Regional Basic Professional Training Course in Korea

Regional Basic Professional Training Course (BPTC) on Nuclear Safety
Both figures of merit give different information on component importance. Thanks to a
combination of these figures, it is possible to make selection (PSA-based critical
components). However, it is noted that the global selection process includes both
probabilistic and deterministic aspects. The deterministic aspects, which are considered to
identify important components, are, for example, potential initiation of an EOP, or a
regulatory definition of safety significant components.
This hierarchy allows focusing on maintenance programs for the most important
components. This is efficient not only for maintenance costs, but also for safety, by
identifying the main safety related components.
9.6.6. PSA for improved plant design
In view of the current state of the art and past experience in the field of nuclear power,
deterministic rules and standards have generally been used as the basis for nuclear power
plant design. However, PSA provides an additional efficient method of measuring and
improving plant safety. For future reactors, PSA is being used as a design tool and as a
means of ensuring improved performance.
9.6.6.1. An aid in improving present reactor safety
In Switzerland, to date, the main application of PSA has concerned the re-evaluation of
various Swiss plants, in terms of identification of potential plant-specific vulnerabilities.
This has been the main focus of regulatory authority (HSK)’s PSA evaluation activities,
within the framework of plant-specific licensing actions and/or the periodic safety review,
as a complementary tool to the deterministic safety analysis.
These studies enabled identification of the weakest points in plant design and
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