ASTM C1592/C1592M-21
(Guide)Standard Guide for Making Quality Nondestructive Assay Measurements
Standard Guide for Making Quality Nondestructive Assay Measurements
SIGNIFICANCE AND USE
4.1 NDA measurement practices aimed at achieving quality results are described in this guide. The application of the material provided in this guide should be determined on a case by case basis. Not all elements are required for all applications.
4.2 Nondestructive assay measurements are typically performed when the items measured or goals of the measurement program favor or require NDA over destructive analysis. NDA is typically favored when collecting a representative sample of the item is difficult or impractical (for example, scrap and waste items), personnel exposure would be significant, spread of contamination from sampling would occur, generation of secondary waste must be minimized, the weight and/or tare weight of the item cannot easily be determined (for example, in place process equipment), rapid turn-around of the measurement results is needed, or the NDA measurement is significantly less expensive than the equivalent destructive analysis.
4.3 The principles provided in this guide should be used to determine which type of measurement is best suited to the measurement application. This determination involves consideration of the characteristics of the items to be measured, as well as the goals of the measurement program.
4.4 This guide applies to the suite of NDA instruments and measurement methods, many of which are described in detail in Refs (1) and (2) .7 A partial listing of measurement methods and applicable use references is provided in 5.5.1. It is incumbent upon the user to seek additional guidance within ASTM method-specific standards, as this guide does not take precedence. Additional information on specific methods is best found in technical meeting transactions, journals, commercial application notes, and NRC/DOE publications.
4.5 This guide may be applied to many situations spanning the range of nuclear materials from product through waste. Typical applications include: the measurement and characterization of transuranic wastes,...
SCOPE
1.1 This guide is a compendium of Quality Measurement Practices for performing measurements of radioactive material using nondestructive assay (NDA) instruments. The primary purpose of the guide is to assist users in arriving at quality NDA results, that is, results that satisfy the end user’s needs. This is accomplished by providing an acceptable and uniform basis for the collection, analysis, comparison, and application of data. The recommendations are guidelines to achieving quality NDA measurements in most areas.
1.2 This guide applies to the use of NDA instrumentation for the measurement of nuclear materials by the observation of spontaneous or stimulated nuclear or atomic radiations, including photons, neutrons, or heat. Recommended calibration, operating, and assurance methods represent guiding principles based on current NDA technology. The diversity of industry-wide nuclear materials measurement applications and instrumentation precludes discussion of specific measurement situations. As a result, compliance with practices recommended in this guide must be based on a thorough understanding of contributing variables and performance requirements of the specific measurement application.
1.3 Selection of the best instrument for a given measurement application and advice on the use of this instrument must be provided by a qualified NDA professional following guidance provided in Guide C1490. This guide is to be used as a reference, and to supplement the critical thinking, professional skill, expert judgment, and experimental test and verification needed to ensure that the instrumentation and methods have been properly implemented.
1.4 The intended audience for this guide includes but is not limited to Management, Auditor Support, NDA Qualified Instrument Operators, NDA Technical Specialists, and NDA Professionals.
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as...
General Information
- Status
- Published
- Publication Date
- 31-May-2021
- Technical Committee
- C26 - Nuclear Fuel Cycle
- Drafting Committee
- C26.10 - Non Destructive Assay
Relations
- Effective Date
- 01-Dec-2023
- Effective Date
- 01-Nov-2023
- Effective Date
- 01-Oct-2023
- Effective Date
- 15-Mar-2019
- Effective Date
- 01-Feb-2019
- Effective Date
- 01-Oct-2018
- Effective Date
- 01-Sep-2018
- Effective Date
- 01-Jul-2018
- Effective Date
- 01-Jul-2018
- Effective Date
- 01-Apr-2018
- Refers
ASTM C1726/C1726M-10(2018) - Standard Guide for Use of Modeling for Passive Gamma Measurements - Effective Date
- 01-Apr-2018
- Effective Date
- 01-Apr-2018
- Effective Date
- 01-Apr-2018
- Effective Date
- 01-Apr-2018
- Effective Date
- 01-Apr-2018
Overview
ASTM C1592/C1592M-21, titled "Standard Guide for Making Quality Nondestructive Assay Measurements," is an international standard developed by ASTM for ensuring quality in nondestructive assay (NDA) measurements of radioactive materials. NDA techniques provide a means of measuring nuclear material by detecting their emitted radiation-such as photons, neutrons, or heat-without altering or destroying the item being analyzed. This guide helps organizations establish reliable practices, select appropriate instruments, and achieve measurement results that meet quality objectives, all while minimizing sample handling and exposure risks.
Key Topics
Scope and Purpose
- Focuses on general principles for achieving high-quality NDA results
- Intended to guide users in collecting, analyzing, comparing, and applying NDA measurement data
- Relevant to measurements performed when destructive analysis is impractical, risky, or more expensive
Audience
- Designed for management, auditor support, instrument operators, technical specialists, and NDA professionals
Measurement Methods
- Covers a range of NDA instruments and techniques, including gamma spectrometry, neutron counting, calorimetry, and tomographic scanning
- Emphasizes the importance of choosing methods matched to the material, item characteristics, and measurement goals
Calibration and Validation
- Stresses the need for rigorous calibration and validation tailored to each application
- Notes that calibration activities must be documented and periodically verified to maintain measurement accuracy
Quality Assurance
- Recommends establishing quality control programs and adherence to relevant method-specific standards
- Points to detailed guidance found in other ASTM standards and industry publications
Applications
Nondestructive assay methods described in ASTM C1592/C1592M-21 are vital for a variety of nuclear industry operations, particularly where safety, representativeness, contamination, or turnaround time are concerns. Common applications include:
Radioactive Waste Characterization
- Measuring and characterizing transuranic, low-level, and mixed radioactive wastes
- Determining compliance with regulatory thresholds
Facility and Process Monitoring
- Confirming inventories of nuclear materials in storage or process equipment
- Supporting criticality safety evaluations and safeguards programs
Operational Support
- Assessing holdup of special nuclear material during decontamination or decommissioning of nuclear facilities
- In-situ analyses of glove boxes, hot cells, and facility environments before and after demolition
Program Optimization
- Ensuring rapid turnaround of measurement results for operational efficiency
- Reducing personnel exposure and minimizing secondary waste generation
Related Standards
For comprehensive quality assurance, calibration, and method selection in NDA measurements, ASTM C1592/C1592M-21 should be used together with related standards, including:
- ASTM C1490 - Guide for the Selection, Training, and Qualification of NDA Personnel
- ASTM C1133/C1133M - Test Method for Nondestructive Assay of Special Nuclear Material in Low-Density Scrap and Waste by Segmented Passive Gamma-Ray Scanning
- ASTM C1207 - Test Method for Nondestructive Assay of Plutonium in Scrap and Waste by Passive Neutron Coincidence Counting
- ASTM C1514 - Test Method for Measurement of Uranium Fraction Using Enrichment Meter Principle
- ANSI N15.36 - NDA Measurement Control and Assurance
- ANSI N15.5 - Statistical Terminology and Notation for Nuclear Materials Management
Other referenced guides cover calibration, system quality control, data analysis procedures, and training best practices. Referencing these documents ensures a robust approach to NDA measurement programs, supporting both compliance and operational excellence.
Keywords: nondestructive assay, NDA measurements, ASTM C1592/C1592M, radioactive material measurement, nuclear material assay, quality assurance, calibration, nuclear industry standards
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Frequently Asked Questions
ASTM C1592/C1592M-21 is a guide published by ASTM International. Its full title is "Standard Guide for Making Quality Nondestructive Assay Measurements". This standard covers: SIGNIFICANCE AND USE 4.1 NDA measurement practices aimed at achieving quality results are described in this guide. The application of the material provided in this guide should be determined on a case by case basis. Not all elements are required for all applications. 4.2 Nondestructive assay measurements are typically performed when the items measured or goals of the measurement program favor or require NDA over destructive analysis. NDA is typically favored when collecting a representative sample of the item is difficult or impractical (for example, scrap and waste items), personnel exposure would be significant, spread of contamination from sampling would occur, generation of secondary waste must be minimized, the weight and/or tare weight of the item cannot easily be determined (for example, in place process equipment), rapid turn-around of the measurement results is needed, or the NDA measurement is significantly less expensive than the equivalent destructive analysis. 4.3 The principles provided in this guide should be used to determine which type of measurement is best suited to the measurement application. This determination involves consideration of the characteristics of the items to be measured, as well as the goals of the measurement program. 4.4 This guide applies to the suite of NDA instruments and measurement methods, many of which are described in detail in Refs (1) and (2) .7 A partial listing of measurement methods and applicable use references is provided in 5.5.1. It is incumbent upon the user to seek additional guidance within ASTM method-specific standards, as this guide does not take precedence. Additional information on specific methods is best found in technical meeting transactions, journals, commercial application notes, and NRC/DOE publications. 4.5 This guide may be applied to many situations spanning the range of nuclear materials from product through waste. Typical applications include: the measurement and characterization of transuranic wastes,... SCOPE 1.1 This guide is a compendium of Quality Measurement Practices for performing measurements of radioactive material using nondestructive assay (NDA) instruments. The primary purpose of the guide is to assist users in arriving at quality NDA results, that is, results that satisfy the end user’s needs. This is accomplished by providing an acceptable and uniform basis for the collection, analysis, comparison, and application of data. The recommendations are guidelines to achieving quality NDA measurements in most areas. 1.2 This guide applies to the use of NDA instrumentation for the measurement of nuclear materials by the observation of spontaneous or stimulated nuclear or atomic radiations, including photons, neutrons, or heat. Recommended calibration, operating, and assurance methods represent guiding principles based on current NDA technology. The diversity of industry-wide nuclear materials measurement applications and instrumentation precludes discussion of specific measurement situations. As a result, compliance with practices recommended in this guide must be based on a thorough understanding of contributing variables and performance requirements of the specific measurement application. 1.3 Selection of the best instrument for a given measurement application and advice on the use of this instrument must be provided by a qualified NDA professional following guidance provided in Guide C1490. This guide is to be used as a reference, and to supplement the critical thinking, professional skill, expert judgment, and experimental test and verification needed to ensure that the instrumentation and methods have been properly implemented. 1.4 The intended audience for this guide includes but is not limited to Management, Auditor Support, NDA Qualified Instrument Operators, NDA Technical Specialists, and NDA Professionals. 1.5 The values stated in either SI units or inch-pound units are to be regarded separately as...
SIGNIFICANCE AND USE 4.1 NDA measurement practices aimed at achieving quality results are described in this guide. The application of the material provided in this guide should be determined on a case by case basis. Not all elements are required for all applications. 4.2 Nondestructive assay measurements are typically performed when the items measured or goals of the measurement program favor or require NDA over destructive analysis. NDA is typically favored when collecting a representative sample of the item is difficult or impractical (for example, scrap and waste items), personnel exposure would be significant, spread of contamination from sampling would occur, generation of secondary waste must be minimized, the weight and/or tare weight of the item cannot easily be determined (for example, in place process equipment), rapid turn-around of the measurement results is needed, or the NDA measurement is significantly less expensive than the equivalent destructive analysis. 4.3 The principles provided in this guide should be used to determine which type of measurement is best suited to the measurement application. This determination involves consideration of the characteristics of the items to be measured, as well as the goals of the measurement program. 4.4 This guide applies to the suite of NDA instruments and measurement methods, many of which are described in detail in Refs (1) and (2) .7 A partial listing of measurement methods and applicable use references is provided in 5.5.1. It is incumbent upon the user to seek additional guidance within ASTM method-specific standards, as this guide does not take precedence. Additional information on specific methods is best found in technical meeting transactions, journals, commercial application notes, and NRC/DOE publications. 4.5 This guide may be applied to many situations spanning the range of nuclear materials from product through waste. Typical applications include: the measurement and characterization of transuranic wastes,... SCOPE 1.1 This guide is a compendium of Quality Measurement Practices for performing measurements of radioactive material using nondestructive assay (NDA) instruments. The primary purpose of the guide is to assist users in arriving at quality NDA results, that is, results that satisfy the end user’s needs. This is accomplished by providing an acceptable and uniform basis for the collection, analysis, comparison, and application of data. The recommendations are guidelines to achieving quality NDA measurements in most areas. 1.2 This guide applies to the use of NDA instrumentation for the measurement of nuclear materials by the observation of spontaneous or stimulated nuclear or atomic radiations, including photons, neutrons, or heat. Recommended calibration, operating, and assurance methods represent guiding principles based on current NDA technology. The diversity of industry-wide nuclear materials measurement applications and instrumentation precludes discussion of specific measurement situations. As a result, compliance with practices recommended in this guide must be based on a thorough understanding of contributing variables and performance requirements of the specific measurement application. 1.3 Selection of the best instrument for a given measurement application and advice on the use of this instrument must be provided by a qualified NDA professional following guidance provided in Guide C1490. This guide is to be used as a reference, and to supplement the critical thinking, professional skill, expert judgment, and experimental test and verification needed to ensure that the instrumentation and methods have been properly implemented. 1.4 The intended audience for this guide includes but is not limited to Management, Auditor Support, NDA Qualified Instrument Operators, NDA Technical Specialists, and NDA Professionals. 1.5 The values stated in either SI units or inch-pound units are to be regarded separately as...
ASTM C1592/C1592M-21 is classified under the following ICS (International Classification for Standards) categories: 27.120.30 - Fissile materials and nuclear fuel technology. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM C1592/C1592M-21 has the following relationships with other standards: It is inter standard links to ASTM C1807-15(2023), ASTM E1488-23, ASTM C1268-23, ASTM C1493-19, ASTM C1718-10(2019), ASTM C1254-18, ASTM C1156-18, ASTM C1215-18, ASTM C1297-18, ASTM C1133/C1133M-10(2018), ASTM C1726/C1726M-10(2018), ASTM C1207-10(2018), ASTM C1673-10a(2018), ASTM C1221-10(2018), ASTM C1030-10(2018). Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ASTM C1592/C1592M-21 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1592/C1592M − 21
Standard Guide for
Making Quality Nondestructive Assay Measurements
This standard is issued under the fixed designation C1592/C1592M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope each system are not necessarily exact equivalents; therefore, to
ensure conformance with the standard, each system shall be
1.1 This guide is a compendium of Quality Measurement
used independently of the other, and values from the two
Practices for performing measurements of radioactive material
systems shall not be combined.
using nondestructive assay (NDA) instruments. The primary
1.6 This standard does not purport to address all of the
purpose of the guide is to assist users in arriving at quality
safety concerns, if any, associated with its use. It is the
NDA results, that is, results that satisfy the end user’s needs.
responsibility of the user of this standard to establish appro-
This is accomplished by providing an acceptable and uniform
priate safety, health, and environmental practices and deter-
basis for the collection, analysis, comparison, and application
mine the applicability of regulatory limitations prior to use.
of data. The recommendations are guidelines to achieving
1.7 This international standard was developed in accor-
quality NDA measurements in most areas.
dance with internationally recognized principles on standard-
1.2 This guide applies to the use of NDA instrumentation
ization established in the Decision on Principles for the
for the measurement of nuclear materials by the observation of
Development of International Standards, Guides and Recom-
spontaneous or stimulated nuclear or atomic radiations, includ-
mendations issued by the World Trade Organization Technical
ing photons, neutrons, or heat. Recommended calibration,
Barriers to Trade (TBT) Committee.
operating, and assurance methods represent guiding principles
based on current NDA technology. The diversity of industry-
2. Referenced Documents
wide nuclear materials measurement applications and instru-
2.1 ASTM Standards:
mentation precludes discussion of specific measurement situ-
C986 Guide for Developing Training Programs in the
ations.As a result, compliance with practices recommended in
Nuclear Fuel Cycle (Withdrawn 2001)
this guide must be based on a thorough understanding of
C1009 Guide for Establishing and Maintaining a Quality
contributing variables and performance requirements of the
AssuranceProgramforAnalyticalLaboratoriesWithinthe
specific measurement application.
Nuclear Industry
1.3 Selection of the best instrument for a given measure-
C1030 TestMethodforDeterminationofPlutoniumIsotopic
ment application and advice on the use of this instrument must
Composition by Gamma-Ray Spectrometry
be provided by a qualified NDA professional following guid-
C1068 Guide for Qualification of Measurement Methods by
ance provided in Guide C1490. This guide is to be used as a
a Laboratory Within the Nuclear Industry
reference, and to supplement the critical thinking, professional
C1128 Guide for Preparation of Working Reference Materi-
skill, expert judgment, and experimental test and verification
als for Use in Analysis of Nuclear Fuel Cycle Materials
needed to ensure that the instrumentation and methods have
C1133/C1133M Test Method for Nondestructive Assay of
been properly implemented.
SpecialNuclearMaterialinLow-DensityScrapandWaste
by Segmented Passive Gamma-Ray Scanning
1.4 The intended audience for this guide includes but is not
C1156 Guide for Establishing Calibration for a Measure-
limited to Management, Auditor Support, NDA Qualified
ment Method Used to Analyze Nuclear Fuel Cycle Mate-
Instrument Operators, NDA Technical Specialists, and NDA
rials
Professionals.
C1207 Test Method for Nondestructive Assay of Plutonium
1.5 The values stated in either SI units or inch-pound units
in Scrap and Waste by Passive Neutron Coincidence
are to be regarded separately as standard. The values stated in
Counting
This guide is under the jurisdiction ofASTM Committee C26 on Nuclear Fuel
Cycle and is the direct responsibility of Subcommittee C26.10 on Non Destructive For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Assay. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved June 1, 2021. Published November 2021. Originally Standards volume information, refer to the standard’s Document Summary page on
approved in 2004. Last previous edition approved in 2009 as C1592/C1592M – 09 the ASTM website.
which was withdrawn January 2018 and reinstated June 2021. DOI: 10.1520/C1592 The last approved version of this historical standard is referenced on
_C1592M-21. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1592/C1592M − 21
C1210 Guide for Establishing a Measurement System Qual- surement Control And Assurance
ity Control Program for Analytical Chemistry Laborato- ANSI N15.5 Statistical Terminology and Notation for
ries Within Nuclear Industry Nuclear Materials Management
C1215 Guide for Preparing and Interpreting Precision and
2.3 Other Documents:
Bias Statements in Test Method Standards Used in the 5
ESARDA NDA Good Practices Guide
Nuclear Industry
NPL Good Practices Guide
C1221 Test Method for Nondestructive Analysis of Special
Nuclear Materials in Homogeneous Solutions by Gamma-
3. Terminology
Ray Spectrometry
3.1 Definitions presented here are confined to those terms
C1297 Guide for Qualification of Laboratory Analysts for
not defined in Terminology C1673, other common nuclear
the Analysis of Nuclear Fuel Cycle Materials
materials glossaries/references or whose use is specific to this
C1254 Test Method for Determination of Uranium in Min-
application.
eral Acids by X-Ray Fluorescence
C1268 Test Method for Quantitative Determination of 3.2 Definitions:
Am in Plutonium by Gamma-Ray Spectrometry
3.2.1 differential die away technique (DDT), n—also re-
C1316 Test Method for Nondestructive Assay of Nuclear
ferred to as DDA, an NDA technique for characterizing
Material in Scrap and Waste by Passive-Active Neutron fissionable material in scrap and waste using prompt neutrons
Counting Using Cf Shuffler
from fissions induced by neutron generator interrogation
C1455 Test Method for Nondestructive Assay of Special source.
Nuclear Material Holdup Using Gamma-Ray Spectro-
3.2.2 in-process material, n—the nuclear material in a
scopic Methods
process stream, excluding holdup.
C1458 Test Method for NondestructiveAssay of Plutonium,
3.2.3 passive neutron coincidence counting, n—a technique
Tritium and Am by Calorimetric Assay
used to measure the rate of temporally coincident neutron
C1490 GuidefortheSelection,TrainingandQualificationof
emission in the assay item.
Nondestructive Assay (NDA) Personnel
3.2.4 Poisson assumption, n—for counting measurements, it
C1493 Test Method for Non-Destructive Assay of Nuclear
is assumed that the net counts in a fixed period of time follow
Material in Waste by Passive and Active Neutron Count-
a Poisson distribution; this assumption can be verified by
ing Using a Differential Die-Away System
comparing the observed standard deviation of a series of
C1500 Test Method for Nondestructive Assay of Plutonium
measurements on an item with the square root of the average
by Passive Neutron Multiplicity Counting
number of counts; if the Poisson assumption is correct, these
C1514 TestMethodforMeasurementof UFractionUsing
numbers should be equal within statistical uncertainty.
Enrichment Meter Principle
C1592 Guide for Making Quality Nondestructive Assay
3.2.5 procedure, n—a set of systematic instructions for
Measurements
using a method of measurement or of the steps associated with
C1673 Terminology of C26.10 Nondestructive Assay Meth-
the method.
ods
3.2.6 qualitative analysis, n—an analysis or measurement in
C1718 Test Method for Nondestructive Assay of Radioac-
which some or all of the attributes or characteristics of an item
tive Material by Tomographic Gamma Scanning
are determined, but no quantitative estimates of the radionu-
C1726/C1726M Guide for Use of Modeling for Passive
clides are made.
Gamma Measurements
3.2.7 quality measurement practice, n—an acceptable way
C1807 Guide for Nondestructive Assay of Special Nuclear
to perform some operation associated with a specific measure-
Material (SNM) Holdup Using Passive Neutron Measure-
ment technique that is known or believed to influence the
ment Methods
quality of a measurement (a way to perform some operation
E177 Practice for Use of the Terms Precision and Bias in
associated with a specific NDA technique in a manner that
ASTM Test Methods
meets the quality requirements of a measurement).
E181 Test Methods for Detector Calibration andAnalysis of
3.2.8 radioactive emissions, n—alpha, beta, gamma-ray,
Radionuclides
x-ray,andneutronemissionsfromspontaneousfission,induced
E691 Practice for Conducting an Interlaboratory Study to
fission, or delayed neutron emission following beta decay.
Determine the Precision of a Test Method
E1323 Guide for Evaluating Laboratory Measurement Prac-
3.2.9 replicate, n—one of several identical experiments,
tices and the Statistical Analysis of the Resulting Data
procedures, or samples; it is the general case for which
E1488 GuideforStatisticalProcedurestoUseinDeveloping
duplicate and triplicate, consisting of two and three
and Applying Test Methods
measurements, respectively, are the special cases.
2.2 ANSI Standards:
ANSI N15.36 Methods Of Nuclear Material Control - Mea-
surement Control Program - Nondestructive Assay Mea-
AvailablefromESARDASecretariatc/oEuropeanCommissionJRCBldg.42A
Via E. Fermi, 2749 21027-Ispra (VA), Italy, https://esarda.jrc.ec.europa.eu.
4 6
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St., Available from National Physical Laboratory, Hampton Road, Teddington,
4th Floor, New York, NY 10036, http://www.ansi.org. Middlesex, TW11 0LW, https://www.npl.co.uk.
C1592/C1592M − 21
3.2.10 segmented gamma scanner, n—an NDA technique tory threshold, estimated for non-detected radionuclides; the
used to measure the gamma-ray emissions from low-density measurement of safeguarded nuclear materials; shipper re-
scrap and waste packaged in cylindrical containers; the tech- ceiver confirmation; confirmation of nuclear material inven-
nique involves independent measurements of the vertical tory; support of nuclear criticality safety evaluations; measure-
segments of the container and may incorporate corrections for ment of holdup of special nuclear material in process systems;
count rate losses and matrix attenuation. support of decontamination and decommissioning activities;
andin-situanalysesoffacilities,glove-boxes,hotcells,andthe
3.2.11 shift-register-based coincidence circuit, n—a dedi-
environment prior to and following demolition.
cated electronic circuit for measuring temporally correlated
quantitities relevant to passive neutron coincidence counting.
4.6 When applied to measurement of waste, this guide
should be used in conjunction with a waste management plan
3.2.12 shuffler, n—an NDA technique for characterizing the
that segregates the contents of assay items into material
delayed neutrons from fissionable nuclides in scrap and waste
categories according to some or all of the following criteria:
using delayed neutrons induced by Cf interrogation source.
bulk density of the waste, chemical forms of the radioactive
3.2.13 verification, n—an evaluation of the critical item
constituents and matrix, (α, n) neutron intensity, hydrogen
characteristics to ensure the collected characterization data
(moderator) and absorber content, geometry, thickness, and
represents the true characteristics of the sample population to
distributionoffissilematerial,andtheassayitemcontainersize
an acceptable degree of accuracy and precision.
and composition. Each matrix may require a different set of
calibration standards and may have different mass calibration
4. Significance and Use
limits. The effect on the quality of the assay (that is, maximiz-
4.1 NDAmeasurement practices aimed at achieving quality
ing precision and minimizing bias) can significantly depend on
results are described in this guide. The application of the
the degree of adherence to this waste management plan.
material provided in this guide should be determined on a case
4.7 This guide addresses elements of quality measurement
bycasebasis.Notallelementsarerequiredforallapplications.
practice such as; nuclear measurement instrumentation and its
4.2 Nondestructive assay measurements are typically per-
care; common hazards; facility readiness and requirements to
formed when the items measured or goals of the measurement
supporttheNDAequipment;projectscoping,requirementsand
program favor or require NDAover destructive analysis. NDA
objectives; assembly and deployment of the instrument; cali-
is typically favored when collecting a representative sample of
bration and test; computational modeling to augment physical
the item is difficult or impractical (for example, scrap and
testing; measurement validation; preventive maintenance; and
waste items), personnel exposure would be significant, spread
the measurement control program.
of contamination from sampling would occur, generation of
secondary waste must be minimized, the weight and/or tare
5. Quality Measurement Practice
weightoftheitemcannoteasilybedetermined(forexample,in
5.1 Introduction—NDA measurements of nuclear material
place process equipment), rapid turn-around of the measure-
are performed to determine the relative or absolute abundance
ment results is needed, or the NDA measurement is signifi-
of one or more nuclides. Typically, such a determination is
cantly less expensive than the equivalent destructive analysis.
made by comparing the observed response of an unknown
4.3 The principles provided in this guide should be used to
amount of material to the response of one or more known
determine which type of measurement is best suited to the
standards by means of a functional relationship established by
measurement application. This determination involves consid-
calibration. NDA refers to the qualification and quantification
eration of the characteristics of the items to be measured, as
of radionuclides using instrumentation capable of detecting a
well as the goals of the measurement program.
feature of the radioactive-decay process. These features in-
4.4 This guide applies to the suite of NDA instruments and
clude such radioactive emissions as alpha, beta, gamma-ray,
measurement methods, many of which are described in detail
x-ray, heat, and neutron emissions from spontaneous fission,
in Refs (1) and (2). A partial listing of measurement methods
induced fission, or delayed neutron emission following beta
and applicable use references is provided in 5.5.1.Itis
decay. The primary goal of NDA measurements is to arrive at
incumbent upon the user to seek additional guidance within
a quality result that satisfies the user’s measurement needs
ASTM method-specific standards, as this guide does not take
without the necessity to alter the item. Adequately analyzing
precedence.Additional information on specific methods is best
problems and applying appropriate measurement techniques
found in technical meeting transactions, journals, commercial
support this goal.
application notes, and NRC/DOE publications.
5.2 Each NDA technique has advantages and limitations
4.5 This guide may be applied to many situations spanning
that must be judged against the specific requirements of the
the range of nuclear materials from product through waste.
intended applications. No single technique can satisfy all
Typical applications include: the measurement and character-
requirements. It is the responsibility of the user to consider the
ization of transuranic wastes, low-level wastes, and mixed
potential problems, and select the proper balance of measure-
wastes; the determination of radioactivity below some regula-
ment capability and desired precision and accuracy for the
specific application.
5.3 The observed response of an NDAsystem shows sensi-
The boldface numbers in parentheses refer to the list of references at the end of
this standard. tivity to a wide variety of factors that can bias the assay result.
C1592/C1592M − 21
Bycarefulselectionofthemeasurementtechnique,attentionto not measured. A passive neutron measurement is made when
potential sources of uncertainty, implementation of operational the neutrons measured are a result of spontaneous fission,
procedures to control item categorization and packaging,
self-induced fission, or (α, n) reaction. Passive neutron assay
operator training and instrument maintenance, supplemental systems are usually more effective for plutonium than for
measurements and calculations, and proper organization and
uranium, although applications for both exist. An active
evaluation of test data, the quality of assay results can be
measurement is performed when the measured neutrons are the
optimized.
result of induced fission from an external neutron source. The
quantity of a particular nuclide may be obtained by measuring
5.4 Because performance requirements for NDA systems
unusually low or high emission rates, distinctive time
are application dependent, only general guidance for the
distributions,ormarkedlydifferentenergyspectra.Toestablish
selection of a system can be provided. If more than one
the quantity of radionuclide of interest from the directly
technique can satisfy the specific measurement requirements,
observable neutron assay result(s) relative isotopic information
other considerations such as economics, ease of operation, and
is necessary. Important considerations for making quality
availability of instrumentation will ordinarily determine the
neutron measurements include:
choice of a system. The parameters that should be considered
a) Elements that initiate (α, n) interferences,
when selecting NDA measurement systems are listed below,
b) Hydrogen content,
not necessarily in the order of priority:
c) Neutron moderation and absorption (poisons),
a) The radionuclides to be measured, including the ex-
d) Container wall effects,
pected range of assays and interferences that may arise
e) Influence of uranium on plutonium assay or of pluto-
between radionuclides,
nium on uranium assay,
b) The physical form (particle size, particle density, radio-
active material distribution, etc.), f) Source self-shielding,
g)Non-uniformityinsource/matrixdistributionasitrelates
c) The chemical form (for example, oxide, fluoride etc.),
d) The matrix (for example, pure product, oily waste, dry to neutron moderation and absorption,
waste, degree of heterogeneity, average density, composition, h) Unexpected sources of neutrons,
etc.), i) Chemical composition,
e) The container and packing material (for example, size, j) System dead-time,
wall thickness, mass, wall material, etc.), k) Item size (physical dimensions and amount of fission-
f) Environmental conditions, able material),
g) Measurement quality objectives, l) Measurement geometry,
h) The degree to which parameters affecting measurement
m) Background radiation (for example, spallation
results are known,
neutrons),
i) Location(s) at which measurements are needed,
n) Density,
j) Background radiation,
o) Neutron multiplication,
k) Costs (instrument, set up, personnel, and operating
p) Delayed neutron emissions from fission or nuclear
costs),
reactions,
l) Availability of instrumentation,
q) (γ, n) emissions, perhaps resulting from (n, γ) reactions
m) System maintenance requirements (reliability, stability,
or gamma-rays, (n, 2n) reactions, and
250 252
ruggedness, etc.),
r) Buildup of Cf in aging Cf sources used for
n) Training requirements,
calibration.
o) Ease of operation,
5.5.2.1 Passive Neutron Counting—The primary strength of
p) Program schedule,
passive neutron counting is that it usually does not depend on
q) Surface dose rate, and
the use of external sources of radiation and that passive
r) Item throughput.
neutrons are of sufficient energy to escape from most items
without significant attenuation. The costs for passive neutron
5.5 NDA methods are often nuclide-sensitive rather than
element-sensitive. Frequently the reaction of interest is pos- emission measurement programs are often considerably less
sible in more than one species of nucleus present. Determina- than for active neutron measurement techniques. In addition,
tion of the elemental content of an item from a measurement of because external neutron sources are not required, risk of
radiations emitted by nuclide(s) of the elemental species and, personnel exposure to radiation is generally lower for passive
in some cases, by their decay products requires knowledge of neutron assay. The primary disadvantages of passive neutron
the relative radionuclide composition of the item assayed.
assay relative to other neutron assay methods are that counting
5.5.1 ManyoftheapproachestospecificNDAmeasurement rates are often lower and contaminants (for example, (α, n)
techniques are described by ASTM Standards as shown in neutrons, presence of poisons) might influence the total and
Table 1. A list of applicable ASTM and ANSI standards are coincident neutron count rate resulting in a bias.
also provided in Table 1. Other standards may also be (1) Total Neutron Counting is most suitable if the material
considered. to be assayed is homogeneous with respect to all attributes
5.5.2 Neutron Measurement Techniques—Neutron tech- affecting the measurement, if it contains little or well charac-
niques are based on the detection of neutrons, which are terized (α, n) target material, and if the nuclide ratios are well
emitted with various energies. Neutron energies are generally known. When the measured items do not have all of these
C1592/C1592M − 21
TABLE 1 ASTM Standards Related to NDA Techniques
NDA
Techniques and
Information
Photon Neutron Heat Other
Techniques Techniques Techniques Information
Pu Isotopic (C1030) Coincidence (C1207) Calorimetry (C1458) Terminology (C1673)
SGS (C1133/C1133M) Cf Scuffler (C1316) Training (C1490)
Solution (C1221) DDT (C1493) Making Quality NDA
XRF (C1254) Multiplicity (C1500) Meas.(C1592)
Am-241 in Pu (C1268) Neutron Holdup (C1807)
Holdup (C1455)
Enrichment Meter
(C1514)
TGS (C1718)
Modeling Passive
Gamma (C1726/C1726M)
Acronym List
DDT—Differential Die-away Technique
TGS—Tomographic Gamma Scanning
SGS—Segmented Gamma Scanning
XRF—X-ray Flourescence
Applicable ASTM Standards:
Guide C986—Standard Guide for Developing Training Programs in the Nuclear Fuel Cycle
Guide C1009—Standard Guide for Establishing a Quality Assurance Program for Analytical Chemistry Laboratories within the Nuclear Industry
Guide C1068—Standard Guide for Qualification of Measurement Methods by a Laboratory within the Nuclear Industry
Guide C1128—Standard Guide for Preparation of Working Reference Materials for Use in the Analysis of Nuclear Fuel Cycle Materials
Guide C1156—Standard Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials
Guide C1210—Standard Guide for Establishing a Measurement System Quality Control Program
Guide C1297—Standard Guide for Laboratory Analysts for the Analysis of Nuclear Fuel Cycle Materials
Test Method C1500—Standard Test Method for Nondestructive Assay of Plutonium by Passive Neutron Multiplicity Counting
Guide C1514—Standard Test Method for Measurement of U Fraction Using the Enrichment Meter Principle 235
Practice E177—Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
Test Methods E181—Standard Test Methods for Detector Calibration and Analysis of Radionuclides
Practice E691—Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
Guide E1323—Standard Guide for Evaluating Laboratory Measurement Practices and the Statistical Analysis of the Resulting Data
Guide E1488—Standard Guide for Statistical Procedures to Use in Developing and Applying ASTM Test Methods
Applicable ANSI Standards:
ANSI N15.36—NDA Measurement Control and Assurance
ANSI N15.5—Statistical Terminology and Notation for Nuclear Materials Management
attributes, the user must be cautious with respect to sources of lower count rates for the higher moments. It can be used to
measurementuncertainty.Thepresenceof(α, n)targetmaterial reduce the impact of cosmic ray background even when the
can result in a bias unless the relative amount of this material count rates for the higher moments are low.
and its yield are well-known and appropriate compensation is 5.5.2.2 Active Neutron Interrogation is applicable
included in quantity estimates. when U is present or when passive signals are weak.
(2) Passive Coincidence-neutron Counting is a viable tech- Selection of an appropriate interrogating-neutron source is
240 238
nique for the measurement of Pu effective mass or Uin important. Active techniques are sometimes used when the
lowenricheduranium.Isotopicratiosarenecessarytocompute uncertainty in the passive result is unacceptable. Costs may be
the elemental mass. Coincidence neutron counting is less significantly higher than for passive assay systems. In addition,
sensitivetomanyofthebiasestypicaloftotalneutroncounting the matrix in which the measured nuclides are contained is
(for example, the presence of [α, n] target material) because often an important consideration.
their effect is reduced. Spontaneous fission of Cm and (1) Thermal neutrons can be used for active neutron assay
certain other nuclides interferes with the measurement of Pu systems if they can adequately penetrate the item. Additional
effective mass. informationmayberequiredaboutthegeometry,homogeneity,
(3) Multiplicity Counting is a viable assay technique for and the mass level of the fissile material to be assayed. The
plutonium in cases where sufficient counting precision may be presence of thermal-neutron absorbers such as gadolinium
obtained for higher order coincidences. In principle, the (Gd)inlight-water-reactor(LWR)fuelmayprecludetheuseof
technique does not require representative standards, but they a thermal neutron interrogation. Thermalneutron interrogation
are often used to provide corrections to assays. It provides may be possible for small items with high moderation, (for
improved accuracy over conventional coincidence counting in example, hydrogen (H) content, solutions). Interrogation with
cases where the measured items are impure or heterogeneous thermal neutrons offers the advantage of higher detection
and the multiplication and/or (α, n) yield are not known prior sensitivity because of increased fission cross sections at low
to the measurement.The precision is usually poorer because of neutron energies in fissile material. Active neutron counters
C1592/C1592M − 21
such as the Active Well Coincidence Counter (AWCC) which c) Non-representative calibration standards,
use thermal neutron based interrogation of uranium bearing d) Attenuation,
samples, are widely used in nuclear safeguards and security e) Shielding and collimation as appropriate,
applications. f) Graded shielding to minimize interference of X-rays
from higher Z shielding materials,
(2) For the assay of fissile items that have poor penetrabil-
ity for thermal neutrons, interrogation by neutrons having g) Low signal to noise ratio,
h) Signal distortion (for example, tailing, pulse pileup/
energies greater than thermal is recommended. Interrogating-
neutron spectra can originate from various sources such as random coincidence summing, true coincidence summing)
i) Dead-time correction,
spontaneous fission nuclides, neutron generators or accelera-
j) Measurement geometry,
tors.
k) Item size (physical dimensions),
(3) A major problem in active neutron assay is differentia-
l) Container packaging and matrix attenuation,
tion between the interrogating radiation and the stimulated
m) Background radiation,
responseradiation.Ideally,thedetectorshouldbeinsensitiveto
n) Interfering radiation, and
the interrogating radiation. Although total insensitivity is
o) Decay of radioactive sources used to routinely test the
seldom achieved, the amount of interrogating radiation de-
stability/functionality of a measurement system, transmission
tected can be reduced by several techniques. These techniques
sources, and rate-based correction sources.
include using an energy-biased detector (for example, bare and
5.5.4.1 Isotopic Composition—Gamma-ray spectrometry
cadmium covered neutron detectors), coincidence counting,
may be used to determine isotopic composition (Test Methods
timing, and shielding.
C1030, C1268). Isotopic composition from gamma-ray spec-
5.5.3 Calorimetric Assay—Applications of calorimetry to
trometry is often used to support both calorimetry (Test
NDA refer to the measurement of heat flow generated from
Method C1458) and neutron techniques (Test Methods C1207,
radioactive decay. Calorimetric assay typically provides very
C1493, C1500, and C1316), as well as for other applications.
good precision and low bias. It is most often used to assay
5.5.4.2 Quantitative Assay—Gamma-ray spectrometry is
plutonium with Am, and tritium. Typical assay times range
used for quantitative assay of specific nuclides in situations
from 4 to 24 hours. Typically calorimeter chambers are
where attenuation by the container wall, by the item’s matrix,
0.203 m [8 in.] diameter or less. To estimate the quantity of
and self-attenuation by the radionuclides is not excessive, or
radionuclide of interest present, the effective specific power, or
can be accurately estimated. Estimates of attenuation are
amount of heat generated per unit mass per unit time, must be
typically obtained from process knowledge, item density,
determined from knowledge of the item’s actinide isotopic
transmission, or differential peak analysis. The assay geometry
composition. For plutonium, this is typically accomplished
including the source-detector distance, shielding, collimator
using high-resolution gamma-ray spectrometry. Important con-
aperture, field of view should be optimized.
siderations in making quality calorimetric assays include:
a) Heat-generating contaminants (for example, chemical 5.6 Specific radionuclides may not be directly quantifiable
curing, biological decay, bacterial reaction, and radiolysis), by certain NDA measurement techniques in given situations.
b) Isotopic composition, However,whentheabundanceofanunobservableradionuclide
c) Chemical reactions that produce or consume heat, of interest is known (either from independent analysis or
d) Phase changes that produce or consume heat, established correlation functions) relative to that of one or
more radionuclides that can be directly measured, it is possible
e) Item position,
f) Heat transfer characteristics of the item and its to infer its quantity. Subject matter experts must address the
validity and accuracy of the estimate.
packaging, which might affect total measurement time and
results, and
5.7 Calibration—Calibration provides a mathematical rela-
g) Drift in bridge potential (or baseline power for servo-
tionship to correlate detector response with characteristics of
control method).
the measured item. In the context of photon-based NDA
5.5.4 Photon Techniques are based on the detection of
techniques, three main types of detector calibration can be
gamma or X-rays that are emitted with discrete energies
distinguished: (1) Energy, (2) Peak shape, (3) Efficiency.
characteristic of specific nuclides or elements. The intensity of
Methods used for calibration are specific to a particular NDA
photons of a specific energy is related to the quantity or
measurement technique. In general, calibrations are performed
fraction of a particular nuclide or element. The relative
in such a manner that overall calibration uncertainty is sub-
intensity of gamma-rays from different radionuclides can be
stantially lower than the target uncertainty for item measure-
related to the relative abundance of those nuclides. There are a
ments. The amount of effort expended on calibration should be
variety of detectors available, which generally span the range
associated with the quality objectives of the measurement
of efficiency and resolution from relatively high to low.
results for items of unknown content (for example, a 0.1 %
Important considerations for making quality photon mea- calibration uncertainty is not necessary for a measurement
surements include: system that will produce results with 50 % total uncertainty).
a) Radial/axial non-uniformity of the radioactive source The measurement quality objectives are often, in turn, driven
material in the item, by regulatory, economic and ease of operation considerations.
b) Matrix heterogeneity, source geometry (for example, Some considerations that apply to calibration methods include:
lumps) causing self-absorption, a) Determining the intrinsic system response,
C1592/C1592M − 21
b) Energy and Peak shape (FWHM) calibration for photon 5.7.3 Calibration verification and validation may be per-
methods, formed to ensure that the calibration accurately reflects the
response of the measurement instrumentation to radiation of
c) Assessing correction methods (for example neutron
interest. This can sometimes be conducted as a part of the
moderation, attenuation, absorption, geometry, self
measurement control program. Depending on regulatory
attenuation),
requirements, the validation may be conducted using standards
d) Measuring instrument repeatability,
or process materials that are not traceable to a national
e) Determining the sources and magnitude of bias, and
measurement base, but whose radionuclide content is well
f) Determining total calibration uncertainty.
known. Measured values for these items must agree within
5.7.1 Calibration Standards should be selected carefully. It
stated measurement uncertainty to validate the calibration. The
is not always necessary for NDA calibration standards to
validation requirements for a new measurement technique
bracket the anticipated system measurement range. The se-
should be more rigorous than for a mature measurement
lected standards, however, should have characteristics that are
method. Calibration validation typically includes measurement
the same as items to be measured with respect to parameters
of actual process items. Parameters important to the assay
that affect the measurement results. Standards should be
method should, where practical, be varied to ensure that the
constructed so as to eliminate the possibility of a redistribution
calibration is valid over the range of expected values for each
of the radionuclide content during use. Considerations for
parameter.
selection of calibration standards include:
5.7.4 Calibration activities need to be documented. Docu-
a) Standard type (element, state, etc.),
mentation should include sufficient information to reconstruct
b) Durability and stability under routine use,
each calibration for each instrument. Documentation should
c) NDA measurement method,
include the calibration procedure, calibration measurement
d) Container size,
results,traceabilityofstandardsused,NDApersonnelperform-
e) Matrix attenuation properties,
ing the measurement, and other information deemed important
f) Gamma self-attenuation properties,
to the calibration activities by measurement personnel.
g) Emission rate for radiation of interest,
5.8 Operation:
h) Number of standards required,
5.8.1 A measurement procedure is needed for each NDA
i) Replacement interval and accounting for standards with
technique. The measurement procedure should describe the
short half-life, chemical instability, or pressure build up,
steps required to perform measurements of items of unknown
j) Time-dependent isotopic composition,
content. Operational procedures typically describe administra-
k) Uncertainty and traceability requirements,
tive responsibilities for staffing, oversight of measurements,
l) Neutron self-shielding, and
and performance of measurements.Any safety precautions are
m)Availability, transportability, cost, handling and storage
usually noted in measurement procedures. Materials needed to
risks, and practicality.
conduct the measurements are listed. Procedures also are used
5.7.1.1 Sometimes sufficiently representative standards may
to define item acceptance criteria (that is, describe the charac-
not be available for calibration. Mathematical modeling tech-
teristics of items for which the technique is capable of
niques can be used in such cases. However, the model-based
providingaccuratemeasurementresults).Measurementcontrol
calibrations must be validated using sufficiently representative
requirements and procedures for performing measurements in
measurementsandproperlydocumented.Calculatedcorrection
support of the measurement control program are also de-
factorsmaybeappliedtogenericcalibrationstandardstoallow
scribed. Reporting and data storage requirements are also
for the difference(s) between calibration standards and items.
typically included in measurement procedures. Developing a
The calibration range may be extended by calculation for one
procedure for an analytical method is not an adequate substi-
or more parameters. Similarly calculation is often used to
tute for expertise of the technical personnel involved.
assess the uncertainty associated with the calibrations. The
5.8.2 Training of measurement personnel is required. The
calculation may use established radiation transport codes that
level of training needed is dependent upon the complexity of
have been validated and verified for similar uses. The calcula-
the measurement technique and the responsibilities of the
tions should be documented sufficiently to allow replication.
personnel.GuideC1490includesextensiveguidanceregarding
This should be performed by suitably qualified and experi-
training programs.
enced personnel and reviewed by a peer member. Examples
5.8.3 Training requirements often extend beyond measure-
252 240
include: Cf can be used as surrogate to Pu ; modeling
eff
ment personnel. Obtaining the best results from NDA tech-
can correct results for items for neutron self-multiplication and
niques require training of personnel who package items for
gamma-ray self-shielding in items containing fissile materials.
measurement, install and maintain measurement
5.7.2 Total calibration uncertainty should be determined as instrumentation, perform instrument calibrations, perform
a part of the calibration process. Calibration uncertainty is then measurements, and interpret measurement results. Managers
included in propagated uncertainty as a systematic uncertainty. who have oversight of NDA results must also be adequately
Uncertainty in standard values, uncertainty of calibration trained.
measurements because of counting statistics, uncertainty from 5.8.4 Analysis of data obtained from NDAmeasurements is
fitting calibration curves, and other parameters affect the total
required to convert counting information to the desired results,
calibration uncertainty. typically mass or activity of radionuclides contained in each
C1592/C1592M − 21
measured item. Depending on the assay technique used, the should be consulted for each measurement application to
measurementinstrumentationandsoftwareavailable,theresult determine the best methods for use in assessing measurement
may be provided automatically or a significant amount of data control.
processing by qualified professionals may be required.
5.9.4 In general, the quality of the measurements is moni-
5.8.5 Reviews of data analysis methods should be con-
tored by periodically measuring a designated measurement
ducted by qualified professionals for all measurement tech-
control standard and comparing the measured value to an
niques. Expert review software may be used to perform part of
expected range of values. If the measured value of the standard
the review for individual items. Administrative reviews typi-
is consistent within expected statistical bounds, the measure-
cally include checks to ensure that items are correctly
mentprocessissaidtobeincontrol.Ifthemeasuredvaluefalls
identified, values have been correctly entered, measurement
outside the expected statistical bounds, it is an indicator of a
control has been properly established and verified, and that all
potential problem with the measurement process. Potential
applicable procedures have been followed. In addition, expert
problems must be investigated and resolved to ensure that the
technical reviews are conducted to ensure the appropriateness
measurements being made are of the required quality. The
oftheassaytechniquefortheitemsmeasuredandtoreviewthe
measurements of the control standard and the expected range
raw data and measurement results for potential problems. Final
of values are evaluated using a valid statistical technique.
results should not be reported until all necessary reviews have
5.9.5 Multiple standards may be used to demonstrate the
been completed.
quality of measurements across a range of values. Separate
comparisons may be made for each measurement control
5.9 Quality Control:
standard or they may be combined into a single comparison.
5.9.1 A measurement control program shall be established
Additionally, measurement system software may be pro-
for all measurement systems. ANSI N15.36 provides informa-
grammed to automatically perform certain measurement con-
tion regarding measurement control programs for NDAinstru-
trol checks.
mentation. The purpose of a measurement control program is
to demonstrate that a measurement process produces measured
5.9.6 A measurement control standard need not be a certi-
values of the required quality over the period of time the fied reference material, but should have a well-established
process is operating. For all NDA systems, the measurement measurement history and provide a stable decay-corrected
control monitors the stability of the system. Typically, radio-
result. The expected range of values of the standard can be
activesourcesusedformeasurementcontrolarenotrequiredto derived from estimates of the measurement uncertainty and
adequately represent the unknown item’s characteristics. The
biasandisusuallychosentorepresentanintervalthatspansthe
measurement control program indicates if the measurement range of expected measurements. The measurement uncer-
system’s performance has changed relative to its performance
tainty includes the precision, but may include other sources of
during calibration and operational verification. Precision, measurement variability. This is discussed further in the next
accuracy, total uncertainty, or minimum detectable quantity
section.
may represent the quality of a measurement system. Further
5.9.7 Total Measurement Uncertainty (TMU) Analysis—
discussion on precision, accuracy, and total uncertainty is
When a new measurement process is being adopted or an
contained in 5.9.7.
existing measurement process is being significantly altered, the
5.9.2 Conditions unique to measurement control assessment
qualityofthemeasurementsproducedbytheprocessshouldbe
of NDA instrumentation exist. Because NDA instrumentation
evaluated. Typically, the quality of a measurement process is
measures radioactive materials, the values of sources used to
represented by the precision and accuracy (or bias) of the
track instrument performance do not remain constant over time
measurement. Definitions of these terms are provided below.
and, in many cases, change considerably with time. This is
These quantities are used when reporting measurement results
commonly accounted for by decay-correcting the results of
to provide an indication of the quality of the measurement
measurement control data to a common date for a given
result. They are also used in establishing a measurement
instrument or measurem
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