The UK regulatory approach to determinsistic and probabilistic safety analysis in criticality safety cases

摘要

In the UK, the Health and Safety Executive (HSE) regulates most nuclear activities by means of conditions attached to nuclear site licences. As part of the regulatory process HSE published its revised Safety Assessment Principles (SAPs) in 1992 [1]-principally for its own use. The SAPs are essentially a set of goals, including both deterministic and probabilistic nuclear criticality principles. The Nuclear Installations Inspectorate (NII), which forms part of HSE, is also developing supplementary "Assessment Guides" which provide NII staff with additional guidance on these principles. This paper discusses the balance between deterministic and probabilistic safety assessment methods and the approach taken by the NII in assessing the adequacy of licensee's criticality safety cases. The licensing regime is deliberately non-prescriptive which allows industry to develop safety cases suited to local applications.