ASTM C1068-21

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: C1068 − 15 C1068 − 21
Standard Guide for
Qualification of Measurement Methods by a Laboratory
Within the Nuclear Industry
This standard is issued under the fixed designation C1068; 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 provides guidance for selecting, validating, and qualifying measurement methods when qualification is required for
a specific program. The recommended practices presented in this guide provide a major part of a quality assurance program for
the laboratory data (see Fig. 1). Qualification helps to assure that the data produced will meet established requirements.
1.2 The activities intended to assure the quality of analytical laboratory measurement data are diagrammed in Fig. 1. Discussion
and guidance related to some of these activities appear in the following sections:
Section
Selection of Measurement Methods 5
Validation of Measurement Methods 6
Qualification of Measurement Methods 7
Control 8
Personnel Qualification 9
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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
C1128 Guide for Preparation of Working Reference Materials for Use in Analysis of Nuclear Fuel Cycle Materials
C1156 Guide for Establishing Calibration for a Measurement Method Used to Analyze Nuclear Fuel Cycle Materials
C1210 Guide for Establishing a Measurement System Quality Control Program for Analytical Chemistry Laboratories Within
Nuclear Industry
C1297 Guide for Qualification of Laboratory Analysts for the Analysis of Nuclear Fuel Cycle Materials
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 June 1, 2015Oct. 1, 2021. Published June 2015October 2021. Originally approved in 1986. Last previous edition approved in 20112015 as
C1068 – 03 (2011).C1068 – 15. DOI: 10.1520/C1068-15.10.1520/C1068-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1068 − 21
FIG. 1 Quality Assurance of Analytical Laboratory Data
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E2554 Practice for Estimating and Monitoring the Uncertainty of Test Results of a Test Method Using Control Chart Techniques
E2655 Guide for Reporting Uncertainty of Test Results and Use of the Term Measurement Uncertainty in ASTM Test Methods
2.2 ISO Standards:
ISO/IEC 17025 General Requirements for the Competence of Testing and Calibration Laboratories
2.3 Other Standards:
ASME NQA-1 Quality Assurance Requirements for Nuclear Facility Applications
IEEE/ASTM SI 10 American National Standard for Metric Practice
JCGM-100JCGM 100 Evaluation of Measurement Data – Guide to the Expression of Uncertainty in Measurement (GUM)
JCGM-200JCGM 200 International Vocabulary of Metrology – Basic and General Concepts and Associated Terms (VIM)
3. Terminology
3.1 Except as otherwise defined herein, definitions of terms are as given in Terminology C859.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 fitness for purpose, n—degree to which data produced by a measurement process enables a user to make technically and
administratively correct decisions for a stated purpose (1).
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org.
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), 445 Hoes Ln., Piscataway, NJ 08854-4141, http://www.ieee.org.
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http://www.iso.org.ISO Central
Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland, https://www.iso.org.
The boldface numbers in parentheses refer to a list of references at the end of this standard.
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3.2.2 qualification—a formal process to provide a desired level of confidence that measurement methods used will produce data
suitable for their intended use. The methods must meet established criteria prior to use and must be used under conditions
established for qualifications.
3.2.3 representative sample, n—a sample resulting from a sampling plan that can be expected to adequately reflect the properties
of interest of the parent population (1).
3.2.4 validation, n—a verification that a measurement method fulfills specified requirements that are adequate for an intended use
(adapted from JCGM 200).
3.2.5 validation,verification, n—investigation to determine the applicability of a measurement method to a particular use.provision
of objective evidence that a given measurement method fulfills specified requirements (adapted from JCGM 200 by changing
“item” to “measurement method”).
3.2.5.1 Discussion—
Examples of verification include but are not limited to: (a) confirmation that performance properties or legal requirements of a
measuring system are achieved; (b) confirmation that a target measurement uncertainty can be met.
4. Significance and Use
4.1 Because of concerns for safety and the protection of nuclear materials from theft, stringent specifications are placed on
chemical processes and the chemical and physical properties of nuclear materials. Strict requirements for the control and
accountability of nuclear materials are imposed on the users of those materials. Therefore, when analyses are made by a laboratory
to support a project such as the fabrication of nuclear fuel materials, various performance requirements may be imposed on the
laboratory. One such requirement is often the use of qualified methods. Their use gives greater assurance that the data produced
will be satisfactory for the intended use of those data. A qualified method will help assure that the data produced will be comparable
to data produced by the same qualified method in other laboratories.
4.2 This guide provides guidance for qualifying measurement methods and for maintaining qualification. Even though all practices
would be used for most qualification programs, there may be situations in which only a selected portion would be required. Care
should be taken, however, that the effectiveness of qualification is not reduced when applying these practices selectively. The
recommended practices in this guide are generic; based on these practices, specific actions should be developed to establish a
qualification program.
5. Selection of Measurement Methods
5.1 General:
5.1.1 Before qualifying a method for a specific application, there should be assurance that the method has been properly selected
for that application. The guidance given in this section can be used to assess the adequacy of the method’s application. The
guidance can also be used to select a new method when a new measurement capability is required within a laboratory.
5.1.2 Measurement methods generally can be classified as one of three types as follows:
5.1.2.1 Those published as national or international consensus standards,
5.1.2.2 Those established as acceptable for a specific application based on long-term and wide usage, and
5.1.2.3 Those having limited use, for example, those used only by a few laboratories or those that are relatively new.
5.1.3 For some applications, there is a choice available of two or more acceptable methods. In those cases, one method is usually
recognized as the reference method, particularly if it is a published standard or if it is capable of producing the least bias and best
precision.
5.1.4 The selection of a method should be based on the criteria in 5.2. In situations where a reference method and one or more
acceptable methods are available, there should be no technical restrictions placed on which method is used.
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5.2 Recommended Practices for Method Selection:
5.2.1 Technical Basis—The method should be based on sound technology. This means that proven laboratory and instrumental
techniques are used in ways recognized and accepted by the community of users.
5.2.2 Interferences—The method should not be adversely affected by components in the matrix of the material to be analyzed.
Knowledge about the method’s limitations and about the composition of the material should be used to determine if the analysis
will be affected by interferences. Other potential interferences such as environmental or electrical/electronic conditions should be
considered in the selection process.
5.2.3 Range—The method should be capable of responding adequately across the range of concentration levels that will be
encountered for the constituent to be measured. This requirement is most often of concern for methods used to measure impurities
in materials since impurity concentrations may fluctuate to a greater extent than other constituents. It is important that the
measurement technique used discriminates adequately between concentration levels encountered. The lowest concentration level
that can be measured reliably should be clearly established (detection limit).
5.2.4 Reliability of Method—The method must be capable of producing data that will meet the bias and precision requirements
established for the required analysis under the expected conditions of use. The requirements are usually established by the user
of the data and they should be based on the concentration levels of the constituents to be measured and on specification limits set
for the constituents.
5.2.5 Fitness for Purpose of Safeguards and Nuclear Safety Applications—Methods intended for use in safeguards and nuclear
safety applications shall meet the additional requirements specified in Annex A1.
6. Verification and Validation of Measurement Methods
6.1 Verification—Objective evidence that the proposed measurement method meets applicable requirements, such as those
described in 5.2, should be obtained and documented.
6.2 Validation—There are occasions when it is desirable to investigate the applicability of a method to a particular use. This may
be the case when the method has had limited use or it is being considered for a new or unique application. To provide some
confidence that a qualification effort would be successful, it may be desirable to validate the application of the method. Validation
is not a mandatory step in the selection and qualification process, but it can prevent wasted effort from attempts to qualify
inadequate methods.
6.3 Validation of a method is usually done by an analyst under controlled conditions. Basically, validation involves investigating
any or all of the selection criteria in 5.2. The intent is to define method capability and to determine if the method can be properly
applied as intended. If modification of the method is required for it to be applicable, validation will provide the technical
information needed for modification. Validation also provides the experience and information to write a detailed procedure if
necessary. The result of the validation process will be either the rejection of a proposed method or confidence that it is acceptable
for use as intended.
7. Qualification of Measurement Methods
7.1 General:
7.1.1 Although a method is selected based on the criteria in 5.2 of this guide, there is no assurance that a laboratory can actually
obtain the performance expected from the method. In addition, there may not be sufficient assurance that the method is in fact
adequate for its intended use. To provide those assurances, demonstration is included in the qualification process.
7.1.2 Qualification requires having a laboratory demonstrate that a method can produce acceptable data under specified conditions
of qualification. Demonstration must be done under actual operating conditions and not under ideal test conditions. A specified
material is analyzed to produce a specified amount of data. These data are evaluated by the person or organization that is
responsible for approving qualification. The procedure established for demonstration should include provisions for handling
failures in the demonstration and for repeating the demonstration should the method not be used for a specified period of time.
Demonstration could also include producing other evidence such as appropriate literature references that the method is in fact
applicable to the material to be analyzed.
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7.2 Recommended Practices:
7.2.1 Procedures—The use of a method to make a laboratory measurement involves taking discrete actions in a specific order. Any
change in an action or in the order may produce unsatisfactory data. To minimize potential problems, written, stepwise procedures
should be provided within the methods. It is important that procedures are well-written, complete, and correct. They should receive
technical and editorial reviews, and should be approved by appropriate management. Approval by the user of the data to be
produced also may be required. Procedures prepared in accordance with Guide C1009 will meet these criteria.
7.2.2 Method Performance Requirements—To provide acceptable data, the method must be capable of meeting performance
requirements for bias, precision, and range. Before a laboratory demonstrates its capability, these requirements should be clearly
established (this should be done even before a method is selected for use; see 5.2). Specifications established for a process or
material are the primary source of information on which the performance requirements are based. The performance requirements
should be used to establish conditions required for qualification. Such conditions may require a statistically designed experiment
to allow for other sources of variability such as the number of analysts or instruments, or both, as well as the concentration range
of interest.
7.2.3 Test Materials—The material or materials that will be used for demonstration should be specified. The test materials should
be as similar as possible to the material that will be analyzed. When possible, the composition or properties of test materials should
be defined by measurements traceable to certified reference materials. See Guide C1128.
7.2.3.1 Major Constituents—When the method is to be used to determine a major constituent (for example, uranium in uranium
oxide), a single test material may be specified. The concentration of the constituent in this test material should approximate the
specification value established for the constituent in the material to be analyzed. The concentration value of the test material should
not be given to the laboratory; only those responsible for evaluating the data and approving qualification should know the value
(see 7.2.4.47.2.4.5). The calibration standard should be specified. See Guide C1156.
7.2.3.2 Impurities—When the method is to be used to determine an impurity, at least two test materials should be specified. One
should serve as a test standard, meeting the same criteria given in 7.2.3.1 of this guide. Another should be used to demonstrate
the detection limit of the method. When possible, the detection limit should be sufficiently below the specification limit to
determine whether or not the concentration level of the impurity is within specification. Both test materials would serve to
demonstrate the range of the method. When a method requires one or more standards for calibration, the calibration standard(s)
that will be used should be specified. See Guide C1156.
7.2.4 Qualification Requirements—A procedure to be followed during demonstration should be established. The procedure that
will govern qualification should include the following criteria:
7.2.4.1 Measurement Uncertainty—Equations should be developed t
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