ML100640032

Generic Letter 2008-01, Supplement Response

ML100640032
Person / Time
Site:	Oconee
Issue date:	03/02/2010
From:	Baxter D Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-08-001
Download: ML100640032 (5)

Text

Duke DAVE BAXTER SEnergy Vice President Oconee Nuclear Station Duke Energy ON01 VP / 7800 Rochester Highway Seneca, SC 29672 864-873-4460 864-873-4208 fax dabaxter@dukeenergy.

com March 2, 2010 U. S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 ATTENTION:

Document Control Desk

Subject:

Duke Energy Carolinas, LLC (Duke)Oconee Nuclear Station, Unit 1 Docket No. 50-269 Generic Letter 2008-01, Supplemental Response On January 11, 2008, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems. The GL required a written response within nine months consistent with the requested actions and information of the GL. If the requested response date could not be met, a 3-month response was requested to provide the proposed alternative course of action.By letter dated May 8, 2008, Duke provided an alternative course of action for Oconee as well as Catawba and McGuire. Because some of the system piping referenced in the GL is located in areas inaccessible during power operation (i.e., Containment), the field verifications could not be completed until the upcoming refueling outages. Once the outage related field verifications were complete, the results would be provided to the NRC within 90 days of the end of the refueling outage. By letter dated September 25, 2008, the NRC accepted Duke's alternative course of action.The attachment to this letter provides the Oconee Unit 1 post outage, Supplemental response to Duke's GL 2008-01 9-month response dated October 13, 2008.www.duke-energy com U.S. Nuclear Regulatory Commission March 2, 2010 Page 2 There are no new commitments contained in this supplemental response.Please contact Russ Oakley at (864) 873-3829 if additional questions arise.I declare under penalty of perjury that the foregoing is true and correct. Executed on March 2, 2010.Sincerely, Dave Baxter, Vice President Oconee Nuclear Site Attachment U.S. Nuclear Regulatory Commission

'March 2, 2010 Page 3 cc: w/attachment Mr. Luis Reyes Regional Administrator, Region II U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, GA 30303-8931 Mr. Jon Thompson (addressee only)Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Mail Stop 0-8 G9A Washington, D.C. 20555 Mr. John Stang Project Manager U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Mail Stop 0-8 G9A Washington, D. C. 20555 Mr. Andy Sabisch NRC Senior Resident Inspector Oconee Nuclear Station Attachment Oconee Unit I Generic Letter (GL) 2008-01 9-Month Supplemental Response This attachment contains the results of field verifications performed during the Oconee Unit I fall 2009 refueling outage for the Low Pressure Injection (LPI), Core Flood (CF), and High Pressure Injection (HPI) systems' piping inside the Unit 1 Containment and Unit 1 Letdown Storage Tank (LDST) Room (deemed inaccessible for the GL 08-01 initial 9-month response).

The Unit 1 Building Spray (BS) system piping did not require any further field verifications due to the design of the system. Piping for the BS system inside containment is open to the building atmosphere and is normally empty.Survey Measurements Field surveys were performed inside containment and Letdown Storage Tank Room to verify the relative slope of the horizontal piping sections.

The piping slope surveys were performed by site personnel.

Survey acceptance criteria were the same as described in Oconee's October 13, 2008 GL response.Based upon piping configuration review, selected confirmatory Ultrasonic Testing (UT) locations were inspected and were verified to be water solid. Surveys identified eight locations which could be potential gas accumulation sites due to adverse pipe slope conditions.

Based on review of the slope survey results, two additional high point locations on the HPI piping in the LDST Room were identified and vent valves were installed in these locations.

In addition, one location on HPI discharge piping inside containment, and two locations on the LPI piping inside containment were identified which warrant future installation of an effective vent valve. Two additional program monitoring locations were also identified.

The addition of vent valves and enhanced monitoring described above are not required as conditions of operability.

Operability is assured by current venting procedures without additional changes to system configuration or vent valve additions.

The vent valve additions are an enhancement to current venting capability.

Corrective Actions No corrective actions were identified which are needed to ensure continued operability of these systems.

Conclusion Pipe slope surveys and selected UT inspections were performed during the Oconee Unit 1 fall outage for the inaccessible portions of High Pressure Injection, Low Pressure Injection, and Core Flood systems. The results of this effort did not change the conclusions of Oconee's October 13, 2008 GL response or result in any additional corrective actions required for continued operability.