Chapters authored
Seismic Safety Analysis and Upgrading of Operating Nuclear Power Plants
Part of the book: Nuclear Power
Issues of the Seismic Safety of Nuclear Power Plants
Seismic safety of nuclear power plants became an eminent importance after the Great Tohoku earthquake on 11th of March, 2011 and subsequent disaster of the Fukushima Dai-ichi nuclear power plant. Intensive works are in progress all over the world that include review of the site seismic hazard assessment, revision of the design bases, evaluation of vulnerability, and development of accident management capabilities of the plants. The lessons learned from the Fukushima-accident changed the paradigm of the design. Preparedness to the impossible, i.e. the development of means and procedures for ensuring the plant safety in extreme improbable situations became great importance. Main objective of the Chapter is to provide brief insight into the actual issues of seismic safety of nuclear power plants, provide interpretation of these issues, and show the possible solutions and scientific challenges. The “specific-to-nuclear” aspects of the characterisation of seismic hazard, including fault displacement are discussed. The actual design requirements, safety analysis procedures are briefly presented with main focus on the design extension situations. Operation aspects and problems for restart after earthquake are also discussed. The Chapter is more focusing on seismic safety of the inland plants, located on soil sites, in low-to-moderate (diffuse) seismicity regions.
Part of the book: Earthquakes
Natural Hazards and Nuclear Power Plant Safety
The safety of nuclear power plants with respect of natural hazards can be ensured by adequate characterization of hazards and proven design solutions to cope with natural hazard effects. Design and severe accident management require characterization of very rare event. The events identified for the design basis and for the safety analysis are with annual probability 10−4–10−5 and 10−7, respectively. In this chapter, a brief insight into the actual issues of natural hazard safety of nuclear power plants and related scientific challenges is provided. The state of the art of ensuring safety of nuclear power plants with respect to natural hazard is briefly presented with focus on the preparedness to the accident sequences caused by rare natural phenomena. The safety relevance of different hazards and vulnerability of NPPs to different hazards are discussed. Specific attention is made to the non-predictable phenomena with sudden devastating effects like earthquakes and fault ruptures. Post-event conditions that affect the on-site and off-site accident management activities are also considered. The “specific-to-nuclear” aspects of the characterization of hazards are discussed. This is a great challenge for the sciences dealing with hazard characterization. The possibility for ensuring nuclear safety is demonstrated presenting cases when the nuclear power plants survived severe natural phenomena.
Part of the book: Natural Hazards