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:
states of equipment (such as for establishing success criteria) • Other engineering information needed to support the base PRA modeling of the plant It is recognized that for reactors in the design or construction stage, the level of operational and maintenance information may vary. As a plant operates over time, its associated risk may change. This change may occur for the following reasons: • Operating data may change the availability or reliability of the plant’s structures, systems, and components. • Plant design or operation may change. • The base PRA model may change as a result of improved methods or techniques. Therefore, to ensure the base PRA represents the risk of the current as-built and as-operated plant, the base PRA is maintained and upgraded over time. Table 15 provides the characteristics and attributes needed for an acceptable process for maintaining and upgrading the base PRA. In addition, Appendix C provides guidance on whether the change to the PRA model is to be considered PRA maintenance or a DG-1362, Page 38 PRA upgrade. COL holders should meet all requirements in ASME/ANS RA-Sa-2009, as endorsed in Appendix A of this regulatory guide, when the PRA is updated as required by 10 CFR 50.71(h)(2) and 10 CFR 50.71(h)(3). Table 15. Summary of Technical Characteristics and Attributes for a PRA Configuration Control Process Characteristics and Attributes • Monitor PRA inputs and collect new information • Ensure cumulative impact of pending plant changes are considered • Maintain configuration control of the computer codes used in the base PRA • Identify when the base PRA model should be updated based on new information or new models/techniques/tools • Ensure peer review is performed on PRA upgrades 2. National Consensus PRA Standards and Industry PRA Programs One acceptable approach to demonstrate conformance with regulatory position C.1 is to use a national consensus PRA standard or standards, as endorsed by the NRC staff with