The accident at the Fukushima Daiichi Nuclear Power Plant underlined the need to assess the nuclear safety of multi-unit sites considering the accident sequences involving more than one reactor units on site. The objective of this Safety Report is to provide a methodology for the development of a Multi-unit Probabilistic Safety Assessment (MUPSA). It provides practical examples and an overview of the actual state of practice in this area. The publication provides a detailed description of Level 1 MUPSA methodology, the principles of development of Level 2 MUPSA models and the path forward for multi-unit consequence analysis (Level 3 MUPSA). In addition, it summarizes the experience available in Member States in the area of MUPSA. The scope of this Safety Report includes consideration of various hazards and plant operational states normally considered in PSA development in the multi-unit context.

Reliability and Probabilistic Safety Assessment in Multi-Unit Nuclear Power Plants presents the risk contributions from single and multi-unit Nuclear Power Plants to help aggregate the risks that may arise due to applicable hazards and operating states. The book combines the key features of multi-unit risk assessment in one resource, reviewing the practices adopted in various countries around the globe to exemplify the dependencies between units on a site. These dependencies include multi-unit interactions, environmental stresses, the sharing of systems, and the sharing of human resource in a control room, factors which can all introduce an increase potential for heightened accident conditions. This book helps readers systematically identify events and evaluate techniques of possible accident outcomes within multi-units. It serves as a ready reference for PSA analysts in identifying a suitable site and the sharing of resources, while carrying out multi-unit risk assessments to ensure the safety of the public and the environment. It will also be valuable for nuclear researchers, designers and regulators of nuclear power plants, nuclear regulatory agencies, PSA engineers and practicing safety professionals. - Provides a framework for nuclear and PSA researchers and professionals on the design and operation of multi-unit risk assessments - Reviews practices adopted in various regions around the globe to analyze dependencies between units - Includes modeling techniques of inter-connections and shared resources, as well as risk aggregation

The objective of this Safety Guide is to provide recommendations for meeting the requirements of GSR Part 4 (Rev. 1) in the development and application of Level 1 Probabilistic Safety Assessments (PSAs) for nuclear power plants (NPPs). The recommendations provided in this publication promoting technical consistency among Level 1 PSA studies, in order to provide reliable support for applications of PSAs and risk informed decision making, particularly to support the design of NPPs and decision making during plant commissioning and operation. The revised Safety Guide's scope encompasses the main methodological aspects of PSA and in particular has been updated to reflect developments in specific areas, such as passive systems reliability, computer based systems reliability, combinations of hazards, human reliability analysis and to expand the scope of PSA to include site level risk considerations such as multi-unit and spent fuel pool PSA.

Probabilistic Safety Assessment (PSA) is a structured, comprehensive, and logical analysis method aimed at identifying and assessing risks in complex technological systems, such as the nuclear power plants. It is also known as probabilistic risk assessment – PRA. This book presents the theoretical basis to understand the numerous and complex aspects that are covered by PSA and it will help the reader to better understand and to effectively manage risks. The book provides PSA methods and techniques and it includes recommended procedures that are based on the experience of the authors and applicable to different levels and types of PSA that are used for nuclear power plants applications. It can be used as extra reading for PSA courses for practitioners and it provides quantitative risk methodology documentation for PSA.

Safety and Reliability of Complex Engineered Systems contains the Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015, held 7-10 September 2015 in Zurich, Switzerland. It includes about 570 papers accepted for presentation at the conference. These contributions focus on theories and methods in the area of risk, safety and

Safety and Reliability – Safe Societies in a Changing World collects the papers presented at the 28th European Safety and Reliability Conference, ESREL 2018 in Trondheim, Norway, June 17-21, 2018. The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk management Safety and Reliability – Safe Societies in a Changing World will be invaluable to academics and professionals working in a wide range of industrial and governmental sectors: offshore oil and gas, nuclear engineering, aeronautics and aerospace, marine transport and engineering, railways, road transport, automotive engineering, civil engineering, critical infrastructures, electrical and electronic engineering, energy production and distribution, environmental engineering, information technology and telecommunications, insurance and finance, manufacturing, marine transport, mechanical engineering, security and protection, and policy making.

The technical approach described in this publication builds on the use of a single unit probabilistic safety assessment (PSA) and identifies considerations that are needed from the multi-unit perspective. This is the first attempt to expand the current PSA process to take account of multi-unit issues, and has been done by distilling lessons learned from the Fukushima Daiichi accident and other multi-unit events, and by reviewing previous PSAs and supporting research that have addressed the risks of multi-unit accidents. The publication provides a roadmap and methodology for performing a multi-unit PSA, proposes a set of site level risk metrics, and presents examples of approaches to resolve specific issues.

The objective of this Safety Report is to provide a methodology for the development of a Multi-unit Probabilistic Safety Assessment (MUPSA). It provides practical examples and an overview of the actual state of practice in this area.

Provides an approach for achieving the technical consistency of probabilistic safety assessments (PSAs) needed to support various PSA applications. The approach involves the consideration of a set of technical features, called attributes, of the major PSA elements relevant for various applications.