照射試験片の再生技術への開発; 平成5年度原研・IHI共同研究成果報告書

Development of reconstitution technique of irradiated specimen; Progress report for FY1993 on cooperated research between JAERI and IHI

鬼沢 邦雄 ; 深谷 清; 西山 裕孝 ; 鈴木 雅秀; 柴田 勝之; 鴻坂 厚夫; 貝原 正一郎*; 中村 照美*; 佐藤 彰*; 吉田 和夫*; 酒井 啓一*

Onizawa, Kunio; Fukaya, Kiyoshi; Nishiyama, Yutaka; Suzuki, Masahide; Shibata, Katsuyuki; Kosaka, Atsuo; Kaihara, Shoichiro*; Nakamura, Terumi*; Sato, Akira*; Yoshida, Kazuo*; Sakai, Keiichi*

原子力プラントの供用期間を延長する場合、原子炉圧力容器の監視試験用試験片が不足する可能性がある。そのため、試験済みのシャルピー衝撃試験片を有効に利用し、シャルピー試験片を再生する手法として、表面活性化接合法の適用性を検討した。表面活性化接合法では、真空中で回転摩擦を用いて表面を活性化することにより、原理的に試験片を溶融させずに低温で接合させることが可能である。本報告では、原子炉圧力容器用鋼材を用いて、表面活性化接合法によるシャルピー試験片再生法の基礎的検討を行った。この結果から、接合部近傍の組織変化領域幅を片側1.5mm以下、照射温度以上に上昇する領域幅を片側3mm以下に抑えることができることがわかった。本手法が、他の溶接による接合法と比較して、より優れた試験片再生法であることが確認できた。

Regulatory codes require the surveillance test to evaluate the irradiation embrittlement of reactor pressure vessel during operation. However , it is anticipated that the number of those specimens is insufficient in case plant life is extended. Reconstitution techniques by electron beam weld, laser weld, arc stud weld as well as surface-activated joining (SAJ) have been investigated for the re-use of un-deformed parts from tested Charpy impact specimen. The important items for the reconstitution technique are to reduce the width of heat affected zone to maximize the material available, and to lower the maximum temperature of specimen during joining process to preclude the recovery of radiation damage. SAJ can be achieved from a removal pf surface contamination by rotating one-side specimen in vacuum with applying modest friction force. Therefore, SAJ method is expected to be suitable for specimen reconstitution in view of material heating and melting. This paper describes preliminary study to develop Charpy specimen reconstitution technique using reactor pressure vessel steel, A533B-1, by SAJ method. Test results showed that the SAJ method had a capability of joining affected zone less than 1.5mm in half width, and over-temperature region less than 3 mm in half width above reactor operating temperature during joining. It was also found that transition temperature from reconstituted Charpy specimen could be evaluated.