原子力発電所の耐震設計における「安全余裕」の意味 : 柏崎刈羽原子力発電所を例として

概要

論文の詳細を見る
A strong earthquake, the Niigata Prefecture Chuetsu-oki, with a magnitude of 6.8, occurred at 10:13 a.m. on 16 July 2007, affecting the 7 units of Kashiwazaki-Kariwa Nuclear Power Plant, located approximately 16 km south of the epicenter of the earthquake. Though the levels of seismic ground motion planned for in the design of the plant as the design basis event(DBE) were very significantly exceeded by the earthquake, and the sheer force caused by the earthquake was a little stronger than the designed value of the unit 1 reactor, the safety related structures, systems and components of all seven units of the plant demonstrated exceptionally good performance in ensuring basic safety functions concerning control of reactivity, cooling and confinement. Consequently nuclear plant safety was maintained, due to the large safety margins provided for in the original design. However, the destructive force of the earthquake decreased public trust in nuclear power plants, in spite of the safety margin allowed for by the design of the plant, because the exceeding of planned-for levels of seismic ground motion meant that the safety precautions of this nuclear power plant were no longer enough.
2009-03-31