Document: NRC Regulatory Guide
Document ID: 921f4c90-482e-4f9e-a835-28839c357dcb
Document Type: regulatory_guide
Title: Flexible Mitigation Strategies for Beyond-Design-Basis Events + HISTORY - HISTORY 11/2015 – DG-1301 , Proposed Revision 0
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1316/ML13168A031.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.226
CFR Part: 
CFR Title: 

Content:
contain guidance about BDBEE mitigation similar to guidance under revision by the IAEA. C. STAFF REGULATORY GUIDANCE This RG endorses, with clarifications, the methods described in NEI 12-06, Rev. 1A, dated October 2015. The NRC staff has determined that the methods described in the NEI 12-06, Rev. 1A constitute procedures and processes generally acceptable to the NRC for demonstrating compliance with the regulatory requirements in 10 CFR 50.155 subject to the following clarifications. 1. Development and Implementation Process 10 CFR 50.155(b) and (b)(1) require that applicants or licensees develop and implement an integrated response capability that includes strategies and guidelines to mitigate beyond-design- basis external events from natural phenomena that result in an ELAP concurrent with either a loss of normal access to the ultimate heat sink (LUHS) or, for nuclear power plants with passive reactor designs, a loss of normal access to the normal heat sink. The strategies and guidelines developed and implemented under those sections must be capable of being implemented site-wide and must include maintaining or restoring core cooling, containment, and spent fuel pool cooling capabilities; and the acquisition and use of offsite assistance and resources to support those functions. 1.1. Establishment of Baseline Coping Capability Section 1.3 of NEI 12-06, Rev. 1A, discusses the objectives and guiding principles of the FLEX program that are responsive to 10 CFR 50.155(b)(1). These principles retain the three-phase approach that had been required under Order EA-12-049 and provide that plant-specific analyses will determine the duration of each phase. Section 2 of NEI 12-06, Rev. 1A, provides a high-level discussion of the site-specific nature of the actions required by each licensee to properly implement the performance-based requirements in the regulations. Sections 2.1 through 2.5 of NEI 12-06, Rev. 1A discuss the coping capacities, types of external hazards,