An international team of nuclear safety experts led by the International Atomic Energy Agency (IAEA) has completed a review of safety practices at the Kori 1 Nuclear Power Plant (NPP) near Busan in the Republic of Korea. The IAEA assembled the team at the request of Korea Hydro and Nuclear Power Co., Ltd. (KHNP) following a station blackout event on 9 February 2012.
The team - comprised of experts from Belgium, France, Sweden, United Kingdom and the IAEA - conducted its mission from 4 to 11 June 2012 under the leadership of the IAEA's Division of Nuclear Installation Safety. The expert mission applied the methodology of the IAEA's Operational Safety Review (OSART) missions and covered the areas of Management, Organization and Administration; Operations; Maintenance and Operating Experience.
The conclusions of the review are based on the IAEA's Safety Standards, which are developed by the Agency to help nations improve their nuclear safety practices, which are the responsibility of every nation that undertakes nuclear-related activities.
Throughout the review, the exchange of information between the experts and plant personnel was very open, professional and productive.
Prior to the mission, Korea's Nuclear Safety and Security Commission completed an interim investigation, and it continues to perform additional investigations and technical reviews. The Commission identified corrective actions for the plant concerning reinforcing safety culture, emergency diesel generator reliability, configuration control and risk management during refueling outage, test and maintenance procedures and emergency action level declaration. The expert mission confirmed that some corrective actions have already been completed and others are in progress. The expert mission found the management and staff of Kori 1 NPP to be committed and working hard to complete all improvements.
The root cause analysis of the event at Kori 1 NPP is still in progress and is expected to lead to further corrective actions in safety culture, process and design enhancements.
The expert mission team performed its own analysis of the station blackout event, including the non-reporting of the event, the violation of plant Technical Specifications by not immediately taking steps restore emergency diesel generators to operable conditions, and by starting a fuel movement the next day without operable emergency diesel generators. As a result of this analysis, the team identified additional contributing causes and corrective actions for Kori 1 NPP.
Some of the important contributing causes identified by the expert mission include:
The expert mission made recommendations to address these contributing factors, including to improve safety culture at the plant, to support leadership in decision-making, and to develop stronger defences in dealing with unexpected or difficult situations.
In addition, the team made recommendations and suggestions concerning the plant's practice of reporting events, event analysis, independent oversight, main control room activities and the workmanship of maintenance staff and contractors. Implementation of the IAEA recommendations and suggestions will considerably improve safety at Kori 1 NPP.
Plant management stated its commitment to address all the areas identified for improvement.
The expert mission also identified good plant conditions and programmes, including:
The technical notes of the expert mission were handed over to plant operators, and the final report will be submitted to Korea Hydro and Nuclear Power Co., Ltd and the Nuclear Safety and Security Commission of Korea by the end of June 2012.