New Swedish codes and regulations for safety of pressurized components

The authors discuss the new Swedish regulations for safety of pressurized components in nuclear plants. A main part deals with selection of objects for and performance of in-service inspections. The basic principles for the selection procedure are derived from a paradigm of probabilistic reasoning and this leads to an engineering type scheme for assessment of failure propensity and importance of components for the nuclear safety. The selection procedure involves determination of a failure and a consequence index for each component or part of component. Based on these indices a division into control groups is made which regulates the amount of inspection efforts. It is also recognized that the NDE efforts must be of high quality. In order to ensure this requirements on the examination of NDE-personnel as well as technical requirements on the NDE devices are stated in the regulations. The acceptance rules for detected damage are based on the ASME-code procedures and complemented by the CEGB R6-procedure