Energia i regulacje · 22/12/2005

Proposed Generic Communication Post-Fire Safe-Shutdown Circuit Analysis Spurious Actuations

On October 19, 2005 (70 FR 60859), the NRC published for public comment a generic letter (GL) to: (1) Request addressees to review their fire protection program to confirm compliance with existing applicable regulatory requirements regarding their assumptions of the phrase "one-at-a-time" in light of the information provided in this GL and, if appropriate, take additional actions to return to compliance. Specifically, although some licensees have performed their post-fire, safe-shutdown circuit analyses based on an assumption of only a single spurious actuation per fire event or that spurious actuations will occur "one-at-a-time," recent industry cable fire test results demonstrated that these assumptions are not valid. (2) Require addressees to submit a written response to the NRC in accordance with NRC regulations in Title 10 of the Code of Federal Regulations (10 CFR) Section 50.54(f). The Nuclear Energy Institute (NEI) has requested a 45-day extension of the comment period. NEI believes that additional time will be needed to provide appropriate comments on the draft GL. NEI based its request on the time needed to perform an assessment of the safety significance of multiple sequ