Uranium dioxide is used as a nuclear-reactor fuel. Gadolinium oxide is used as an additive to uranium dioxide. In order to be suitable for this purpose, these materials must meet certain criteria for impurity content. This test method is designed to determine whether the carbon content meets Specifications C 753, C 776, C 888, and C 922.

1.1 This test method covers the determination of carbon in nuclear-grade uranium oxide powders and pellets to determine compliance with specifications.

1.2 Gadolinium oxide (Gd₂O₃) and gadolinium oxide-uranium oxide powders and pellets may also be analyzed using this test method.

1.3 This test method covers the determination of 5 to 500 μg of residual carbon.

1.4 This test method describes an induction furnace carrier gas combustion system equipped with an infrared detector. It may also be applied to a similar instrument equipped with a thermal conductivity detector.

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

1.5.1 The preferred system of units is micrograms carbon per gram of sample (μg/g sample) or micrograms carbon per gram of uranium (μg/g U).

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