ZrC coated particle fuel development

Coated particle fuels with ZrC coatings have been developed at the Japan Atomic Energy Research Institute since early 1970s. Studies include (1) fabrication processes and characterization techniques developments, (2) out-of-pile and in-pile performance tests and (3) post-irradiation heating tests. The present design of ZrC-coated particle fuel is based on the Triso-type concept. The ZrC-Triso fuel particles showed excelled performance. One notable advantage is the resistance of the ZrC coating to the Pd attack, which is a life-limiting factor of the conventional Triso-coated fuel particles having the SiC interlayer. Greater susceptibility to the Pd-attack of the SiC compared with the ZrC is related to a difference in the nature of grain boundaries of the two carbides. Physical properties of the two carbides are compared in view of the coating performance. The ZrC-coated particle fuel with its excellent high-temperature stability is also a candidate fuel for the space reactors. (author)