材料試験炉ホットラボ排気筒におけるアンカーボルト減肉及びフランジプレートとアンカーボルトナット間の隙間に関する原因調査
Cause investigation for thinning of anchor bolts and gaps between anchor bolt nuts and a flange plate at the JMTR hot laboratory exhaust stack
著者:
柴田 晃 Akira SHIBATA 北岸 茂 Shigeru KITAGISHI 渡士 克己 Katsumi WATASHI 松井 義典 Yoshinori MATSUI 近江 正男 Masao OHMI 相沢 静男 Shizuo SOZAWA 那珂 通裕 Michihiro NAKA
発刊日:
公開日:
AgeingAnchor boltEarth quakeGrains sizeHot laboratoryThinningWater infiltration
概要
The exhaust stack of Japan Materials Testing Reactor Hot laboratory is a part of gaseous waste treatment system. It was built in 1970 and is 40 m in height. In 2015, thinning was found at some anchor bolts on base of the stack. When thinning of anchor bolts were investigated, gaps between anchor bolt nuts and flange plate was found. JAEA removed steel cylinder of stack which is 33 m in height for safety. In the end of investigation, thinning was found in all anchor bolts of the stack. Cause investigation for the thinning and the gaps were performed. It is concluded that the thinning was caused by water infiltration over a long period of time and the gaps were caused by elongation of thinning part of anchor bolts by the 2011 earthquake off the Pacific coast of Tohoku.
