Document: NUREG-0800
Document ID: dd4f84a9-8976-44c4-b631-d7c0254f4efc
Document Type: srp
Title: PROBABILISTIC RISK ASSESSMENT AND SEVERE ACCIDENT EVALUATION FOR
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1416/ML14161A594.pdf
Revision Date: 2023-06
Chapter: 19
Section ID: 19.0
CFR Part: 
CFR Title: 

Content:
of the contributors for internal events, the contributors for internal floods, the contributors for seismic events, the contributors for internal fires, etc.). Applicants may also elect to develop an integrated list of significant risk contributors that summarize the results across all hazard groups. 17. In the context of the PRA results and insights, the term “significant” is intended to be consistent with its definition provided in RG 1.200. The definitions of “significant accident sequence” and “significant contributor” are suitable for both LERF and LRF. Using any other definition of “significant” inconsistent with the definitions provided by RG 1.200 shall be subject to additional staff review and approval. 18. PRA maintenance should commence at the time of application for both DC and COL applicants. Once the certification is issued, the generic PRA would not need to be updated except as appropriate in connection with a DC amendment request. The PRA performed in support of a COL application should be updated to reflect plant modifications if there are changes to the design during the design, construction and operation phases of the facility. COL applicants should describe their PRA maintenance process in FSAR Chapter 19, including planned implementation of the program during design, construction and operation phases of the facility. The NRC expects COL applicants to describe their approach for maintaining and periodically upgrading the PRA in accordance with RG 1.206, Section C.I.19.7 and RG 1.200. For purposes of reporting the effects of plant modifications and changes to the NRC in accordance with the requirements of 10 CFR 50.71(e), the NRC expects the following when changes affect the PRA: 19.0-17 Draft Revision 3 –November 2014 A. PRA numerical changes should be reported when the cumulative risk impact of the changes resulting from the plant modifications, design changes or departures from the DC is more than a 10% change (either