ML113500277

Withdrawal of Licensee Event Report 2010-004-00 - Unplanned Limiting Condition for Operation Entry Due to Low Header Pressure on the 2B Essential Service Water Pump

ML113500277
Person / Time
Site:	Braidwood
Issue date:	12/16/2011
From:	Enright D Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BW110138, LER 10-004-00
Download: ML113500277 (2)

Text

10 CFR 50.73 December 16, 2011 BW110138 U. S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Unit 2 Facility Operating License No. NPF-77 NRC Docket No. STN 50-457

Subject:

Withdrawal of Licensee Event Report 2010-004 Unplanned Limiting Condition for Operation Entry Due to Low Header Pressure on the 2B Essential Service Water Pump

Reference:

Letter from A. Shahkarami (Exelon Generation Company, LLC) to U.S. NRC, "Unit 2 Unplanned Limiting Condition for Operation Entry Due to Low Header Pressure on the 2B Essential Service Water Pump" dated October 25,2010 The referenced Licensee Event Report (LER) involved an event with the essential service water (SX) system. The basis for reportability as described in LER 2010-004-00 was an August 24, 2010 event where the SX system discharge pressure was reduced to below design requirements during performance of a surveillance on the 2B SX pump. It was determined that with the SX operating at reduced system pressure, if an emergency actuation signal had occurred, pump flow and performance could not be predicted based on available data.

Therefore, LER 2010-004-00 was issued in accordance with 10 CFR 50.73(a)(2)(i)(B).

An evaluation was performed to review the operating conditions during the event to determine how the reduced header pressure may have affected the SX system supported components.

Based on SX system flow model runs performed, the conditions that existed at the time of the low SX header pressure would have resulted in low flow supplied to multiple safety related components. However, the safety function to provide necessary cooling to required safety-related safe shutdown equipment would have been met under design basis conditions with the auto-start of the 2A SX pump.

December 16, 2011 U. S. Nuclear Regulatory Commission Page 2 Based on the results of the evaluation, it has been determined the condition no longer satisfies any 10 CFR 50.73 reporting requirements. Accordingly, the referenced LER is being withdrawn.

Should you have any questions concerning this submittal, please contact Mr. Chris VanDenburgh, Regulatory Assurance Manager, at (815) 417-2800.

Respectfully, Daniel J. Enright Site Vice President Braidwood Station cc: NRR Project Manager - Braidwood Station Illinois Emergency Management Agency - Division of Nuclear Safety US NRC Regional Administrator, Region III US NRC Senior Resident Inspector (Braidwood Station)

Illinois Emergency Management Agency - Braidwood Rep