Abstract
For the design on the VHTR graphite components, it is desirable to employ graphite material with higher strength. IG-430 graphite has been developed as an advanced candidate for VHTR. However, the new developed IG-430 does not have enough databases for the design of HTGR. In this paper, the compressive strength of IG-430, one of important strengths for design data, is statistically evaluated, and the minimum ultimate strength for compression, Suc, one of fundamental strengths in the graphite structural design code, is also evaluated. The component reliability is evaluated based on the safety factors defined by the graphite design code, and the applicability as the VHTR graphite material is discussed. It was found that IG-430 has higher strength (about 11%) and lower standard deviation (about 27%) than IG-110 which is one of traditional graphites used for HTGR. Also, the crack in IG-430 would not easy to propagate rather than IG-110. So, since fracture probability for IG-430 is low, the higher reliability of core-component will be achieved using IG-430. Namely, IG-430 is applicable for VHTR graphite material from view point of compressive strength.
