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:
hods 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, or decisions that have time constraints may be validated using a Level A or Level B method that results in an estimate of the time required to complete the task or manual action or to make and communicate the decision in order to confirm that the time constraint can reasonably be met as specified in NEI 12-06, Rev. 1A, Section 3.2.1.7, principle 6, which states 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.” 2. Consistent with NEI 12-01, “Guideline for Assessing Beyond Design Basis Accident Response Staffing and Communications Capabilities” (Ref. 22) as endorsed by NRC letter dated May 15, 2012 (Ref. 23), additional staff and resources may be assumed to be available commencing at the 6 hour point (or less, with justification). As a result, the use of Level B validation techniques, which are less stringent, may typically be substituted for the use of Level A validation techniques at the 6 hour point. However, prior to substituting Level B validation, licensees should confirm that staff augmentation will improve the capability of plant personnel to complete tasks, manual actions, and decisions. Level B validation should not be substituted for tasks, manual actions, and decisions that have time constraints and that cannot performed more effectively or efficiently through addition of personnel. In addition, the results of the integrated review should be used to assess the need to adjust and revalidate tasks, manual actions, or decisions for which the validation did not provide reasonable confidence in the ability of plant personnel to execute a required task, manual action, or decision. 1.1.1. Phased Approach The regulations in 10 CFR 50.155 do not contain specific