y rays are not
normally used for analysis of those radionuclides when trying to determine them at normal,
environmental levels. Thus, the gamma-spectrometry software may not have these y rays in its
analysis library. It is recommended that a separate library for incident response samples be created
which has these low abundance y rays. Table 5 provides some examples.
31
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 5 - Radiomiclides with Low-Abundance Gamma Rays'
Radionuclide
Principal Decay
Gamma, keV
Abundance, %
Radionuclide
Principal Decay
Gamma, keV
Abundance, %
Radionuclide
Principal Decay
Gamma, keV
Abundance, %
89Sr
P"
909
9.6xlO~3
232Th
a
911
(from 228Ac)
27.2
241pu
P"
149
1.9xlO-4
90y
P"
2,186
1.4xlO-6
235U"
a
186(143,
163)
54(11,5)
242pu
a
44.9
4.2xlO~2
129j
P"
40 (32 X-ray)
7.5 (92.5)
237Np
a
86.5
12.6
243Cm
a
278
14
2iopo 226Ra"
a a
80.3 186 (262)
l.lxlQ-3 3.3(5xlQ-3)
238pu 239pu 240pu
a a a
55.3 112.9 54.3
4.7xlO~2 4.8xlO~2 5.2xlQ-2
227Ac
P"
236
11.5
228Th
a
84
1.21
241Am
a
59.5
35.7
Values in parentheses represent the next most abundant photopeaks.
"Care must be taken with this identification as 226Ra and 235U gamma rays may not be resolved at this energy.
These gamma rays can be used for qualitative identification of these radionuclides. Their presence
in the gamma-ray spectrum should direct the analyst to perform chemical separations followed by
a- or p-specific detection.
Aluminum absorbers can be used to qualitatively identify the presence of beta-emitting radionuclides
based on the ability of their beta emissions to penetrate the aluminum. Thus if an aluminum absorber
of 6.5 mg/cm2 thickness is used and the measured beta activity is reduced to background, one could
qualitatively state that the beta particle energy of the radionuclide is < 0.067 MeV. Conversely if the
absorber has little effect on the count rate, it can be stated that the beta particle energy is >0.067
MeV. Table 6 identifies some beta-only emitters with their energies and range in aluminum
absorbers. This technique is one option to help estimate the energy of the beta particle, which assists
in the identification of the beta-emitting radionuclide.
TABLE 6 - Beta "Only" Emitters
Radionuclide
Maximum |3 Energy, MeV
Range [2], mg/cm2 for Epmax
241pu
0.021
0.8
63Ni
0.067
6.5
129j
0.150
27
35S
0.167
32
"Tc
0.294
75
32p
1.711
800
90Sr/90Y
(0.546)72.28 [1]
1,100
[1] Based on the sampling plus sample transit time 90Sr/90Y may be in secular equilibrium by the time any analysis is
started. Thus, the 2.28 MeV beta particle of 90Y will, most likely, be present.
[2] U.S. Department of Health, Education and Welfare (HEW). 1970. Radiological Health Handbook, p. 123.
32
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
V. SCENARIO 2 (Priority to Air Samples with Highest Activities)
Air Filter Analysis — Low-Flow Sampler
Uncharacterized source or area
decontamination
Priority to those samples with highest activities
Sample collected for 12 hours to 7 days
1. Rapid
for gross
ab scan
a, 3, or Y
Key
Highest priority
(>500 mrem)
Second priority
(>10-4risk)
Lowest priority
(>10-6risk)
End result
See accompanying tables
for alpha and beta/gamma
concentrations, and
numbered notes
11. Routine gross ct/p by
GPC on filter, gamma
spec on charcoal cartridge
for1311
13a. Cartridge and
undigested filter samples
from Scenario 1
12.
Any a 8, or
Y> Table 7C or7D
10-4ADL
Values
13. Y-ray analysis
(on filter and cartridge)
3.Gamma analysis
(0.5-2 hours each)
4. Dissolve entire filter
14. Dissolve
entire filter
5.Repeat gross
a/3 using GPC
13b. Previously digested
samples from Scenario 1
15. a analyses
6.
Any a,
8, orY> Table 7A
or 7B 500-mrem
ADL Values
7
16. 3 analyses
17. Y analysis
(if not done on filter)
18.
Individual
radionuclides
> 10-4 risk
or sum of fractions
9. Verify all analyses
completed. Compare
individual results to 500
mrem ADL
19.
Individual
radionuclides
10-6risk
or sum of fractions
20.
Gross a/p
& Y results
compare with sum
of activities
10.
Gross a/p
& Y results
compare with sum
of activities
21. Recount all a, 3,
radionuclides;
re-evaluate results
Yes
23. Archive final
sample forms
\
es| Yes
±
22. Notify 1C of results and
any discrepancies
Figure 3 - Air Scenario 2 Analytical Flow
33
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Notes to Scenario 2: Low-Flow Air Sampling
Purpose: Source of contamination may not be completely identified during
early phase of event.
Considerations: Samples may have been taken from an uncharacterized area.
Samples are taken in the intermediate to recovery phase of the
event. Priority to samples with highest activities (> 500 mrem AAL)
The samples may arrive over several days; those with the highest priority are always to be
analyzed first. Only after an analytical step or procedure has been completed for the highest-
priority samples should lower-priority samples be addressed. Lower-priority samples (those
following the yellow and brown flow paths on this chart) may need to be stored for several days
until the highest-priority samples have been analyzed. The samples with the highest priority
(green path) will be the ones with the highest activity. Some of the information in Step 1 is
provided to the laboratory by the field sampling team.
A low-flow sampler 0.50 to 4.0 ft3/min (1.4*10~2 to l.lxlO"1 m3/min) is used to obtain a
participate sample over a longer time period (12 hours to 7 days, compared to Scenario 1 where
the sample collection is minutes to hours) to help ensure representative sampling. Of those
samples taken during the recovery phase of an event, many will be at areas distant from the
original event site. These samples will be used to determine if the 10~4 and 10~6risk AALs are
exceeded (by comparison with their corresponding ADL values in Tables 8A and 8B).
For low-volume samples, a two-inch filter is typically used, with an iodine cartridge following
the particulate filter (in series) when sampling for radioiodines is needed. However, when
different filter sizes are used, lab personnel must know if the shipped sample is only part of a
larger filter. For example, if a 4"-diameter circle is cutfrom8xl2" filter, the sample results must
be multiplied by 7.64 to correct for the activity on the whole filter. The sample chain-of-custody
form must specify if the field measurements were made on the entire filter, or just the portion
shipped, so that the lab measurements can be compared with the field measurements. This will
assist in getting insight into the quantity of short-lived radionuclides that may be present. It is
also important to know the composition of the filter medium so that appropriate steps can be
taken during the filter digestion process. It should also be established by this time in the event
if DRPs exist. Sub-sampling of the particulate filter must be done very carefully (if at all) to
avoid non-representative results.
Low-flow sampling taken over a long period (> 1 day) will collect larger air volumes and may
provide higher radionuclide activities on the collection matrices. This may provide a more
representative average concentration.
Many of the flow diagram shapes are color-coded to reflect the highest-priority analytical flow
path (green), intermediate (next important) flow path (yellow), or the lowest-priority flow path
(brown) based on the time needed to return the required analytical results to the 1C. The
accompanying numbered notes are color-coded in the same fashion, as are the examples in
Appendix III. It is highly advisable to study the flow paths in color, as a black-and-white printing
may be confusing or ambiguous.
Upon receipt, the laboratory will make a rapid scan with a hand-held instrument (or other
instrument capable of high sample scan throughput). The laboratory instruments used for this
purpose might include a survey meter (with alpha and beta channels) or a Geiger-Muller
34
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
(GM) counter with appropriately calibrated beta and gamma detector probes, or a micro-
roentgen meter (gamma only). This step will be conducted in the laboratory initially with the
particulate filter in its container (e.g., a glassine envelope). The first measurement will be for
gross alpha (outside surface), beta and gamma to assess overall exposure and potential
contamination. Once it has been determined if any other precautions are necessary for direct
measurement (e.g., fume hood, protective breathing equipment, etc.), then the filter is
removed from its container so that the alpha measurement can be assessed more accurately.
Unless the identity of the radionuclide contaminant is known, the hand-held survey
instrument should be calibrated using a standard source (e.g., 241Am for a, 90Sr for P, or 137Cs
for P or y) that will replicate the particulate filter geometry.
During this sample processing phase, special precautions should be taken to avoid sample
cross-contamination as well as laboratory contamination from samples that may have loosely
held particulate matter that is radioactive.
Factors to consider when making the gross screening measurements:
• The solids loading (mg/cm2) on the filter medium should be determined (by the
laboratory) in order to assess accurately the activities relative to background. This can
be done by taking the average mass of an unloaded filter and subtracting it from the final
mass of each filter received from the sample team. This mass can then be used to
estimate the normal concentration of naturally occurring radionuclides in airborne dust
and solids within a sampled area (including any unaffected areas). A dust concentration
of ~100 ug/m3 is typical for non-industrial areas due to terrestrial dust resuspension. (See
the discussion of naturally occurring radionuclides in terrestrial dust under "Additional
Points" following the notes to Scenario 1.)
• Iodine cartridges also must be counted by a gross gamma screen in order to be able to
assess the 500-mrem AAL (including decay correction to the midpoint of the sampling
interval for the 125I and 131I radionuclides). This is determined using the 500-mrem ADL
of 1.6x 103, 240, and 1.2x 103 pCi/m3 for 1251,129I, and 131I, respectively (these are for the
sum of the individual iodines on the cartridge from the analysis of the iodine filter plus
the particulate filter), at the 500-mrem ADL. It is likely that an iodine cartridge will be
"face-loaded."14 However, the laboratory must be able to confirm this assumption.
Cartridge orientation when counting, as well as proper calibration for that geometry, must
be ensured. If the radioiodines are detected on the cartridge, a gamma count of the
particulate filter should be performed to identify any additional radioiodine contribution
prior to assessing what AAL may have been exceeded.
14 This term describes the concentration of the radionuclides of interest in a thin slice of the entire cartridge width that
faces the inlet air flow. At low concentrations, this will usually be the case, but loading can be affected by humidity,
temperature, and presence of other gases that may be adsorbed by the cartridge. One technique that may avoid the issue
efface versus fully loaded is to "side count" the cartridge. The gamma spectrometry detector must be calibrated for this
special geometry.
35
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
It is possible that noble gasses, such as krypton and xenon (if present from a nuclear
detonation or power plant accident), also would be captured on the iodine cartridge, and
thus the identifying gamma lines of the noble gas radionuclides should be in the gamma-
ray library.
• Decay products of radium may be found on both the particulate filter and the iodine
cartridge. Change in activity of samples during transport may be significant depending
upon the radionuclide mix. An example of this occurs for radioactivity on an air filter
when the time from the end of sample collection to receipt at a laboratory is about 12
hours. Any collected 222Rn progeny will have decayed to 210Pb (yielding negligible
activity due to its 22 y half-life), since the decay chain is broken by 222Rn not being
collected on the filter.
For 224Ra, the surface concentration existing naturally at many locations yields an air
concentration of 220Rn of 3.5 pCi/m3. This would yield about 2,100 pCi of 212Pb (ignoring
decay while sampling) on the filter (for a 600 m3 sample). Less than 1,000 pCi (<2,200
dpm) would remain during the laboratory's gross beta analysis (when initiated -12 hours
later). The laboratory would calculate a gross beta concentration of-3.5 pCi/m3 from
212Pb plus 212Bi and a gross alpha concentration of-1.75 pCi/m3 from 212Po. Gamma-ray
spectrometry will detect 212Pb/212Bi at this concentration.
Gross alpha and beta radioactivity due to airborne dust (100 ug/m3) from typical soil
concentrations of 238U, 232Th, or 40K may not be negligible for a 24-hour or longer
sampling duration using a high-flow sampler. Because this decision tree addresses the
late intermediate and recovery phases, when turnaround times (TATs) may be longer, it
may be desirable to wait (when permissible) 72 hours from the end of sample collection
before performing the gross alpha and beta analyses. Waiting 72 to 100 hours will allow
for decay of 212Pb and progeny, so that the radionuclides from the event will be measured
with greater precision by gross techniques.
• Ideally, laboratory screening of samples should be detailed enough to assess if there is
an absence of DRPs. If the screen is a single measurement taken on the entire sample,
this assessment may not be possible. If DRPs are detected/suspected, field personnel
should be notified.
• Tritium sampling of the aerosol at this stage of the event will most likely be unnecessary
as atmospheric moisture and precipitation will rapidly dilute any tritium present.
The presence of 208T1 is as good an indicator of the presence of naturally occurring
radionuclides as 212Pb, since the half-life of 208T1 is short and gamma yield (at 583 keV)
is relatively good.
2. A gross a/P screen is performed with a hand-held device to assess the activity level for
laboratory prioritization. The results of the gross a/P screen are compared to the ADLs for
the 500-mrem exposure level to assess the activity level for laboratory prioritization. If all
36
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
measurements are less than their respective ADL values, then the sample follows the lower-
priority path to Step 11.
If the gross a/P screen (performed with a hand-held laboratory device) exceeds any alpha or
beta radionuclide 500-mrem ADL, gamma spectrometry analysis is performed at Step 3.
If the gamma spectrometry results for the iodine cartridge or the filter exceed the ADLs of
1.6xl03, 240, and 1.2xl03 pCi/m3 for 125I, 129I, and 131I, respectively, then the filter and
cartridge should be processed along the higher-priority flow path with gamma spectrometry
analysis at Step 3.
3. The entire filter should be counted by gamma spectrometry. The count time should be long
enough to meet the uUR in Tables 7C and 7D for the 500-mrem AAL. If a sample was taken
using a radioiodine cartridge, ensure that this is counted on a low-energy photon detector so
that the long-lived isotopes of iodine (that have low gamma-ray energies below 60 keV) can
be determined.
4. Effective sample digestion should use a fusion technique that uses a low-temperature flux
or else an acid digestion technique that ensures a single, homogeneous phase. If glass fiber
filters have been used, some form of fluoride treatment (for example, NaF fusion or HF
removal of silica are commonly used techniques) should be used to eliminate silica
precipitation later in the analytical process. Note that any method used to dissolve the filter
will reduce or eliminate the activity of any volatile or semi-volatile radionuclides present on
the filter. Therefore, analyses for radioisotopes of iodine, phosphorus, and sulfur will need
to be performed in a manner that prevents their loss during sample preparation and analysis.
Sufficient final volume of the digested sample should be saved for removal of subsequent
aliquants for specific alpha- and beta-emitting radionuclides. This should include an aliquant
that may need to be recounted by gamma spectrometry for a period of time sufficient to meet
the WMR in Tables 7C and 7D for the 500-mrem AAL. This count time will be much longer
than if the gamma-spectrometric analysis were performed on the entire filter. Ensure that the
calculation of the final activity of the sample corrects for that fraction of the digested solution
or filter actually used in the analysis.
5. A gross a/P analysis of the filter digestate is made at this point. The analytical method and
low-level radiation detection instrumentation should produce an improved detection capa-
bility and a reduced measurement uncertainty for these analyses compared to the survey
meter measurements of Step 1. These results supersede those obtained in Step 2.
6. The results of the gross a/P analyses from Step 5 and the gamma-spectrometric analysis from
Step 4 are compared to the 500-mrem ADL values in Table 7A and 7B. If no 500-mrem ADL
value is exceeded, then the sample follows the lower-priority sample queue (Steps 15, 16,
and potentially 17). Otherwise, alpha- and beta-specific analyses are started immediately
(Steps 7 and 8).
37
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
7. 8. These two steps are done in parallel to improve TAT. Each analysis is performed to
determine if 500-mrem ADL values in Tables 7C and 7D have been exceeded. Priority
should be based on:
• 1C input (when provided)
• Results from previous samples for this location or event;
Gross analysis that yielded the greatest count rate above background; or
• Results of gamma spectrometry from Step 3 (that may indicate certain low y-yield
radionuclides).
NOTES:
Steps 7 and 8 should be performed concurrently. Although all the radionuclides listed in Table
3 are possible contaminants, perform those analyses that are most probable based on previous
samples and direction by the 1C.
Samples from the same event and area may be queued more accurately using the information
already obtained on the first batch of samples. For example, if 241Am is one of the known
contaminants, that analysis would be started first in Step 7.
9. Ensure that all analytical results are available for all of the radionuclides to be analyzed for
each sample. Select the corresponding 500-mrem ADL values for each of the radionuclides
analyzed and compare to the analytical results. Compute the sum of the fractions for all
radionuclides identified above their respective sample-specific critical values.
10. If the results of the analyses performed in Steps 7 and 8 exceed an individual 500-mrem ADL
(values are in Tables 7C and 7D) or if the sum of the fractions results are >1.0, go to Step 22.
The sum of the individual radionuclide concentrations should be approximately equal to the
respective gross activity concentrations (the rule of thumb is within a range of about half to
twice the respective gross value if the measurement is made more than 72 hours after sample
collection15) for each sample. Ensure that any dilution factors or sample splitting have been
taken into account. If there is a discrepancy between the sum of the individual results and the
respective gross results, there may be either missing radionuclides or an error in the analyses
since the gross results indicated activity above the 500-mrem AAL. This discrepancy should
be resolved by recount or re-analysis (Step 21).
11. The gross scan performed at the laboratory has identified these samples as being less than
or equal to the ADL corresponding to the 500-mrem AAL. A gross alpha/beta screen using
a GPC for a longer period of time (see Tables 7C and 7D) should be performed to get a more
accurate assessment of the sample activity.
The solids loading (mg/cm2) on the filter medium should be determined (by the laboratory)
in order to assess accurately the activities relative to background. This can be done by taking
the average mass of an unloaded filter and subtracting it from the final mass of each filter
received from the sample team. This mass can then be used to estimate the normal concentra-
15 If counting were to take place within 72 hours of sampling, the radon progeny would still contribute to the gross alpha/
beta results, and the l/i value should be carefully examined because early gross count values could be artificially high.
38
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
tion of naturally occurring radionuclides in airborne dust and solids within a sampled area
(including any unaffected areas). A dust concentration of-100 ug/m3 is typical for non-
industrial areas due to terrestrial dust resuspension.
The exception to this flow path is for the iodine cartridge. If the iodine-cartridge screening
results indicate a decay-corrected concentration greater than a 500-mrem ADL for any iodine
isotope [e.g., 131I > 1.2x 103 pCi/m3], go directly to Step 3 and gamma-count the cartridge and
filter (separately), regardless of the gross a/P result. This becomes a high-priority analysis
because this high an activity from short-lived radionuclides like 131I or the noble gases is
unlikely weeks after the event and should be immediately investigated. The longer-lived
iodine isotopes will not be detected by gross beta analysis. It is important therefore to assess
their presence by performing gamma spectrometry with a low-energy photon detector.
12. The screening results from Step 11 are compared to the values of 10~4 risk ADL for
• Gross alpha (from Table 7A),
Gross beta (from Table 7B),
• Gamma isotopic, and
131I for the cartridge [If radioiodines are detected on the cartridge, a gamma count of the
particulate filter should be performed to identify any additional radioiodine contribution
prior to assessing what AAL may have been exceeded].
See Table 12B for derivation of these ADL values. Values greater than the ADL will send
the sample to the high-priority path at Step 3. Samples below their respective ADLs are sent
to the lower-priority queue (Step 13) for gamma spectrometry analysis at a later time to
determine if the 10"6 risk ADL has been exceeded. It may be advantageous to use
simultaneous (e.g., a multi-chamber detector system) versus sequential gross alpha/beta
counting for longer time periods than for the previous screening measurements. This will
ensure that the counting time is sufficient to meet the UMR so that a valid comparison to the
ADL for the 10~4 and 10~6 risk can be made.
13. A longer gamma spectrometry analysis (to meet the 10~6 risk MQOs) should be performed
to identify any gamma-emitting radionuclides that may have been undetected during the
gross screening analysis. The gamma spectrometry analysis using a low-energy photon
detector also should be performed on both the filter and any iodine cartridges that may have
been used in the sampling. Ensure that aliquant size and counting time are sufficient to meet
the MMR, so that a valid comparison to the ADL for a 10~6 risk AAL can be made.
13a. Samples from Radioanalytical Scenario I (Step 15) would feed into the analytical processing
scheme at this point and be ready for Step 13 if these samples have not yet been digested.
13b. Samples from Radioanalytical Scenario I (Step 17) would feed into the analytical processing
scheme at this point. Goto Steps 15,16, and 17 if these samples already have been digested.
If the filter has not been counted by gamma spectrometry in Step 17 of Scenario 1 flow
diagram, longer count times will be required here.
39
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
14. Samples in this step have gross a/P and y isotopic activities less than the 500-mrem ADL and
consequently are a lower priority. When detectors are available, the entire filter should be
dissolved and aliquants apportioned for a and P analysis (with sufficient reserve aliquants
for analysis that may require either lower detectability or analysis for radionuclides not in
Table 3).
A fusion technique that uses a low-temperature flux, or an acid digestion that ensures a
single, homogeneous phase, should be applied. If glass fiber filters have been used, some
form of fluoride treatment (for example, NaF fusion or HF removal of silica are commonly
used techniques) should be used to eliminate silica precipitation later in the analytical
process. FTP may be better for samples that only have alpha-emitting radionuclides because
its use minimizes the addition of other solid matter to the final counting form, which in turn
minimizes sample self-absorption.
Sufficient final volume of the digested sample should be saved for removal of aliquants in
the future for specific alpha- and beta-emitting radionuclides. This should include an aliquant
that may need to be recounted by gamma spectrometry for a period of time sufficient to
achieve UMR for the 1CT6 risk level. Ensure that the calculation of the final activity of the
sample corrects for that fraction of the original sample that was used for the analysis after
sample digestion.
NOTES:
Steps 15, 16, and 17 should be performed concurrently. Although all the radionuclides listed
in Table 3 are possible contaminants, perform those analyses that are most probable based on
previous samples and direction by the 1C.
Samples from the same event and area may be queued more accurately using the information
already obtained on the first batch of samples. For example, if 241Am is one of the known
contaminants, that analysis would be started first in Step 15.
15. 16. 17. These three steps should be done concurrently. Prioritization of radionuclide-specific
analysis should be based on:
• 1C input (when provided)
• Results from previous samples for this location or event;
• Gross analysis that yielded the greatest count rate above background; or
• Results of the gamma count from Step 13 (that may indicate certain low gamma-
yield radionuclides).
Samples that were originally on the green path (high priority) may be routed here. They will
have been digested already. An aliquant of the digestate should be analyzed by gamma
spectrometry with a longer count than previously performed (long enough to meet the WMR
from Tables 8A and 8B). Ensure that aliquant size and counting time are sufficient to
determine if the ADL for the 1CT6 risk AAL has been exceeded.
18. As the analytical values are obtained for each of the radionuclides in the tables, they are
compared with the 1CT4 risk factor AAL. If more than one radionuclide is present above its
detection limit (i.e., critical level concentration), the sum of the fractions of the 1CT4 risk
factor is used to assess whether thelCT4 risk factor AAL is exceeded. If the sum of the
40
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
fractions exceeds 1.0 or an individual result exceeds the ADL, proceed to Step 9. Otherwise
go to Step 19.
19. Compare the sample results to the 1CT6 risk factor ADL and the sum of the fractions (if more
than one radionuclide is present) to the 1CT6 risk factor AAL. Any time the specific
radionuclide value for 1CT6 risk factor ADL is exceeded, proceed to Step 9. Otherwise, the
sample processing continues with a lower priority at Step 20. Check to ensure that the gross
sample analyses agree with the sum of the individual analyses for that sample.
20. If there is poor agreement between initial gross screen and final radionuclide-specific
analyses, proceed to Step 21. If all comparisons have been made and found valid and results
are less than the applicable 1CT6 risk factor ADL, and sum of the fractions of all radionuclides
above their detection limit is less than one, proceed to Step 22.
21. If the radionuclide specific analyses do not agree within the range of 0.5 to 2.0 times the
gross sample analysis for alpha and beta, respectively, the discrepancy should be resolved
quickly if possible.
The discrepancy should be quickly resolved, if possible. The samples either should be
recounted or reserved aliquants should be reprocessed to attempt to resolve the discrepancy.
If reprocessing resolves the discrepancy, re-evaluate the sample results against respective
ADL values, and then recalculate the sum of the fractions.
If reprocessing does not resolve the discrepancy, results should be reported with a notation
that the gross activity and radionuclide-specific activity sums do not agree.
22. Notify the 1C of the sample results. Specific note should be made of any radionuclide that
exceeds an ADL or if the sum of the fractions exceeds 1.0. Any discrepancies between the
gross activity measurement and the sum of the final activity results should also be identified.
All results for samples are reported to the 1C, along with any unresolvable discrepancies in
the analytical results.
23. The final sample test source should be archived so that their integrity is maintained and that
they are in a retrievable condition to reproduce counting. Any remaining final sample
fractions should be archived as well, e.g., remaining solution from the digestion of the air
filter. Provide electronic data deliverable (EDD) to field personnel or 1C.
41
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
VI. SCENARIO 3 (Radionuclides in Air Participate Samples Have Been Identified)
Key
I I p emissions only
I I a emissions only
I I u Multiple emissions
I I End result
See accompanying tables
for alpha and beta/gamma
concentrations, and
numbered notes
Air Sample Scenario 3
Known radionuclides
Priorities established by Incident Commander
2,1.
Gross scan for
combination of 2 or 3
emission modes
are emitted by the
sample
2R. Gross scan p only
3
2.3x1 Cr3
pCi/m3
4u. Perform nuchde-specific analysis
following sample dissolution
4a. Perform a-specific analysis
following sample dissolution
specific analyses
4p2
NY p-specifi
analyses
Table 8B
10-4ADL
/ ^
specific analyses
Any p-specific\ Yeg
No
1
9. Report,^ \f.
to 1C J\
' i
ADL/
)/
\ 1 \ ? /
9. Report . \ /
to 1C ' No
f
3k
5
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Notes for Scenario 3: Contaminating Radionuclides Known
Purpose: Support the Specific Needs of the 1C
For this scenario, "a" and "(3" designate paths that are to be followed (and their associated notes)
when samples received from the field contain radionuclides that emit only alpha or only beta
particles, respectively, and "u" designates samples that contain a gamma emitter or a mixture of
emitters (alpha or beta or gamma).
Scenario 3 takes place when the radioactive contaminants have been well characterized. Detailed
analyses are required for the radionuclide(s) known to be in the samples, and at the direction of
the 1C. Thus, the radioanalytical process chart becomes more streamlined, and sample priority
is based upon what is needed by the Incident Commander at the time the samples are taken.
Either high- or low-activity samples may take priority.
Because the radionuclides are known, the gross-screening instruments should be calibrated for
the specific radionuclides of interest if possible. This allows rapid and more accurate assessment
of the activity before more time-consuming analytical separations are performed.
Many of the flow diagram shapes are color-coded to reflect the analytical flow path for various
combinations of decay modes (green for alpha, gray for beta, or brown for multiple emitters). The
accompanying numbered notes are color-coded in the same fashion, as are the examples in
Appendix IV. It is highly advisable to study the flow paths in color, as a black-and-white printing
may be confusing or ambiguous.
The event that has taken place is now characterized and the radionuclide(s) of concern have
been identified. The flowchart is trimmed to deciding which of the three different
radionuclide emissions are present. The emission mode generally determines the final
radioanalytical method that will be used to assess the concentration. Generally, p-only
emitters will be analyzed by GPC or LSC (2P), a-only emitters by either GPC or alpha
spectrometry (AS) (2a), and any combination of the three types of emission by an appropriate
combination of alpha spectrometry, GPC, LSC, or gamma spectrometry (2u). The choice is
determined by what is known about the event. If more than one type of radionuclide emitter
is present, the choice is to follow the multiple emissions mode path (2u). The ranking of total
activity in the samples will be aided by sample gross screening when the samples are
received by the laboratory (see discussion in beginning of description for Scenario 2).
This path is selected only if radionuclides from the event are all pure a emitters.16 The
samples still should be screened to distinguish high- from low-activity samples. Thus, the
instrument used to perform the screening analysis should be calibrated to permit specific
determination of the concentration of the radionuclide of interest.
16 It should be noted that the evaluation for pure alpha or beta emitters should be done based on the principal particle
emission used for routine detection. This means that for the concentrations in air paniculate samples below the 10"4 risk-
level AAL, that241 Am would be considered "alpha only."
43
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
This path is selected only if all radionuclides from the event are P emitters.17 The samples
still should be screened to distinguish high- from low-activity samples. Thus, the instrument
used to perform the screening analysis should be calibrated using the radionuclide of interest.
This path is selected only if the radionuclides from the event emit a combination of a, or P,
or y emitters. The samples still should be screened to distinguish high- from low-activity
samples. The instrument used to perform the screening analysis should be calibrated with the
radionuclides of interest.
The purpose of this step is to distinguish high-activity samples from low-activity
samples and to rank the samples in order of their activity level. The subsequent flow
paths would be selected based on the priority from the 1C. Thus, it is important that
this screening method is able to distinguish high-activity samples from low-activity
samples in a reasonably short time. Table 14 in Appendix VI provides an insight into
the minimum detectable concentration (MDC) and 10% relative counting uncertainty
that can be achieved routinely using specified sampled volumes, and detector count
times using GPC. Although these MDCs are not equivalent and do not relate to a
specific AALs, they are low enough to be used for screening purposes. Once
classified as high or low analytical priority, the samples should be ranked based on
their gross activity measurements.
NOTE: The flow of priority splits here. Either of the paths for the suffixes 1 or 2 may get
the priority. The priority is event-specific and determined by the 1C. Suffix 1 designates
the 10~6 risk requirements, and suffix 2 designates other event-specific MQOs. Flow path
2 would be scaled to the appropriate ADL based on the 10~4 risk level.
It may be advantageous to use simultaneous versus sequential gross alpha/beta
counting (e.g., using a multi-chamber detector system) for longer time periods than
for the previous screening measurements to be able to assess expeditiously if sample
activities are less than the 1CT4 and 1CT6 risk ADLs and also to achieve the respective
UUR values.
The 1C may stipulate an event-specific AAL, ADL, and WMR, whose values are based
on a fraction of the values found in Tables 8 A and 8B.
The first analytical priority when this path is chosen is to determine the known
contaminant(s) from the event. A radionuclide-specific method(s) should be chosen
for all previously identified radionuclides. This will usually require digestion of the
particulate filter as described in Scenario 1.
The analytical methods chosen should be able to meet the WMR at the 1CT6 risk AAL
concentration (Tables 8A and 8B). This path would be chosen if the intent was to
look for unrestricted habitability. As results are validated, if the event-specific
17 See previous footnote concerning the evaluation of pure alpha or beta emitters based on the principal particle emission.
44
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
contaminant concentration is greater than its respective 10~6 risk ADL (Tables 8 A or
8B), notify the 1C. Otherwise, proceed with all other analyses and report results when
all are completed.
This branch of the flow diagram would be chosen if the direction were to identify air
particulate filters that have sufficient activity to cause exposure in excess of the 10~4
risk level, or other event-specific risk level defined by the 1C. If the event-specific
contaminant is less than its respective ADL (based on scaling of concentrations and
in Tables 8A and 8B), then analysis for all other contaminants of concern should
proceed. If the event-specific contaminant concentration is greater than its respective
ADL for that event, notify the 1C that this sample has exceeded the event-specific
AAL.
Perform all other radionuclide analyses required by the 1C.
Select the ADL values from Tables 8 A or 8B to be compared with the final analytical
concentrations for the air sample, and scale the ADL values to the incident-specific
AAL. For example, if the AAL required by the project was 10~5 risk for 232Th, start
with the 10~4 ADL value of2.1xlO~1pCi/m3 (from Table8A)and divide it by 10. The
resulting value for the ADL will be 2.1 x 10~2 pCi/m3, with a UUR value of 3.8* 10~3
pCi/m3.
7. Start by comparing each individual radionuclide result with the incident-specific risk level
ADL values (see Tables 8A and 8B for the default values of 10~4 and 10~6). If the final
reviewed result for any single radionuclide exceeds the project-specific ADL, or the sum of
the fractions exceeds 1.0, report the results immediately to the 1C.
8. Compare the radionuclide-specific results to the screening analyses and verify that no maj or
nuclide has been missed. Verify that the sum of the individual nuclide concentrations is
approximately equivalent to the gross activity concentration (a rule of thumb is within a
range of about half to twice the gross value). However, this may not hold true for low-energy
beta emitters, like tritium, if the screening measurement was made by GPC. This check will
ensure that the sum of the measurements compares reasonably to the total measured gross
activity. Activity concentrations due to decay products should be included in the verification.
If there is a discrepancy between the summed activity concentration of all statistically
significant individual nuclide concentrations (i.e., sum all results detected at levels greater
than the critical level, rather than the incident-specific discrimination limit), check for errors
and resolve any discrepancies prior to proceeding.
9. Two paths lead to this step:
• In Steps 4al, 4pl, and 4ul, the result for the event-specific radionuclide exceeded the
10~4or 10~6 risk level, or
• All analyses have been completed, and the result is < 10~6 risk factor. The priority path
was previously determined by the 1C.
45
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
10. If the results from the radionuclide-specific analysis and the gross measurement do not match
to within a factor of 0.5 to 2.0, then a potential mismatch exists between the individual
radionuclide concentration sum and the gross analysis (potentially missing a radionuclide
contributor. This would indicate a potential mismatch between the individual radionuclide
concentration sum and the gross analysis (potentially missing a radionuclide contributor).
This may require re-analysis starting with the gross-activity measurement.
It is possible that either a short-lived radionuclide decayed away prior to having been
analyzed, or a radionuclide analysis was missed. It may also be possible that a low-energy
alpha, beta, or gamma emitter was not detected during the gross analysis due to self shielding
effects. In either case, the discrepancy should be resolved, which may include specific
correlations for the radionuclides from this event.
Final results are then transmitted to the 1C.
46
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
APPENDIX I. Tables of Radioanalytical Parameters for Radionuclides of Concern
The following tables list the AAL, ADL, and UMR values for the radionuclides of concern. The tables
present gross screening and radionuclide-specific measurements for alpha and beta/gamma-emitting
radionuclides. Derivation of the ADL values for each of these tables can be found in Appendix VI.
Tables 7A and 7B show activities of specific radionuclides. These values were calculated based on
the Type I and Type n error rates presented in Appendix VI.
The listed AALs are applicable as default values based on generic conversions of the dose level to
concentration in air for a specific radionuclide. The required method uncertainty and ADL will
change depending upon the acceptable decision error rate. The 1C may provide incident-specific
AALs or decision error rates that would supersede these values. In this case, the laboratory will need
to develop new tables for all values, using the process described in Appendix VI.
TABLE 7A - Analytical Decision Levels (ADL) and Required Method Uncertainty Using Gross
Alpha Screening Methods
Radionuclide
Gross a
Screen
(pCi/m3)
2-rem
AAL
0.70
2-rem
ADL
0.35
Required
Method
Uncertainty
(*fcp)
0.21
500-mrem
AAL
0.17
500-mrem
ADL
0.085
Required
Method
Uncertainty
(*fcp)
0.052
Am-241
Cm-242
Cm-243
Cm-244
Np-237 [2]
Po-210
Pu-238
Pu-239
Pu-240
Ra-226 [2]
Th-228 [2]
Th-230
Th-232
U-234
U-235
U-238
0.70
11
0.97
1.2
1.3
16
0.62
0.56
0.56
7.0
1.7
0.66
0.61
7.1
7.9
8.3
0.35
5.5
0.49
0.60
0.65
8.0
0.31
0.28
0.28
3.5
0.85
0.33
0.31
3.6
4.0
4.2
0.21
3.3
0.29
0.36
0.40
4.9
0.19
0.17
0.17
2.1
0.52
0.20
0.19
2.2
2.4
2.5
0.17
2.8
0.24
0.29
0.34
3.9
0.15
0.14
0.14
1.8
0.42
0.17
0.15
1.8
2.0
2.1
0.085
1.4
0.12
0.15
0.17
2.0
0.075
0.070
0.070
0.90
0.21
0.085
0.075
0.90
1.0
1.1
0.052
0.85
0.073
0.088
0.10
1.2
0.046
0.043
0.043
0.55
0.13
0.052
0.046
0.55
0.61
0.64
Notes:
[1] Derived air concentration yielding stated committed effective dose assuming a 3 65-day year. Child as
receptor. Value corresponds to solubility class having lowest value.
[2] Includes decay products in the body for the calculation of concentration.
[3] Required method uncertainty values are calculated for the 2-rem or 500-mrem AALs in Appendix VI.
47
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 7B - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty Using Gross Beta-Gamma Screening Methods
Radionuclide
Gross B Screen
Ac-227+DP [2]
Ce-141
Ce-144
Co-577
Co-60
Cs-134
Cs-137
H-3P1
1-125 ^
1-129 [6'4]
1-131 [Ml
IT- 192
Mo-99
P-32
Pd-103
Pu-241
Ra-228 [2]
Ru-103
Ru-106
Se-75
Sr-89
Sr-902
Tc-99
pCi/m3
2-rem
AAL
[i]
420
0.43
1.8xl04
1.3xl03
6.7xl04
2.2xl03
3.3xl03
1.7xl03
2.6xl05
1.3xl04
1.9xl03
9.1xl03
l.OxlO4
6.8xl04
1.7xl04
l.SxlO5
29
4.2
2.3xl04
l.OxlO3
S.OxlO4
8.4xl03
420
S.OxlO3
2-rem
ADL
210
0.22
9.0xl03
650
3.4xl04
l.lxlO3
1.7xl03
850
1.3xl05
6.5xl03
950
4.6xl03
5.0xl03
3.4xl04
8.5xl03
7.5xl04
15
2.1
1.2xl04
500
2.5xl04
4.2xl03
210
2.5xl03
Required
Method
Uncertainty
(«MR)
[3]
130
0.13
5.5xl03
400
2.0xl04
670
l.OxlO3
520
7.9xl04
4.0xl03
580
2.8xl03
3.0xl03
2.1xl04
5.2xl03
4.6xl04
8.8
1.3
7.0xl03
300
1.5xl04
2.6xl03
130
1.5xl03
500-
mrem
AAL
[i]
110
0.11
4.5xl03
320
1.7xl04
550
820
430
6.4xl04
3.2xl03
470
2.3xl03
2.5xl03
1.7xl04
4.3xl03
3.8xl04
7.3
1.0
5.7xl03
250
1.3xl04
2.1xl03
110
1.3xl03
500-
mrem
ADL
55
0.055
2.3xl03
160
8.5xl03
280
410
220
3.2xl04
1.6xl03
240
1.2xl03
1.3xl03
8.5xl03
2.2xl03
1.9xl04
3.7
0.50
2.9xl03
130
6.5xl03
l.lxlO3
55
650
Required
Method
Uncertainty
(«MR)
[3]
33
0.033
1.4xl03
97
5.2xl03
170
250
130
1.9xl04
970
140
700
760
5.2xl03
1.3xl03
1.2xl04
2.2
0.30
1.7xl03
76
4.0xl03
640
33
400
Notes:
[1] Derived air concentration yielding stated committed effective dose assuming a 3 65-day year. Child as
receptor. Value corresponds to solubility class having lowest value.
[2] Includes decay products in the body for the calculation of concentration.
[3] Required method uncertainty values are calculated for the 2-rem or 500-mrem AALs in Appendix VI.
[4] All nuclides can be collected on a fibrous or membrane air filter media except 3H, 1251,129I, and 131I in the
vapor states.
[5] Value determined excluding 227Ac and 228Ra. Sr-90 is used for gross beta screening because it is the most
restrictive in the table and commonly used for instrument calibration.
[6] These values are based on the vapor plus particulate dose rate.
[7] Several nuclides decay by electron capture (see Table 3). These radionuclides cannot be detected using
gross B analysis. The electron-capture decay leads to characteristic X-rays of the progeny nuclide. The
most effective way to detect the X-rays from these electron-capture-decay radionuclides is either with
a low-energy photon detector (LEPD) or a reverse electrode germanium detector N-type semiconductor
detector. The lower range of energy with these detectors is about 10 keV.
48
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 7C - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty Using Alpha Radionuclide Specific Methods
Radionuclide
Am-241
Cm-242
Cm-243
Cm-244
Np-237 [2]
Po-210
Pu-238
Pu-239
Pu-240
Ra-226 [2]
Th-228 [2]
Th-230
Th-232
U-234
U-235
U-238
(pCi/m3)
2-rem
^L
0.70
11
0.97
1.2
1.3
16
0.62
0.56
0.56
7.0
1.7
0.66
0.61
7.1
7.9
8.3
2-rem
ADL
0.49
7.8
0.69
0.85
0.92
11
0.44
0.40
0.40
4.9
1.2
0.47
0.43
5.0
5.6
5.9
Required
Method
Uncertainty
(«MR)
0.088
1.4
0.12
0.15
0.16
2.0
0.081
0.071
0.071
0.88
0.21
0.083
0.077
0.89
0.99
1.0
500-
mrem
^L
0.17
2.8
0.24
0.29
0.34
3.9
0.15
0.14
0.14
1.8
0.42
0.17
0.15
1.8
2.0
2.1
500-
mrem
ADL
0.12
2.0
0.17
0.21
0.24
2.8
0.11
0.099
0.099
1.3
0.30
0.12
0.11
1.3
1.4
1.5
Required
Method
Uncertainty
("MR)
0.021
0.35
0.030
0.037
0.043
0.49
0.020
0.018
0.018
0.23
0.053
0.021
0.019
0.23
0.25
0.26
Notes:
[1] Derived air concentration yielding stated committed effective dose assuming a 365-day year. Child as
receptor. Value corresponds to solubility class having lowest value.
[2] Includes decay products in the body for the calculation of concentration.
[3] Required method uncertainty values are calculated for the 2-rem or 500-mrem AALs in Appendix VI.
49
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 7D - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty Using Beta-Gamma Radionuclide-Specific Methods
Radionuclide
Ac-227+DP [2]
Ce-141
Ce-144
CO-57M
Co-60
Cs-134
Cs-137
H-3P1
I-125&
I-129[5'6]
I-131'5"
Ir-192
Mo-99
P-32
Pd-103
Pu-241
Ra-228 [2]
Ru-103
Ru-106
Se-75
Sr-89
Sr-90[2]
Tc-99
pCi/m3
2-rem
AAL
[i]
0.43
l.SxlO4
1.3xl03
6.7xl04
2.2xl03
3.3xl03
1.7xl03
2.6xl05
1.3xl04
1.9xl03
9.1xl03
l.OxlO4
6.8xl04
1.7xl04
1.5xl05
29
4.2
2.3 xlO4
l.OxlO3
5.0xl04
8.4xl03
420
5.0xl03
2-rem
ADL
0.30
1.3xl04
920
4.7xl04
1.6xl03
2.3xl03
1.2xl03
l.SxlO5
9.2xl03
l.SxlO3
6.4xl03
7.1xl03
4.8xl04
1.2xl04
l.lxlO5
21
3.0
1.6xl04
710
3.5xl04
5.9xl03
300
3.5xl03
Required
Method
Uncertainty
("MR)
[3]
0.054
2.3xl03
160
8.4xl03
280
420
210
3.3xl04
1.6xl03
240
l.lxlO3
l.SxlO3
8.6xl03
2.1xl03
1.9xl04
3.7
0.53
2.9xl03
130
6.3xl03
l.lxlO3
53
630
500-mrem
AAL
[i]
0.11
4.5xl03
320
1.7xl04
550
820
430
6.4xl04
3.2xl03
470
2.3 xlO3
2.5xl03
1.7xl04
4.3 xlO3
3.8xl04
7.3
1.0
5.7xl03
250
l.SxlO4
2.1 xlO3
110
l.SxlO3
500-mrem
ADL
0.078
3.2xl03
230
1.2xl04
390
580
300
4.5xl04
2.3xl03
330
1.6xl03
l.SxlO3
1.2xl04
3.0xl03
2.7xl04
5.2
0.71
4.0xl03
180
9.2xl03
l.SxlO3
78
920
Required
Method
Uncertainty
("MR)
[3]
0.014
570
40
2.1xl03
69
100
54
S.lxlO3
400
59
290
310
2.1xl03
540
4.8xl03
0.92
0.13
720
31
1.6xl03
260
14
160
Notes:
[1] Derived air concentration yielding stated committed effective dose assuming a 3 65-day year. Child as
receptor. Value corresponds to solubility class having lowest value.
[2] Includes decay products in the body for the calculation of concentration.
[3] Required method uncertainty values are calculated for the 2-rem or 500-mrem AALs in Appendix VI.
[4] All nuclides can be collected on a fibrous or membrane air filter media except 3H, 1251,129I, and 131I in the
vapor states.
[5] These values are based on the vapor phase dose rate and would be applied to the cartridges only for
screening purposes.
[6] Several nuclides decay by electron capture (see Table 3). These radionuclides cannot be detected using
gross (3 analysis. The electron-capture decay leads to characteristic X-rays of the progeny nuclide. The
most effective way to detect the X-rays from these electron-capture-decay radionuclides is either with
a low-energy photon detector (LEPD) or a reverse electrode germanium detector N-type semiconductor
detector. The lower range of energy with these detectors is about 10 keV.
50
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 8A - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty at 10~4 and 10~6 Risk Using Alpha Radionuclide-Specific Methods
Radionuclide
Am-241
Cm-242
Cm-243
Cm-244
Np-237 [2]
Po-210
Pu-238
Pu-239
Pu-240
Ra-226 [2]
Th-228 [2]
Th-230
Th-232
U-234
U-235
U-238
pCi/m3
ID'4 Risk
AAL
[i]
0.33
0.62
0.34
0.35
0.43
0.86
0.24
0.22
0.22
0.44
0.094
0.36
0.30
0.45
0.49
0.52
ID'4 Risk
ADL
0.23
0.44
0.24
0.25
0.30
0.61
0.17
0.16
0.16
0.31
0.066
0.25
0.21
0.32
0.35
0.37
Required
Method
Uncertainty
(«MR)
[3]
0.042
0.078
0.043
0.044
0.054
0.11
0.030
0.028
0.028
0.055
0.012
0.045
0.038
0.057
0.062
0.065
ID'6 Risk
AAL
[i]
3.3xlQ-3
6.2xlQ-3
3.4xlQ-3
3.5xlQ-3
4.3xlQ-3
8.6xlQ-3
2.4xlQ-3
2.2xlQ-3
2.2xlQ-3
4.4xlQ-3
9.4xlQ-4
3.6xlQ-3
3.0xlQ-3
4.5xlQ-3
4.9xlQ-3
5.2xlQ-3
ID'6 Risk
ADL
2.3xlQ-3
4.4xlQ-3
2.4xlQ-3
2.5xlQ-3
3.0xlQ-3
6.1xlQ-3
1.7xlQ-3
1.6xlQ-3
1.6xlQ-3
3.1xlQ-3
6.6xlQ-4
2.5xlQ-3
2.1xlQ-3
3.2xlQ-3
3.5xlQ-3
3.7xlQ-3
Required
Method
Uncertainty
(«MR)
[3]
4.2xlQ-4
7.8xlQ-4
4.3xlQ-4
4.4xlQ-4
5.4xlQ-4
l.lxlQ-3
3.0xlQ-4
2.8xlQ-4
2.8xlQ-4
5.5xlQ-4
1.2xlQ-4
4.5xlQ-4
3.8xlQ-4
5.7xlQ-4
6.2xlQ-4
6.5xlQ-4
Notes:
[1] Morbidity for long-term inhalation. Value corresponds to solubility class having lowest value.
[2] Includes decay products in the body for the calculation of risk or concentration.
[3] Required method uncertainty values are calculated for the KT1 and icr6 risk values in Appendix VI.
51
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 8B - Analytical Action and Decision Levels (AAL and ADL) and Required Method
Uncertainty at 10~4 and 10~6 Risk Using Beta-Gamma Radionuclide-Specific Methods
Radionuclide'21
Ac-227+DP[4]
Ce-141
Ce-144
Co-57 ra
Co-60
Cs-134
Cs-137
H-3 Vapor
1-125 [s]
1-129 [5'6]
1-131 [5]
Ir-192
Mo-99
P-32
Pd-103
Pu-241
Ra-228 [4]
Ru-103
Ru-106
Se-75
Sr-89
Sr-90 [4]
Tc-99
pCi/m3
ID'4 Risk
AAL
[i]
0.083
920
69
3.3xl03
120
180
110
1.5xl04
1.2xl03
200
640
510
2.6xl03
890
7.0xl03
14
0.28
1.2xl03
56
2.5xl03
410
29
330
10-4 Risk
ADL
0.059
650
49
2.3 xlO3
85
130
78
l.lxlO4
850
140
450
360
l.SxlO3
630
4.9xl03
9.9
0.20
850
40
l.SxlO3
290
21
230
Required
Method
Uncertainty
"MR
[3]
0.010
120
8.7
420
15
23
14
1.9xl03
150
25
81
64
330
110
880
1.8
0.035
150
7.1
310
52
3.7
42
10-6Risk
AAL
[i]
8.3X10'4
9.2
0.69
33
1.2
1.8
1.1
150
12
2
6.4
5.1
26
8.9
70
0.14
2.8X10-3
12
0.56
25
4.1
0.29
3.3
1Q-6 Risk
ADL
5.9X10'4
6.5
0.49
23
0.85
1.3
0.78
110
8.5
1.4
4.5
3.6
18
6.3
49
0.099
2.0X10'3
8.5
0.40
18
2.9
0.21
2.3
Required
Method
Uncertainty
"MR
[3]
LOxlO'4
1.2
0.087
4.2
0.15
0.23
0.14
19
1.5
0.25
0.81
0.64
3.3
1.1
8.8
0.018
3.5X10'4
1.5
0.071
3.1
0.52
0.037
0.42
Notes:
[1] Morbidity for long-term inhalation. Value corresponds to solubility class having lowest value.
[2] All nuclides can be collected on a fibrous or membrane air filter media except 3H, 1251,129I, and 131I when
their chemical form is in the vapor (vap) state. It is possible for iodine to be in the particulate (part) form.
Note the differences in concentrations for the respective ADL values.
[3] Required method uncertainty values are calculated for the 10~4 and 10~6 risk values in Appendix VI.
[4] Includes decay products in the body for the calculation of concentration.
[5] These values are based on the vapor phase dose rate and would be applied to the cartridges only for
screening purposes.
[6] Several nuclides decay by electron capture (see Table 3). These radionuclides cannot be detected using
gross (3 analysis. The electron-capture decay leads to characteristic X-rays of the progeny nuclide. The
most effective way to detect the X-rays from these electron-capture-decay radionuclides is either with
a low-energy photon detector (LEPD) or a reverse electrode germanium detector N-type semiconductor
detector. The lower range of energy with these detectors is about 10 keV.
52
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
APPENDIX II. Example of High-Concentration Air Particulates (Radioanalytical
Scenario 1)
The number of samples have been minimized and the screening processes have been simplified in
this example. In an actual event, the number and complexity of samples will be much greater than
identified here.
Description
Air samples have been taken in the vicinity of a detonation where it is suspected an RDD has been
used. Initial field readings show indications of radioactivity although no identification of radionuc-
lides has been made. The sequence of events in the laboratory assumes a single analyst following the
analytical flow chart, under conditions of a single sample process stream.
Event Sequence
The incident response organization has just established a field office for coordinating the response
efforts, including a laboratory project manager who reports to the Incident Commander (1C). At 1200
hours of Day 7, the incident response team sends three air particulate samples and three iodine
cartridge samples from areas they believe to have the highest concentrations of airborne particulate
radionuclides based on the field measurements of these samples. The samples arrive at the laboratory
three hours later: it is Day 1, 1500 hours.
Analysis Paths
Field sampling personnel have noted on the chain-of-custody (COC) form that the samples were
taken at a flow rate of 4.0 cfm for 1 hour, yielding a total volume of air sampled of 6.8 m3. Field
measurements of the filter surface using a hand-held alpha probe and a GM detector calibrated with
241 Am for gross alpha and 137Cs for gross beta and gamma, respectively, are noted in the tables below.
| Step 1. | The lab performs a receipt survey of the samples using hand-held instruments for alpha,
beta, and gamma. The data produced by the lab measurements are also listed in the tables below.
Filter ID
1
2
3
Back-
ground
Gross Alpha,
cpm (Field)
70.0
8.0
1.8
1.5
Gross Alpha,
cpm (Lab)
25.4
1.3
1.2
1.1
Gross Beta,
cpm (Field)
46.0
15.8
15
15
Gross Beta,
cpm (Lab)
9.0
8.3
8.2
8.1
Gross gamma,
uR/h (Field)
53
51
50
50
Gross Gamma,
uR/h (Lab)
37
37
37
36
Cartridge ID
1
2
3
Background
Gamma
spectrometry Results
No 131I identified
No 131I identified
No 131I identified
40K
Gross Gamma, nR/h
41
38
36
36
53
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
When the field measurements are compared to the lab measurements, it appears that the alpha and
beta emission rates have both decreased significantly during transport, indicating that there are short-
lived emitters present. Given the similar gamma-count rates between the background and the
measurements of both the particulate filters and the iodine cartridges, there does not appear to be a
significant concentration of gamma emitters present. It is not clear whether the short-lived radionuc-
lides are radon-decay progeny, radionuclides of concern related to the incident, or both. It is Day 1,
1515 hours.
Step la Filters 1, 2, and 3. If the laboratory value for the gross alpha on Filter 1 is used to
calculate18 pCi/m3, we find:
[25.4-1.l]cpm 1 .,. „., 3
• x = 16.1 pCi / m
(0.1[cpm/dpm]) x (2.22 dpm/pCi) 6.8 m3
This value exceeds all the 2-rem ADL values for the alpha-emitting radionuclides shown in Table
7A.
For the beta value, we find
[9.0-8.1]cpm 1 „. , 3
-x - = 0.20pCi/m3
(0.3 [cpm/dpm]) x (2.22 dpm/pCi) 6.8 m3
which is below all the 2-rem and the 500-mrem ADL values for the beta-emitting radionuclides in
Table 7B (with the exception of 227Ac which is a 235U decay product and based on the scenario
evidence 235U was not a possibility).
The dose rate in uR/h is at the background level.
Filter 1 gets the red path for processing (Step 2), with the additional input that beta and gamma
analyses have no significant contribution to the total activity.
For Filter 2, the gross alpha values yield 0.13 pCi/m3, which is less than the 2-rem ADL gross alpha
value but greater than the gross-alpha 500-mrem ADL value in Table 7A. Following the Scenario
1 flow chart (Figure 2), because the gross alpha is between 500 mrem and 2 rem and the gross beta-
gamma is insignificant. The filter should be analyzed as a second priority for all analytes starting at
Step 4.
For Filter 3, the concentration for alpha is 6.6x 10~2, which is less than the 500-mrem ADL for alpha
emitters. Thus, this sample analysis would be continued as a second priority at Step 13.
Step Ib. No samples have been taken for tritium analysis.
18 The detection efficiencies for the laboratory hand-held instruments used in this example are 0.1 for gross alpha and
0.3 for gross beta.
54
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Lc. Cartridges 1, 2, and 3. The gamma-ray spectrometer used for analysis of these cartridges
is calibrated down to 25 keV. It is determined that the UUR values for the three iodine radionuclides
have been met based on the gamma spectrometry count time. Go to Step 3b. It is Day 1, 1530 hours.
Step 2, Filter 1. The microR-meter indicates activity at about the background level. Filter 1 is
counted by gamma spectrometry for 15 minutes. The filter is next counted on the GPC for 10
minutes (See Table 9). It is determined that the UMR values for gross alpha, gross beta and gamma-
specific analyses by screening techniques (Tables 7A and 7B) have been met based on the gamma
spectrometry and GPC count times. Laboratory personnel begin to review the sample results; go to
Step 3a. It is Day 1, 1550 hours.
\ No gamma-ray peaks above their respective critical levels for the radionuclides
of concern are identified by the software. The GPC analysis results on the entire filter are 15.5
pCi/m3 gross alpha, and 2.0 pCi/m3 gross beta. Sample stays on the high-priority path at Step 4, and
a preliminary report is sent to the 1C notifying the 1C of the high result for this filter by laboratory
screening analyses.
Step 3b, Cartridges 1, 2, and 3. There were no samples submitted for tritium analysis, and all the
iodine cartridges have concentrations for the three iodine radionuclides less than their respective
500-mrem ADL values. These samples should be archived until a longer gamma count can be
performed (Step 13).
Step 4, Filter 1. Filter 1 is dissolved using HF digestion that completely solubilizes the filter
material. Laboratory personnel have visually checked the final solution to ensure that no visible
particulate matter is present. Aliquants of the final solution are taken for gross alpha/beta, beta
emitters and alpha isotopic (radium plus uranium and the transuranic elements) analysis. An aliquant
of the remaining solution is archived for any additional analyses (like a follow-up gamma-ray
analysis) that may be required. It is Day 1, 2145 hours.
Step 5, Filter 1. Because the gross alpha 2-rem AAL was exceeded for Filter 1, an aliquant of the
dissolved filter solution is analyzed for gross alpha/beta by GPC. The alpha result is 20.1 pCi/m3,
beta result is 8.2 pCi/m3. This confirms the results from the rapid analysis of the filter with survey
instruments. Note: The sample has been counted about 4 hours after the fusion step has occurred so
that radium progeny will have the opportunity to build in. It is Day 2, 0100 hours
i, Filter 1. The values for gross beta and gross gamma do not yield a ratio of greater than 2.5.
Therefore, there is no indication of the presence of 90Sr at this time. Sample processing should
proceed with alpha analysis started first and the beta emitters next. Proceed to Steps 8 and 9.
The analysis of the digestate for this filter for beta emitters is still a high priority
due to the gross alpha activity. The sample should be analyzed eventually for 90Sr.
Steps 8 and 10, Filter 1. The beta and gamma analyses are not above the 500-mrem AAL. The
significant decay of activity determined in the field vs. the laboratory indicates the short-lived beta
components may be progeny of radium. An analysis of the digestate aliquanted for archiving is
counted by gamma spectrometry for 90 minutes.
55
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Step 9, Filter 1. This sample should be given the top priority for alpha analyses. Analysis for
transuranics, radium, and uranium would be started before the analyses in Steps 8 and 10.
Step 11, Filter 1. The only alpha emitter identified is 226Ra, at a concentration of 15 pCi/m3.
Subsequent beta analyses do not identify any other beta emitters in Table 8B. However, the longer
gamma spectrometry count time of the archived digestate portion will identify the gamma rays from
214Pb/ 214Bi. This result is consistent with radiological decay of 226Ra. The required relative method
uncertainty for radium are met (<13%). The result exceeds the 2-rem ADL (i.e., 15 pCi/m3 is greater
than the ADL of 4.9 pCi/m3). The sum of the fractions of these beta emitters is unnecessary as the
dose is accounted for in the 226Ra activity. It is Day 2, 0800 Hours.
The 1C is notified that a 2-rem AAL has been exceeded on Filter Ifor 226Ra. The
only radionuclides present are 226Ra and its decay products. It is Day 2, 1200 hours.
Step 13, Filters 2 and 3. Filters 2 and 3 are counted by gamma spectrometry for 2 hours. Gamma-
ray peaks from 214Pb and 214Bi are observed as they have now had a significant "in-growth" period.
The GPC count time for gross alpha/beta has been 90 minutes. The count times have been long
enough for each screening analysis to meet the WMR values cited in Tables 7A and 7B for the 500 -
mrem ADL values.
i, Filters 2 and 3. The GPC results are gross alpha 0.15 and 0.050 and gross beta 1.1 and 0.60
pCi/m3, respectively for Filters 2 and 3. Filter 2 takes a second-priority flow path at Step 4 while
Filter 3 is relegated to Step 15.
Step 4, Filter 2. Filter 2 is dissolved using a low-temperature flux fusion technique that completely
solubilizes the filter material. Laboratory personnel have visually checked the final solution to ensure
that no visible particulate matter is present. Aliquants of the final solution are taken for gross
alpha/beta, beta emitters and alpha isotopic (radium plus transuranic elements) analysis. An aliquant
of the remaining solution is archived for any additional analyses (like a follow-up gamma-ray
analysis) that may be required.
Step 5, Filter 2. Because the gross alpha 500-mrem AAL was exceeded for Filter 2, an aliquant of
the dissolved filter solution is analyzed for gross alpha/beta. The gross alpha result is 0.25 pCi/m3
and gross beta is 1.4 pCi/m3. This confirms the results from the filter analysis. Note: The sample has
been counted about 4 hours after the dissolution has occurred so that short-lived progeny will have
had the opportunity to build in.
Step 6, Filter 2. The ratio of the gross beta to gamma activity is much less than 2.5, based on
laboratory protocols for this comparison. Sample processing proceeds to Steps 8, 9, and 10.
Step 7, Filter 2. This step is a low priority because there is no indication of the presence of
strontium. The sample eventually should be analyzed for 90Sr.
Step 8, Filter 2. The beta analyses are a secondary priority as they are possibly above the 500-mrem
PAG AAL. Analysis will be started first for 226Ra as this has already been identified as the main
contaminant.
56
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Step 9, Filter 2. As the gross alpha was above the 500-mrem ADL, the alpha emitters analysis gets
the focus (226Ra is started first as it has already been identified). The beta emitters aliquant is started
shortly after. The results for Filter 1 have indicated that radium progeny were present in this sample.
Analysis for transuranics also proceeds at this point. The UMR values for all the alpha emitters have
been achieved.
Step 10, Filter 2. Gamma spectrometry count time is 2 hours. The UUR values for all the gamma
emitters have been achieved.
Step 11, Filter 2. The analysis results from Filter 2 show the concentration of 226Ra is 0.32 pCi/m3.
Note: The sample has been counted about 4 hours after the dissolution has occurred so that progeny
have had some opportunity to build in. (For this example, re-analysis at Step 16 is unnecessary.)
Step 12. The 1C is notified that the only radionuclides present are 226Ra and its decay products.
Step 15, Filter 3. Filter 3 is archived for analysis at a later time. Store the filter in a closed container
to avoid cross-contamination from other higher activity samples based on the presence of 226Ra.
Step 16. Whenever on the green path and this step has been reached, and an activity that exceeds the
ADL for 500 mrem or 2 rem is determined, the laboratory staff need to assess the discrepancy
between the radiochemical separation value being above the action level and the original screening
value being below the action level.
Step 17. The final sample test sources are archived, as is the residual solution from the fusion of the
filter.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
APPENDIX III. Example of Air Particulate Filters Contaminated at Less than 2 rem
(Radioanalytical Scenario 2)
The number of samples have been minimized and the screening processes have been simplified in
this example. In an actual event, the number and complexity of samples will be much greater than
identified here.
Description
Three weeks ago, a terrorist group detonated an RDD (using several pounds of dynamite) on the roof
of an office building in an urban area. The radionuclides that were identified during the early phase
of the event were 226Ra, 137Cs, and 90Sr. The event sequence in the laboratory assumes a single analyst
following the analytical process chart, under conditions of a single sample process stream.
Event Sequence
The event occurred at 1200 hours on Day 1. Three radionuclides were identified in the first 36 hours:
226Ra, 137Cs, and 90Sr. Recovery activities have been proceeding as expected. The current samples are
from areas that have been decontaminated, and ambient air analysis is being performed to assess
unrestricted use. It is now 22 days after the detonation, no other radionuclides have been detected,
and six samples have been collected by a field team. The sampling location was 10 miles downwind
of the RDD site. Samples were taken at a flow rate of 2 cfm for 6 hours, starting on Day 21 at 1200
hours.
The samples arrive at the laboratory on Day 22 at 1600 hours.
Analysis Paths
Step 1, Filters and Cartridges 7, 8, and 9. The three samples are surveyed upon arrival using a
micro-R or survey meter yielding the following results for alpha, beta and gamma:
Filter ID
7
8
9
Back-
ground
Gross Alpha,
cpm (Field)
16.9
16.5
60
1.5
Gross Alpha,
cpm (Lab)
1.4
1.1
11.0
1.1
Gross Beta,
cpm (Field)
72
70
306
15
Gross Beta,
cpm (Lab)
14
13
14
8.1
Gross gamma,
uR/h (Field)
50
50
53
50
Gross Gamma,
uR/h (Lab)
36
36
39
36
Cartridge ID
7
8
9
Background
Gamma spectrometry
Results
40K
40K
214Pb/214Bi,40K
40K
Gross Gamma, nR/h
36
36
38
36
58
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Steps 2 and 3, Filters 7, 8, and 9. Sample dose rates are measured using a survey meter19, and the
results of the measurements are used to calculate the concentrations. (Note that because the
radionuclides are now known, the survey meter was calibrated using a 230Th source whose energy
is very similar to 226Ra.)
An example of the calculation used by the laboratory for gross alpha on Filter 9 is:
[11.0-1.l]cpm 1
(0.1 [cpm / dpm]) x 2.22 (dpm / pCi) 20.38 nr
•= 2.2pCi/m3
This value exceeds the 500-mrem ADL for 226Ra of 0.90 pCi/m3 (Table 7A), but does not exceed the
2-rem ADL value of 3.5 pCi/m3. This sample stays on the green path for analysis.
The gross alpha and beta activities for Filters 7 and 8 are 0.066 and 0.000 pCi/m3 (alpha) and 0.43
and 0.36 pCi/m3 (beta), respectively. After comparing these results to the ADL values in Tables 7A
and 7B, it is clear that analysis of Filters 7 and 8 will be resumed at Step 11 at a later time.
The iodine cartridges are analyzed by a short count using gamma spectrometry. No iodine activity
is found on any of the cartridges (this would be expected based on the radionuclides found during
the early phase of the incident). It is Day 22 1630 hours.
Step 3, Filter 9. The filter is counted on the gamma-ray spectrometer for 30 minutes to meet the WMR
value of 0.71 x AAL (500-mrem) for the gamma emitters. The iodine cartridges are counted on their
side in a calibrated geometry to meet the WMR values for iodines in Table 7B. Both the filter and the
cartridge for Filter 9 have measurable levels of 214Pb/214Bi. Although these radionuclides are not
directly used in risk assessment, their elevated activities indicate the presence of 226Ra.
It is Day 22 at 1800 hours.
Step 4, Filter 9. The filter is dissolved using an FTP dissolution technique. The residual FTP is driven
off and the sample volume reduced to about 50 mL. Digestion is completed on Day 22 at 2200
hours.
Step 5, Filter 9. A 10-mL aliquant of the Filter 9 digestate is evaporated on a planchet for gross
alpha/beta analysis by GPC. Making the appropriate correction for the fraction of total taken for
analysis, the count time is 120 minutes to achieve the UMR value in Table 7A. (Note: Sufficient time
has elapsed since sampling to allow for the decay of all unsupported decay products.) It is Day 23,
0100 hours.
Step 6, Filter 9. The concentration for gross alpha is calculated from the sample activity as 2.8
pCi/m3 and the concentration is greater than the 500-mrem ADL for 226Ra (from Table 7A). This
value supersedes the previous gross alpha measurement made directly on the filter. The gamma
spectrometry result from Step 3 on Filter 9 has a 137Cs peak and the concentration calculated from
19 The efficiency of detection for the laboratory hand-held instruments used in this example are 0.1 for gross alpha and
0.3 for gross beta.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
that peak area is 100 pCi/m3 This sample analysis remains on the green path due to the alpha activity
exceeding the 500-mrem PAG value.
Steps 7, 8, and 9, Filter 9. Based on the historical assessment of the incident, the analyses for the
three radionuclides already identified (226Ra, 137Cs, and 90Sr) would be the priority. Aliquants of the
final solution from the digestion are taken for analysis of the other listed beta emitters and
transuranic elements (the other gamma emitters would have been determined when the 137Cs was
determined in Step 3). The remaining solution is to be archived for any additional analyses that may
be required. Aliquanting is completed and priority analyses are started. Other analyses are started
when the priority analyses are completed. It is Day 23, 0130 hours.
Step 10, Filter 9.Thevaluesfortheradionuclidesidentifiedfromtheincidentare226Ra(1.8pCi/m3),
137Cs (100 pCi/m3) and 90Sr (2.0xl(T3 pCi/m3). The result for 226Ra is above the 500-mrem ADL
(Table 7C) while the values for 137Cs and 90Sr are less than the 500-mrem ADL(Table 7D). The
results compare favorably with the original laboratory gross activity measurements; however, the 2-
rem AAL may have been exceeded. Whenever an individual ADL is exceeded, or the sum of the
fractions exceeds 1.0 at any decision level, the same criteria should be evaluated at the next higher
action level to determine whether the radionuclide-specific data was exceeded. This is particularly
important for the sum of the fractions. In cases where the next highest action level has been
exceeded, the 1C should be notified immediately.
The sum of the fractions (based on the 2-rem AAL values in Tables 7C and 7D) is:
Sum = (1.8/7.0) + (100 / 1.7xl03) + (2.0xlO~3/4.2xl02)
= 0.26 + 0.059 + 4.8 xlO'6 = 0.32
The sum of the fractions does not exceed the 2-rem AAL. The 1C is notified of the final results.
The analyses are completed on Day 23, 0430 hours.
Step 11, Filters 7 and 8. These analyses were started about 10 hours afterthe samples were initially
screened by laboratory personnel. Each filter is analyzed using GPC for 4 hours. The iodine
cartridges are counted for four hours by gamma spectrometry. All WMR values are achieved using these
count times. It is Day 23, 0630 hours.
Step 12, Filters 7 and 8. The individual activity values are given below, and these do not exceed
the gross alpha, gross beta, or iodine 500-mrem ADL values. It is Day 23, 0700 hours.
Filter
7
8
Gross Alpha
0.077
0.052
Gross Beta
0.50
0.33
Iodine Cartridges
No iodine isotopes above the critical level
No iodine isotopes above the critical level
Step 13, Filters 7 and 8. Based on the low gross gamma screening value for Filters 7 and 8, a 4-hour
gamma spectrometry analysis is performed. Cs-137 is identified in Filter 7 at 0.55 pCi/m3; but no
activity other than that expected from background naturally occurring radioactive materials (NORM)
is found in Filter 8. It is Day 23 1100 hours.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Step 13b, Filters from Scenario 1. No filters have been carried over from the earlier part of this
event (Scenario 1 for this event). Step 17 is not necessary.
Step 14, Filters 7 and 8. Filters 7 and 8 are dissolved using an HF dissolution technique. The
residual FTP is driven off and the sample volume reduced to about 50 mL. It is Day 23 1530 hours.
Steps 15 and 16, Filters 7 and 8. Based on the historical identification of radionuclides from this
incident, analyses for 226Ra and 90Sr (137Cs has already been determined) begin first. Aliquants of the
final solution from the digestion are taken for alpha and beta emitters. The remaining solution is to
be archived for any additional analyses that may be required.
Step 17, Filters from Scenario 1. None.
Step 18, Filters 7 and 8. The values for the radionuclides identified from the incident are:
• Filter 7: 137Cs (0.55 pCi/m3), 226Ra (0.0051 pCi/m3), and 90Sr less than its critical level20 (actual
value is 1.6x10~3pCi/m3) [proceed at Step 9].
• Filter 8: All values are less than their respective critical levels [proceed at Step 19].
All radionuclides on both filters are below their 10~4 risk ADL values. Filter 7 226Ra is above the 10~6
risk ADL value (0.0031 pCi/m3) . The sum of the fractions for the 10~4 risk factor (note that the A AL
values taken from Tables 8A and 8B are used to calculate the sum of the fractions and not the ADL
values) is:
Sum = (0.55/110) + (0.0051/0.44) +(1.6x10^/29)
= 0.0050 + 0.1159 + 0.000055 = 0.13
Filter 7 follows the flow at Step 9. Filter 8 is evaluated at Step 18 at some time in the future. It is
Day 24, 0230 hours.
Step 9, Filter 7. The analyst has checked that all analyses have been completed and the results have
been compared to their respective 10~4 ADL values. (Sum of the fractions at 10~6 risk level does not
need to be verified because 226Ra already exceeds the 10~6 risk.)
Step 10, Filter 7. Only 137Cs and 226Ra have been identified in this sample. The result compares
favorably with the original laboratory gross activity measurement, and is between the 10~4 and 10~6
risk AAL. However, the gross alpha and beta results do not compare favorably with the final sum
of the radionuclide activities determined, and the sum of the fractions does not exceed the 10~4 risk
AAL. The gross alpha measurement at Step 5 was 0.097 pCi/m3 and the final result was 0.0051
pCi/m3. The radionuclide results are within the range of 0.5 to 2 times the gross alpha count
measurement, but just barely. The data reviewer decides to investigate ( Step 21).
Step 21, Filter 7. The data are reviewed by the data validator who notices that the gross alpha counts
on the digestate from Step 5 are so close to background that the gross result is significantly affected
by the background count rate. Even though the final result is much lower than the screen, it would
be difficult in this sample to distinguish between real radium counts and background counts. It is
See Appendix VI for a discussion of critical level.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
decided that this discrepancy is within the bounds of the analysis uncertainty at this level, and it will
be reported in the comments section of the final report. Go to Step 22.
Step 19, Filter 8. Filter 8 is below the 1CT6 risk factor ADLs for the radionuclides determined. Go
to Step 20.
Step 20, Filter 8. The radionuclide-specific results are consistent with the gross analyses.
Step 21, Filter 8. As all results corresponded to the initial laboratory gross screening, no further
action is needed.
Step 22, Filters 7, 8, and 9. Results for Filter 9 are reported immediately after ascertaining that 226Ra
and 137Cs are above the 500-mrem ADLs, and thus above the AAL (see Step 10 Filter 9). The
discrepancy between the gross alpha and sum of alpha emitters is noted. Results for Filters 7 and 8
are reported about 24 hours later. For Filter 7, the 10~6 risk AAL for 226Ra has been exceeded. For
Filter 8 all radionuclide concentrations analyzed for are less than the 10~6 risk AAL values. It is Day
24 at 0400 hours.
Step 23, All final sample test sources. The final sample test sources and any residual solution from
the sample dissolution should be archived in case additional analyses are required.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
APPENDIX IV. Example of Air Particulate Filters With Known Radiological Contamin-
ants (Radioanalytical Scenario 3)
The number of samples have been minimized and the screening processes have been simplified in
this example. In an actual event, the number and complexity of samples will be much greater than
identified here.
Description
Air samples have been taken in the vicinity of an event in which a radioactive aerosol is suspected
to have been sprayed from an airplane. Initial field readings show indications of alpha activity
although no definite identification of radionuclides has been made. The sequence of events in the
laboratory assumes a single analyst following the analytical process chart, under conditions of a
single sample process stream.
Event Sequence
The incident response team has established a field office for coordinating the response efforts,
including a laboratory proj ect manager who reports to the Incident Commander (1C). At 1200 hours
of Day 7, the incident response team sends three air particulate samples and three iodine cartridge
samples to the laboratory. These samples are from areas they believe to have the highest concentra-
tions of airborne particulate radionuclides based on the field measurements of these samples. These
first samples arrive at the laboratory 6 hours later. While the first samples are en route to the
laboratory, the field sampling personnel are taking new samples.
Analysis Paths
When the laboratory receives the first set of samples, they begin by using the Scenario 1 flowchart.
By Day 2 1500 hours, results of radiochemical analyses indicate that 241Am is present together with
a lower amount of 238Pu. The samples have no detectable gamma emitters or radioiodines.
The laboratory calibrates its survey and GPC instruments with241 Am knowing that this is the primary
radionuclide. When the second batch of samples arrive at the laboratory, the chain-of-custody form
shows that the samples were taken at a flow rate of 20 cfm for 24 hours, for a total of 815 m3. The
laboratory now knows that it will be using the Scenario 3 analytical flow on the next group of
samples. The second batch arrived at the laboratory on Day 2 at 1900 hours.
A survey meter with a thin window alpha probe calibrated using241 Am for gross alpha measurements
is used to make the measurements on the filters noted in the tables below. Also noted are the lab
measurements made when they arrived at the laboratory with similar instrumentation. The 1C has
decided to establish the extent of the spread of the radioactive contamination and wants the lowest
activity samples analyzed first to the 5x 1CT6 risk AAL values.
NOTE: The values for the 1 x 10 6 risk values in Tables
8 A and 8B must be multiplied by 5 to generate values
for5xlO-6riskADL.
The 1C also has been given evidence to support the presence of 238Pu as well as 241Am, but at lower
concentrations than the 241Am. The 1C therefore wants 238Pu analysis performed as the laboratory's
63
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
second priority. The ADL values for 241Am and 238Pu are 1.2xlCT2 and 8.5xlCT3, respectively.
Although the tables for 1 x 1CT6 risk are based on radionuclide-specific methods, in this instance they
are used for screening purposes to help prioritize these samples, because an unknown component
(238Pu) may be present.
Filter ID
A
B
C
Background
air filter sample*
Gross Alpha,
cpm (Field)
682
710
715
680
Gross Alpha,
cpm (Lab)
610
700
720
600
Gross Beta,
cpm (Field)
1530
1510
1485
1505
Gross Beta,
cpm (Lab)
420
415
495
420
*This represents the routine ambient sample count rate from samples taken at this location
prior to this event with similar delivery times to the laboratory.
Step 1. All Filters. | The a path is chosen because the principal radionuclides specified by the 1C for
analysis are both alpha emitters (although 241Am is a gamma emitter, gamma spectrometry would
require very long count times at the concentrations expected in the samples).
Step 2a. All Filters. Samples are to be screened using GPC analysis where the instrument is
calibrated with 241Am. It is Day 2 1930 hours.
Step 3a. All Filters. The laboratory analysis using GPC has determined that the sample with the
lowest activity is A. The B and C filters will be processed subsequent to the analysis of filter A. Day
3 0330 hours
Step 4at. Filter A. Filter A is digested and then americium-specific separations are performed. The
value determined for 241Am based on alpha spectrometry is 5.5x 1CT5 pCi/m3. It is Day 3 0530 hours.
[Step 5a. Filter A. The same aliquant of the digestate from the filter is used for determination of
plutonium by sequential separation steps when the 241Am was performed. Analysis for 238Pu is
performed using alpha spectrometry. The value determined is 1.2>
-------
Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
= 0.0034 + 0.001
= 0.0044
This is less than 1.0.
Step 9. Filter A. Results are reported to the 1C. Final analysis of Filters B and C is performed at the
direction of the 1C. It is Day 3 0830 hours.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
APPENDIX V. Representative Analytical Processing Times
The vertical position of the milestones depicted in the following three figures correspond to the
elapsed time on the timelines to the right or left. The timelines are approximate and assume the use
of rapid analytical separation methods (versus traditional methods) for environmental levels of the
analytes represented in this document.
Samples arrive at lab
Rapid gross analyses completed for p/y and a
3H and radioiodine
analyses completed
Sample exceeds a
PAG limit
Gamma spectrometry
completed
Sample digestion completed.
Aliquants taken.
Gross a/p completed
90Sr analysis completed if
necessary
Other p-only emitters
completed
Review all results and
report to Incident
Commander
Sample does not
exceed any PAG
concentration limit
Commence a-, P-, y-specific
analyses based on direction of
Incident Commander
(follow Scenario 2 flow chart)
90Sr recount
Archive final
sample forms
Timeline (Hours)
0.0
1.0
2.5
4.5
5.0
10
16.5
20
22
26
30
Figure 5 - Approximate Timeframe for Radiochemical Analyses (Radioanalytical
Scenario 1)
66
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Timeline*
(Hours)
<500 mrem
0.0
10
14
24
36
50
60
Samples arrive at lab
Rapid gross a-, |3-, y
lab scan completed
Gamma analyses
(0.5 to 2 hours each)
on filter completed
Sample digestion completed;
Routine qross a, B separate alicluants removed |
analyses on filter and
y on charcoal
Gross a, B analyses
byGPC
completed
Routine y analysis of filter
Sample digestion 90gr gnd specjfic p.emitters
completed analyses comoleted
I Commence a-, (3-, y-specific Specific a
! analyses for 1 0'4 and 1 0'6 risk AALs analyses
I completed
90Sr recount if Review all results and
necessary report to 1C
analyses completed Review all
report to 1C Archive final
sample forms
Timeline
(Hours)
>500 mrem
0.0
2.5
4.5
7.5
26
30
32
35
The <500-mrem timeline assumes that high priority samples are GPC-counted after digestion before any lower-priority samples.
Figure 6 -Approximate Timeframe for Radiochemical Analyses (Radioanalytical
Scenario 2)
67
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Timeline
without Y
(hours)
0.5
1.5
14.0
20.0
22.0
24.0
Samples arrive at laboratory
Review data from field and lab
hand-held screening
instruments
Gross a/p
screen by GPC
completed
Y analysis
screen
completed
a-specific
analysis
commenced
Y analysis
for 10-6
risk level
Y analysis
for 10~4
risk level
Gross a/p
screen by GPC
completed
p-specific
commenced
completed
Archive final
sample forms
Timeline
with Y
(hours)
1.0
4.5
9.5
10.5
20.0
26.0
28.0
30.0
Figure 7 - Approximate Timeframe for Radiochemical Analyses (Radioanalytical
Scenario 3)
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 9 - Air Monitoring: Air Filter Counting Times for Various PAGs and Sampling Rates and
Durations
PAG/
RISK
2 rem/y
500
mrem/y
10 4 Risk
10 6 Risk
Flow
Rate
(cfm)
40
40
2
2
2
40
40
2
2
40
40
2
2
40
40
40
2
2
2
Sampling
Duration
Ih
5m
10 h
Ih
10m
24 h
Ih
Ih
8h
24 h
8h
24 h
7d
24 h
7d
24 h
24 h
7d
7d
Volume
Collected
(m3)
68
5.7
34
3.4
0.57
1631
68
3.4
27
1631
544
82
571
1631
11,420
1631
82
571
571
Counting
Instrument
GPC*
GPC
GPC
GPC
GPC
GPC
GPC
GPC
GPC
GPC
GPC
GPC
GPC
GPC/GPC
GPC/GPC
aAS**/GPC
aAS**/GPC
GPC/GPC
aAS**/GPC
Alpha Screening
Counting Time
(Minutes) for
Detectabilityt*
~1
-20
~2
<30
-300
<1
~4
<200
<10
<1
<1
~2
<1
-10
-2
-10
-120
-40
-20
Beta Screening
Counting Time
(Minutes) for
Detectabilityf
<«1
<«1
<«1
<«1
«1
<«1
<«1
<«1
«1
<«1
<«1
<«1
<«1
<«1
<«1
<«1
«1
«1
«1
**
Counting time to have net count rate equal to 3 times the net count rate uncertainty.
Counting times presented for 239Pu. Counting times for the other alpha-emitting nuclides of interest are similar or
shorter except for 228Th and 210Po which are much longer.
gas proportional counter: Alpha detection efficiency/background—10% / 0.05 cpm; beta detection efficiency/
background—30% /1 cpm.
Alpha spectrometry counting after radiochemistry processing assuming 100%yield; detector efficiency background—
22% / 0.005 cpm.
To calculate counting times to reach a relative 10% net count rate uncertainty, multiple the counting times in the table
by 11.
The "~" symbol is used for count times because the efficiency will vary slightly from detector to detector. The "<"
symbol indicates that the count times are less than the stated value regardless of the efficiency.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
APPENDIX VI. Establishing DQOs and MQOs for Incident Response Analysis
Three distinct radioanalytical scenarios are presented for air particulate filters potentially
contaminated with radionuclides. The first two assume that the mixture of radionuclides in the sample
is unknown. The third situation, a shortened version of the first two, assumes that the radioactive
contaminants are known. In each scenario there is special emphasis on the implementation of the
decision trees presented within that scenario for prioritizing sample processing by the laboratory. This
emphasis on the decision trees is to support timely decision making by the 1C regarding actions to
protect human health for the first two cases, and in the third case, to expedite analysis so that areas
suitable for reoccupation may be identified. Specific MQOs associated with the flow diagrams in
Figures 2, 3, and 4 are given in Tables 11, 12, and 13.
This appendix covers single-sample screening measurement decisions by the laboratory. The 1C may
need to make decisions based on the final radionuclide-specific concentrations based on the mean of
the set of samples taken from an area. Measurement quality objectives (MQOs) would need to be
developed separately for this case. The required method uncertainty (WMR) should be smaller in this
case compared to the laboratory's screening decisions, perhaps by a factor of three (see MARLAP
Appendix C).
Is the
parameter of
interest greater
than the
action level
9
The flowcharts depicted in this document contain decision points.
There are three basic symbols on these flowcharts: rectangles, which
represent activities or tasks; decision point diamonds, which represent
decision points; and arrows, which represent flow of control. In these
flow diagrams, there are many diamond-shaped decision points. Most
often they are of the form shown in Figure 8. This is the general form
of a theoretical decision rule as discussed in Step 5 of the data quality FIGURE 8 — A Decision
objectives (DQO) process. The parameter of interest usually is the Point in a Flowchart
"measurand" of the radiochemical analysis being performed (e.g.,
concentration of a radionuclide, total activity, etc.). The AALs will have been set according to criteria
involving the appropriate PAGs. The arrows specify the alternative actions to be taken.
The DQO process may be applied to all programs involving the collection of environmental data with
objectives that cover decision making activities. When the goal of the study is to support decision -
making, the DQO process applies systematic planning and statistical hypothesis testing methodology
to decide between alternatives. Data quality objectives can be developed using the Guidance in EPA
(2006) Guidance on Systematic Planning Using the Data Quality Objectives Process (EPA QA/G-4).
The DQO process is summarized in Figure 9.
Table 10A summarizes the DQO process. From this, MQOs can be established using the guidance
in MARLAP. The information in this table should be sufficient to enable the decision maker and
laboratory to determine the appropriate MQOs. The output should include an AAL, discrimination
limit, gray region, null hypothesis, analytical decision level (ADL, referred to in MARLAP as "critical
level"), and required method uncertainty at the AAL. A table summarizing DQO process for each
decision point diamond can be prepared in advance and summarized as shown in Tables 11A and
11B.
70
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Step 1. State
Define the problem that
identify the planning team,
i
the Problem.
necessitates the study;
examine budget, schedule.
r
Step 2. Identify the Goal of the Study.
State how environmental data will be used in meeting objectives and
solving the problem, identify study questions, define alternative outcomes.
i
r
Step 3. Identify Information Inputs.
Identify data and information needed to answer study questions.
i
r
Step 4. Define the Boundaries of the Study.
Specify the target population and characteristics of interest,
define spatial and temporal limits, scale of inference.
Step 5. Develop the Analytic Approach.
Define the parameter of interest, specify the type of inference,
and develop the logic for drawing conclusions from findings.
Decisionmaking
(hypothesis testing)
I
1
Estimation and other
analytic approaches
i
Step 6. Specify Performance or Acceptance Criteria.
Specify the probability limits for
false rejection and false
acceptance decision errors.
i
Develop performance criteria for new data
being collected or acceptable criteria for
existing data being considered for use.
r
Step 7. Develop the Plan for Obtaining Data.
Select the resource-effective sampling and analysis plan
that meets the performance criteria.
Figure redrawn from EPA G-4 (2006).
Figure 9 - The Data Quality Objectives Process
71
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 10A - The DQO Process Applied to a Decision Point
STEP
Step 1 . Define the problem
Step 2. Identify the decision
Step 3. Identify information
needed for the
decision
Step 4. Define the boundaries
of the study
Step 5. Develop a decision rule
This defines the decision point
diamond.
OUTPUT
. . . with a preliminary determination of the type of data needed and how
it will be used; identify decision maker.
...among alternative outcomes or actions, and a list of decision
statements that address the problem.
Analytical action levels that will resolve the decision and potential
sources for these; information on the number of variables that will need
to be collected; the type of information needed to meet performance or
acceptance criteria; information on the performance of appropriate
sampling and analysis methods.
Definition of the target population with detailed descriptions of
geographic limits (spatial boundaries); detailed descriptions of what
constitutes a sampling unittimeframe appropriate for collecting data and
making the decision or estimate, together with any practical constraints
that may interfere with data collection; and the appropriate scale for
decision making or estimation.
Identification of the population parameters most relevant for making
inferences and conclusions on the target population; for decision
problems, the "if.., then... else..." theoretical decision rule based upon a
chosen AAL.
The theoretical decision rule specified in Step 5 can be transformed into statistical hypothesis tests
that are applied to the data. Due to the inherent uncertainty with measurement data, there is some
likelihood that the outcome of statistical hypothesis tests will lead to an erroneous conclusion, i.e.,
a decision error. This is illustrated in Table 10B.
TABLE 10B - Possible Decision Errors
Decision Made
Decide that the parameter of interest is
greater than the action level
Decide that the parameter of interest is
less than the action level
True Value of the parameter of interest
Greater than the action level
Correct decision
Decision Error
Less than the action level
Decision Error
Correct decision
In order to choose an appropriate null hypothesis (or baseline condition), consider which decision
error should be more protected against. Choose the null hypothesis which if falsely rejected would
cause the greatest harm. Then the data will need to be convincingly inconsistent with the null
hypothesis before it will be rejected, and the probability of this happening (a Type I error) is more
easily controlled during the statistical design.
Failing to detect a sample that exceeds the AAL could have consequences to public health. But
screening additional samples will slow the overall process and therefore also may impact the public
health. The probability that such decision errors occur is defined as the parameters a and P in Steps
6.1 and 6.2 in Table IOC. Values of alpha and beta should be set based on the consequences of
72
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
making an incorrect decision. How these are balanced will depend on the AAL, sample loads, and
other factors as specified by the 1C.
The most commonly used values of alpha and beta are 5%, although this is by tradition and has no
sound technical basis. These values may be used as a default, but should be optimized in Step 7 of
the DQO process according to the actual risk of the decision error being considered.
TABLE IOC - The DQO Process Applied to a Decision Point
STEP
OUTPUT
Step 6. Specify limits on
decision errors
Step 6.1 Determine analyti-
cal action level (AAL) on
the gray region boundary
and set baseline condition
(null hypothesis, H0)
Which is considered the worse: decision error (a) deciding that the parameter of
interest is less than the AAL when it actually is greater, or (b) deciding that the
parameter of interest is greater than the AAL when it actually is less? Case (a) is
usually considered to be a conservative choice by regulatory authorities, but this
may not be appropriate in every case.
If (a), the AAL defines the upper boundary of the gray region. The null hypothesis
is that the sample concentration is above the AAL. (All samples will be assumed
to be above the AAL unless the data are convincingly lower.) A desired limit will
be set on the probability (a) of incorrectly deciding the sample is below the AAL
when the sample concentration is actually equal to the AAL.
If (b), the AAL defines the lower boundary of the gray region. The null hypothesis
is that the sample concentration is below the AAL. (All samples will be assumed
to be below the AAL unless the data are convincingly higher.) A desired limit will
be set on the probability (a) of incorrectly deciding the sample is above the AAL
when the sample concentration is actually equal to the AAL.
6.2 Define the discrimina-
tion limit (DL)
If (a), the discrimination limit defines the lower boundary of the gray region.1 It
will be a concentration below the AAL where the desired limit will be set on the
probability (ft) of incorrectly deciding the sample is above the AAL.
If (b), the discrimination limit defines the upper boundary of the gray region.2 It
will be a concentration above the AAL where the desired limit will be set on the
probability (ft) of incorrectly deciding the sample is below the AAL.
6.3 Define the required
method uncertainty at the
AAL
According to MARLAP Appendix C, under either case (a) or case (b) above, the
recommended required method uncertainty is:
UBGR - LBGR A
u
''MR —
where z,_a and zt_p are the 1-a and 1-ft quantiles of the standard normal
distribution function.
Step 7. Optimize the design
for obtaining data
Iterate Steps 1-6 to define optimal values for each of the parameters and the
measurement method required.
NOTES:
1 The DL is the point where it is important to be able to distinguish expected signal from the AAL. When one expects background
activity, then it might be zero. If one expects activity near the AAL, however, it might be at 90% of the AAL.
2 The DL is the point where it is important to be able to distinguish expected signal from the AAL. If the AAL is near zero, the DL
would define a concentration deemed to be too high to be undetected. Thus, the DL may be set equal to the MDC. If one expects
activity near the AAL, however, it might be at 110% of the AAL.
73
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
Figures 10 and 11 illustrate the concepts above for case (a) and case (b) respectively.
a*
~
VI ,
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Action Level
True Value of the Parameter (Mean Concentration, ppm)
Figure 10 - Example Illustrating Case (a).
Baseline Condition (null hypothesis): Parameter
Exceeds the Analytical Action Level
t
o
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wa
IS
II
P
Sff
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Action Level
True Value of the Parameter (Mean Concentration, ppm)
Figure 11 - Example Illustrating Case (b).
Baseline Condition (null hypothesis): Parameter
Does Not Exceed the Analytical Action Level
Figures taken from EPA G-4 (2006)
In Figure 10, the AAL = 100, the DL = 80, A = 100 - 80 = 20 a = ft = 0.1 and
A 20
UMR ^
z, p 1.282 + 1.282
= 7.8.
In Figure 11, the AAL =100, the DL = 120, A = 120-100 = 20 a= P = 0.1 and
A 20
UMR ^
1.282 +1.282
= 7.8.
Table 10D - Values of z^ (or z^,) for
Some Commonly Used Values of ct (or
a or p
0.001
0.01
0.025
0.05
0.10
0.20
0.30
0.50
Z!_a (or Zl-e)
3.090
2.326
1.960
1.645
1.282
0.842
0.524
0.000
74
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
The concentration that indicates the division between values leading to rejecting the null hypothesis
and those that do not is termed the "critical level." Possible values of the concentration can be divided
into two regions, the acceptance region and the rejection region. If the value of the concentration
comes out to be in the acceptance region, the null hypothesis being tested is not rejected. If the
concentration falls in the rejection region, the null hypothesis is rejected. The set of values of a
statistic that will lead to the rej ection of the null hypothesis tested is called the critical region. Critical
region is a synonym for rejection region.
In the context of analyte detection, the critical value (see MARLAP Attachment 3B.221) is the
minimum measured value (e.g., of the instrument signal or ^ho, analyte concentration) required to give
confidence that a positive (nonzero) amount of analyte is present in the material being analyzed. The
critical value is sometimes called the critical level.
In case (a), the critical value will be UBGR - z,_a WM, where WM is its combined standard uncertainty
of the measurement result, x. Only measurement results less than the critical value will result in
rejecting the null hypothesis that the true concentration is greater than the AAL. This process can be
completed for each diamond in each flowchart to fill in Tables 11 A, 1 IB, 12A, 12B, and 13. In these
tables, values have been rounded to 2 or 3 significant figures.
In case (b), the critical value will be LBGR + z,_a WM, where WM is its combined standard uncertainty
of the measurement result, x. Only measurement results greater than the critical value will result in
rejecting the null hypothesis that the true concentration is less than the AAL.
In the following tables, MQOs were determined for screening using a discrimination level of zero and
Type I and Type II error rates of a=/? = 0.05. These are the MQOs usually associated with developing
MDCs and result in a relative method uncertainly of 30% at the AAL, and an ADL value of 0.5 times
the AAL.
For radionuclide-specific measurements the requirements are more stringent, using a discrimination
level of one-half the AAL and Type I and Type II error rates of a = 0.01 with/? = 0.05. This results
in a relative required method uncertainty of 13% at the AAL and an ADL value of 0.71 times the
AAL.
Note that gamma spectrometric measurements using an HPGe are always radionuclide-specific, and
therefore have the more stringent MQOs
21 In this appendix, we use the term critical value to be consistent with MARLAP terminology. It should be noted that
the critical value in the context of this document refers to the ADL value.
75
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE HA- DQOs and MQOs for Radioanalytical Scenario 1. Laboratory Prioritization Decisions
Based on Screening (Gross a,
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Null Hypothesis H0
Choose > AAL or
-------
Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 11B - DQOs and MQOs for Scenario 1. Values Reported to the Incident Commander Based
on Radionuclide-Specific Measurements
03
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= AAL - 2.326 [ (AAL-0.5 AAL)/(2.326 + 1.645) ]
= AAL -2.326(0.13 xAAL) * 0.71 x AAL.
Specific values for the ADL are listed in Tables 7C and 7D.
[2] When following a green pathway in the flow diagram for Scenario 1, use the 500-mrem AAL MQOs.
When following a red pathway in the flow diagram for Scenario 1, use the 2-rem AAL MQOs.
77
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 12A- DQOs and MQOs for Radioanalytical Scenario 2. Laboratory Prioritization Decisions
Based on Screening (Gross a,
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Table 7B
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from Table 7B
10-4riska
screening AAL
from Table 8A
1 04 risk P AAL
from Table 8B
Notes:
All numbers rounded to two significant figures.
[1] Mathematically computed from data obtained earlier in measurement
[2] Mathematically computed from data obtained earlier in measurement
rectangles 2 and 5.
rectangles 2, 7, and 8.
78
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 12B - DQOs and MQOs for Scenario 2. Values Reported to the Incident Commander Based
on Radionuclide-Specific Measurements
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10^ risk AAL
10^ risk AAL
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1Q-6 risk AAL
These are regulatory derived values.
1-0.05^
Notes:
[1] In case (a), the critical value is UBGR - zl__a uu = AAL - Zj_0 01 [A/(zj_0 01
= AAL - 2.326 [ (AAL-0.5 AAL)/(2.326 + 1.645) ]
= AAL -2.326(0.13 xAAL) * 0.71 x AAL.
Specific values for the ADL are listed in Tables 8a and 8B.
[2] When following a green pathway in the flow diagram for Scenario 2, use the 500-mrem MQOs. When
following a yellow pathway in the flow diagram for Scenario 2, use the 10~4 risk MQOs.
[3] Mathematically computed from data obtained earlier.
79
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
TABLE 13 - DQOs and MQOs for Scenario 3. Values Reported to the Incident Commander Based
on Radionuclide-Specific Measurements.
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
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81
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
APPENDIX VII. Glossary
accuracy. The closeness of a measured result to the true value of the quantity being measured.
Various recognized authorities have given the word "accuracy" different technical definitions,
expressed in terms of bias and imprecision. Following MARLAP, this document avoids all of
these technical definitions and uses the term "accuracy" in its common, ordinary sense.
aerosol. A suspension of fine solid or liquid particles within a gaseous matrix (usually air).
aliquant: A representative portion of a homogeneous sample removed for the purpose of analysis or
other chemical treatment. The quantity removed is not an evenly divisible part of the whole
sample. An aliquot, by contrast, is an evenly divisible part of the whole.
analyte: See target analyte.
analytical action level (AAL): The value of a quantity that will cause the decision maker to choose
one of the alternative actions. The analytical action level may be a derived concentration level
(such as the derived air concentration in this document), background level, release criteria,
regulatory decision limit, etc. The AAL is often associated with the type of media, tar get analyte,
and concentration limit. Some AALs, such as the release criteria for license termination, are
expressed in terms of dose or risk. MARLAP uses the term "action level." See total effective dose
equivalent (TEDE) and derived air concentration (DAC).
analytical decision level (ADL). The minimum measured value for the radionuclide concentration
in a sample that indicates the amount of radionuclide present is equal to or greater than the
analytical action level at a specified Type II error rate (assumes that method uncertainty
requirements have been met). Any measurement result equal to or greater than the applicable
ADL is considered to have exceeded the corresponding analytical action level. MARLAP uses
the term "critical level."
background (instrument): Radiation detected by an instrument when no source is present. The back-
ground radiation that is detected may come from radionuclides in the materials of construction
of the detector, its housing, its electronics, and the building, as well as the environment and
natural radiation.
background level: A term that usually refers to the presence of radioactivity or radiation in the
environment. From an analytical perspective, the presence of background radioactivity in samples
needs to be considered when clarifying the radioanalytical aspects of the decision or study
question. Many radionuclides are present in measurable quantities in the environment.
bias (of a measurement process): A persistent deviation of the mean measured result from the true
or accepted reference value of the quantity being measured, which does not vary if a measurement
is repeated.
82
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Radiological Laboratory Sample Analysis Guide for Incidents of National Significance - Radionuclides in Air
blank (analytical or method): A sample that is assumed to be essentially free of the target analyte
(the "unknown"), which is carried through the radiochemical preparation, analysis, mounting, and
measurement process in the same manner as a routine sample of a given matrix.
calibration: The set of operations that establishes, under specified conditions, the relationship
between values indicated by a measuring instrument or measuring system, or values represented
by a material measure, and the corresponding known value of a parameter of interest.
calibration source: A prepared source, made from a certified reference material., that is used for
calibrating instruments.
certified reference material: A radioactive material, accompanied by an uncertainty at a stated level
of confidence, with one or more values certified by a procedure that establishes its traceability to
accepted standard values. A "standard reference material" is a certified reference material issued
by the National Institute of Standards and Technology (NIST) in the United States. NIST certifies
a standard reference material for specific chemical or physical properties and issues it with a
certificate that reports the results of the characterization and indicates the intended use of the
material.
chain of custody: Procedures that provide the means to trace the possession and handling of a sample
from collection to data reporting.
check source: A material used to validate the operability of a radiation measurement device,
sometimes used for instrument quality control. See source, radioactive.
critical level. Termed analytical decision level in this document in the context of evaluating sample
results relative to an analytical action level. In the context of analyte detection, critical level
means the minimum measured value (e.g., of the instrument signal or the radionuclide concentra-
tion) that indicates a positive (nonzero) amount of a radionuclide is present in the material within
a specified probable error. The critical level is sometimes called the critical value or decision
level.
data quality objective (DQO) Qualitative and quantitative statements that clarify the study
objectives, define the most appropriate type of data to collect, determine the most appropriate
conditions from which to collect the data, and specify tolerable limits on decision error rates.
Because DQOs will be used to establish the quality and quantity of data needed to support
decisions, they should encompass the total uncertainty resulting from all data collection activities,
including analytical and sampling activities.
derived air concentration (DAC). The concentration of a radionuclide, in pCi/m3, that would result
in exposure to a specified dose level. Generally refers to & protective action guide or other
specified dose- or risk-based factor expressed in equivalent radionuclide concentration and
referred to in this document as an analytical action level. Thus, the "500-mrem AAL for 239Pu"
is the derived air concentration of 239Pu, in pCi/m3, that would result in an exposure of 500 mrem
and would refer to the 500-mrem PAG. The DAC is radionuclide-specific
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derivedradionuclide concentration (DRC). General application term used in discussions involving
both of the terms derived air concentration and derived water concentration.
discrimination limit (DL). The DL is the point where it is important to be able to distinguish
expected signal from the analytical action level. The DL limit is one of the boundaries of the gray
region.
dose equivalent: Quantity that expresses all radiations on a common scale for calculating the effective
absorbed dose. This quantity is the product of absorbed dose (grays [Gy] or rads) multiplied by
a quality factor and any other modifying factors (MARSSIM, 2000). The quality factor adjusts
the absorbed dose because not all types of ionizing radiation create the same effect on human
tissue. For example, a dose equivalent of one sievert (Sv) requires 1 Gy of beta or gamma
radiation, but only 0.05 Gy of alpha radiation or 0.1 Gy of neutron radiation. Because the sievert
is a large unit, radiation doses often are expressed in millisieverts (mSv). See total effective dose
equivalent and roentgen.
gray (Gy): The International System of Units (SI) unit for absorbed radiation dose. One gray is 1 j oule
of energy absorbed per kilogram of matter, equal to 100 rad. See sievert.
gray region: The range of possible values in which the consequences of decision errors are relatively
minor. Specifying a gray region is necessary because variability in the analyte in a population and
imprecision in the measurement system combine to produce variability in the data such that the
decision may be "too close to call" when the true value is very near the analytical action level.
The gray region establishes the minimum distance from the analytical action level where it is
most important to control Type II decision errors.
incident of national significance (INS): An actual or potential high-impact event that requires a
coordinated and effective response by an appropriate combination of federal, state, local, tribal,
nongovernmental, or private-sector entities in order to save lives and minimize damage, and
provide the basis for long-term community recovery and mitigation activities.
measurement quality objective (MQO): The analytical data requirements of the data quality
objectives, which are project- or program-specific and can be quantitative or qualitative. These
analytical data requirements serve as measurement performance criteria or objectives of the
analytical process. MARLAP refers to these performance objectives as MQOs. Examples of
quantitative MQOs include statements of required analyte detectability and the uncertainty of the
analytical protocol at a specified radionuclide concentration, such as the analytical action level.
Examples of qualitative MQOs include statements of the required specificity of the analytical
protocol (e.g., the ability to analyze for the radionuclide of interest [or target analyte} given the
presence of interferences).
method uncertainty: The predicted uncertainty of the result that would be measured if the method
were applied to a hypothetical laboratory sample with a specified analyte concentration. Although
individual measurement uncertainties will vary from one measured result to another, the required
method uncertainty is a target value for the individual measurement uncertainties and is an
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estimate of uncertainty before the sample is actually measured. See also uncertainty, required
method uncertainty, and required relative method uncertainty .
method validation: The demonstration that the method selected for the analysis of a particular analyte
in a given matrix is capable of providing analytical results to meet the project's measurement
quality objectives and any other requirements in the analytical protocol specifications.
minimum detectable concentration (MDC): An estimate of the smallest true value of the analyte
concentration that gives a specified high probability of detection.
nuclide-specific analysis: Radiochemical analysis performed to isolate and measure a specific
radionuclide.
null hypothesis (Hf): One of two mutually exclusive statements tested in a statistical hypothesis test
(compare with alternative hypothesis). The null hypothesis is presumed to be true unless the test
provides sufficient evidence to the contrary, in which case the null hypothesis is rejected and the
alternative hypothesis (Hj) is accepted.
performance evaluation (PE) program: A laboratory's participation in an internal or external
program of analyzing proficiency-testing samples appropriate for the analytes and matrices under
consideration (i.e., PE program traceable to a national standards body, such as NIST). Reference-
material samples used to evaluate the performance of the laboratory are called performance-
evaluation or proficiency-testing samples or materials. See certified reference material.
precision: The closeness of agreement between independent test results obtained by applying the
experimental procedure under stipulated conditions. Precision may be expressed as the standard
deviation. Conversely, imprecision is the variation of the results in a set of replicate
measurements.
protective action guide (PAG). The radiation dose to individuals in the general population that
warrants protective action following a radiological event. In this document, PAGs limit the
projected radiation doses for different exposure periods: not to exceed 2-rem total effective dose
equivalent (TEDE) during the first year, 500-mrem TEDE during the second year, or 5 rem over
the next 50 years (including the first and second years of the incident). See total derived water
concentration and analytical action level.
quality assurance (QA): An integrated system of management activities involving planning,
implementation, assessment, reporting, and quality improvement to ensure that a process, item,
or service is of the type and quality needed and expected. Quality assurance includes quality
control.
quality control (QC): The overall system of technical activities that measures the attributes and
performance of a process, item, or service against defined standards to verify that they meet the
stated requirements established by the project; operational techniques and activities that are used
to fulfill requirements for quality. This system of activities and checks is used to ensure that
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measurement systems are maintained within prescribed limits, providing protection against out-
of-control conditions and ensuring that the results are of acceptable quality.
reference material. See certified reference material.
rent; The common unit for the effective or equivalent dose of radiation received by a living organism,
equal to the actual dose (in rads) multiplied by a factor representing the danger of the radiation.
Rem is an abbreviation for "roentgen equivalent man," meaning that it measures the biological
effects of ionizing radiation in humans. One rem is equal to 0.01 Sv. See sievert and dose
equivalent.
required method uncertainty («MR): Method uncertainty at a specified concentration. A key
measurement quality objective. See also required relative method uncertainty .
required relative method uncertainty (q^'. The required method uncertainty divided by the
analytical action level. The required relative method uncertainty is applied to radionuclide
concentrations above the analytical action level. A key measurement quality objective.
roentgen (R) A unit of exposure to ionizing radiation. It is that amount of gamma rays or X-rays
required to produce ions carrying one electrostatic unit of electrical charge in one cubic centimeter
of dry air under standard conditions. The unit of exposure rate is roentgens per hour (R/h). For
environmental exposures, the typical units are microroentgens per hour (uR/h), or 10~6 R/h. In SI
units, 1 R = 2.58x 10~4 C/kg (coulombs per kilogram).
sample: (1) A portion of material selected from a larger quantity of material. (2) A set of individual
samples or measurements drawn from a population whose properties are studied to gain informa-
tion about the entire population.
sample test source: The product of a chemical or physical process prepared for the purpose of activity
determination (ASTM D7282). Also considered to be the final form in a geometry that will be
counted by a radiation detector.
screening method: An economical gross measurement (alpha, beta, gamma) used in a tiered approach
to method selection that can be applied to analyte concentrations below an analyte level in the
analytical protocol specifications or below a fraction of the specified action level.
sievert (Sv): The SI unit for the effective dose of radiation received by a living organism. It is the
actual dose received (grays in SI or rads in traditional units) times a factor that is larger for more
dangerous forms of radiation. One Sv is 100 rem. Radiation doses are often measured in mSv. An
effective dose of 1 Sv requires 1 gray of beta or gamma radiation, but only 0.05 Gy of alpha
radiation or 0. 1 Gy of neutron radiation.
source, radioactive: A quantity of material configured for radiation measurement.
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source term radionuclide: A radionuclide that is a significant contaminant in an environmental
sample and results in dose contributions that will be important in decisionmaking.
sum of the fractions. A calculated value to determine whether the summed contributions to dose by
all radionuclides in a sample, divided by their respective dose limits, exceeds 1.0. For purposes
of this calculation, the actual analytical action level (derived air concentration or protective
action guide) is used rather than an analytical decision level.
swipe: A filter pad used to determine the level of general radioactive contamination when it is wiped
over a specific area, about 100 cm2 in area. Also called smears or wipes.
target analyte: A radionuclide on the list of radionuclides of interest or a radionuclide of concern for
a project.
total effective dose equivalent: The sum of the effective dose equivalent (for external exposure) and
the committed effective dose equivalent (for internal exposure), expressed in units of Sv or rem.
See dose equivalent.
Type I decision error: In a hypothesis test, the error made by rejecting the null hypothesis when it is
true. A Type I decision error is sometimes called a "false rejection" or a "false positive."
Type IIdecision error: In a hypothesis test, the error made by failing to reject the null hypothesis
when it is false. A Type II decision error is sometimes called a "false acceptance" or a "false
negative."
uncertainty: A parameter, associated with the result of a measurement, that characterizes the
dispersion of the values that could reasonably be attributed to the measurand. See method
uncertainty.
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