This specification covers sintered uranium dioxide pellets containing ²³⁵U for use in nuclear reactors. Chemical requirements include uranium content, impurity content, stoichiometry, and moisture content. Maximum concentration limits are specified for impurity elements such as: aluminum, carbon, calcium+magnesium, chlorine, chromium, cobalt, fluorine, hydrogen, iron, nickel, nitrogen, silicon, and thorium. Chemical analyses shall be performed. Nuclear requirements include isotopic content and equivalent boron content. The following are physical characteristics of the material: dimensions, pellet density, grain size and pore morphology, pellet integrity–surface cracks and chips, and cleanliness and workmanship. Fuel pellet irradiation stability shall be estimated. Pellet lot shall be retained throughout processing without mixing with other established lots.

1.1 This specification is for finished sintered uranium dioxide pellets. It applies to uranium dioxide pellets containing uranium of any ²³⁵U concentration for use in nuclear reactors.

1.2 This specification recognizes the presence of reprocessed uranium in the fuel cycle and consequently defines isotopic limits for uranium dioxide 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 uranium. 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 or (b) requirements for health and safety. Observance of this specification does not relieve the user of the obligation to be aware of and conform to all federal, state, and local regulations pertaining to possessing, shipping, processing, or using source or special nuclear material. Examples of U.S. Government documents are Code of Federal Regulations (Latest Edition), Title 10, Part 50, Title 10, Part 71, and Title 49, Part 173.

1.4 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 and health practices and determine the applicability or regulatory limitations prior to use.