Standard Active Last Updated: Feb 15, 2021
ASTM C922-21

Standard Specification for Sintered Gadolinium Oxide-Uranium Dioxide Pellets for Light Water Reactors


This specification covers finished pellets composed of sintered gadolinium oxide-uranium dioxide of any concentration for use in light-water reactors. Materials shall adhere to specified chemical (impurity content, stoichiometry, moisture content, and gadolinium oxide concentration), nuclear (isotopic content), and physical (dimensions, density, homogeneity, integrity, axial and circumferential surface cracks, cylindrical surface chips, pellets ends, cleanliness and workmanship, identification, and irradiation stability) requirements.


1.1 This specification is for finished sintered (U,Gd)O2 pellets. It applies to (U,Gd)O2 pellets containing uranium (U) of any 235U concentration and any concentration of gadolinium oxide (Gd2O3) for use in nuclear reactors.

1.2 This specification recognizes the presence of reprocessed U in the fuel cycle and consequently defines isotopic limits for (U,Gd)O2 pellets made from commercial grade UO2. Such commercial grade UO2 is defined so that, regarding fuel design and manufacture, the product is essentially equivalent to that made from unirradiated U. UO2 falling outside these limits cannot necessarily be regarded as equivalent and may thus need special provisions at the fuel fabrication plant or in the fuel design.

1.3 This specification does not include (a) provisions for preventing criticality accidents, (b) requirements for health and safety, (c) avoidance of hazards, or (d) shipping precautions and controls. Observance of this specification does not relieve the user of the obligation to be aware of and conform to all applicable international, federal, state, and local regulations pertaining to possessing, shipping, processing, or using source or special nuclear material. Examples of U.S. Governmental documents are Code of Federal Regulations (Latest Edition), Title 10, Part 50, Title 10, Part 70, Title 10, Part 71, and Title 49, Part 173.

1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 The following precautionary caveat pertains only to the technical requirements portion, Section 4, of this specification: 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.

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Book of Standards Volume: 12.01
Developed by Subcommittee: C26.02
Pages: 4
DOI: 10.1520/C0922-21
ICS Code: 27.120.30