On March 11th,2011, 4th largest earthquake attacked Fukushima Nuclear Power Plant and around one hour later, the enormous Tsunami attacked it also. After the large earthquake attacked, the automatic shutdown was performed and the emergency diesel generators automatically started and Is olation condenser cooled down the core for unit 1 and RCIC cooled down the cores for unit 2 and 3. However, the large Tsunami damaged all emergency diesel generators and all ECCS pumps. The core melted and the hydrogen gas w...
英字タイトル:
IAEA報告及び基準と福島事故

Last February JSME organized the new organization which was “Research Group on Optimization of Nuclear Safety Regulation“ . This January we organized the research group on European maintenance and inspection of the nuclear plant and visited Finland and France which are ones having the most sophisticated technology. For example Finland made the world record of the shortest duration on the fuel change which was 7 days and 4 hours. The Japanese record was 29 days at Hamaoka which was four times compared with ...
英字タイトル:
Research on European Maintenance and Inspection of Nuke

Fort Calhoun NPP(FCNPP) experienced flood due to the elevation of water level of Missouri river from June to August, 2011. FCNPP took various responses including constructing the berm around the important facilities, and could maintain the safety of the reactor with difficulty. The response of FCNPP, which includes both good and bad aspects, will help us in examining the response to flooding at Japanese nuclear plants. In response to the occurrence of the fire of safety related breaker at FCNPP, June ...
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Response for Flooding and Effort of Plant Restart at Fort Calhoun NPP

In many countries, online maintenance has been already introduced. Especially in US, online maintenance has been introduced to many nuclear plants which has (N+1) redundant safety systems as Japanese plants. There experience will contribute us to discuss how to introduce online maintenance in Japan. In IAEA's nuclear safety criteria and guidance, it is recognized that the outage of one safety system for maintenance is usual operation. This is normal sense in the world. In US, the ris k when online maintena...
英字タイトル:
Status of Online Maintenance in the world