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:
-11-0093 (Ref. 8) to identify any actions that could, and in the staff’s judgment should, be taken in the near term given consideration to the wide range of regulatory tools available. The staff’s response to this Commission direction is contained in SECY-11-0124, “Recommended Actions to be Taken without Delay from the Near-Term Task Force Report,” dated September 9, 2011(Ref. 9). In SRM-SECY-11-0093, the Commission further directed that all the regulatory actions in the report should be prioritized, and SECY-11-0137, “Prioritization of Recommended Actions to be Taken in Response to Fukushima Lessons Learned,” dated October 3, 2012 (Ref. 10) provides the staff’s response to this direction. After receiving the Commission’s direction in SRM-SECY-11-0124 (Ref. 11) and SRM-SECY- 11-0137 (Ref. 12), the NRC conducted public meetings to discuss enhanced mitigation strategies intended to maintain or restore core cooling, containment, and SFP cooling capabilities following a BDBEE. At these meetings, the industry described its proposal for a diverse and flexible mitigation capability (FLEX), as documented in NEI’s letter, dated December 16, 2011 (Ref. 13). FLEX was proposed as a strategy to fulfill the key safety functions of core cooling, containment integrity, and spent fuel cooling. Stakeholder input influenced the NRC to pursue a performance-based approach to improve the safety of operating power reactors different than envisioned in NTTF Recommendation 4.2, SECY-11-0124, and SECY-11-0137. On February 17, 2012, the NRC staff provided SECY-12-0025, “Proposed Orders and Requests for Information in Response to Lessons Learned from Japan’s March 11, 2011, Great Tohoku Earthquake and Tsunami” (Ref. 14) to the Commission, including the proposed order to implement the enhanced mitigation strategies. As directed by SRM-SECY-12-0025 (Ref. 15), the NRC issued Order EA-12-049. On March 30, 2012, the Commission issued Memorandum and Order CLI-12-09 (Ref. 16),