Effects of fast reactor irradiation conditions on tensile and transient burst properties of ferritic/martensitic steel claddings

フェライト/マルテンサイト鋼被覆管の引張及び急速加熱バースト特性に及ぼす高速炉照射条件の影響

矢野 康英  ; 吉武 庸光 ; 山下 真一郎   ; 赤坂 尚昭; 小野瀬 庄二 ; 渡辺 精一*; 高橋 平七郎

Yano, Yasuhide; Yoshitake, Tsunemitsu; Yamashita, Shinichiro; Akasaka, Naoaki; Onose, Shoji; Watanabe, Seiichi*; Takahashi, Heishichiro

高速実験炉「常陽」で燃料照射をした高強度フェライト/マルテンサイト鋼(PNC-FMS)及びHT9M被覆管の照射後強度試験、具体的には、引張及び急速加熱バースト試験を実施し、両鋼の照射後強度特性評価を行った。

The effects of fast neutron irradiation have been investigated on the mechanical properties of 11Cr-0.5Mo-2W, Nb, V ferritic/martensitic (F/M) stainless steel (PNC-FMS) and 10.5Cr-1.5Mo, Nb, V F/M stainless steel (HT9M) claddings, especially tensile and transient burst properties. These two F/M claddings were irradiated in the experimental fast reactor JOYO using the PFB090 fuel test assembly. Post irradiation tensile and temperature-transient-to-burst tests were carried out for defueled cladding specimens. The results of mechanical tests for PNC-FMS cladding showed that there was no significant degradation in tensile and transient burst strengths even after fast neutron irradiation. However, these strengths for HT9M cladding tended to shift to lower values than those of as-received specimens. This different behavior of tensile and transient burst strengths was attributed to martensite structural stability which was related to the stable solid solution elements.