Overview of PSA for the UK ABWR Generic Design Assessment

A Probabilistic Safety Assessment (PSA) was provided as an integral part of the safety case for the United Kingdom Advanced Boiling Water Reactor (UK ABWR) Generic Design Assessment (GDA). The main objectives of PSA for GDA is to provide a demonstration of the compliance, for a single unit UK ABWR, with numerical risk targets defined in the UK Safety Assessment Principles (SAP) and to support the “As Low As Reasonably Practicable” (ALARP) assessment. This content of this paper includes: • An overview of the UK ABWR PSA • Identification of the PSA scope • PSA model development to compare with numerical risk targets and inform design and operational features • Illustration of PSA results, e.g., Core Damage Frequency (CDF), Large Release Frequency (LRF) and Large Early Release Frequency (LERF) • Peer reviews • Use of PSA in ALARP assessment