Exelon Generation Company, LLC., Receipt of Request for Action

Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Nuclear Regulatory Commission [NRC-2012-0203; Docket Nos. STN 50-456, STN 50-457, STN 50-454 AND STN 50-455; License Nos. 72, 77, 37, and 66] Notice is hereby given that by petition dated April 20, 2012, Mr. Barry Quigley has requested that the U.S. Nuclear Regulatory Commission (NRC, the Commission) take action with regard to Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2. The petitioner requests that the NRC require Exelon Generation Company, LLC (Exelon) to shut down immediately, Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, until all turbine building (TB) high-energy line break (HELB) concerns are identified and those important to safety are corrected. As the basis for this request, the petitioner states the following: An adequate supply of combustion air for the diesel generators (DG) is threatened because the combustion air can be diluted with steam. Although the combustion air is drawn from an air shaft (not the TB), it is also the same air shaft that supplies ventilation for the DG room. Under certain conditions, the ventilation damper alignment is such that steam that enters the DG room from the ventilation exhaust can flow back into the inlet air shaft. From there it can be drawn into the engine, potentially starving the engine of air. The effects of high temperature in the engineered safety feature (ESF) switchgear rooms on the protective relaying setpoints has not been evaluated. The concern is that high temperatures could…