Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Watanabe, Norio
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(4), p.396 - 406, 2004/12
The U. S. Nuclear Regulatory Commission has been carrying out the Accident Sequence Precursor (ASP) Program to identify and categorize precursors to potential severe core damage accident sequences using the PSA technique. The ASP Program has identified a lot of risk significant events as precursors that occurred at U. S. nuclear power plants. The results from the ASP Program include valuable information that could be useful for obtaining risk significant insights and for monitoring risk trends in nuclear power industry. The present study examines and discusses quantitative risk trends for the industry level, using two indicators, that is, the occurrence frequency of precursors and the annual core damage probability, deriving from the ASP analysis results. It is shown that the core damage risk at U.S. nuclear power plants has been lowered and the likelihood of risk significant events has been remarkably decreasing. Also, the present study demonstrates that two risk indicators used here can provide quantitative information useful for monitoring risk trends in nuclear power industry.
Okoshi, Minoru
Hoken Butsuri, 37(3), p.197 - 207, 2002/09
The concept of clearance has been introduced by IAEA in 1996 and is very useful for the management of very low-level solid materials generating from the decommissioning of nuclear facilities. Therefore, the Nuclear Safety Commission of Japan started the derivation of clearance levels for solid materials arising from nuclear reactors in 1997 and published the reports in 1999 and 2001, respectively. EC also published the several guides to clear metals, concrete, building and other solid materials from regulatory control. Some organizations including IAEA and USNRC are still discussing how to derive the clearance levels. In this exposition, the present status of clearance in Japan and other organizations and countries is summarized. And some information to realize the concept of clearance is given, and the problems related to the clearance are also discussed.
Watanabe, Norio; Suzudo, Tomoaki
JAERI-Review 98-013, 78 Pages, 1998/09
JAERI-Review-98-013.pdf:5.87MB
no abstracts in English
