Document: NRC Regulatory Guide
Document ID: 8a2332d3-66ca-40af-84e1-507db8b26559
Document Type: regulatory_guide
Title: TRIAL - Acceptability of Probabilistic Risk Assessment Results for Non-Light Water Reactor Risk-Informed Activities
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2123/ML21235A008.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.247
CFR Part: 
CFR Title: 

Content:
essures, actuation timing, environmental operating limits); • spatial layout, sizing, and accessibility information related to SSCs relied on for prevention and mitigation of releases of radioactive material; • other design information needed to support the modeling of the plant in the PRA for any stage of the licensing process; • the design margins addressed by the capabilities of the SSCs; • operating environment limits of equipment; • expected thermal-hydraulic plant response to different operational states of equipment (such as for establishing success criteria); and • other relevant engineering information (e.g., relevant information for a related technology, generic industry information) needed to support the modeling of the plant in the PRA for any stage of the licensing process. For plants that have operational experience, the sources of information used in the development of a PRA should also include, but are not limited to, those that provide the following types of information: • historical information related to the maintenance practices and experience at the plant; and • information on planned and typical unplanned tests and maintenance activities and their relationship to the status, timing, and duration of equipment availability. The information sources listed above should be accurate and representative of the design and operating characteristics and have an adequate technical basis to support the associated analysis. RG 1.247, Page 54 As plant design, construction, and operations progress over time, its associated risk may change for the following reasons: • Operating data may change the availability or reliability of the plant’s SSCs. • Plant design or operation may change. • The PRA model may change as a result of improved methods or techniques. Therefore, to ensure that the PRA represents the risk of the as-designed, as-to-be-built, or as-to-be-operated plant or the current as-built and as-operated plant, depending on the