ASTM C968-06

1.1 These test methods cover procedures for the analysis of sintered gadolinium oxide-uranium dioxide pellets to determine compliance with specifications.

1.2 The analytical procedures appear in the following order:

1.3 The values stated in SI units are to be regarded as the standard.

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.

1.4 This test method describes the determination of nitrogen in gadolinium oxide-uranium dioxide pellets (Gd 2 O 3 /UO 2 ). With a 2 to 5-g sample, concentrations from 5 to 100 g of nitrogen are determined without interference.

1.5 The homogeneity of Gd 2 O 3 in UO 2 has been cited in Specification C 922 as an important requirement for this fuel form. The uniform distribution of gadolinia in urania will result in up to three components in the pellet: free Gd 2 O 3 , free UO 2 , and a Gd 2 O 3 -UO 2 solid solution. There are a number of ways for assessing uniformity of which the ceramographic method described here may not be the most definitive. This technique has been used over the gadolinia concentration range from 1 to 10 weight %.