Assessment of Defence in Depth for Nuclear Power Plants

This publication provides specific technical information on implementation of the defence in depth concept in the siting, design, construction and operation of nuclear power plants (NPPs). It describes a method for verifying capabilities for implementation of defence in depth in existing NPPs. For given objectives of each level of defence, a set of challenges to achieve these objectives is identified as well as several constitutive mechanisms leading to these challenges, and a list of possible safety provisions which contribute to prevention of these mechanisms is provided. This book is intended to serve as a reference primarily for self-assessment of the comprehensiveness and quality of defence in depth provisions by NPP operators, but it can also be used by regulators or independent reviewers. It offers a complementary tool for evaluation of the strengths and weaknesses of defence in depth in a specific NPP.