Document: NUREG-0800
Document ID: 8e754440-b70e-4b8a-9816-b4a64b631220
Document Type: srp
Title: Initial – February 2012
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1136/ML113640138.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
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CFR Title: 

Content:
erministic engineering evaluation that is supplemented by risk insights information. As stated in RG 1.177, the licensee should determine how the change impacts defense-in-depth aspects of the plant's design and operation and should determine the adequacy of safety margins following the proposed change. The licensee should consider how plant and industry operating experience relates to the proposed change, and whether potential compensatory measures could be taken to offset any negative impact from the proposed change. NRC staff has been receiving license amendment requests for one-time or permanent AOT extensions for the EDGs and offsite power sources from the current AOT up to 14 days to perform online maintenance of EDGs and offsite power sources. Maintenance may include both planned and unplanned activities. The purpose of this Branch Technical Position (BTP) is to provide guidance from a deterministic perspective in reviewing such amendment requests. 8-8-3 Initial - February 2012 B. BRANCH TECHNICAL POSITION The Electrical Engineering Branch (EEB) staff evaluates AOT extension requests for onsite or offsite power sources to allow on-line maintenance on EDGs that would normally be performed during refueling outages or maintenance of offsite power source(s) such as a transformer or bus. The on-line maintenance can help reduce the risk for loss of power during plant refueling outages when refueling activities are conducted. The staff evaluates the licensee’s request for AOT extension from deterministic as well as PRA perspectives. The risk-impact evaluation is performed by the PRA Licensing Branch. The traditional deterministic evaluation is performed by EEB. Consistent with the Commission’s final policy statement, it is expected that a license amendment request for an onsite or offsite AOT extension will contain a PRA assessment. However, this BTP specifically discusses the defense-in-depth aspects for onsite and offsite power sources from a deterministic