著者

大西 信秋 落合 政昭 石島 清見 丹沢 貞光

出版者

一般社団法人 日本原子力学会

雑誌

日本原子力学会誌 (ISSN:00047120)

巻号頁・発行日

vol.24, no.4, pp.289-300, 1982-04-30 (Released:2010-01-08)

参考文献数

7

被引用文献数

2 3

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It is considered one of important subjects in the reactor safety under the postulated RIA condition to study the failure behavior of a waterlogged fuel rod, since relatively small amount of energy deposition is enough to cause its failure which induces mechanical energy release.Failure behaviors of a waterlogged fuel rod in the NSRR tests are discussed in the present paper. The parameters in these experiments are as follows: (1) quantity of water within the rods, (2) reactor period, (3) axial power profile, (4) pellet-cladding gap width and (5) with or without a pin hole. The effects of each on the failure behavior of a waterlogged fuel rod have been studied in the experiments.The test results have revealed the failure threshold energy of waterlogged fuel rod and that its failure mechanism is the overpressure of cladding tube due to rapid enthalpy increase of water within the rods. The results have also revealed that there are two kinds of the failure mode of waterlogged fuel rod. One is "low temperature rupture", which occurs before the cladding temperature increases. The other is "high temperature rupture". This kind of failure occurs with the increase in the cladding temperature which results in the decrease of cladding strength.The release of mechanical energy was revealed to be induced only by the low temperature rupture.