60 Risk-Informed Licensing, Regulation, and Safety Management of NPPs in Finland Available to Purchase

Chapter 60 authored by Reino Virolainen and Kaisa Simola cover Risk-Informed Licensing, Regulation and Safety Management of NPPS in Finland. The authors discuss the four operating nuclear power plant units in Finland. The TVO power company has two 840 MWe BWR units supplied by Asea-Atom at the Olkiluoto site. The FORTUM corporation (formerly IVO) has two 500 MWe VVER 440/213 units at the Loviisa site. All the units were commissioned between 1977 and 1982. In addition a 1600 MWe European Pressurized Water Reactor (EPR) supplied by the Framatome ANP—Siemens Consortium is under construction at the Olkiluoto site. Current international safety requirements and especially French and German operating experience have been used in the design. Finnish requirements and operating experience have also been used, especially regarding site-specific features. Severe accident management and protection against collision of a large passenger airplane are implemented in the plant design.

In Finland, risk-informed applications are formally integrated in the regulatory process of NPPs that are already in the early design phase, run through the construction and operation phases through the entire plant service-time-living PRA models have been developed for both the Olkiluoto 1/2 and Loviisa 1/2 NPPs. The PRA studies include level 1 and level 2 models. Level 1 comprises the calculation of severe core damage frequency (probability per year) and level 2 the determination of the size and frequency of the release of radioactive substances to the environment. At the moment, level 1 studies for full power operation cover internal events, area events (fires, floods), and external events such as harsh weather conditions, and seismic events. The shutdown and low power states of level 1 PRA cover internal events, floods, fires, harsh weather conditions and seismic events. Special attention is devoted to the use of various risk informed PRA applications in the licensing of Olkiluoto 3 project, such as RI-ISI, RITechSpecs, RI-IST and safety classification of SSCs. In this context this chapter makes several references to the ASME standards on RI-ISI and the European Network for Inspection and Qualification, ENIQ and its RI-ISI related activities. The chapter is has several tables and schematics in addition to references and acronyms to explain the terminology used in this chapter.

The scope of the coverage includes Risk- Informed Regulatory Frame with discussions about PRA in Nuclear Safety Legislation and Risk Informed Regulation Policy sequences. The authors also dwell on PRA IN THE REGULATORY PROCESS and address Development of PRA Requirements for Nuclear Power Plants, and PRA in the Licensing Process of New Designs with tables to support their presentation. Risk- Informed Applications for a Construction License, for Operating License, Risk-Informed Applications during operation control and Review Process of PRA also discussed with the help of schematics, examples and experiences of Olkiluoto 3 NPP Risk Informed Licensing along with EPR safety features. The authors dwell on the European orientation to risk and cover European network for inspection and qualification, ENIQ task group risk, ENIQ documents supporting the RI-ISI framework document, and ENIQ recommended practices. As a part of the extension of risk-informed activities authors dwell on analysis of oil spills, and probabilistic fire simulation, risk-informed regulatory inspections. The authors close the chapter with summary and conclusions.