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 and strategies requires that the estimate of capability be kept current to reflect plant conditions following facility changes such as modifications or equipment outages. Changes in the facility can impact the duration for which the initial response phase can be accomplished, the required initiation times for the transition phase, and the required delivery and initiating times for the final phase. c) The use of best-estimate analyses for establishing the baseline coping capabilities is appropriate in the context of the beyond-design-basis external events for 10 CFR 50.155(b)(1). This includes the use of normal fluid levels for tanks that are maintained by procedure or administrative controls rather than the minimum levels allowed by Technical Specifications. d) Consistent with the goal of mitigation strategies for BDBEE, the validation method documented in Appendix E of NEI 12-06, Rev. 1A is endorsed as a method to (1) assess whether it is feasible, considering design basis, or reevaluated hazard conditions determined under the § 50.54(f) request for information of March 12, 2012 (as applicable), to execute tasks, manual actions and decisions (i.e., human actions) required DG-1301, Page 8 by the mitigation strategies described in NEI 12-06, Rev. 1A and (2) support a conclusion that the strategies mitigate, to the extent practical, the adverse effects of BDBEEs on the ability of personnel to perform the required human actions. NEI 12006, Rev. 1A, Appendix E neither proposes nor is endorsed as a method to assess whether required human actions are reliable. 1. The use of Level C validation methods should be limited to those tasks, manual actions and decisions that do not have a time constraint for the strategy to be successful. This is because the Level C validation methods do not result in an estimate of the time necessary to perform the tasks, manual action, or decision and cannot provide a basis that a time constraint can reasonably be met. Tasks, manual actions,