1. 1) R. Huddle: OECD High Temperature Reactor Project (Dragon), Paper 17, (1971), July.
2. 2) T. Kondo, N. Kikuyama and M. Shindo: Private Communication.
3. 3) The HTGR Heat-Resistant Materials Research Committee under the Japanese Society for the Promotion of Science: Research Report of the HTGR Heat-Resistant Materials Research Committee, No. 2, (1974), 20.
4. 4) J. M. Francis, J. A. Jutson and J. H. Buddery: J. Mater. Sci., 2 (1967), 78.
5. 5) The Chemical Society of Japan: Kagaku-Binran (Chemistry Reference Book), Kisohen-II, Maruzen, Tokyo, (1966), p. 1253.