ML110610475

Prairie Island Nuclear Generating Plant, Unit 1 - Request for Additional Information Related to Request to Revise the Technical Specification 3.8.1, AC Sources - Operating, Footnote Requiring Battery Charger Modifications

ML110610475
Person / Time
Site:	Prairie Island
Issue date:	03/04/2011
From:	Wengert T J Plant Licensing Branch III
To:	Schimmel M A Northern States Power Co
Wengert, Thomas
References
TAC ME5426
Download: ML110610475 (4)

Text

UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555-6001 March 4, 2011 Mr. Mark A. Schimmel Site Vice President Prairie Island Nuclear Generating Plant Northern States Power Company

-Minnesota 1717 Wakonade Drive East Welch, MN 55089-9642 PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT 1 -REQUEST FOR ADDITIONAL INFORMATION RELATED TO REQUEST TO REVISE THE TECHNICAL SPECIFICATION 3.8.1, "AC SOURCES -OPERATING," FOOTNOTE REQUIRING BATTERY CHARGER MODIFICATIONS (TAC NO. ME5426)

Dear Mr. Schimmel:

By letter to the U.S. Nuclear Regulatory Commission (NRC) dated February 3,2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 110350055), the Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy, requested a license amendment to revise the Technical Specification (TS) 3.8.1, <lAC Sources -Operating", Surveillance Requirement (SR) 3.8.1.10 footnote requiring battery charger modifications for Prairie Island Nuclear Generating Plant (PINGP), Unit 1. The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with Mr. Dale Vincent of your staff on March 1, 2011, it was agreed that you would provide a response to this request within 14 days of the date of this letter. The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff'resources.

M. Schimmel -If circumstances result in the need to revise the requested response date, please contact me at (301) 415-4037.

Sincerely, -

Thomas J. Wengert, Senior Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No.

Request for Additional cc w/encl: Distribution via REQUEST FOR ADDITIONAL INFORMATION NORTHERN STATES POWER COMPANY -MINNESOTA PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT 1 DOCKET NO. 50-282 By letter dated February 3, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 110350055), the Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy, requested a license amendment to revise the Technical Specification (TS) 3.8.1, !lAC Sources -Operating", Surveillance Requirement (SR) 3.8.1.10 footnote requiring battery charger modifications for Prairie Island Nuclear Generating Plant (PINGP), Unit 1. To complete its review, the U.S. Nuclear Regulatory Comrnission staff requests the following additional information. Provide a comparison of the major electrical parameters, including the minimum voltage requirement (drop-out and reset) of the alternating current (AC) input breaker/contactor, for the existing and proposed new battery chargers.

Discuss in detail the electrical parameters for the proposed new charger that are different from the existing 12 Battery Charger and how these parameters were determined to be acceptable. Discuss whether the description of the existing and new battery chargers will be provided in a future revision of the PINGP Updated Final Safety Analysis Report (UFSAR). Confirm that the proposed new battery charger can recharge its associated battery to the fully charged state within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> while supplying its normal loads after a battery discharge to the bounding design basis event discharge state in accordance with PINGP UFSAR Section 8.5.3 and TS SR 3.8.4.2. Industry operating experience has shown that momentary overvoltage or undervoltage transients experienced during switching, fault or lightning-related perturbations can trigger a self-protecting lockout feature in battery chargers resulting in disabling the chargers.

Provide details on the magnitude and duration of transient and sustained overvoltage/undervoltage conditions resulting from grid perturbations (or the emergency diesel generator system) that have been evaluated for operation of the proposed battery charger. TS SR 3.8.1.10 NOTE 3 states that the 12 Battery Charger is not required to be energized during performance of SR 3.8.1.1 O(c) until the completion of Unit 1 2011 refueling outage. The license amendment request proposes a footnote stating that the battery charger equipment will be modified during or prior to the Unit 1 2011 refueling outage. State why NOTE 3 was not modified to apply only until the new equipment has been installed and tested. Enclosure M. Schimmel If circumstances result in the need to revise the requested response date. please contact me at (301)

Docket No.

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