J-GLOBAL ID:200904021752596138  Research Project code:9911003213 Update date:Jun. 15, 2006

Study on severe accidents of nuclear reactors

Study period:1984 - 2005
Research overview:
During a sever accident of a light water reactor(LWR), the reactor core is heated up and severely damaged due to insufficient core cooling. This results in the release of a large amount of fission products(FPs) and generation of hydrogen from the reactor core. If the molten core is released into a containment vessel due to the failure of the lower head of a reactor pressure vessel(RPV), various phenomena that threaten the integrity of the containment vessel could occur. The occurrence of a severe accident is extremely unlikely since the designs of LWRs are based on the defense-in-depth concept. However, to quantify the safety margin and potential risks of LWRs, continued severe accident research is essential. Studies are also required for the evaluation of accident managment measures to prevent and mitigate severe accidents. Research activities at JAERI address core melt progression, containment integrity, the source term, and the integrity of a reactor coolant piping system. This research is being performed following the research subjects "Research on the evaluation of severe accident consequences" and "Research on the mitigation of severe accident consequences" in the Five-Year Plan for the Safety Research on the Nuclear Installations of the Nuclear Safety Commission.
Keywords (9):
severe accident ,  accident management ,  source term ,  integrity of reactor vessel ,  integrity of containment vessel ,  molten core coolability ,  Steam explosion ,  FP behavior ,  原子炉冷却系配管健全性
Project Organization (1):
  • (A163001001)
Research program: Nuclear and Atomic Science Research
Ministry with control over the research :
Ministry of Education, Culture, Sports, Science and Technology

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