Issues regarding transient analysis examined by the Sizewell B Public Inquiry

Issues on PWR safety transient analysis that were discussed at the Sizewell B Public Inquiry are presented. The Public Inquiry was set up by the UK Government under an Inspector, Sir Frank Layfield, to examine all aspects of the construction, safety and operation of a 1200 MW(e) PWR on the Sizewell site. The terms of reference were broad ranging, and the constitution of the Inquiry was to make a recommendation under three Acts of Parliament which apply to the construction and operation of nuclear electrical plant. The Inquiry also covered local planning aspects, which are the responsibility of the Local Authority - in this case the Suffolk County Council. The Inspector examined and made recommendations on the safety of the Station, but consideration by Public Inquiry is outside the formal safety and licensing process, which is the business of the Utility (the CEGB) and the Nuclear Installations Inspectorate (the NII). The paper therefore takes a broader look at the question of safety, dealing with the licensing process, the requirements of the safety case and the forward strategies adopted by the CEGB in terms of research and development. This is considered for transient analysis, and the aim is to set the discussions and conclusions of the Public Inquiry into their proper context with regard to nuclear safety in the UK. The Inquiry went into some depth on the topic of LOCA, as an example of safety analysis. In the summary of the evidence and cross-examination the Inspector accepted the adequacy of the LOCA safety case without major reservations, and was satisfied further work in progress would resolve any residual criticisms. In particular support was given for the CEGB commitment to the development and use of more physically realistic calculational methods