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:
Rev. 0 to NEI 12-06 incorporating many of the remaining exceptions and clarifications. On August 21, 2012, NEI submitted Rev. 0 to NEI 12-06, making various editorial corrections. The NRC reviewed the August 21, 2012 submittal of Rev. 0 of NEI 12-06 dated August 2012 and endorsed it in JLD-ISG-2012-01 as a process the NRC considers acceptable for meeting the regulatory requirements with noted clarifications. On August 25, 2015, NEI submitted Rev. 1 to NEI 12-06 (Ref. 21), incorporating lessons learned in the implementation of Order EA-12-049 and alternative approaches taken by licensees for compliance to that order. Following a public webinar discussion of potential exceptions and clarifications on September 21, 2015, NEI submitted Rev. 1A to NEI 12-06. The NRC is issuing 10 CFR 50.155 to, among other things, make the requirements of Order EA- 12-049 generically applicable, taking into account lessons learned during the implementation of the orders and input from stakeholders. This RG endorses, with clarifications, NEI 12-06, Rev. 1A as an acceptable method for applicants and licensees to demonstrate compliance, in part, with the regulatory requirements. NEI 12-06, Rev. 1A was developed by NEI to incorporate lessons learned and additional alternative approaches to meet the requirements of Order EA-12-049. The guidelines in NEI 12-06, Rev. 1A recommend a three-phase approach for mitigating BDBEEs. The initial phase makes use of installed equipment and resources to maintain or restore key safety functions including core cooling, containment, and SFP cooling. The transition phase includes providing sufficient, portable, onsite equipment and consumables to maintain or restore these functions until they can be accomplished with resources brought from offsite. The final phase includes obtaining sufficient offsite resources to sustain these functions indefinitely. External Documents Endorsed in This Guide This RG endorses, in part, the use of one or more codes, standards,