PRA Data

Purpose

Different types of data related to plant components, procedures, and other characteristics are the basis for quantifying the risk associated with a plant. Given that advanced reactor designs are much different from current LWR designs, lack of data and operator / plant personnel experience becomes an area of concern and high priority of research.

Scope

Advanced reactors currently lack the amount of data associated with component reliability, component uncertainty, human error that LWRs have accumulated over thousands of reactor years of operation. Methods to gather data related to advanced reactors are still being considered including identifying differences in needs between advanced reactor designs.

Data

A universal concern that was provided by both reactor vendors and potential plant owner / operators was the lack of operational experience and data for advanced reactor designs; this being a particularly critical concern for non-LWR reactor designs. It is expected that some of the issues related to operational data will be the subject of experimental work and initial prototyping. However, significant uncertainties likely will persist for advanced reactor designs until several commercial reactors for the various designs have been built and operated for a period of time to build an operational experience base. Additionally, as specific plant designs become more complete and reactor vendors gain more feedback from interactions with operating utilities and regulatory authorities, it is likely that additional areas requiring research and development related to plant PRAs will be identified. Another concern identified by stakeholder interviews was that there is not only a lack of experience, but also a lack of component reliability data, specifically for non-LWRs such as liquid sodium reactors. Methods that address plant and component data issues can be found in Table 3.5 of the Research Roadmap (EPRI 3002026495).

Reliability and Integrity Management (RIM) was discussed an example of a new risk-informed application for advanced reactors. It was developed to support detecting and managing degradation of materials, which will support the justification of the SSC reliability and failure rate data used in the PRA models.

Research Roadmap (EPRI 3002026495) Actions Supported:

• Develop Guide on Leveraging Legacy Reactor Experience: In addition to design-specific data, legacy operational experience may also provide support for safety analysis and risk assessments. The outcome of this R&D activity will support the use of legacy data by identifying and prioritizing the overall data needs.
• Provide Joint Recommendations to North American Regulators (NRC and CNSC) on Regulatory Alignment: A common element of reactor licensing will be the experimental and (when available) operational data that will be used to substantiate and qualify the plant licensing basis including both traditional plant safety analyses and risk assessments. The outcome of this R&D activity generally supports the identification of the data needed to support these analyses for licensing of advanced reactors. This task should be performed, to the extent practicable, to support licensing beyond the US and Canada.