PSA provides a numerical indication of risk to the public, workers and society. Comparison against numerical targets is a regulatory requirement that must be met in most countries before permission is given to design, construct and operate a nuclear power plant or facility.
Compliance with these targets is used to support the demonstration that the risk associated with the operation of nuclear power plants is As Low As Reasonably Practicable (ALARP). PSA can also be used to demonstrate a ‘balanced’ design such that no fault, or group of faults, dominates the operational risk. PSA can also provide a huge range of additional insights including pointing to potential shortfalls in the deterministic safety case.
CRA has the largest integrated team of PSA/Human Factors/Safety Case Consultants in the UK. Our strength lies in translating complex systems into logical models that can then be populated with relevant plant, engineering and human failure data to gain valuable risk insights.
We have the capability to develop Level 1, Level 2 and Level 3 PSAs, providing a full risk analysis from frequency of core damage due to plant faults and hazards (e.g. fire, flood, and seismic), to the radiological risk to the public and environment. Our team has considerable experience of using a range of fault tree/event tree analysis software, including FT+, and the suite of Risk Spectrum software. Also, we have developed a number of state-of-the-art approaches to maintaining PSA models in line with international best practice and regulatory expectations.
Initiating Event Analysis & Fault Schedule Development
Accident Sequence (Event Tree) Analysis
System Reliability (Fault Tree) Analysis
Component Failure Data Analysis
Human Reliability Analysis (HRA)
Common Cause Failure (CCF) Assessment
Level 2 PSA - Accident Progression & Containment Analysis
PSA Training
Level 3 PSA - Impact on Public & Environment
PSA Applications (e.g. Risk Monitors)
Regulatory Guidance
Quantification & Analysis of Results
Today, CRA is maintaining the PSA/HFA models for the existing UK fleet of nuclear power plants, aiding the development of PSA/HFA for the next generation of nuclear power plants, and leading the debate in the future of integrated PSA/HFA/Safety Case development.
