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:
d 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, strategies, and controls each licensee should implement to meet the requirements in the regulations. Section 3 of NEI 12-06, Rev. 1A provides performance attributes, general criteria and baseline assumptions for use in the development and implementation of the strategies and guidelines under 10 CFR 50.155(b)(1). NEI 12-06, Rev. 1A further provides that licensees should use these criteria and assumptions for analyses used to establish a baseline coping capability. The assumptions include the initial conditions listed in section 3.2.1.3 that include a loss of offsite power affecting all units at a plant site and the specification that “[a]ll design basis installed sources of emergency on-site ac power and SBO alternate ac power sources [as defined in 10 CFR 50.2] are assumed to be not available and not imminently recoverable.” DG-1301, Page 7 NEI 12-06, Rev. 1A specifies in section 3.2.1.7 that “[s]trategies that have a time constraint to be successful should be identified and a basis provided that the time can reasonably be met.” NEI 12-06, Rev. 1A specifies in section 11.4.3 that FLEX support guidelines (FSGs) will be developed to provide guidance that can be employed for a variety of conditions and that the FSGs will be reviewed and validated to ensure they are feasible. NEI 12-06, Rev. 1A, Appendix E provides a method for validation of the FSGs. NEI 12-06, Rev. 1A, Section 3.2.1.13 specifies that best-estimate analyses are appropriate for the purpose of establishing the baseline coping capabilities. Staff Position: Sections 1, 2 and 3 and Appendix E of NEI 12-06, Rev. 1A provide an acceptable method for licensees to follow to develop a baseline coping capability for mitigating an ELAP concurrent with either an LUHS or, for nuclear power plants with passive