1.1 这种做法是测试方法的替代方法 C698 用于测定烧结混合氧化物燃料（MOX）芯块中的氧与金属原子比（O/M）。试验方法中给出的方法 C698 是测定烧结MOX粉末和球团中O/M比的一步热重法。如试验方法所述 C698 使用两步加热循环的热重方法也是令人满意的 ( 1 , 2 ) . 2 本试验方法提出的方法为两步加热循环法。本试验方法适用于含有高达10重量%PuO的烧结MOX球团 2 . 1.2 以SI单位表示的值将被视为标准值。本标准不包括其他计量单位。 1.3 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ======意义和用途====== 5.1 MOX被用作核反应堆燃料。本试验方法旨在确定O/M比是否符合燃料规范的要求。在说明书中给出了建立燃料规格的示例 C833 . 5.2 该方法适用于所有含有高达12重量%PuO的烧结MOX球团 2 当UO 2 和普奥 2 符合规范要求 C753 和 C757 .

1.1 This practice is an alternative method to Test Method C698 for the determination of the oxygen-to-metal atom ratio (O/M) in sintered mixed oxide fuel (MOX) pellets. The method presented in Test Method C698 is a one-step thermogravimetric method for determining O/M ratio in sintered MOX powders and pellets. As stated in Test Method C698 , thermogravimetric methods using a two-step heating cycle are also satisfactory ( 1 , 2 ) . 2 The method presented in this test method is a two-step heating cycle method. This test method is applicable to sintered MOX pellets containing up to 10 weight percent PuO 2 . 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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, health, and environmental 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. ====== Significance And Use ====== 5.1 MOX is used as a nuclear-reactor fuel. This test method is designed to determine whether the O/M ratio meets the requirements of the fuel specification. Examples for establishing a fuel specification are given in Specification C833 . 5.2 This method is suitable for all sintered MOX pellets containing up to 12 weight % PuO 2 when the UO 2 and PuO 2 meet the requirements of Specifications C753 and C757 .