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Scheduling Updates of Probabilistic Risk Assessments: The Arkansas Nuclear One‐Unit 1 Experience
Author(s) -
Paula Henrique M.,
Guthrie Ver H.,
Campbell David J.
Publication year - 1992
Publication title -
risk analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.972
H-Index - 130
eISSN - 1539-6924
pISSN - 0272-4332
DOI - 10.1111/j.1539-6924.1992.tb00671.x
Subject(s) - probabilistic logic , probabilistic risk assessment , scope (computer science) , nuclear power , nuclear power plant , scheduling (production processes) , engineering , operations research , computer science , risk analysis (engineering) , reliability engineering , operations management , business , artificial intelligence , physics , nuclear physics , programming language
This paper presents the results of a study that identified how often a probabilistic risk assessment (PRA)should be updated to accommodate the changes that take place at nuclear power plants. Based on a 7‐year analysis of design and procedural changes at one plant, we consider 5 years to be the maximum interval for updating PRAs. This conclusion is preliminary because it is based on the review of changes that occurred at a single plant, and it addresses only PRAs that involve a Level 1 analysis (i.e., a PRA including calculation of core damage frequency only). Nevertheless, this conclusion indicates that maintaining a useful PRA requires periodic updating efforts. However, the need for this periodic update stems only partly from the number of changes that can be expected to take place at nuclear power plants–changes that individually have only a moderate to minor impact on the PRA, but whose combined impact is substantial and necessitates a PRA update. Additionally, a comparison of two generations of PRAs performed about 5 years apart indicates that PRAs must be periodically updated to reflect the evolution of PRA methods. The most desirable updating interval depends on these two technical considerations as well as the cost of updating the PRA. (Cost considerations, however, were beyond the scope of this study.)