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-designed or the as-to-be built and as-to-be operated plant, as applicable in each stage. Assumptions used in external flood plant response analysis (e.g., screening out external flood initiators and external flood-induced failures, human error event identification and development) should be clearly identified, documented, and tracked to ensure their continued validity across different stages. RG 1.247, Page 42 C.1.3.14 Other Hazards Probabilistic Risk Assessment Element This section identifies the hazard group-specific PRA analysis elements, the objectives of those analysis elements, and the characteristics and attributes that are needed for an acceptable other hazards NLWR PRA that addresses all radiological sources, all POSs, and all levels of PRA analysis. As discussed in Regulatory Position C.1.1, “other hazards” are those hazards that are not categorized under the internal events, internal flood, internal fire, seismic, high wind, or external flood hazards groups. An other hazards PRA is performed when other hazards cannot be screened out by a screening analysis. The objective for each other hazards PRA analysis element is briefly described, and the characteristics and attributes needed to achieve the objective are provided below. The other hazards PRA analysis elements are as follows: • other hazards analysis, • other hazards fragility analysis, and • other hazards plant response analysis. Screening methods can often be used to show that the contribution of a hazard to risk metrics is not significant. The considerations in this section apply to those hazards identified in Table B-1 of Appendix B that are not screened out based on a screening and conservative analysis for all modeled POSs and sources of radioactive materials. Because of the limited collective experience of the analysis community in the area of PRA for other hazards, an extensive peer review is particularly important for such a PRA. PRA models of other hazards are based on an