Melting Temperature Measurement Of Nuclear Fuel, 1; Development of the Melting Temperature Measurement Technology for MOX Fuel and the Melting Temperature Measurement of MOX Fuel

Morimoto, Kyoichi ; Kato, Masato   ; Aono, Shigenori; Uno, Hiroki*

The use of high plutonium concentration MOX fuel is considered because of an increase of high-order plutonium from high burnup fuel, the shortage of the enriched uranium etc. The melting temperature and the thermal conductivity etc are necessary for the using of MOX fuel from the viewpoint of the safety evaluation and the fuel design. But reports about the melting temperature of MOX are few, so it is necessary to obtain more melting temperature data. This report describes the melting temperature measurement of MOX fuel whose compositions are from 0 to 100 atom% PuO2 (O/M is 2.00) and that whose O/M are from 1.922 to 1.983 (Pu concentration is 28 atom%). The result of the former experiment agree approximately with that of previous reports. About the later experiment, the variance of melting temperature by O/M is so complicated that this behavior did not show a simple increasing tendency or decreasing tendency. In these experiments, it is found that MOX samples with high O/M reacts with tungsten which is a material of sample container. In order to prevent this reaction, the sample container was made from alloy of tungsten and rhenium. And the applicability of this container was evaluated.