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:
s include the applicable design, operation, maintenance, and engineering characteristics of the plant. For those SSCs and human actions used in the development of the PRA, the following information is identified, integrated, and used in the PRA: • plant design information reflecting the normal and emergency configurations of the plant, • plant operational information about procedures and practices, • plant test and maintenance procedures and practices, and • engineering aspects of the plant design. Further, plant walkdowns are conducted to ensure that information sources being used actually reflect the plant’s as-built and as-operated condition. In some cases, corroborating information obtained RG 1.247, Page 53 from the documented information sources for the plant and other information may be gained only by direct observations. At the design and initial licensing stages, plant walkdowns are not possible; however, in these cases, available data on the plant design and operations information should be evaluated. The sources of information that should be used in the development of a PRA include, but are not limited to, those that provide the following types of information: • the safety functions relied on to maintain the plant in a safe, stable state and prevent damage to radionuclide transport barriers and releases of radioactivity; • identification of those SSCs that are credited in the PRA to perform the above functions; • the functional relationships among the SSCs, including both functional and hardware dependencies; • the normal and emergency configurations of the SSCs; • the automatic and manual (human interface) aspects of equipment initiation, actuation, and operation, as well as isolation and termination; • SSCs’ capabilities (flows, pressures, actuation timing, environmental operating limits); • spatial layout, sizing, and accessibility information related to SSCs relied on for prevention and mitigation of releases of radioactive