ML14070A478

Update to Generic Ltr 2008-01 Commitment

ML14070A478
Person / Time
Site:	Limerick
Issue date:	03/11/2014
From:	Dougherty T Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LG-14-033
Download: ML14070A478 (3)

Text

LG-14-033 March 11, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Limerick Generating Station, Unit 1 Facility Operating License No. NPF-39 NRC Docket No. 50-352

Subject:

Update to Generic Letter 2008-01 Commitment

Reference:

1. Letter from K.R. Jury (Exelon Generation Company, LLC/AmerGen Energy Company, LLC) to U.S. NRC "Nine-Month Response to Generic Letter 2008-01," dated October 14, 2008

2. Letter from C.H. Mudrick (Exelon Generation Company, LLC ) to U.S.

NRC "Update to Generic Letter 2008-01 Commitment,"

dated April 9, 2010

3. Letter from W.F. Maguire (Exelon Generation Company, LLC ) to U.S.

NRC "Update to Generic Letter 2008-01 Commitment,"

dated January 23, 2012 In the nine-month response to Generic Letter 2008-01 "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (Reference 1), Exelon Generation Company, LLC (Exelon) committed to the U.S.

Nuclear Regulatory Commission (NRC) that it would install three new vents on the Limerick Unit 1 High Pressure Coolant Injection (HPCI) system during the 2010 refueling outage (1R13) as documented in Attachment 16 of the Reference 1 letter. These vents were to be installed as a result of a review of system design basis and field walkdowns of areas determined to be susceptible to air entrainment. Installation of the three new vents was completed in accordance with the commitment made in Reference 1. These vents have been installed on the HPCI discharge flow element, suppression pool suction, and injection to the feedwater piping.

As described in Reference 2, based on a review of the internal Technical Evaluation of the HPCI system in response to GL 2008-01, it was determined that the installation of a fourth vent on the HPCI system is needed. This vent involves the HPCI Condensate Storage Tank (CST) suction piping; however, it could not be installed during the 1R13 outage due to valve through-leakage which could not be completely isolated. Following the unsuccessful piping isolation, a freeze seal of the line was attempted but was also unsuccessful. A "hot tap" of the piping was not possible due to proximity to other station components. Therefore, Exelon notified the NRC by letter dated April 9, 2010 that the additional vent on the HPCI system would be installed during the spring 2012 refueling outage (1R14).

As described in Reference 3, installation of the HPCI CST suction line vent was rescheduled to align the work with a CST internal inspection, in the spring 2014 refueling outage (1R15), which also requires draining of the CST. However, the CST internal inspection has been removed from the 2014 refueling outage (1R15) and will be performed during a future outage opportunity. The HPCI CST suction line vent will be installed during the next draining of the Unit 1 HPCI CST suction line.

This schedule is acceptable based on the information below.

The pipe at the intended vent location has been periodically ultrasonically tested since the spring 2010 refueling outage (1R13) which demonstrated that no air is accumulating at this location. With the exception of maintenance activities, the likelihood of introducing air to this location from other mechanisms is low. There are no planned activities to drain this portion of the HPCI suction piping. However, if draining of this piping is required the current HPCI system fill and vent procedure includes ultrasonic testing at this location to support operability of the HPCI system. In addition, this location will continue to be periodically monitored in accordance with the current program until installation of the vent is completed during the next draining of the Unit 1 HPCI CST suction line.

One regulatory commitment is contained in the attachment of this letter.

If you have any questions, please contact the Regulatory Assurance Manager at 610-718-3400.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 11th day of March 2014.

Sincerely, Original signed by Thomas J. Dougherty Vice President - Limerick Generating Station Exelon Generation Company, LLC

Attachment:

Summary of Regulatory Commitments cc: Administrator Region I, USNRC USNRC Senior Resident Inspector, LGS

ATTACHMENT

SUMMARY

OF REGULATORY COMMITMENTS The following table identifies commitments made in this document. (Any other actions discussed in the submittal represent intended or planned actions. They are described to the NRC for the NRCs information and are not regulatory commitments.)

Commitment Type Committed Date Commitment Or "Outage" One-Time Action Programmatic (Yes/No) (Yes/No)

For the HPCI system, one During the next Yes No new vent will be installed draining of the during the next draining of Unit 1 HPCI CST the Unit 1 HPCI CST suction line.

suction line.