Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Tamaki, Hitoshi; Yoshida, Kazuo; Hamaguchi, Yoshikane*
Proceedings of International Topical Meeting on Probabilistic Safety Assessment and Analysis (PSA 2008) (CD-ROM), 12 Pages, 2008/00
A Probabilistic Safety Assessment (PSA) procedure for MOX fuel fabrication facilities (MFFF) was developed at Japan Atomic Energy Agency from 2001 to 2005 and some improvement has been continued. The developed procedure consists of two steps. The first step called as preliminary PSA is carried out for selection of significant events with relatively higher risk among abnormal events that cause potentially release of radioactive materials. The second step is carried out to evaluate risks of the selected significant events in more detail. This step includes the accident scenario analysis, the evaluation of accident frequencies and consequences. The latter step is called as detailed PSA, because it is carried out in the same way of level 1 PSA and level 2 PSA for nuclear power plants. To understand a trend of risk-profile of typical MFFF, the developed procedure was applied to a model facility of MFFF that was based on the information of process design and handling quantities of materials obtained from open documents of a planned MOX fabrication plant in Japan. As the results of application of the procedure to the model plant, a risk-profile was obtained that was drawn by the risk of dominant accident sequences anticipated in whole process of the plant.
Ishida, Michihiko; Suto, Toshiyuki; Inano, Masatoshi; Aoshima, Atsushi; Muramatsu, Ken; Ueda, Yoshinori*
no journal, ,
A study to evaluate component failure rates for a reprocessing plant has started at the Japan Atomic Energy Agency (JAEA). The study is sponsored by the Japan Nuclear Energy Safety Organization (JNES) as a contract research. The Tokai Reprocessing plant(TRP) has been operating over 30 years since 1977. Maintenance records of plant components have been accumulated and compiled in the Tokai Reprocessing Plant Maintenance Support System (TORMASS). Since the TORMASS was thought to be an effective source to pick up component failure information, the evaluation work of component failure rates started at 2005 based on the maintenance records in the TORMASS. By the end of 2006, failure rates for 17 types of 392 components had been evaluated. This result is expected to contribute to building up generic database for reprocessing plant component failure rates in order to promote the utilization of the risk information for reprocessing plants in Japan.