BWR環境下で長期間使用されたニッケル基合金の応力腐食割れ
Stress Corrosion Cracking in Ni-base Alloy Used for a Long Time in a BWR
著者:
青木 孝行 Takayuki AOKI 服部 成雄 Shigeo HATTORI 安齋 英哉 Hideya ANZAI 住本 秀樹 Hideki SUMIMOTO
発刊日:
公開日:
aging degradationBoiling water reactorlong time serviceNi-base alloystress corrosion cracking
概要
In recent years, several cases have been reported that SCC was found in reac- tor internals and reactor nozzle safe-end and penetrations of BWR. Therefore, it is getting more important to understand what kind of characteristics Ni-base alloy used for a long time in BWR have. In this study, the results of the investiga- tion on SCC found in the shroud support (Ni-base alloy) of the oldest BWR in Japan, Tsuruga unit 1, in 1999 are discussed. Based on the discussion, the conclusions are summarized as follows. Tsuruga original shroud support mate- rial had no sign or symptom of aging degradation. In-service inspection program focusing on Alloy 182 weld is more effective because of higher SCC susceptibil- ity than Alloy 600 and 82. In the weld between the reactor pressure vessel (RPV) and shroud support, there was no crack penetrating into RPV (low alloy steel) itself.
