The aim of this book is to summarize probabilistic safety assessment (PSA) of nuclear power
plants with WWER440 reactors and demonstrate that the plants are safe enough for producing
energy even in light of the Fukushima accident. The book examines level 1 and 2 full power low
power and shutdown PSA and summarizes the author's experience gained during the last 35 years
in this area. It provides useful examples taken from PSA training courses the author has
lectured and organized by the International Atomic Energy Agency. Such training courses were
organised in Argonne National Laboratory (Chicago IL USA) Abdus Salaam International Centre
for Theoretical Physics (Trieste Italy) Malaysia Vietnam and Jordan to support experts from
developing countries.The role of PSA for the plants is an estimation of the risks in absolute
terms and in comparison with other risks of the technical and the natural world. Plant-specific
PSAs are being prepared for the plants and being applied for detection of weaknesses design
improvement and backfitting incident analysis accident management emergency preparedness
prioritization of research and development and to support the regulatory activities.There are
three levels of PSA being performed for full power and low power operation and shutdown
operating modes of the plants: level 1 2 and 3 PSA. The nuclear regulatory authorities do not
require the level 3 PSA for the plants in the member countries of the European Union. This
means that only a limited number of NPPs in Europe have the level 3 PSA available. However in
the light of the Fukushima accident the performance of such analyses is strongly recommended in
the future. This book is intended for professionals working in the nuclear industry
researchers and students interested in safety of operational plants.
