Graphite and carbon materials for nuclear reactor

In nuclear energy field (fission reactors), graphite and carbon materials are used for core components in Gas Cooled Reactor (Magnox reactor). Advance Gas-cooled Reactor (AGR), High Temperature Gas-cooled Reactor (HTGR) and Very High Temperature Reactor (VHTR). This paper explains the application of the graphite and carbon materials to the core components in the HTGR taking the application in High Temperature Engineering Test Reactor (HTTR) as an example. The graphite components are categorized into core components and core support components considering safety features and the possibility of replacement, and the safety requirements for the component design are decided in the graphite structural design code for the HTTR. The inspection standard of graphite was established to assure the properties of the graphite required in the graphite structural design code. Neutron irradiation effects on the core graphite components should be considered in the design data. For the R and Ds on the VHTR graphite components, it is important to evaluate the neutron irradiation effects and to extend their lifetime. For the carbon materials, the development of control rod elements with C/C composite is an important subject for the VHTR with high temperature in-core condition. (author)