D232 BWR配管減肉規格(2006年版)の改訂案の概要と技術的根拠(OS6 保全・設備診断技術(7))

Abstract

The pipe rupture accident at Mihama Nuclear Power Station occurred in August 2004. Japan Society of Mechanical Engineers (JSME) established the rules on pipe wall thinning management for BWR and PWR in 2006 to prevent such pipe ruptures. The rules for each type of plant were based on field data obtained by wall thinning measurement at that time. In these rules, field data and technical knowledge regarding pipe wall thinning phenomena including FAC and LDI were adopted. Since the establishment of the rules, JSME has been working on the improvement of the methods for more proper prediction and updating the field data to enhance the pipe wall thinning management and to revise the present rules. In this paper, an overview for the revision proposals of the management for BWR is described according to the field data.