ASTM C 1128:2023

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 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.

27.120.30