Institute of Nuclear TechnologyWorking to further enhance the safety
and reliability of nuclear power

Working to further enhance the safety and reliability of nuclear power
Learning from cases around the world

Our nuclear power information research project focuses on overseas trouble information analysis and regulatory compliance updates in countries of Europe and the US, as its two main research activities.
First, regarding overseas trouble information analysis, every year we obtain approximately 4,000 of event reports of accidents, troubles and good practices at foreign nuclear power plants, through downloading from websites of NRC, WANO, INPO and so on, and also visiting overseas sites, to collect required data promptly, building up our database with classification and processing, in order to perform our analysis efficiently. These analysis results are regularly provided to Japanese utilities which own pressurized water reactors (PWRs). And through the activities, we propose our suggestions of needed countermeasures for which are especially considered as needed of improvement and reflection for enhancing safety, preventing recurrence of similar troubles and so on; for those points which don’t have specific improvement but are worth calling out attention, we presented them as the reference information.
Second, we make research visits of European and US nuclear power stations to understand their actions in response to the regulations, in order to help our stakeholders meet new domestic regulation standard and to improve safe operations. The information is provided to them.
As stated above, our project is developing our research with continuously holding problem awareness as to what we can contribute to the improvement of safety in nuclear power generation.

Information Analysis Flow Chart

Key Achievements

Recommendations for improvement
Approximately 10 recommendations for improvements given to PWR electric companies annually

Computer-simulated transient analysis for emergency backup diesel generators

Root cause analysis for problems at overseas nuclear power plants

  • Problems more often occurred from management aspects rather than from equipment aspects.
  • In terms of equipment aspects, more problems resulted from design failure.
  • In terms of management aspects, more problems occurred from poor maintenance and mis-operation.
  • Both poor maintenance and mis-operation more often resulted from poor planning and failure by workers (operators).


  • Nuclear Power Information Research ProjectLeader
    Hiroshi YamaguchiLINK
  • Nuclear Power Information Research Project
    Munehiro NagayamaLINK
  • Nuclear Power Information Research Project
    Takeshi SuyamaLINK
  • Nuclear Power Information Research Project
    Masashi ShinzakiLINK
  • Nuclear Power Information Research Project
    Satoshi TokuhisaLINK