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:
e an acceptable method to demonstrate compliance with § 50.155(c)(1). 3. Reasonable Protection 10 CFR 50.155(c)(2) requires that the equipment relied upon for the mitigation strategies required by § 50.155(b)(1) be reasonably protected from the effects of natural phenomena. NEI 12-06, Rev. 1A, Appendix A, defines reasonable protection as… “Storing on-site FLEX equipment in configurations such that no one external event can reasonably fail the site FLEX capability (N) when the required FLEX equipment is available.” Staff Position: NEI 12-06, Rev. 1A, provides an acceptable approach for reasonably protecting equipment from the effects of natural phenomena. This approach includes the following: • Identification of the natural phenomena for which reasonable protection is necessary, • Determination of the method of protection to be used, • Establishment of controls on unavailability of the equipment, and • Provision of a method of transporting the portable equipment from its storage location to the site in which it will be used. Individual elements of reasonable protection are discussed below. 3.1. Evaluation of External Hazards Section 4 of NEI 12-06, Rev. 1A, discusses the overall methodology for identifying external hazards and evaluating their impact. Appendix B of NEI 12-06, Rev. 1A discusses the identification of external hazards for which licensees should provide reasonable protection. NEI 12-06, Rev. 1A, Sections 5 through 9, discuss the evaluation of the effects of natural phenomena to meet the baseline coping capability. DG-1301, Page 12 Staff Position: Sections 5 through 9 and Appendix B of NEI 12-06, Rev. 1A, provide an acceptable method for the evaluation and equipment considerations to address the effects of external hazards in order to satisfy that element of reasonable protection. 3.2. Protection from External Hazards Sections 5 through 9 of NEI 12-06, Rev. 1A discuss methodologies for the protection of the equipment. The methods of