Principle Design of Graphite Components for HTTR and R&D on Nuclear Graphite for HTGR in JAEA

Nuclear energy is one of the most promising energy sources to satisfy energy security, environmental protection, and efficient supply. The High Temperature Gas-cooled Reactor (HTGR) has attractive inherent safetyfeatures and it can be used as many kinds of heat applications such as hydrogen production, electricity generation, process heat supply, district heating and desalination. Many countries, especially developing countries, show their interests in HTGR. Graphitematerials are used for the core components of the HTGR. IG-110 graphite, fine-grained isotropic graphite, with high strength and high oxidation resistance is used in the High temperature Engineering Test Reactor (HTTR) of Japan Atomic Energy Agency (JAEA) and High Temperature Reactor- Pebble-bed Modules (HTR-PM) in China. IG-110 graphiteis a major candidate for the core graphitecomponents of the Very High Temperature Reactor(VHTR) which is one of HTGRs and one of the most promising candidates as the Generation-IV nuclear reactor systems. This paper describes design of core components of HTTR and R&D on nuclear graphitefor HTGR. JAEA established the graphitestructural design code and inspection standard of graphiteto construct the HTTR. JAEA developed an in-service inspection method and a draft graphitestructural design code for future HTGR on the basis of the HTTR technologies. Moreover, JAEA are now developing the design data base of IG-110 graphiteand IG-430 graphiteincluding irradiation data for HTGR.