Document: NRC Regulatory Guide
Document ID: 22ccfd5e-c5d8-4615-a02c-32369aa9f533
Document Type: regulatory_guide
Title: Acceptability of Probabilistic Risk Assessment Results for Risk-Informed Activities (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1930/ML19308B636.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.200
CFR Part: 
CFR Title: 

Content:
d or is one that involves a fundamental change to a state-of- practice method. An NDM is not a state-of practice or a consensus method. PRA An approach is considered to be a PRA when it (1) provides a quantitative assessment of the identified risk in terms of scenarios that result in undesired consequences (e.g., core damage or a large early release) and their frequencies, and (2) is comprised of specific technical elements in performing the quantification. PRA acceptability The ability of a PRA to support risk-informed regulatory decisionmaking. PRA acceptability is measured in terms of PRA scope; the level of detail in the PRA; the PRA’s conformance with the PRA technical elements in regulatory position C.1.2 of this RG; and how closely the PRA represents a plant’s actual configuration and operations PRA application A documented analysis based in part or whole on a plant-specific PRA that is used to assist in decision-making with regard to the design, licensing, procurement, construction, operation, or maintenance of a nuclear power plant. PRA maintenance4 A change in the PRA that does not meet the definition of PRA upgrade. 4 These terms and their definitions are reproduced from PWROG-19027-NP, Revision 1 DG-1362, Page 56 PRA method An analytical approach used to satisfy a supporting requirement or collection thereof from a national consensus PRA standard in the PRA. An analytical approach is generally a compilation of the analyses, tools, assumptions, and data used to develop a model. For example, application of the MELCOR code, a system level code which contains engineering analyses and assumptions supported by experimental data, is the method used to develop a response model that predicts the performance of the core during PRA transients. PRA upgrade4 A change in the PRA that results in the applicability of one or more supporting requirements that were not previously included within the PRA (e.g., performing qualitative screening for Part 4 of ASME/ANS