抄録
Interest in the future hydrogen economy has prompted the research and development of the Very High-Temperature Gas-Cooled Reactor (VHTR). To achieve the targeted outlet gas temperature exceeding 950°C, material problems have yet to be solved. The development of advanced coated particle fuel is also due in view of the vulnerability of the SiC layer of conventional TRISO-coated particle fuel at temperatures exceeding 1,600°C. The coated particle fuel employing ZrC instead of SiC has been developed in JAEA. Although the past irradiation tests on the ZrC-coated particle fuel were exclusively on samples from the laboratory scale production, the promising results have been obtained. The properties, fabrication and inspection techniques as well as the results of irradiation and post-irradiation tests are reviewed. The post-irradiation heating tests at accident temperatures above 1,600°C revealed the durability of the ZrC-layer, which maintained the tightness to noble-gas and volatile metal fission products. From 2004, JAEA started (1) ZrC-coating process development by large-scale coater, (2) inspection method development of ZrC coating and (3) irradiation test and post irradiation experiment of ZrC coated particles under contract research which is entrusted to the JAEA and MEXT.
