Post irradiation examination of the MEGAPIE samples at JAEA, 2

JAEAにおけるMEGAPIE照射試料の照射後試験,2

斎藤 滋   ; 菊地 賢司*; 鈴木 和博; 畠山 祐一; 遠藤 慎也; 鈴木 美穂; 大久保 成彰   ; 近藤 啓悦  

Saito, Shigeru; Kikuchi, Kenji*; Suzuki, Kazuhiro; Hatakeyama, Yuichi; Endo, Shinya; Suzuki, Miho; Okubo, Nariaki; Kondo, Keietsu

世界初のメガワット級鉛ビスマス核破砕ターゲットであるMEGAPIE(MEGAwatt Pilot Experiment)ターゲットは運転終了後、解体され照射後試験用の試料が作製された。原子力機構の試料はビーム窓(T91)及びフローガイドチューブ(SS316L)から切り出された。照射条件は、陽子エネルギーが580MeV、照射温度は251-341C、はじき出し損傷は0.16-1.57dpaであった。SP(small punch)及び3点曲げ試験は室温、大気中で実施された。直径2.4mmの鋼球を用いたSP試験では8mm角で厚さ0.5mmの試験片を用いた。T91試料はビーム窓部から、SS316L試料はフローガイド管からそれぞれ採取した。3点曲げ試験の試料はSS316Lのみで、ノッチ無し試験片を用いた。SP試験の結果より、照射によるSP破壊エネルギーや推定破壊靱性値の変化が明らかになった。また、3点曲げ試験の結果より照射の影響は、引っ張り試験よりも顕著には表れないことが分かった。表面観察で見られたピットの断面観察の結果、亀裂などは見られなかった。TEMによる微細組織観察の結果も併せて報告する。

The world's first megawatt-class lead-bismuth target, MEGAPIE (MEGAwatt Pilot Experiment), was dismantled and post irradiation examination (PIE) samples were prepared at PSI hot-lab. The samples were shipped to each institutions including JAEA. The samples were cut from the beam window (BW, T91) and the flow guide tube (FGT, SS316L). And all samples are prepared without LBE. The irradiation conditions of the specimens irradiated at SINQ target were as follows: proton energy was 580 MeV, irradiation temperatures were ranged from 251 to 341C, and displacement damage levels were ranged from 0.16 to 1.57 dpa. PIE including SP (small punch) and three point bending tests were performed. SP tests were executed for T91 and SS316L specimens at R.T. in air condition. Specimen size for SP test with 2.4 mm steel-ball is 8 mm 8 mm 0.5 mm. T91 specimens were cut from the Spitze (triangle) sample and polished to thickness of 0.5 mm. The OM/SP specimens of SS316L were polished to thickness of 0.5 mm. Three point bending tests were executed for SS316L specimens at R.T. in air condition. The bend bar specimens of SS316L without notch were employed. Results of the SP tests and three point bending tests on the irradiated specimens will be presented at the workshop. Cross sectional observation on the Spitze sample and microstructural observation by TEM will be also reported.