ML070590333

Supplement to Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt-Welds

ML070590333
Person / Time
Site:	Palisades
Issue date:	02/27/2007
From:	Harden P Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML070590333 (3)

Text

N Committed to Nuclear EXC Palisades Nuclear Plant Operated by Nuclear Management Company, LLC February 27,2007 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Palisades Nuclear Plant Docket 50-255 License No. DPR-20 Supplement to Inspection and Mitigation of Alloy 6001821182 Pressurizer Butt-Welds By letter dated January 30, 2007, NMC submitted information regarding inspection and mitigation of Alloy 600/82/182 pressurizer butt-welds for the Palisades Nuclear Plant (PNP). On February 21, 2007, and February 23, 2007, conference calls with the NRC staff took place to discuss the January 30, 2007, letter. It was determined that a supplement to the January 30,2007, letter was necessary.

In addition to the commitments listed in the January 30, 2007, letter, NMC is committing to six new commitments and revising two commitments for PNP. The commitments were discussed with the NRC staff and are listed below.

Summaw of Commitments This letter contains six new commitments as follows:

1. NMC will determine unidentified leakage daily whenever the unit is in Mode 1, 2, or 3 steady state operations, until the completion of the 2007 refueling outage at PNP. NMC will implement this commitment no later than March 8, 2007. NMC will notify the NRC in writing, prior to making any changes to this commitment.

2. If the unidentified Primary Coolant System (PCS) leakage increases 0.1 gallons per minute (gpm) over the previous daily reading and is sustained for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, NMC will take action to be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, and perform a bare metal visual examination of the Alloy 6001821182 butt-weld locations, unless it can be confirmed the increase is not from these pressurizer welds, until the completion of the 2007 refueling outage at PNP.

NMC will implement this commitment no later than March 8, 2007. NMC will notify the NRC in writing, prior to making any changes to this commitment.

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3. If unidentified PCS leakage increases 0.25 gpm above baseline (see item 4) and is sustained for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, NMC will take action to be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and Mode 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, and perform a bare metal visual examination of the Alloy 600/82/182 butt-weld locations, unless it can be confirmed the increase is not from these pressurizer welds, until the completion of the 2007 refueling outage at PNP. NMC will implement this commitment no later than March 8, 2007. NMC will notify the NRC in writing, prior to making any changes to this commitment.

4. NMC will determine the baseline PCS leakage rate from data obtained during the first 7 days of steady state operation at approximately 100% power, after the most recent bare metal visual examination of the pressurizer Alloy 600/82/182 butt-welds, until the completion of the 2007 refueling outage at PNP. NMC will implement this commitment no later than March 8, 2007. NMC will notify the NRC in writing, prior to making any changes to this commitment.

5. NMC will provide inspection results of any bare metal visual examinations performed as a result of these requirements to the NRC in a written report within 60 days of plant restart until the completion of the 2007 refueling outage at PNP. NMC will notify the NRC in writing, prior to making any changes to this commitment.

6. NMC will complete inspections of the pressurizer Alloy 600/82/182 butt-welds at PNP during the 2007 refueling outage per the industry guidance, MRP-139.

NMC will notify the NRC in writing, prior to making any changes to this commitment.

This letter contains two revised commitments as follows:

Commitment made by letter dated January 30, 2007:

1. Until all Alloy 600/82/182 pressurizer butt-welds are either mitigated or replaced, all Alloy 600/82/182 pressurizer butt-welds will be examined per the industry guidance on Alloy 600/82/182 butt-welds (MRP-139).

Revised commitment:

7. NMC will inspect the Alloy 600/82/182 pressurizer butt-welds per MRP-139, on a frequency of at least every four years, until the Alloy 600/82/182 pressurizer butt-welds are mitigated or removed at PNP. NMC will notify the NRC in writing, prior to making any changes to this commitment.

Document Control Desk Page 3 Commitment made by letter dated January 30, 2007:

2. Until all Alloy 600/82/182 pressurizer butt-welds are either mitigated or replaced, reports of future inspection results will be submitted to the NRC within 60 days of the end of the station refueling outage during which the inspection was performed.

Revised commitment:

8. NMC will provide results of future inspections, including inspections on unmitigated welds and any corrective or mitigative actions taken on the pressurizer surge, spray, safety, or relief nozzle and safe end welds containing Alloy 600/82/182 material, within 60 days of the end of the station refueling outage during which the inspection was performed, until the Alloy 600/82/182 pressurizer butt-welds are mitigated or removed at PNP. NMC will notify the NRC in writing, prior to making any changes to this commitment.

n-3 r 7 Paul A. Harden Site Vice President, Palisades Nuclear Plant Nuclear Management Co., LLC cc: Administrator, Region Ill, USNRC Project Manager, Palisades Nuclear Plant, USNRC Resident Inspector, Palisades Nuclear Plant, USNRC