Opinion Paper on Accident at KEPCO Mihama Power Station
Japan Federation of Bar Associations
June 17, 2005
Summary
An accident occurred at the Mihama Nuclear Power Station Unit 3 of the Kansai Electric Power Co., Inc. (KEPCO) on August 9, 2004, was a serious one in which five workers were killed and six others were injured by superheated steam blowing out of ruptured secondary piping in a pressurized water reactor. The accident was resulted from lack of strength of the piping due to erosion and corrosion which reduced the thickness of the pipe wall. The secondary piping was not included in the items to be inspected and had never inspected for 28 years since starting its operation.
Following this accident, the KEPCO submitted its investigation result on this accident and a report on actions to prevent a recurrence on March 1, 2005. However, their contents were unsatisfactory. In addition, problems still remain in the national regulatory administration for nuclear safety.
Therefore, in order to prevent a recurrence of such a serious accident, the Japan Federation of Bar Associations compiled its opinions at the meeting of the Board of Governors on June 17, 2005.
This opinion paper was submitted to authorities concerned including the Ministry of Economy, Trade and Industry and electric power companies on June 17, 2005.
Main points
- The nation and the KEPCO should reconsider their preventive actions to be appropriate ones by further investigating on this accident and identifying responsibility for it.
- The nation should not give permission to resume the operation of the Mihama Nuclear Power Station Unit 3 until the KEPCO takes sufficient actions to prevent a recurrence of such an accident.
- The nation and electric companies should immediately overhaul piping in all nuclear plants to determine whether there is any corrosion wastage.
- The nation should set the effective period of permission to build a nuclear plant to be 25 years, and for a renewal of the permission, the nation should strictly review safety prior to its renewal and the period of its validity should be within 10 years.
