ASTM C1128-23

Standard Guide for Preparation of Working Reference Materials for Use in Analysis of Nuclear Fuel Cycle Materials

SIGNIFICANCE AND USE
5.1 Certified reference materials (CRMs) prepared from nuclear materials are well characterized, traceable, and sufficiently homogenous and stable for their intended use. Usually they are certified using the most unbiased and precise measurement methods available, often with more than one laboratory being used on a national or international level. CRMs are at the top of the metrological hierarchy of reference materials. A graphical representation of a typical national nuclear measurement system is shown in Fig. 3.
FIG. 3 Typical National Nuclear Measurement System  
5.2 Working reference materials (WRMs) need to have quality characteristics that are similar to CRMs, although the rigor used to achieve those characteristics is not usually as stringent as for CRMs. Similarly, production of WRMs should be in accordance with applicable requirements of ISO 17034. Where possible, CRMs are typically used to calibrate the methods used for establishing reference values assigned to WRMs, thus providing traceability to CRMs as required by ISO/IEC 17025. A WRM is normally prepared for a specific application.  
5.3 Because of the importance of having highly reliable measurement data from nuclear material analysis, particularly for material control and accountability purposes, CRMs are used for calibration when available. However, CRMs prepared from nuclear materials are not always available for specific applications. Thus, there may be a need for a laboratory to prepare nuclear material WRMs to meet specific needs; for example, to match the matrix in process samples. In such cases, a WRM can be tailored to meet specific needs of a process or laboratory. Also, CRM supply may be too limited for use in the quantities needed for long-term, routine use. When properly prepared, WRMs will serve equally well as CRMs for most applications, and using WRMs will help preserve supplies of CRMs.  
5.4 Difficulties may be encountered in the preparation of RMs from nuclear materials becaus...
SCOPE
1.1 This guide covers the preparation and characterization of working reference materials (WRM) that are produced by a laboratory for its own use in the analysis of nuclear fuel cycle materials. Guidance is provided for proper planning, preparation, packaging, and storage; requirements for characterization; homogeneity and stability considerations; and value assignment. When traceability to SI is desired for a WRM, it will be achieved by a defined, statistically sound characterization process that is traceable to a certified value on a certified reference materials. While the guidance provided is generic for nuclear fuel cycle materials, detailed examples for some materials are provided in the appendixes.  
1.2 This guide does not apply to the production and characterization of certified reference materials (CRM). Refer to ISO 17034 and ISO Guide 35 for guidance on reference material production, characterization, certification, sale, and distribution requirements.  
1.3 The information provided by this guide is found in the following sections:    
Section  
Perform WRM Planning  
6  
Prepare and Process Materials  
7  
Packaging and Storage of Materials  
8  
Perform Homogeneity Study  
9  
Perform Stability Studies  
10  
Characterize Materials  
11  
Perform Uncertainty Analysis  
12  
Produce Documentation  
13  
Carry Out WRM Utilization and Monitoring  
14  
1.4 The values stated in SI units are to be regarded as standard. The non-SI units of molar, M, and normal, N, are also regarded as standard. Any non-SI units of measurement shown in parentheses are for information only.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6...

General Information

• Status: Published
• Publication Date: 31-Dec-2022
• ICS: 27.120.30 - Fissile materials and nuclear fuel technology
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.08 - Quality Assurance, Statistical Applications, and Reference Materials

Relations

• Refers: ASTM C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM C1672-23 - Standard Test Method for Determination of the Uranium, Plutonium or Americium Isotopic Composition or Concentration by the Total Evaporation Method Using a Thermal Ionization Mass Spectrometer
• Effective Date: 01-Dec-2023
• Refers: ASTM C1168-23 - Standard Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• Effective Date: 01-Oct-2023
• Refers: ASTM C1625-19 - Standard Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances by Thermal Ionization Mass Spectrometry
• Effective Date: 15-Sep-2019
• Refers: ASTM C1297-18 - Standard Guide for Qualification of Laboratory Analysts for the Analysis of Nuclear Fuel Cycle Materials
• Effective Date: 01-Jul-2018
• Refers: ASTM C1672-17 - Standard Test Method for Determination of Uranium or Plutonium Isotopic Composition or Concentration by the Total Evaporation Method Using a Thermal Ionization Mass Spectrometer
• Effective Date: 01-Jan-2017
• Refers: ASTM C1168-15 - Standard Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• Effective Date: 01-Sep-2015
• Refers: ASTM C859-14a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jun-2014
• Refers: ASTM C859-14 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jan-2014
• Refers: ASTM C1672-07(2014) - Standard Test Method for Determination of Uranium or Plutonium Isotopic Composition or Concentration by the Total Evaporation Method Using a Thermal Ionization Mass Spectrometer
• Effective Date: 01-Jan-2014
• Refers: ASTM C859-13a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM C859-13 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-May-2013
• Refers: ASTM C1009-13 - Standard Guide for Establishing and Maintaining a Quality Assurance Program for Analytical Laboratories Within the Nuclear Industry
• Effective Date: 01-Jan-2013
• Refers: ASTM C1108-12 - Standard Test Method for Plutonium by Controlled-Potential Coulometry
• Effective Date: 01-Jul-2012
• Refers: ASTM C1625-12 - Standard Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances by Thermal Ionization Mass Spectrometry
• Effective Date: 01-Jun-2012

Overview

ASTM C1128-23: Standard Guide for Preparation of Working Reference Materials for Use in Analysis of Nuclear Fuel Cycle Materials provides comprehensive guidance on the preparation, characterization, and use of working reference materials (WRMs) within labs analyzing nuclear fuel cycle materials. Published by ASTM International, this standard helps laboratories develop in-house materials that support calibration, quality control, and method validation when certified reference materials (CRMs) are unavailable, limited in supply, or cost-prohibitive.

WRMs, while not certified to the rigorous standard of CRMs, are well-characterized and designed to meet the specific needs of analytical methods in nuclear fuel laboratories. The guide addresses planning, material selection, packaging, storage, homogeneity and stability studies, value assignment, traceability, and uncertainty analysis-ensuring reliable reference materials for nuclear safeguards, accountability, and process control.

Key Topics

ASTM C1128-23 covers several critical aspects for WRM development in the nuclear fuel cycle:

• Project Planning and Documentation: Guidance on defining the scope, requirements, and resources for WRM production, including WRM quantity, end use, required properties, and intended measurement methods.
• Preparation and Processing: Instructions for selecting, processing, and verifying the identity and suitability of raw materials; ensuring effective sampling strategies.
• Packaging and Storage: Recommendations for appropriate containment to maintain stability, prevent contamination, and ensure safety over the WRM’s intended shelf life.
• Homogeneity and Stability Assessment: Procedures for verifying that WRMs are uniform and remain stable over time, supporting consistent analytical performance.
• Characterization and Value Assignment: Statistically sound methods for assigning property values traceable to CRMs, often following ISO/IEC 17025 and ISO 17034 principles.
• Uncertainty Analysis: Approaches to evaluating, calculating, and documenting measurement uncertainty, critical for regulatory and quality assurance purposes.
• Traceability: Steps to ensure all WRM results are traceable through a documented chain to the SI or a recognized CRM.
• Utilization and Monitoring: Best practices for using WRMs in routine analysis and ongoing monitoring for continued validity and stability.

Applications

ASTM C1128-23 is highly valuable for:

• Analytical Laboratories operating in the nuclear industry that require reliable internal standards for instrument calibration, method validation, and quality assurance.
• Nuclear Material Accountancy and Safeguards: Ensuring accurate, traceable data for material control, regulatory compliance, and international safeguards.
• Process Control and Routine Monitoring: Supporting ongoing operations with in-house materials that reflect process-specific matrices and characteristics.
• Replacing or Supplementing Commercial CRMs: Allowing laboratories to tailor reference materials to specific processes or sample matrices when CRMs are unavailable, cost-prohibitive, or insufficient in quantity.

Following ASTM C1128-23 ensures consistency, quality, and traceability for nuclear analysis, helping laboratories meet strict quality management, safety, and regulatory requirements.

Related Standards

ASTM C1128-23 references and complements several key international standards and ASTM guides:

• ISO/IEC 17025: General requirements for the competence of calibration and testing laboratories.
• ISO 17034: Competence requirements for reference material producers.
• ISO Guide 35: General and statistical principles for certification and characterization of reference materials.
• ISO Guide 33 & Guide 80: Good practice guides for using reference materials and preparing quality control materials.
• ASTM C1009: Guide for establishing a QA program for analytical laboratories in the nuclear industry.
• ASTM C1068 & C1297: Qualification of measurement methods and analysts.
• IAEA TECDOC-1350: International guidelines for developing and using reference and quality control materials.

Keywords: ASTM C1128-23, working reference materials, nuclear fuel cycle, certified reference materials, WRM, reference materials, nuclear analysis, quality assurance, metrological traceability, ISO/IEC 17025, ISO 17034, laboratory standards, measurement uncertainty, process control, nuclear safeguards.

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: C1128 − 23
Standard Guide for
Preparation of Working Reference Materials for Use in
Analysis of Nuclear Fuel Cycle Materials
This standard is issued under the fixed designation C1128; 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 responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 This guide covers the preparation and characterization
mine the applicability of regulatory limitations prior to use.
of working reference materials (WRM) that are produced by a
1.6 This international standard was developed in accor-
laboratory for its own use in the analysis of nuclear fuel cycle
dance with internationally recognized principles on standard-
materials. Guidance is provided for proper planning,
ization established in the Decision on Principles for the
preparation, packaging, and storage; requirements for charac-
Development of International Standards, Guides and Recom-
terization; homogeneity and stability considerations; and value
mendations issued by the World Trade Organization Technical
assignment. When traceability to SI is desired for a WRM, it
Barriers to Trade (TBT) Committee.
will be achieved by a defined, statistically sound characteriza-
tion process that is traceable to a certified value on a certified
2. Referenced Documents
reference materials. While the guidance provided is generic for
2.1 ASTM Standards:
nuclear fuel cycle materials, detailed examples for some
C859 Terminology Relating to Nuclear Materials
materials are provided in the appendixes.
C1009 Guide for Establishing and Maintaining a Quality
1.2 This guide does not apply to the production and char-
Assurance Program for Analytical Laboratories Within the
acterization of certified reference materials (CRM). Refer to
Nuclear Industry
ISO 17034 and ISO Guide 35 for guidance on reference
C1068 Guide for Qualification of Measurement Methods by
material production, characterization, certification, sale, and
a Laboratory Within the Nuclear Industry
distribution requirements.
C1108 Test Method for Plutonium by Controlled-Potential
1.3 The information provided by this guide is found in the Coulometry
following sections:
C1165 Test Method for Determining Plutonium by
Controlled-Potential Coulometry in H SO at a Platinum
Section
2 4
Perform WRM Planning 6
Working Electrode
Prepare and Process Materials 7
C1168 Practice for Preparation and Dissolution of Plutonium
Packaging and Storage of Materials 8
Materials for Analysis
Perform Homogeneity Study 9
Perform Stability Studies 10
C1210 Guide for Establishing a Measurement System Qual-
Characterize Materials 11
ity Control Program for Analytical Chemistry Laborato-
Perform Uncertainty Analysis 12
ries Within Nuclear Industry
Produce Documentation 13
Carry Out WRM Utilization and 14
C1267 Test Method for Uranium by Iron (II) Reduction in
Monitoring
Phosphoric Acid Followed by Chromium (VI) Titration in
1.4 The values stated in SI units are to be regarded as
the Presence of Vanadium
standard. The non-SI units of molar, M, and normal, N, are also
C1297 Guide for Qualification of Laboratory Analysts for
regarded as standard. Any non-SI units of measurement shown
the Analysis of Nuclear Fuel Cycle Materials
in parentheses are for information only.
C1347 Practice for Preparation and Dissolution of Uranium
Materials for Analysis
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the C1625 Test Method for Uranium and Plutonium Concentra-
tions and Isotopic Abundances by Thermal Ionization
Mass Spectrometry
This guide is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel
Cycle and is the direct responsibility of Subcommittee C26.08 on Quality
Assurance, Statistical Applications, and Reference Materials. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Jan. 1, 2023. Published February 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1989. Last previous edition approved in 2018 as C1128 – 18. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1128-23. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1128 − 23
C1637 Test Method for Determination of Impurities in 3.2.1.1 Discussion—The uncertainty interval for each certi-
Plutonium Materials—Acid Digestion and Inductively fied property of the material is usually constructed as the
Coupled Plasma-Mass Spectroscopy (ICP-MS) Analysis interval between the certified property value minus the ex-
C1672 Test Method for Determination of Uranium or Pluto- panded uncertainty (see 3.2.6) of the value, and the property
nium Isotopic Composition or Concentration by the Total value plus the expanded uncertainty. For the expanded
Evaporation Method Using a Thermal Ionization Mass uncertainty, its coverage factor is chosen so as to provide the
Spectrometer stated level of confidence. For example, to provide a stated
C1689 Practice for Subsampling of Uranium Hexafluoride level of 95 % confidence, the coverage factor is usually
D1193 Specification for Reagent Water approximately 2.
D8293 Guide for Evaluating and Expressing the Uncertainty
3.2.2 characterization, n—of a reference material, determi-
of Radiochemical Measurements
nation of the property values or attributes of a reference
2.2 ISO Standards:
material, as part of the production process. ISO Guide 30
ISO 10576–1 Statistical Methods – Guidelines for the
3.2.3 combined standard uncertainty, n—standard uncer-
Evaluation of Conformity with Specified Require-
tainty that is obtained using the individual standard uncertain-
ments – Part 1: General Principles
ties associated with the input quantities in a measurement
ISO/IEC 17025 General Requirements for the Competence
model. JCGM 200
of Calibration and Testing Laboratories
ISO 17034 General Requirements for the Competence of
3.2.3.1 Discussion—The combined standard uncertainty is
Reference Material Producers
the combination of one or more individual components of
ISO Guide 30 Terms and Definitions Used in Connection
uncertainty that make up the uncertainty budget for an attri-
with Reference Materials
bute. It is understood to be the equivalent of one times the
ISO Guide 31 Reference Materials – Contents of
standard deviation.
Certificates, Labels and Accompanying Documentation
3.2.4 coverage factor, n—number larger than one by which
ISO Guide 33 Reference Materials – Good Practice in Using
a combined standard uncertainty is multiplied to obtain an
Reference Materials
expanded uncertainty. JCGM 200
ISO Guide 35 Reference Materials – General and Statistical
3.2.5 commutability, n—property of a reference material
Principles for Certification
that relates to agreement between measurement results from a
ISO Guide 80 Guidance for the In-House Preparation of
reference material and measurement results from the sample
Quality Control Materials (QCMs)
material for the given application.
2.3 Joint Committee for Guides in Metrology:
3.2.6 expanded uncertainty, n—product of a combined stan-
JCGM 100 Evaluation of Measurement Data—Guide to the
dard uncertainty and a coverage factor. adapted from JCGM
Expression of Uncertainty in Measurement (ISO GUM
1995 with Minor Corrections (2008))
JCGM 200 International Vocabulary of Metrology—Basic
3.2.7 homogeneity, n—uniformity of a specified property
and General Concepts and Associated Terms (VIM) (ISO/
value throughout a defined portion of a reference material
IEC Guide 99)
(RM). ISO Guide 30
2.4 IAEA Documents:
3.2.7.1 Discussion—A reference material is said to be ho-
IAEA-TECDOC-1350 Development and Use of Reference
mogenous with respect to a specified property if the property
Materials and Quality Control Materials
value, as determined by tests on samples of specified size, is
found to lie within the specified uncertainty interval.
3. Terminology
3.2.7.2 Discussion—The ‘defined portion’ may be, for
3.1 Except as otherwise defined herein, definitions of terms
example, an RM batch or a single unit within the batch. ISO
are as given in Terminology C859.
Guide 30
3.2 Definitions: 3.2.8 measurement uncertainty, n—non-negative parameter
3.2.1 certified reference material (CRM), n—reference ma- characterizing the dispersion of the quantity values being
terial (RM) characterized by a metrologically valid procedure
attributed to a measurand. adapted from JCGM 200
for one or more specified properties, accompanied by an RM
3.2.8.1 Discussion—Measurement uncertainty may be ex-
certificate that provides the value of the specified property, its
pressed as either standard uncertainty or expanded uncertainty
associated uncertainty, and a statement of metrological
and any expression should indicate which form is being used.
traceability. ISO Guide 30
3.2.9 metrological traceability, n—property of a measure-
ment result whereby the result can be related to a reference
through a documented unbroken chain of calibrations, each
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
contributing to the measurement uncertainty. JCGM 200
4th Floor, New York, NY 10036, http://www.ansi.org.
Available from Bureau International des Poids et Mesures, Pavillon de Breteuil,
3.2.10 period of validity, n—of a reference material, time
F-92312 Sèvres Cedex, France, www.bipm.org.
interval during which the producer of the reference material
Available from International Atomic Energy Agency (IAEA), Vienna Interna-
tional Centre, PO Box 100, 1400 Vienna, Austria, www.iaea.org. warrants its stability. ISO Guide 30
C1128 − 23
3.2.10.1 Discussion—In nondestructive analysis (NDA), pe- covering the values that could reasonably be attributed to this
riod of validity is frequently referred to as “working life.” characteristic. ISO 10576–1
3.2.20.1 Discussion—An uncertainty interval is expressed
3.2.11 property value, n—of a reference material, value
in terms of probability of α or Type 1 error (for example, 0.05
corresponding to a quantity representing a physical, chemical
or 5 %), while a confidence interval is expressed in terms of (1
or biological property of an RM. ISO Guide 30
– α); for example, 0.95 or 95 %.
3.2.11.1 Discussion—The terms “property value” and
“quantity value” may be used interchangeably.
3.2.21 working reference material (WRM), n—reference
material, which is not certified, but is characterized using
3.2.12 quality control material (QCM), n—material used
defined, statistically sound characterization processes, and can
routinely to assess the precision of test procedures. ISO Guide
be used routinely to calibrate, control, or verify measuring
instruments or measuring systems.
3.2.12.1 Discussion—Such materials are variously referred
3.2.21.1 Discussion—Adapted from definition of “working
to in the open literature as “in-house reference materials,”
measurement standard” in JCGM 200.
“quality control samples,” “check samples,” “set up samples,”
3.2.21.2 Discussion—WRMs are distinct from QCMs (as
and so forth. ISO Guide 80
defined herein and in ISO Guide 80) in that WRMs are RMs
3.2.12.2 Discussion—QCMs are used to demonstrate that a
and provide metrological traceability to a CRM or other stated
procedure is under statistical control.
reference.
3.2.12.3 Discussion—QCMs have assigned values that are
3.2.21.3 Discussion—A WRM is prepared by a laboratory
indicative, and do not require characterization by metrologi-
for its own use for calibration or for quality control, or for the
cally valid procedures. As such, QCMs cannot be expected to
validation of a measurement method (see Guide C1068) as
establish metrological traceability or trueness of a measure-
indicated in Fig. 1.
ment result. QCMs should always be sufficiently homogeneous
3.2.21.4 Discussion—The definition of “quality control ma-
and stable with respect to the properties of interest.
terial” in IAEA-TECDOC-1350 is similar to the definition of
3.2.13 reference material (RM), n—material, sufficiently
WRM in this guide, and is as follows: “Material used for the
homogeneous and stable with respect to one or more specified
purposes of internal quality control and subjected to the same
properties, which has been established to be fit for its intended
part of the same measurement procedure as that used for test
use in a measurement process. ISO Guide 30
materials.” IAEA-TECDOC-1350 anticipates these materials
to provide metrological traceability, unlike QCMs as defined in
3.2.13.1 Discussion—Standards used for calibration and for
ISO Guide 80.
quality control are two types of reference materials.
3.2.14 reference material certificate, n—document contain-
3.3 Definitions of Terms Specific to This Standard:
ing the essential information for the use of a CRM, confirming
3.3.1 fitness for purpose, n—degree to which a WRM, when
that the necessary procedures have been carried out to ensure
used as intended in a measurement process, enables a user to
the validity and metrological traceability of the stated property
make technically and administratively correct decisions
values. ISO Guide 30
(adapted from Guide C1068).
3.2.15 reference material document, n—document contain-
3.3.2 project plan, n—document which specifies what a
ing all the information that is essential for using any reference
WRM project needs to accomplish and how the WRM will be
material. adapted from ISO 17034
produced and characterized.
3.2.15.1 Discussion—Adapted from the definition of “prod-
3.3.3 qualification—process of determining WRM to be fit
uct information sheet” in ISO Guide 30.
for purpose.
3.2.16 reference method, n—measurement method, that has
been shown to have the appropriate trueness and precision for 3.3.3.1 Discussion—The process of qualification does not
result in a certificate such as for a CRM. The degree of rigor
its intended use and has been officially defined as reference
method by a competent body. ISO Guide 30 applied in the qualification process is based on the intended use
of the WRM.
3.2.17 stability, n—ability of a reference material, when
stored under specified conditions, to maintain a stated property
4. Summary of Guide
value within specified limits for a specified period of time. ISO
Guide 30
4.1 This guide covers the preparation of WRMs from
nuclear fuel cycle materials. Examples of these materials are
3.2.18 standard uncertainty, n—measurement uncertainty
compounds and metal of uranium and plutonium, absorber
expressed as a standard deviation. JCGM 200
materials such as boron carbide, and cladding materials such as
3.2.19 uncertainty budget, n—statement of a measurement
zirconium and stainless steel. The criteria governing the
uncertainty, of the components of that measurement
preparation of reliable WRMs are identified and discussed.
uncertainty, and of their calculation and combination. JCGM
While the guidance provided is generic for nuclear fuel cycle
materials, detailed examples for some materials are provided in
3.2.20 uncertainty interval, n—interval derived from the the appendixes. A flow diagram to illustrate an approach to
actual measurement of the characteristic and its uncertainty, producing WRMs is given in Fig. 2.
C1128 − 23
FIG. 1 Essential Elements of Analytical Laboratory Quality Assurance System
4.2 This guide distinguishes between three categories of 5. Significance and Use
reference materials:
5.1 Certified reference materials (CRMs) prepared from
4.2.1 Certified reference materials (CRM), as described in
nuclear materials are well characterized, traceable, and suffi-
ISO 17034 and ISO Guides 30, 33, and 35.
ciently homogenous and stable for their intended use. Usually
4.2.2 Working reference materials (WRM), which are the
they are certified using the most unbiased and precise mea-
focus of this guide. It is important to note that:
surement methods available, often with more than one labora-
4.2.2.1 WRMs are not certified as described in ISO 17034,
tory being used on a national or international level. CRMs are
and they are typically produced using a CRM to provide
at the top of the metrological hierarchy of reference materials.
metrological traceability. However, the preparation guidelines
A graphical representation of a typical national nuclear mea-
in ISO 17034 generally apply to WRMs.
surement system is shown in Fig. 3.
4.2.2.2 The process of WRM qualification provides metro-
5.2 Working reference materials (WRMs) need to have
logical traceability to SI (see 13.1) through a CRM, or a stated
quality characteristics that are similar to CRMs, although the
reference, and may be used for calibration. As such, WRMs are
rigor used to achieve those characteristics is not usually as
generally equivalent to what IAEA-TECDOC-1350 refers to as
stringent as for CRMs. Similarly, production of WRMs should
“quality control materials.”
be in accordance with applicable requirements of ISO 17034.
4.2.3 Quality control materials (QCM), as defined in ISO
Where possible, CRMs are typically used to calibrate the
Guide 80, are produced by a laboratory with limited charac-
methods used for establishing reference values assigned to
terization to only provide an indication of its relevant property
WRMs, thus providing traceability to CRMs as required by
values for statistical control of a measurement system. A QCM
ISO/IEC 17025. A WRM is normally prepared for a specific
is not certified and cannot be expected to provide metrological
application.
traceability. QCMs may not be used for calibration, but are
typically utilized by a laboratory for a limited scope of usage. 5.3 Because of the importance of having highly reliable
Examples of uses include: preparation of control charts, measurement data from nuclear material analysis, particularly
instrument performance checks, and the determination of for material control and accountability purposes, CRMs are
operator variability. used for calibration when available. However, CRMs prepared
C1128 − 23
FIG. 2 General Process for Preparing Working Reference Materials
from nuclear materials are not always available for specific 6.1.1 The WRM planning process involves the following
applications. Thus, there may be a need for a laboratory to elements:
prepare nuclear material WRMs to meet specific needs; for
6.1.1.1 Identifying the scope of the project, including all
example, to match the matrix in process samples. In such cases,
needs and requirements for WRM production, characterization,
a WRM can be tailored to meet specific needs of a process or
and value assignment (see 6.2 and Appendix X1).
laboratory. Also, CRM supply may be too limited for use in the
6.1.1.2 Developing a detailed WRM project plan (6.3) that
quantities needed for long-term, routine use. When properly
addresses all of the needs and requirements identified; and
prepared, WRMs will serve equally well as CRMs for most
6.1.1.3 Performing the selection and collection of materials
applications, and using WRMs will help preserve supplies of
that will be used to produce the WRM units (6.4).
CRMs.
6.1.2 The amount of detail in the project plan, and the level
5.4 Difficulties may be encountered in the preparation of of effort to prepare it, should be based on the size and
RMs from nuclear materials because of the chemical and
complexity of the WRM preparation task. In some cases the
physical properties of the materials. Chemical instabilities,
project plan can be brief as long as it contains the necessary
problems in ensuring stoichiometry, homogeneity, and radio-
information for the project to be completed successfully. If the
activity are among the factors to be considered, with all three
project is to produce a WRM that has been produced
factors being involved with some materials. Those preparing previously, much of the needed information may already be
WRMs from nuclear materials need to be aware of how these
available, and the planning process streamlined accordingly.
factors may affect preparation, as well as being aware of the
6.2 Define WRM Needs and Requirements / Determine
other criteria governing the preparation of reliable WRMs.
Purpose—Producing a WRM requires forethought to ensure
5.5 While use of WRMs provides benefits for the laboratory,
the completed WRM meets the needs of its end-users and
it is important to observe the distinction between WRMs,
stakeholders and the requirements for its application. A de-
which are prepared by a laboratory for use by that laboratory
tailed project plan that specifies needs and how the WRM will
(or, in some cases, an affiliated satellite laboratory or produc-
be produced should be prepared and approved in advance of
tion facility served by the laboratory), and CRMs which
any work. The subjects discussed in this section should be
provide certificates of analysis (in accordance with ISO Guide
considered and addressed as appropriate. Failure to properly
31) and can be offered for sale.
define all needs and requirements can result in wasted time,
funding, and materials, as well as requiring rework.
6. Perform WRM Planning
6.2.1 Needs and requirements for the WRM should be
6.1 General: identified and documented. These can include the following:
C1128 − 23
FIG. 3 Typical National Nuclear Measurement System
(1) Key elements of the WRM project purpose and scope; (14) Selection and validation of characterization meth-
(2) Quantity of WRMs needed; od(s);
(3) Intended purpose(s) of the WRM; (15) Control of measurement equipment calibration and
(4) Physical and chemical properties of the WRM; traceability to the SI;
(5) Important aspects and limitations of end-user’s mea- (16) Control of unit storage;
surement method(s); (17) Guidance on value assignment and uncertainty calcu-
(6) Measurand(s) level and uncertainty; lation;
(7) Data quality objectives; (18) Period of validity; and
(8) Fitness for purpose considerations; (19) Post-production stability monitoring.
(9) Criteria for material selection and collection; 6.2.1.1 Appendix X1 provides a template containing ques-
(10) Requirements for producing stable and homogeneous tions and statements that may be used to aid in documenting
WRM units; the WRM project plan requirements.
(11) Criteria for container selection; 6.2.2 The planning process should follow the concept of
(12) Sampling criteria; defining needs and requirements, then documenting how the
(13) Environmental controls during production and charac- selected material will be used to produce stable and homog-
terization; enous WRM units that will then be characterized. The project
C1128 − 23
plans should outline the process that will be used for value (18) Ensure appropriate control of transportation, if re-
assignment and calculating the expanded uncertainty and the quired for production, characterization, or storage;
(19) Ensure adequate storage facilities and conditions; and
uncertainty budget.
(20) Ensure post-production stability monitoring, if appli-
6.2.3 The producer of a WRM should consider whether a
cable.
commercially-available reference material is fit for purpose
and could be used instead of producing a WRM. If a commer-
NOTE 1—ISO Guide 35 provides additional guidance on aspects of
cial RM does not meet one or more of the following conditions developing a project plan.
for the planned end-user application, then a WRM should be
6.3.2 Activities and milestones should be scheduled and
prepared:
tracked to completion by the project leader or management.
(1) An existing, available RM does not match the needs of
6.3.3 All tasks should be assigned to experienced, trained,
the end-users and the requirements of each measurement
and qualified staff.
method;
6.3.4 One individual may be assigned to perform or lead
(2) An existing RM is not available in sufficient quantity to
more than one aspect of the WRM production,
meet usage needs;
characterization, and value assignment.
(3) An existing RM is not available at an acceptable cost
6.3.5 The WRM project plan should:
compared to producing a WRM;
(1) Identify WRM needs and requirements;
(4) Another justification as determined by the preparer of
(2) Identify WRM production execution plan;
the proposed WRM.
(3) Identify WRM characterization execution plan, includ-
6.2.3.1 The preparer of the WRM may document the basis
ing value assignment;
for their make-versus-buy decision in their planning document.
(4) Identify work control documents and procedures that
will be needed to implement the execution plans and ensure
6.3 Develop WRM Project Planning Documents—The
that they are complete and available when needed;
WRM producer is responsible for ensuring that all aspects of
(5) Develop plans for performing any required homogene-
the production and characterization are well planned and
ity and stability studies; and
documented in sufficient detail to ensure that all identified
(6) Guide the material selection and collection process.
needs and requirements are implemented effectively.
6.3.6 If sufficient information is not available to perform or
6.3.1 The planning process should include the follow
to complete the project plan, it may be necessary to perform
activities, which are adapted from a similar list in ISO 17034:
feasibility studies on specific aspects of the WRM project such
(1) Perform material selection, including any sampling and
as:
verification of identify of the material;
(1) Studies to determine if the material selected is fit for
(2) Select inner-most container that is durable, long-
purpose according to the defined scope;
lasting, resistant to damage from radioactive decay, and com-
(2) Studies to determine the best ways to process and
patible with the chemical properties of the WRM;
prepare the selected materials without compromising desired
(3) Maintain suitable environments for production (and
property values; or
subsequent characterization);
(3) Studies to test, improve, or verify that equipment,
(4) Define material processing;
personnel, and measurement procedures meet standards for
(5) Define acceptance criteria for measurand levels and
performance required for producing or characterizing the
their uncertainties;
WRM, or both, to the specific requirements. Feasibility studies
(6) Specify acceptance criteria for, and assessment of,
should be simple in scope.
homogeneity, including sampling;
6.3.7 Planning should include defining resources needed to
(7) Specify acceptance criteria for, and assessment/
ensure efficient production and characterization campaigns to
monitoring of, stability, including sampling;
contain costs and minimize delays. This includes financial
(8) Design and organize appropriate characterization, in-
resources, availability of qualified personnel to prepare the
cluding sampling;
WRM, availability of instrumentation and equipment required
(9) Select appropriate measurement procedures;
for characterization, homogeneity and stability studies, equip-
(10) Validate measurement procedures;
ment required for packaging the WRM, availability of any
(11) Verify and calibrate measuring equipment;
outside resources for activities that the laboratory is not able to
(12) Establish metrological traceability for measurement
perform itself, and so forth.
result(s), as appropriate;
6.3.7.1 The WRM producer is responsible for evaluating
(13) Assess commutability, when applicable;
any outside collaborators and their ability to meet performance
(14) Assign property value(s);
requirements in accordance with relevant ASTM and ISO
(15) Calculate expanded uncertainty(ies) and uncertainty
standards during the planning process. Limitations on re-
budget(s);
sources or collaborators can negatively impact WRM quality
(16) Issue WRM documents for production,
and the time required to complete the project.
characterization, and value assignment, as well as documents
6.3.8 Develop Plan for Production Execution:
addressing safety and regulatory compliance;
(17) Ensure appropriate labeling and packaging of WRM
6.3.8.1 The execution plan for production should provide a
including appropriate hazard communication labeling; step-by-step summary of processes and procedures that will be
C1128 − 23
performed on the selected material(s). The plan should docu- 6.3.10.1 Homogeneity Assessment (Section 9)—The project
ment all aspect of material handling, including preparation plan should include details for homogeneity studies when
steps to ensure homogeneity, stability, and any specific material needed. The results from the study are included when calcu-
characteristics as well as the packaging of WRM units and their lating expanded uncertainties for the assigned values.
subsequent storage and distribution for characterization. The
6.3.10.2 Stability (Short and long term) Assessment and
plan should be written in a manner that illustrates how all Monitoring (Section 10)—The project plan should include
identified production requirements will be satisfied.
details for stability studies when needed. The results from the
study are included when calculating the expanded uncertainties
6.3.9 Develop Plan for Characterization Execution:
for the assigned values.
6.3.9.1 The characterization plan should document which
measurement method will be used for each measurand to be 6.3.11 Environmental, Safety, and Health—Identify and as-
sess environmental, safety, and health concerns. These may
determined. The plan should provide a step-by-step summary
of process and procedures that will be performed on the include the following:
selected units of the WRM. Quality assurance requirements 6.3.11.1 Chemical and Radiological Hazards—Performance
including QC standards, blank, and measurement sequence of a hazard analysis to identify activity-based hazards and the
administrative and engineered controls required to minimize
should be described in sufficient detail to illustrate that char-
acterization requirements and data quality objectives will be them.
satisfied. The characterization plan should document the fol- 6.3.11.2 Radiolysis—Assessment of the risk of radiolysis
lowing aspects: (generation of hydrogen, oxygen, or both) due to radioactive
(1) Random selection of units; sampling parameters includ- decay of actinides in solution.
ing minimum sample size;
6.3.11.3 Criticality—Assessment for the risk of criticality
(2) Sample dissolution, dilution, treatment, and analytical when handling and storing materials with fissile content.
preparation;
6.3.11.4 Waste Management—Assessment of the waste that
(3) Measurement protocols;
will be generated and how it will be disposed.
(4) Data collection and reporting; and
6.3.11.5 Laboratory Safety Basis—Review of the activity
(5) The calculation of quantity values, expanded
against the safety limits within which the laboratory is required
uncertainties, and uncertainty budgets.
to operate.
6.3.9.2 The plan should be written in a manner that illus-
6.3.11.6 Industrial Hygiene—Ensure that applicable re-
trates how all identified characterization requirements will be
quirements of the international Globally Harmonized System
satisfied.
for labeling of packages and communication of hazards using
6.3.9.3 The analysis scheme should be developed that will Safety Data Sheet are implemented.
directly link the traceability of measurements made on the
6.3.11.7 Transportation of Radioactive Materials—Ensure
WRM aliquots to a CRM or other established reference,
that applicable transportation regulations (for example, Depart-
assuming traceability to the SI is required. Consideration also
ment of Transportation regulations in the United States) are
should needs to be given to the calibrations and controls when
followed for shipping of selected materials, WRM units, and
using common laboratory equipment such as analytical bal-
samples for characterization.
ances or calibrated labware. Corrections made to the measure-
6.4 Select and Collect Materials—Selection of materials is
ments for interferences or contaminations should also be
an important part of planning that should be based on identified
validated using a CRM when available. When designing an
requirements.
analysis plan consulting with a statistician experienced in
6.4.1 Proper material selection is critical to achieving
analytical processes is recommended.
credible, stable, and homogenous WRMs. The planning pro-
6.3.9.4 How the final measurand is calculated and assigned
cess will evaluate the importance and relative significance of
as well as the calculation of the expanded uncertainty should be
material availability (source), cost, chemical and physical
included in the project plan.
properties, and stoichiometry. The starting materials for the
6.3.9.5 Procedures that will be used for production or
preparation of WRMs may already be in the desired chemical
characterization activities should be identified and developed if
and physical form or it may need to be processed. In the former
needed.
case, the starting material may be a process material. For
6.3.9.6 Materials and equipment should be identified. If any
example, a batch of uranium dioxide pellets, boron carbide
items must be procured, the procurement requirements and
powder, or plutonium nitrate solution might be taken directly
purchase orders must be generated with sufficient lead time.
from a nuclear material process, treated as necessary, packaged
6.3.9.7 The project plan should include requirements for
as a WRM, and then characterized. In the latter case, various
packaging and storage (see Section 8).
approaches are used to produce the form desired. For example,
6.3.9.8 If any production or characterization tasks will be
high-purity uranium hexafluoride might be dissolved and the
performed by subcontractors, the preparer of the WRM is
solution converted to urano-uranic oxide (U O ) to prepare a
3 8
responsible for verifying that they have the necessary technical
pure or matrix matched WRM (see Appendix X3).
competence and an appropriate quality assurance program to
NOTE 2—Consideration for environmental, safety, and health factors
perform the task assigned to them in a manner consistent with
when handling the bulk material is an important aspect in the selection
the WRM planning requirements.
process. An activity-based hazard analysis of the chemical and radiologi-
6.3.10 Develop Plan for Homogeneity and Stability Studies: cal hazards associated with the work will assist in establishing the controls
C1128 − 23
required to do the work safely.
technique sometimes used for solutions is to evaporate each
weighed portion to near-dryness in its packaging container,
7. Prepare and Process Materials
giving a weighed amount of the element of interest for a
one-time use. Various aspects of packaging are discussed in
7.1 Preparation:
this section. A procedure to illustrate packaging a WRM
7.1.1 The objective of preparation is to make physical and
solution is given in Appendix X4.
chemical manipulations so as to produce a homogeneous and
stable material in the form required for a WRM. For a given 8.1.1 Container—It is important that the container material
WRM, the physical and chemical manipulations that will be
be chemically compatible with the WRM matrix and that the
used depend on the starting material(s), the WRM form material will not contribute to the contamination of the WRM.
required, and the physical and chemical properties of the To avoid contamination, containers are often specially cleaned
materials involved. Various aspects of preparation are dis- before packaging. When radioactive material such as pluto-
cussed in this section. nium is involved, the primary container is often packaged in a
7.1.2 The form of the WRM can be any stable state of the secondary or outer container to protect against radioactive
element of interest or a somewhat unstable state whose contamination. For long term storage, considerations must also
stoichiometry is easily reproducible. The forms most com- be given for the degradation of container materials due to
monly used for nuclear materials have been oxides as powder various causes (such as pressurization, radiolysis, radiolitic
or pellets, metal, and nitrate solutions. aging, chemical degradation, and so forth).
8.1.2 Addition to Container—The manner of adding WRM
7.2 Processing—Processing of the material includes prepa-
to containers depends on the nature of the material (for
ration and subdividing into usable WRM aliquots.
example, whether the WRM is solid, liquid, or gas), the type of
7.2.1 A preparation procedure should be written using a
container, and whether the weight of each WRM portion is
scheme for preparing the WRM developed during the planning
required. It is exceedingly important that the WRM be deliv-
stage. The procedure should include the necessary steps for
ered into each container without any part of the material
making the required chemical and physical manipulations, and
adhering to the neck or top of the container (or outside of the
it should include requirements for recording data generated
container), particularly when solution is added to glass am-
during preparation. If the reference value will be calculated
poules that will be heat sealed. Special apparatus is sometimes
based on process or make-up parameters (weights, volumes,
used for delivery to the containers (see Fig. 4 as an example).
and so forth), write the procedure accordingly to minimize the
When a WRM is to be apportioned by weight, it is usually
possibilities of losing any material during processing. Informa-
added to tared containers, which are reweighed after addition.
tion for preparation and dissolution of uranium and plutonium
When radioactive material is involved, special care is required
materials can be found in Practices C1347 and C1168, respec-
to keep the outsides of the containers free of contamination.
tively. Procedures to illustrate the preparation of two WRM
Each container should be surveyed after addition, and those
solutions are given in Appendix X4.
contaminated should be discarded.
7.2.2 Subdividing—During the creation of the WRM ali-
quots it must be ensured that homogeneity of the bulk material 8.1.3 Cover Gas—With some materials, stability is en-
is maintained. Key factors to consider when developing a plan hanced by packaging the WRM in an inert gas or dry air. A
to subdivide the bulk material are listed below. common way to do this is to package in a glove box containing
7.2.2.1 Liquids should be thoroughly homogenized prior to the atmosphere desired. The materials most often packaged in
being subdivided, and regularly stirred or agitated to ensure an inert and dry atmosphere or simply in dry air are the oxides,
that the solution remains homogenous while it is subdivided. If particularly powders. This is done to ensure stability and
filtration is required, it should be done before subdividing. integrity, even when an oxide is basically stable. When a
7.2.2.2 The separation of finer particulates from the bulk special atmosphere is used, care must be taken to ensure that
material when subdividing solids and powders should be containers will not lose the atmosphere over the shelf life of the
considered and assessed if deemed to be significant. WRM.
7.2.2.3 Subdividing of the bulk material should be per-
8.1.4 Sealing Containers—If a special atmosphere is used as
formed as quickly as possible.
discussed in 8.1.3, the method of sealing the containers is
important. For screw cap containers, sealing the caps with a
8. Packaging and Storage of Materials
sealant over the cap is one way. Using glass ampoules that are
heat sealed is another approach (a procedure for sealing glass
8.1 Packaging—Once preparation is complete, the WRM is
ampoules is given in Appendix X4). Glass ampoules are
packaged for use. A frequent practice is to divide the WRM
commonly used for solutions to avoid loss of integrity through
into essentially equal portions or units, each of which repre-
evaporation. When simply closing a vial or bottle with a screw
sents enough material for a one-time use. If a WRM is
cap is satisfactory, a cap liner that provides a reasonably
sufficiently stable, it could be divided into larger portions for
air-tight seal should be used.
multiple uses over a short time duration. There is a risk here,
however, because each time a container is opened there is a 8.1.5 Labeling—Each WRM container should be labeled for
potential for loss of WRM integrity (for example, from identification. Individual identification of each container or
contamination or evaporation). The key to packaging is to unit is recommended, and required if each unit needs to be
contain the WRM portions in such a manner as to preserve uniquely identifiable (for example, by a characteristic that
their integrity for the life of the WRM (see Section 6). A affects the use of the WRM, such as the net weight of the
C1128 − 23
FIG. 4 Example of a Polychlorotrifluoroethylene (Fluorothene)
Knockout Tube (used for uranium hexafluoride; see Practice
C1689 for additional details)
WRM). As a minimum, information on a label must provide evaluate homogeneity of bulk material before subdividing, as
traceability to the WRM. It should have the date of preparation
well as after subdividing.
and must have shelf life information indicated on the label. It
9.3 Acceptance Criteria—The standard uncertainty of the
is essential that labels be firmly attached to the containers and
between-unit homogeneity study (S ) contributes to the overall
h
that their markings be non-smearing and non-fading. Bar-code
combined standard uncertainty of the WRM assigned value. In
labeling may be desirable since more information can be added
some cases, the magnitude of S can be negligible in compari-
h
in a smaller space.
son to the batch characterization standard uncertainty (S )
m
8.2 Storage—Although a major purpose of packaging is to
while at other times it may be equal to S . Acceptance criteria
m
preserve the integrity of WRMs, attention should also be given
for the contribution of inhomogeneity to the overall combined
to how and where the packaged WRMs are stored. Exposure
standard uncertainty should be established based on fitness for
over time to large fluctuations in temperature, or to above-
purpose.
ambient temperatures, could adversely affect the container
9.4 Homogeneity Study:
seals and the WRMs themselves. Exposure to conditions that
would damage or destroy labels, or even damage containers,
9.4.1 Sampling—The number of units selected for sampling
should be avoided.
should be economically feasible while still maintaining repre-
sentation of the whole batch. Stratified random sampling
8.3 Transportation—If the WRM is to be transported from
should be employed for selection of the units. A minimum of
one facility (such as a primary laboratory) to another (such as
two replicates should be measured in a random sequence in
a satellite laboratory or a production facility), packaging needs
to be sufficient for maintaining integrity, radiological control order to differentiate between a trend in unit filling sequence as
and safety, and applicable regulatory requirements. opposed to analytical drift. The measurement sequence must be
planned to detect analytical drift, otherwise a trend in filling
9. Perform Homogeneity Study
sequence may be offset. For example, the first replicate
9.1 Summary—WRMs are often subdivided from a large measurement sequence can be measured in a random order and
batch into individual units. The purpose of the homogeneity the second replicate measurement sequence could be a reverse
study is to assess the contribution of components of the
of the first.
uncertainty budget to the overall WRM expanded uncertainty
9.4.2 Measurement Method—The analytical method used
due to heterogeneity between units. Special care should be
for measurement requires good repeatability, otherwise S may
h
taken when preparing and packaging the WRM to minim
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C1128 − 18 C1128 − 23
Standard Guide for
Preparation of Working Reference Materials for Use in
Analysis of Nuclear Fuel Cycle Materials
This standard is issued under the fixed designation C1128; 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
1.1 This guide covers the preparation and characterization of working reference materials (WRM) that are produced by a
laboratory for its own use in the analysis of nuclear fuel cycle materials. Guidance is provided for proper planning, preparation,
packaging, and storage; requirements for characterization; homogeneity and stability considerations; and establishing traceability
of WRMs to certified reference materials value assignment. When traceability to SI is desired for a WRM, it will be achieved by
a defined, statistically sound characterization process. process that is traceable to a certified value on a certified reference materials.
While the guidance provided is generic for nuclear fuel cycle materials, detailed examples for some materials are provided in the
appendixes.
1.2 This guide does not apply to the preparationproduction and characterization of certified reference materials (CRM). Refer to
ISO 17034 and ISO Guide 35 for those guidance on reference material production, characterization, certification, sale, and
distribution requirements.
1.3 The information provided by this guide is found in the following sections:
Section
Perform WRM Planning 6
Select, Collect, Prepare, and Process 7
Materials
Prepare and Process Materials 7
Packaging and Store Materials 8
Packaging and Storage of Materials 8
Perform Homogeneity Study 9
Perform Stability Studies 10
Characterize Materials 11
Perform Uncertainty Analysis 12
Produce Documentation 13
Carry Out WRM Utilization and 14
Monitoring
1.4 The values stated in SI units are to be regarded as standard. The non-SI units of molar, M, and normal, N, are also regarded
as standard. Any non-SI units of measurement shown in parentheses are for information only.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
This guide is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.08 on Quality Assurance,
Statistical Applications, and Reference Materials.
Current edition approved Jan. 1, 2018Jan. 1, 2023. Published January 2018February 2023. Originally approved in 1989. Last previous edition approved in 20152018 as
C1128 – 15.C1128 – 18. DOI: 10.1520/C1128-18.10.1520/C1128-23.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1128 − 23
1.6 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.
2. Referenced Documents
2.1 ASTM Standards:
C859 Terminology Relating to Nuclear Materials
C1009 Guide for Establishing and Maintaining a Quality Assurance Program for Analytical Laboratories Within the Nuclear
Industry
C1068 Guide for Qualification of Measurement Methods by a Laboratory Within the Nuclear Industry
C1108 Test Method for Plutonium by Controlled-Potential Coulometry
C1165 Test Method for Determining Plutonium by Controlled-Potential Coulometry in H SO at a Platinum Working Electrode
2 4
C1168 Practice for Preparation and Dissolution of Plutonium Materials for Analysis
C1210 Guide for Establishing a Measurement System Quality Control Program for Analytical Chemistry Laboratories Within
Nuclear Industry
C1267 Test Method for Uranium by Iron (II) Reduction in Phosphoric Acid Followed by Chromium (VI) Titration in the
Presence of Vanadium
C1297 Guide for Qualification of Laboratory Analysts for the Analysis of Nuclear Fuel Cycle Materials
C1347 Practice for Preparation and Dissolution of Uranium Materials for Analysis
C1625 Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances by Thermal Ionization Mass
Spectrometry
C1637 Test Method for Determination of Impurities in Plutonium Materials—Acid Digestion and Inductively Coupled
Plasma-Mass Spectroscopy (ICP-MS) Analysis
C1672 Test Method for Determination of Uranium or Plutonium Isotopic Composition or Concentration by the Total
Evaporation Method Using a Thermal Ionization Mass Spectrometer
C1689 Practice for Subsampling of Uranium Hexafluoride
D1193 Specification for Reagent Water
D8293 Guide for Evaluating and Expressing the Uncertainty of Radiochemical Measurements
2.2 ISO Standards:
ISO 10576–1 Statistical Methods – Guidelines for the Evaluation of Conformity with Specified Requirements – Part 1: General
Principles
ISO/IEC 17025 General Requirements for the Competence of Calibration and Testing Laboratories
ISO 17034 General Requirements for the Competence of Reference Material Producers
ISO Guide 30 Terms and Definitions Used in Connection with Reference Materials
ISO Guide 31 Reference Materials – Contents of Certificates, Labels and Accompanying Documentation
ISO Guide 33 Reference Materials – Good Practice in Using Reference Materials
ISO Guide 35 Reference Materials – General and Statistical Principles for Certification
ISO Guide 80 Guidance for the In-House Preparation of Quality Control Materials (QCMs)
2.3 Joint Committee for Guides in Metrology:
JCGM 100:2008100 Evaluation of Measurement Data—Guide to the Expression of Uncertainty in Measurement (ISO GUM
1995 with Minor Corrections (2008))
JCGM 200:2012200 International Vocabulary of Metrology—Basic and General Concepts and Associated Terms (VIM)
(ISO/IEC Guide 99)
2.4 IAEA Documents:
IAEA-TECDOC-1350 Development and Use of Reference Materials and Quality Control Materials
3. Terminology
3.1 Except as otherwise defined herein, definitions of terms are as given in Terminology C859.
3.2 Definitions:
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from Bureau International des Poids et Mesures, Pavillon de Breteuil, F-92312 Sèvres Cedex, France, www.bipm.org.
Available from International Atomic Energy Agency (IAEA), Vienna International Centre, PO Box 100, 1400 Vienna, Austria, www.iaea.org.
C1128 − 23
3.2.1 certified reference material (CRM)—(CRM), n—reference material, accompanied by a certificate, material (RM) character-
ized by a metrologically valid procedure for one or more of whose property values are certified by a procedure, which establishes
its traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value
is accompanied by an uncertainty interval at a stated level of confidence.specified properties, accompanied by an RM certificate
that provides the value of the specified property, its associated uncertainty, and a statement of metrological traceability. adapted
from ISO Guide 30
3.2.1.1 Discussion—
The uncertainty interval for each certified property of the material is usually constructed as the interval between the certified
property value minus the expanded uncertainty (see 3.2.6) of the value, and the property value plus the expanded uncertainty. For
the expanded uncertainty, its coverage factor is chosen so as to provide the stated level of confidence. For example, to provide a
stated level of 95 % confidence, the coverage factor is usually approximately 2.
3.2.2 certifying body—technically competent body (organization or firm, public or private) that issues a reference material
certificate which provides the information detailed in ISO Guide 31. ISO Guide 30
3.2.2 characterization—characterization, n—of a reference material, determination of one or more physical, chemical, biological,
or technological property values that are relevant to its intended end use.the property values or attributes of a reference material,
as part of the production process. adapted from ISO Guide 30
3.2.3 combined standard uncertainty—uncertainty, n—standard uncertainty that is obtained using the individual standard
uncertainties associated with the input quantities in a measurement model. JCGM 200:2012200
3.2.3.1 Discussion—
The combined standard uncertainty is the combination of one or more individual components of uncertainty that make up the
uncertainty budget for an attribute. It is understood to be the equivalent of one times the standard deviation.
3.2.4 coverage factor—factor, n—number larger than one by which a combined standard uncertainty is multiplied to obtain an
expanded uncertainty. JCGM 200:2012200
3.2.5 commutability, n—property of a reference material that relates to agreement between measurement results from a reference
material and measurement results from the sample material for the given application.
3.2.6 expanded uncertainty—uncertainty, n—product of a combined standard uncertainty and a coverage factor. adapted from
JCGM 200:2012200
3.2.7 homogeneity—homogeneity, n—condition of being of uniform structure or composition with respect to one or more specified
properties.uniformity of a specified property value throughout a defined portion of a reference material (RM). ISO Guide 30
3.2.7.1 Discussion—
A reference material is said to be homogenous with respect to a specified property if the property value, as determined by tests
on samples of specified size, is found to lie within the specified uncertainty interval.adapted from ISO Guide 30
3.2.7.2 Discussion—
The ‘defined portion’ may be, for example, an RM batch or a single unit within the batch. ISO Guide 30
3.2.8 measurement uncertainty—uncertainty, n—non-negative parameter characterizing the dispersion of the quantity values being
attributed to a measurand. adapted from JCGM 200:2012200
3.2.8.1 Discussion—
Measurement uncertainty may be expressed as either standard uncertainty or expanded uncertainty and any expression should
indicate which form is being used.
3.2.9 metrological traceability—traceability, n—property of a measurement result whereby the result can be related to a reference
through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty. JCGM 200:2012200
3.2.10 period of validity, n—of a reference material, time interval during which the producer of the reference material warrants
its stability. ISO Guide 30
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3.2.10.1 Discussion—
In nondestructive analysis (NDA), period of validity is frequently referred to as “working life.”
3.2.11 property value, n—of a reference material, value corresponding to a quantity representing a physical, chemical or biological
property of an RM. ISO Guide 30
3.2.11.1 Discussion—
The terms “property value” and “quantity value” may be used interchangeably.
3.2.12 quality control material (QCM)—(QCM), n—material used routinely to assess the precision of test procedures. ISO Guide
3.2.12.1 Discussion—
Such materials are variously referred to in the open literature as “in-house reference materials,” “quality control samples,” “check
samples,” “set up samples,” and so forth. ISO Guide 80
3.2.12.2 Discussion—
QCMs are used to demonstrate that a procedure is under statistical control.
3.2.12.3 Discussion—
QCMs have assigned values that are indicative, and do not require characterization by metrologically valid procedures. As such,
QCMs cannot be expected to establish metrological traceability or trueness of a measurement result. QCMs should always be
sufficiently homogeneous and stable with respect to the properties of interest.adapted from ISO Guide 80
3.2.13 reference material (RM)—(RM), n—material or substance material, sufficiently homogeneous and stable with respect to one
or more of whose property values are sufficiently homogenous and well established specified properties, which has been
established to be fit for its intended use such as the calibration of an apparatus, the assessment of a measurement method, or for
assigning values to materials.in a measurement process. ISO Guide 30
3.2.13.1 Discussion—
Reference material property values are assigned by a procedure (or procedures) which establish the traceability of those
values.Standards used for calibration and for quality control are two types of reference materials.
3.2.11.2 Discussion—
A reference material may be referred to in this guide also as a calibration standard or a control standard.
3.2.14 reference material certificate—certificate, n—document accompanying a certified reference material stating one or more
property values and their uncertainties, and containing the essential information for the use of a CRM, confirming that the
necessary procedures have been carried out to ensure their validity and traceability.the validity and metrological traceability of the
stated property values. ISO Guide 30
3.2.15 reference material document—document, n—document containing all the information that is essential for using any
reference material. adapted from ISO 17034
3.2.15.1 Discussion—
Adapted from the definition of “product information sheet” in ISO Guide 30.
3.2.16 reference method—method, n—thoroughly investigated method, clearly and exactly describing the necessary conditions and
procedures, for the measurement of one or more property values measurement method, that has been shown to have accuracy the
appropriate trueness and precision commensurate with for its intended use and that can therefore be used to assess the accuracy
of other methods for the same measurement, particularly in permitting the characterization of an RM.has been officially defined
as reference method by a competent body. ISO Guide 30
3.2.17 stability—stability, n—ability of a reference material, when stored under specified conditions, to maintain a stated property
value within specified limits for a specified period.period of time. ISO Guide 30
3.2.18 standard uncertainty—uncertainty, n—measurement uncertainty expressed as a standard deviation. JCGM 200:2012200
3.2.19 uncertainty budget—budget, n—statement of a measurement uncertainty, of the components of that measurement
uncertainty, and of their calculation and combination. JCGM 200:2012200
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3.2.20 uncertainty interval—interval, n—interval derived from the actual measurement of the characteristic and its uncertainty,
covering the values that could reasonably be attributed to this characteristic. ISO 10576–1
3.2.20.1 Discussion—
An uncertainty interval is expressed in terms of probability of α or Type 1 error (for example, 0.05 or 5 %), while a confidence
interval is expressed in terms of (1 – α); for example, 0.95 or 95 %.
3.2.21 working reference material (WRM)—(WRM), n—reference material, which is not certified, but is characterized using
defined, statistically sound characterization processes, and can be used routinely to calibrate calibrate, control, or verify measuring
instruments or measuring systems. adapted from JCGM 200:2012
3.2.21.1 Discussion—
Adapted from definition of “working measurement standard” in JCGM 200.
3.2.21.2 Discussion—
WRMs are distinct from QCMs (as defined herein and in ISO Guide 80) in that WRMs are RMs and provide metrological
traceability to a CRM or other stated reference.
3.2.21.3 Discussion—
A WRM is prepared by a laboratory for its own use for calibration or for quality control, or for the validation of a measurement
method (see Guide C1068) as indicated in Fig. 1.
3.2.21.4 Discussion—
The definition of “quality control material” in IAEA-TECDOC-1350 is similar to the definition of WRM in this guide, and is as
follows: “Material used for the purposes of internal quality control and subjected to the same part of the same measurement
procedure as that used for test materials.” IAEA-TECDOC-1350 anticipates these materials to provide metrological traceability,
unlike QCMs as defined in ISO Guide 80.
3.2.19.1 Discussion—
FIG. 1 Quality AssuranceEssential Elements of Analytical Laboratory DataQuality Assurance System
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WRMs are distinct from QCMs (as defined herein and in ISO Guide 80) in that WRMs are RMs and provide metrological
traceability to a CRM or other stated reference.
3.2.19.2 Discussion—
A WRM is usually prepared by a single laboratory for its own use as a calibration standard, as a control standard, or for the
qualification of a measurement method (see Guide C1068) as indicated in Fig. 1.
3.2.19.3 Discussion—
The definition of “quality control material” in IAEA-TECDOC-1350 is similar to the definition of WRM in this guide, and is as
follows: “Material used for the purposes of internal quality control and subjected to the same part of the same measurement
procedure as that used for test materials.” IAEA-TECDOC-1350 anticipates these materials to provide metrological traceability,
unlike QCMs as defined in ISO Guide 80.
3.3 Definitions of Terms Specific to This Standard:
3.3.1 fitness for purpose—purpose, n—degree to which a WRM, when used as intended in a measurement process, enables a user
to make technically and administratively correct decisions for a stated purpose (adapted from Guide C1068).
3.3.2 project plan, n—document which specifies what a WRM project needs to accomplish and how the WRM will be produced
and characterized.
3.3.3 qualification—process of determining WRM to be fit for purpose.
3.3.3.1 Discussion—
The process of qualification does not result in a certificate such as for a CRM. The degree of rigor applied in the qualification
process is based on the intended use of the WRM.
4. Summary of Guide
4.1 This guide covers the preparation of WRMs from nuclear fuel cycle materials. Examples of these materials are compounds
and metal of uranium and plutonium, absorber materials such as boron carbide, and cladding materials such as zirconium and
stainless steel. The criteria governing the preparation of reliable WRMs are identified and discussed. While the guidance provided
is generic for nuclear fuel cycle materials, detailed examples for some materials are provided in the appendixes. A flow diagram
to illustrate an approach to producing WRMs is given in Fig. 2.
FIG. 2 General Process for Preparing Working Reference Materials
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4.2 This guide distinguishes between three categories of reference materials:
4.2.1 Certified reference materials (CRM), as described in ISO 17034 and ISO Guides 30, 33, and 35.
4.2.2 Working reference materials (WRM), which are the focus of this guide. It is important to note that:
4.2.2.1 WRMs are not certified as described in ISO 17034, and they are typically produced using a CRM. CRM to provide
metrological traceability. However, the preparation guidelines in ISO 17034 generally apply to WRM.WRMs.
4.2.2.2 WRMs provide The process of WRM qualification provides metrological traceability to SI (see 13.1) through a CRM, or
a stated reference, and may be used for calibration. As such, WRMWRMs are generally equivalent to what IAEA-TECDOC-1350
refers to as “quality control materials.”
4.2.3 Quality control materials (QCM), as defined in ISO Guide 80, are produced by a laboratory with limited characterization
to only provide an indication of its relevant property values for statistical control of a measurement system. A QCM is not certified
and cannot be expected to provide metrological traceability. QCMs may not be used for calibration, but are typically utilized by
a laboratory for a limited scope of usage. Examples of uses include: preparation of control charts, instrument performance checks,
and the determination of operator variability.
5. Significance and Use
5.1 Certified reference materials (CRMs) prepared from nuclear materials are generally well characterized well characterized,
traceable, and sufficiently homogenous and stable for their intended use. Usually they are certified using the most unbiased and
precise measurement methods available, often with more than one laboratory being used on a national or international level, and
they level. CRMs are at the top of the metrological hierarchy of reference materials. A graphical representation of a typical national
nuclear measurement system is shown in Fig. 3.
5.2 Working reference materials (WRMs) need to have quality characteristics that are similar to CRMs, although the rigor used
to achieve those characteristics is not usually as stringent as for CRMs. Similarly, producersproduction of WRMs should comply
be in accordance with applicable requirements of ISO 17034, which are less stringent for WRMs than the requirements for
producers of CRMs. 17034. Where possible, CRMs are typically used to calibrate the methods used for establishing reference
values assigned to WRMs, thus providing traceability to CRMs as required by ISO/IEC 17025. A WRM is normally prepared for
a specific application.
5.3 Because of the importance of having highly reliable measurement data from nuclear material analysis, particularly for material
control and accountability purposes, CRMs are used for calibration when available. However, CRMs prepared from nuclear
materials are not always available for specific applications. Thus, there may be a need for a laboratory to prepare nuclear material
WRMs to meet specific needs. Also, CRMs are often too expensive, or their supply is needs; for example, to match the matrix in
process samples. In such cases, a WRM can be tailored to meet specific needs of a process or laboratory. Also, CRM supply may
be too limited for use in the quantities needed for long-term, routine use. When properly prepared, WRMs will serve equally well
as CRMs for most applications, and using WRMs will help preserve supplies of CRMs.
5.4 Difficulties may be encountered in the preparation of RMs from nuclear materials because of the chemical and physical
properties of the materials. Chemical instabilities, problems in ensuring stoichiometry, homogeneity, and radioactivity are among
the factors to be considered, with all three factors being involved with some materials. Those preparing WRMs from nuclear
materials need to be aware of how these factors may affect preparation, as well as being aware of the other criteria governing the
preparation of reliable WRMs.
5.5 While use of WRMs provides benefits for the laboratory, it is important to observe the distinction between WRMs, which are
prepared by a laboratory for use by that laboratory (or, in some cases, an affiliated satellite laboratory or production facility served
by the laboratory), and CRMs which provide certificates of analysis (in accordance with ISO Guide 31) and can be offered for sale.
6. Perform WRM Planning
NOTE 1—Material from the planning modules in the 2016 IAEA Technical Meeting on the Preparation of Working Standards for Safeguards (1) have been
used in this section.
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FIG. 3 Typical National Nuclear Measurement System
6.1 General:
6.1.1 The WRM planning process involves the following elements:
6.1.1.1 Identifying the scope of the project, including all needs and requirements for WRM production, characterization, and value
assignment (see 6.2 and Appendix X1).
6.1.1.2 Developing a detailed WRM project plan (6.3) that addresses all of the needs and requirements identified; and
6.1.1.3 Performing the selection and collection of materials that will be used to produce the WRM units (6.4).
6.1.2 The amount of detail in the project plan, and the level of effort to prepare it, should be based on the size and complexity
of the WRM preparation task. In some cases the project plan can be brief as long as it contains the necessary information for the
project to be completed successfully. If the project is to produce a WRM that has been produced previously, much of the needed
information may already be available, and the planning process streamlined accordingly.
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6.2 Define the Scope: WRM Needs and Requirements / Determine Purpose—Producing a WRM requires forethought to ensure the
completed WRM meets the needs of its end-users and stakeholders and the requirements for its application. A detailed project plan
that specifies needs and how the WRM will be produced should be prepared and approved in advance of any work. The subjects
discussed in this section should be considered and addressed as appropriate. Failure to properly define all needs and requirements
can result in wasted time, funding, and materials, as well as requiring rework.
6.2.1 Needs and requirements for the WRM should be identified and documented. These can include the following:
(1) Key elements of the WRM project purpose and scope;
(2) Quantity of WRMs needed;
(3) Intended purpose(s) of the WRM;
(4) Physical and chemical properties of the WRM;
(5) Important aspects and limitations of end-user’s measurement method(s);
(6) Measurand(s) level and uncertainty;
(7) Data quality objectives;
(8) Fitness for purpose considerations;
(9) Criteria for material selection and collection;
(10) Requirements for producing stable and homogeneous WRM units;
(11) Criteria for container selection;
(12) Sampling criteria;
(13) Environmental controls during production and characterization;
(14) Selection and validation of characterization method(s);
(15) Control of measurement equipment calibration and traceability to the SI;
(16) Control of unit storage;
(17) Guidance on value assignment and uncertainty calculation;
(18) Period of validity; and
(19) Post-production stability monitoring.
6.2.1.1 Appendix X1 provides a template containing questions and statements that may be used to aid in documenting the WRM
project plan requirements.
6.2.2 The planning process should follow the concept of defining needs and requirements, then documenting how the selected
material will be used to produce stable and homogenous WRM units that will then be characterized. The project plans should
outline the process that will be used for value assignment and calculating the expanded uncertainty and the uncertainty budget.
6.2.3 Define What is Needed—Producing a WRM requires forethought to ensure the completed WRM meets the needs of the
laboratory and its data users. A detailed plan that specifies needs and how the WRM will be produced should be prepared in
advance of any work. The subjects discussed in this section should be considered and addressed as appropriate. Failure to properly
define the needs can easily result in wasted time, funding, and materials, as well as requiring rework. Questions to ask in defining
the need include, but are not necessarily limited to the following:The producer of a WRM should consider whether a
commercially-available reference material is fit for purpose and could be used instead of producing a WRM. If a commercial RM
does not meet one or more of the following conditions for the planned end-user application, then a WRM should be prepared:
NOTE 2—Answers to some of the questions below may not be immediately available. An iterative process may be required to ask questions, collect
information and then answer or re-answer one or more of the questions before proceeding to the project plan.
(1) An existing, available RM does not match the needs of the end-users and the requirements of each measurement method;
(2) An existing RM is not available in sufficient quantity to meet usage needs;
(3) An existing RM is not available at an acceptable cost compared to producing a WRM;
(4) Another justification as determined by the preparer of the proposed WRM.
6.2.3.1 How is the WRM Defined? The definition should contain as much detail as possible to ensure that the final WRM meets
the needs for the measurement and is fit for purpose. A fit for purpose checklist is included to assist in defining the principle
attributes the need to have reference values. Questions to ask in defining the WRM include, but are not necessarily limited to the
following:preparer of the WRM may document the basis for their make-versus-buy decision in their planning document.
(1) What are the requirements of the project or customer? What will the data be used for? What are the quality objectives for
the project/customer? What information does the project/customer require?
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(2) What Measurement Methods will the WRM Support? Will the WRM be used for a single method of analysis or for multiple
methods? As an example, a WRM might be prepared for determination of uranium in uranium dioxide. If a WRM is also required
for the isotopic abundance analysis of uranium, it might be possible to prepare and characterize the same WRM for isotopic
abundance analysis as well.
NOTE 3—Careful consideration should be given to the preparation of multi-purpose WRMs, because they tend to be difficult to prepare and characterize.
(3) What are the Target Attributes (or properties) to be Characterized?
• Identify the target attributes for the WRM and their desired measurement uncertainties. This will be based on process
knowledge of the measurement system and analytical quality control requirements for the samples. Examples of target attributes
to consider may include concentration, matrix characteristics, particle size distribution, and isotopic composition.
• Acceptable measurement uncertainty for a given attribute is determined by the end use of the material (such as calibration
or quality control) and the rigor and required precision to attain acceptable expanded uncertainty for the method as a whole
(considering, for example, process control versus safeguards or accountancy).
• For example, to produce a WRM used for calibration of a measurement process, more care in preparation and rigor in
characterization are required.
(4) Which analytical methods will be used to characterize the material? These will depend on how the material will ultimately
be used and the acceptable expanded uncertainty, as well as the attributes of the WRM. Considering the methods used to
characterize the material can also assist in the planning process (6.2.4).
(5) What are the Desired Chemical and Physical Properties? The WRM physical and chemical properties should match those
of the samples as closely as possible, giving consideration for how the WRM will be used. The two largest sources of measurement
uncertainty in an analytical protocol are the ones associated with sample preparation (digestion, separation, extraction, and so forth)
and measurement of the analyte in that preparation. A WRM that more closely mimics the chemical and physical properties of the
samples will provide a more accurate assessment of digestion procedures and the induced matrix effects and interferences for the
analytes measured by a given measurement technique.
(6) What are the Impurity Limits or Concentrations Desired? This will be based on process knowledge for the measurement
system and samples analyzed. Impurities which cause chemical or physical interferences in the measurement system will be
important properties to consider for the WRM.
NOTE 4—Careful consideration should be given to the spiking and blending of impurities into a material. Artificially produced impurities may not match
the chemical species of the samples and may give a false indication of the performance for sample preparations and measurements. Extra planning and
preparation during production will have to be planned to match impurity species to those which are in the samples. Ideally to match the impurities of
the WRM to a sample it is best to procure the raw material from an active process from which the samples are pulled for the analyses.
(7) What quantity is required? The quantity of WRM prepared will depend on such factors as the length of time required for
its use, the quantity of material required for a measurement, the frequency of use, the amount of raw material available, and the
WRM’s anticipated for shelf life. Consideration will need to be given to the amount of WRM that will be needed for
characterization (including for homogeneity and stability studies) and for archival purposes. Additional needs may develop during
the use of a WRM such as the exchange of materials with another laboratory for an interlaboratory testing program. For this and
other possible contingencies, the preparation of a quantity beyond the anticipated amount should be planned.
6.1.1.2 What raw materials are available which meet the requirements? See Section 6 for more information.
6.1.1.3 What are the shelf life requirements? When planning for shelf life, stability of the materials over time will also have to
be considered in addition to degradation of container materials for the environmental conditions the units will be stored. Generally,
materials used for standards in the nuclear fuels cycle are inherently stable but there are factors to consider for nuclear materials
that will be sealed for long periods of time. These include buildup of gas and pressure within the container due to radiolysis or
nuclear reactions from alpha decay with elements of the container walls. Also, change in mass for hydroscopic materials over time
will need to be considered.
6.1.1.4 How will the WRM be packaged and stored? See Section 8 for more information. Depending on packaging requirements,
equipment may be required for such things as sealing glass ampoules or packaging a WRM in a special atmosphere.
6.1.2 Define When It Is Needed—The need date will affect the amount of resources that need to be applied to preparing the WRM.
It is based on the current and projected laboratory workload and existing supplies of WRM, if any.
6.1.3 Define Collaborations and Resources—A plan for collaborations and defining resources will ensure an efficient production
campaign to contain costs and minimize delays. This includes financial resources, availability of qualified personnel to prepare the
WRM, availability of instrumentation and equipment required for characterization, homogeneity and stability studies, equipment
required for packaging the WRM, availability of outside resources for activities that the laboratory is not able to perform itself,
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and so forth. An evaluation of any outside collaborators and their ability to meet performance requirements per the relevant ASTM
and ISO standards is an important step in the planning process. Limitations on resources or collaborators can negatively impact
the total time required to complete the project.
6.1.4 Finalize the Scope—The scope is finalized based on the considerations in 6.1.1 through 6.1.3. This may be an iterative
process, balancing available resources with need dates.
6.1.5 Document the Scope—It is important to document the scope to ensure agreement and common understanding, and as the
basis for the project plan. The degree of detail and complexity of documentation should be commensurate with the size and
complexity of the project itself. An example of documentation is as follows:
6.1.5.1 Summary statement that identifies what analyte or analytes will be determined using the WRM; what matrix will be used;
and uncertainty requirements (expressed as expanded uncertainty or combined standard uncertainty). The statement should also
include an estimate of demand (how much will be used in a year or other appropriate time period). Traceability requirements should
also be included.
6.1.5.2 Estimated resource requirements, including cost, personnel, use of laboratory equipment, and so forth. Availability of these
resources should be verified.
6.1.5.3 Estimated time required to prepare the WRM. This time frame should not extend beyond the need date. If it does, consider
options for reducing the estimated time.
6.3 Develop the Project Plan—WRM Project Planning Documents—Once the scope and available resources have been defined,
a project plan should be developed for preparing the WRM. The project plan typically includes the following tasks:The WRM
producer is responsible for ensuring that all aspects of the production and characterization are well planned and documented in
sufficient detail to ensure that all identified needs and requirements are implemented effectively.
NOTE 5—ISO Guide 35 provides additional guidance in aspects of developing the project plan.
6.3.1 The planning process should include the follow activities, which are adapted from a similar list in ISO 17034:
(1) Perform material selection, including any sampling and verification of identify of the material;
(2) Select inner-most container that is durable, long-lasting, resistant to damage from radioactive decay, and compatible with
the chemical properties of the WRM;
(3) Maintain suitable environments for production (and subsequent characterization);
(4) Define material processing;
(5) Define acceptance criteria for measurand levels and their uncertainties;
(6) Specify acceptance criteria for, and assessment of, homogeneity, including sampling;
(7) Specify acceptance criteria for, and assessment/monitoring of, stability, including sampling;
(8) Design and organize appropriate characterization, including sampling;
(9) Select appropriate measurement procedures;
(10) Validate measurement procedures;
(11) Verify and calibrate measuring equipment;
(12) Establish metrological traceability for measurement result(s), as appropriate;
(13) Assess commutability, when applicable;
(14) Assign property value(s);
(15) Calculate expanded uncertainty(ies) and uncertainty budget(s);
(16) Issue WRM documents for production, characterization, and value assignment, as well as documents addressing safety and
regulatory compliance;
(17) Ensure appropriate labeling and packaging of WRM including appropriate hazard communication labeling;
(18) Ensure appropriate control of transportation, if required for production, characterization, or storage;
(19) Ensure adequate storage facilities and conditions; and
(20) Ensure post-production stability monitoring, if applicable.
NOTE 1—ISO Guide 35 provides additional guidance on aspects of developing a project plan.
6.3.2 Activities and milestones should be scheduled and tracked to completion by the project leader or management.
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6.3.3 All tasks should be assigned to experienced, trained, and qualified staff.
6.3.4 One individual may be assigned to perform or lead more than one aspect of the WRM production, characterization, and value
assignment.
6.3.5 The WRM project plan should:
(1) Identify WRM needs and requirements;
(2) Identify WRM production execution plan;
(3) Identify WRM characterization execution plan, including value assignment;
(4) Identify work control documents and procedures that will be needed to implement the execution plans and ensure that they
are complete and available when needed;
(5) Develop plans for performing any required homogeneity and stability studies; and
(6) Guide the material selection and collection process.
6.3.6 Feasibility Studies—These studies should be simple in scope. They are used in cases where sufficient knowledge or data If
sufficient information is not available prior to execution of the plan and will ensure that the WRM produced will meet all
requirements defined in the scope. Examples include the following.to perform or to complete the project plan, it may be necessary
to perform feasibility studies on specific aspects of the WRM project such as:
6.2.1.1 Studies to determine if the material selected is fit for purpose according to the defined scope.
(1) Studies to determine if the material selected is fit for purpose according to the defined scope;
(2) Studies to determine the best ways to process and prepare the selected materials without compromising desired property
values; or
(3) Studies to test, improve, or verify that equipment, personnel, and measurement procedures meet standards for performance
required for producing or characterizing the WRM, or both, to the specific requirements. Feasibility studies should be simple in
scope.
6.2.1.2 Studies to determine the best ways to process and prepare the raw material without compromising its desired property
values.
6.2.1.3 Studies to test, improve, or verify that equipment, personnel, and measurement procedures meet standards for performance
required for producing and characterizing the WRM to the specific requirements defined.
6.3.7 Homogeneity Assessment (Section 9)—The project plan should include details for homogeneity studies. The results from the
study are included in the measurand’s expanded uncertainty.Planning should include defining resources needed to ensure efficient
production and characterization campaigns to contain costs and minimize delays. This includes financial resources, availability of
qualified personnel to prepare the WRM, availability of instrumentation and equipment required for characterization, homogeneity
and stability studies, equipment required for packaging the WRM, availability of any outside resources for activities that the
laboratory is not able to perform itself, and so forth.
6.3.7.1 The WRM producer is responsible for evaluating any outside collaborators and their ability to meet performance
requirements in accordance with relevant ASTM and ISO standards during the planning process. Limitations on resources or
collaborators can negatively impact WRM quality and the time required to complete the project.
6.3.8 Stability (short and long term) Assessment and Monitoring (Section Develop Plan for Production Execution: 10)—The
project plan should include details for stability studies. The results from the study are included in the measurand’s expanded
uncertainty.
6.3.8.1 The execution plan for production should provide a step-by-step summary of processes and procedures that will be
performed on the selected material(s). The plan should document all aspect of material handling, including preparation steps to
ensure homogeneity, stability, and any specific material characteristics as well as the packaging of WRM units and their subsequent
storage and distribution for characterization. The plan should be written in a manner that illustrates how all identified production
requirements will be satisfied.
6.3.9 Characterization Plan (SectionDevelop Plan for 11)—Characterization Execution: The project plan should include details
for the characterization of the WRM. The plan should provide sufficient detail to ensure that the measurements will be performed
as planned. The following are topics recommended to be addressed.
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6.3.9.1 The characterization plan should document which measurement method will be used for each measurand to be determined.
The plan should provide a step-by-step summary of process and procedures that will be performed on the selected units of the
WRM. Quality assurance requirements including QC standards, blank, and measurement sequence should be described in sufficient
detail to illustrate that characterization requirements and data quality objectives will be satisfied. The characterization plan should
document the following aspects:
(1) Random selection of units; sampling parameters including minimum sample size;
(2) Sample dissolution, dilution, treatment, and analytical preparation;
(3) Measurement protocols;
(4) Data collection and reporting; and
(5) The calculation of quantity values, expanded uncertainties, and uncertainty budgets.
6.3.9.2 The plan should be written in a manner that illustrates how all identified characteriz
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