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Baba, Shinichi; Nemoto, Makoto*; Sozawa, Shizuo; Yamaji, Masatoshi*; Ishihara, Masahiro; Sawa, Kazuhiro
JAERI-Tech 2005-055, 157 Pages, 2005/09
JAERI-Tech-2005-055.pdf:19.06MB
The Japan Atomic Energy Research Institute (JAERI) has been carrying out the research on radiation damage mechanism of heat-resistant ceramics composite materials, as one of the subjects of the innovative basic research on high temperature engineering using the High Temperature Engineering Test Reactor (HTTR). A series of preliminary irradiation tests is being made using the Japan Materials Testing Reactor (JMTR). The present report describes results of post-irradiation examinations so far on specimens irradiated in the second and third capsule, designated 98M-41A and 99M-30A, to fast neutron fluences of 1.0
10
m
(E
1MeV) at temperatures of 973K-1173K and 1273K-1473K. The PIE were conducted as the fundamental statistics index of the diametral dimensions for irradiated specimen, irradiation induced dimensional change rate and thermal expansion rate.
Sumita, Junya; Shibata, Taiju; Nakagawa, Shigeaki; Hanawa, Satoshi; Iyoku, Tatsuo; Ishihara, Masahiro
Transactions of 18th International Conference on Structural Mechanics in Reactor Technology (SMiRT-18), p.4822 - 4828, 2005/08
Graphite materials are used for structural components in High Temperature Gas-Cooled Reactor (HTGR) core because of their excellent thermo/mechanical properties. Thermal conductivity of graphite components is reduced by neutron irradiation in reactor operation. The reduced conductivity is expected to be recovered by thermal annealing effect when irradiated graphite component is heated above irradiated temperature. In the present study, temperature analyses considering the annealing effect of the HTGR core at a depressurization accident were carried out and influence of annealing effect on maximum fuel temperature was investigated. The analyses show that the annealing effect can reduce the fuel temperature about 100
C at the maximum, and it is possible to evaluate the maximum fuel temperature more appropriately. It was also shown that the core-temperature of High Temperature Engineering Test Reactor (HTTR) at the safety demonstration tests can be analyzed with the developed evaluation method considering annealing effect.
Sumita, Junya; Nakano, Masaaki*; Tsuji, Nobumasa*; Shibata, Taiju; Ishihara, Masahiro
JAERI-Tech 2004-055, 25 Pages, 2004/08
JAERI-Tech-2004-055.pdf:4.25MB
Neutron irradiation remarkably reduces the thermal conductivity of graphite, and the reduced thermal conductivity is recovered by annealing effect if the graphite is heated above the irradiation temperature. Therefore, it is expected that the reduced thermal conductivity of graphite components in the HTGR could be recovered by the annealing effect in accidents, such as a depressurization accident. Then, an analytical investigation of the annealing effect on thermal performance of a HTGR core was carried. The analysis showed that the annealing effect reduces the maximum fuel temperature about 70C, and it is important to introduce the annealing effect appropriately in the temperature analysis of the core components and reactor internals. In addition, an annealing test method was investigated to evaluate the effect quantitatively, and the test plan was made.
Sumita, Junya; Shibata, Taiju; Baba, Shinichi; Ishihara, Masahiro; Iyoku, Tatsuo
Nihon Kikai Gakkai M&M 2004 Zairyo Rikigaku Kanfarensu Koen Rombunshu, p.141 - 142, 2004/07
Neutron irradiation reduces the thermal conductivity of graphite, but the reduced thermal conductivity is recovered by annealing effect if the graphite is heated above the irradiation temperature. In this research, annealing effect of thermal conductivity on thermal stress of graphite is investigated. In addition, effect of recovered thermal conductivity on membrane, point and peak stress is also investigated.
Iwata, Tadao; Iwase, Akihiro
Nuclear Instruments and Methods in Physics Research B, 61, p.436 - 440, 1991/00
Times Cited Count：6 Percentile：62.89(Instruments & Instrumentation)no abstracts in English
Hoshiya, Taiji; ; Kizaki, Minoru; *; Sudo, Kenji; ;
JAERI-M 89-205, 68 Pages, 1989/12
no abstracts in English
Li, S.; Yamaguchi, Yoshihito; Katsuyama, Jinya; Sun, W.*; Deng, D.*; Li, Y.
no journal, ,
