Noto Peninsula Earthquake: Nuclear Plant Equipment Verification

This document details the verification of power plant equipment failures and malfunctions at the Shiga Nuclear Power Station following the Noto Peninsula earthquake on January 1, 2020. The Atomic Energy Council, through the Knowledge Sorting SWG, examined cases including transformer damage (insulating oil leaks and pressure relief plate operations), emergency diesel generator (D/G) automatic stoppage during trial operation, spent fuel storage pool (SFP) equipment falling, control rod drive (CRD) housing support fittings detachment, campus road subsidence, seawall tilting, and pure water tank leaks. The study aimed to derive lessons for voluntary safety improvements. Key findings include that transformer piping damage occurred due to accelerations exceeding design values, but redundancy in external power sources mitigated total loss. For D/G, focus was on reducing automatic stops during parallel operation. SFP items falling posed no direct fuel damage risk but required foreign matter prevention. CRD component detachment risked loose parts, necessitating structural reviews. The document emphasizes proactive measures to enhance seismic resilience and operational reliability, contributing to safer nuclear power plant operations.