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 PuO₂.

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.