Document: NRC Regulatory Guide
Document ID: bbd6ed7f-058c-4bd2-8849-f708d0179bbf
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:
ll as the maintenance of an overall program document and record of changes. Staff Position: Section 11.8 of NEI 12-06, Rev. 1A provides an acceptable method for maintaining configuration control of an integrated response capability under 10 CFR 50.155(b)(1) and (f). 6. Treatment of Reevaluated Hazards under the Requests for Information of March 12, 2012 10 CFR 50.155(c)(2)(i) requires that each licensee that received the March 12, 2012, NRC letter issued under § 50.54(f) concerning reevaluations of seismic and flooding hazard levels provide DG-1301, Page 14 reasonable protection against that reevaluated seismic or flooding hazard(s) if it exceeds the design basis of its facility. 6.1. Treatment of Reevaluated Seismic Hazards The following guidance establishes the necessary considerations to evaluate the equipment used in the guidance and strategies required by 10 CFR 50.155(b)(1) with respect to the reevaluated hazard as required under 10 CFR 50.155(c)(2)(i). Detailed implementation methods will be developed as necessary. Staff Position: Licensees with reevaluated seismic hazards that exceed the design basis of the facility should demonstrate reasonable protection for the reevaluated seismic hazard of the equipment used in the guidance and strategies required by 10 CFR 50.155(b)(1) as required under 10 CFR 50.155(c)(2)(i). Past seismic reevaluations, to the extent they meet the standards of reasonable protection described here, can be used to meet the requirements. a. The demonstration of reasonable protection should address all phases of mitigation and consider FLEX equipment as well as installed equipment or structures, systems, and components of the facility relied upon in mitigating strategies under 10 CFR 50.155(b)(1). b. Licensees should evaluate the equipment and SSCs within the scope of the demonstration considering all pertinent failure modes (both the individual and system level failure modes) that could prevent the functional performance needed for the