Document: NRC Regulatory Guide
Document ID: cde52d5a-adf9-49be-9d1f-59449dfca895
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:
dependencies, functional dependencies, and dependencies on operator actions) are correctly represented. This minimum level of detail is implicit in the elements making up the PRA and their associated characteristics and attributes. For a given PRA element and specific PRA analysis elements, the level of detail modeled may vary. The detail may vary from the degree to which (1) plant design and operation are modeled, (2) plant-specific experience is incorporated into the model, and (3) realism is incorporated into the analyses that reflect the expected plant response. Regardless of the level of detail included in the PRA, all technical characteristics and attributes should be addressed. That is, each characteristic and attribute are always addressed, but the degree to which they are addressed may vary. In general, the level of detail needed in a PRA that supports a risk-informed decision depends on the application under consideration. For reviews of an application, the PRA may be used during different stages of plant design, construction, and operation. Because levels of available information and operating experience vary for each of these stages, the submitted PRA will likewise differ in level of detail for the different stages. For example, a PRA used to support a DC may not have the same level of detail as a PRA for an operational plant that has several years of operating experience. While it is recognized that the level of detail may vary depending on the application, each PRA element and its attributes and characteristics should be addressed. C.1.3 Elements of a Probabilistic Risk Assessment and Associated Characteristics and Attributes The PRA elements are defined in terms of the fundamental technical analyses needed to develop and quantify the PRA model for its intended purpose (e.g., determination of a specific risk metric). The characteristics and attributes of the PRA elements define specific requirements that should be met to successfully perform those