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Vol.12 No.1previousAA SP23 (AA172-173)-AA174 NT97

Academic Articles
Regular Paper Vol. 12 No. 1 (2020) p.7 - p.13

Application of Charpy Specimens Reconstituted by Electron Beam Welding for the Evaluation of Irradiation Embrittlement of Reactor Pressure Vessels


Seiji SAKURAYA1, Yasuo MORISHIMA2, Tetsuya TOYOTA3 and Takayuki KAMINAGA4

1Nippon Nuclear Fuel Development Co., Ltd., 2163 Narita-cho, Oarai-machi, Higashi-ibaraki-gun, Ibaraki-ken 311-1313, Japan
2Toshiba Energy Systems & Solutions Corporation, 8, Shinsugita-Cho, Isogo-Ku, Yokohama-shi, Kanagawa-ken 235-8523, Japan
3Hitachi-GE Nuclear Energy, Ltd,1-1, Saiwai-cho 3-chome, Hitachi-shi, Ibaraki-ken 317-0073, Japan
4Tokyo Electric Power Company Holdings, Inc., 2-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo, 100-0011, Japan
According to the recent Japanese regulations regarding plant life extension of light water reactors for operation exceeding 40 years, additional surveillance tests are required for the evaluation of irradiation embrittlement of reactor pressure vessel materials. The number of loaded specimens in boiling water reactors is limited; accordingly, securing surveillance specimens is an important issue. Reconstitution of tested Charpy specimens is one way to secure the required number of specimens. Electron beam welding has the advantages of low heat input and realization of a highly reliable weldment property; therefore, it is a candidate for the specimen reconstitution method. In this study, applicability of reconstituted Charpy specimens was studied. Electron beam welding of irradiated surveillance specimens was carried out in the hot laboratory by remote manipulation. After the welding, specimens were processed into the shape of Charpy impact specimens, and Charpy impact tests were performed. The soundness of the welded joints was evaluated and the obtained results satisfied the requirements of the Japan Electric Association Code.
Reconstitution, Reactor pressure vessel, Electron beam welding, Irradiation embrittlement, Low alloy steel
Full Paper: PDF
Article Information
Article history:
Received 23 October 2018
Accepted 11 April 2020