【国外标准】 Standard Specification for Nuclear-Grade, Sinterable Uranium Dioxide Powder

This specification covers nuclear-grade, sinterable uranium dioxide (UO2) powder and applies to uranium dioxide powder containing uranium of any 235U concentration in the production of nuclear fuel pellets for use in nuclear reactors. This specification refers expressly to calcined UO2 powder before the addition of any die lubricant, binder, or pore former, and defines isotopic limits for commercial grade UO2 so that, regarding fuel design and manufacture, the product is essentially equivalent to that made from unreprocessed uranium and. Provisions for preventing criticality accidents or requirements for health and safety are not included in this specification. The powder shall conform to the specified chemical requirements including uranium content, oxygen-to-uranium ratio, impurity content (such as aluminum, carbon, calcium and magnesium, chlorine, fluorine, iron, lead, manganese, molybdenum, nickel, nitrogen, phosphorus, silicon, tantalum, thorium, tin, titanium, tungsten, vanadium, and zinc), moisture content, isotopic content, equivalent boron content, and cleanliness and workmanship. The powder shall also meet the specified physical requirements including particle size, bulk density, and sinterability. Sampling requirements for the test specimen and the test methods for chemical analysis and acceptance testing are detailed.1.1 This specification covers nuclear-grade, sinterable UO2 powder. It applies to UO2 powder containing uranium (U) of any 235U concentration in the production of nuclear fuel pellets 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 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 unreprocessed 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 provisions for preventing criticality accidents or 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 international, national, or federal, state, and local regulations pertaining to possessing, shipping, processing, or using source or special nuclear material.1.4 This specification refers expressly to UO2 powder before the addition of any die lubricant, binder, or pore former. If powder is sold with such additions or prepared as press feed, sampling procedures, allowable impurity contents, or powder physical requirements may need to be modified by agreement between the buyer and the seller.1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.1.6 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.1.7 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.