L-2007-025, Supplemental Response Regarding Inspection and Mitigation of Alloy 82/182 Pressurizer Butt Welds

Supplemental Response Regarding Inspection and Mitigation of Alloy 82/182 Pressurizer Butt Welds

ML070530548
Person / Time
Site:	Seabrook
Issue date:	02/21/2007
From:	Stall J Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2007-025
Download: ML070530548 (3)

Text

0 FPLEnergy AN FPL GROUP COMPANY FEB 2 12007 L-2007-025 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Re: FPL Energy Seabrook, LLC Seabrook Station Docket No. 50-443 Supplemental Response Regarding Inspection and Mitigation of Alloy 821182 Pressurizer Butt Welds By letter dated January 31, 2007, Florida Power and Light Company and FPL Energy Seabrook, LLC (FPL Energy Seabrook), hereafter referred to collectively as FPL, notified the Nuclear Regulatory Commission (NRC) of the actions taken or planned for inspecting or mitigating Alloy 82/182 butt welds on pressurizer connections for St. Lucie Nuclear Plant, Units 1 and 2, Turkey Point Nuclear Plant, Units 3 and 4, and Seabrook Station.

During a subsequent telephone conference call between NRC staff members and FPL management on February 12, 2007, FPL management agreed to make additional commitments pertaining to Seabrook Station in regard to required elements of an enhanced leakage monitoring program and the acceleration of the April 2008 refueling outage into 2007 if calculations being developed by Nuclear Energy Institute (NEI) and Material Reliability Program (MRP) do not demonstrate an adequate level of safety.

Accordingly, the following information supplements the Seabrook Station inspection and mitigation of Alloy 82/182 commitments provided in Attachment 3 to FPL letter (L-2007-013) dated January 31, 2007:

(561) 691-7177 - 10 PO Box 14000 9 Juno Beach, Florida 33408-0420 a (561) 691-7171 Fax:

Seabrook Station, Docket No. 50-443 L-2007-025, Page 2 of 3 RCS Leakage Monitoring/Action Commitment Until the mitigation of the pressurizer Alloy 600/82/182 butt weld locations at Seabrook Station is complete, the following enhanced reactor coolant system (RCS) leakage monitoring requirements will be implemented by FPL Energy Seabrook:

1. FPL Energy Seabrook will perform daily measurements of unidentified RCS leakage

2. FPL Energy Seabrook will take the following actions based on identification of unidentified RCS leakage rates during steady state operating conditions greater than either of the following limits:

a. 0.25 gpm greater than a baseline value.

Note: This baseline should be established after RCS leakage has stabilized within 7 days of full power operation after startup following the last bare metal visual examination of the pressurizer Alloy 600/82/182 butt weld locations.

b. 0.1 gpm increase between two consecutive daily measurements.

c. If unidentified leakage during steady state operating conditions exceeds either limit set forth in Section 2.a or 2.b, FPL Energy Seabrook shall identify the source of the RCS leak within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or shutdown the plant and perform bare metal visual examinations of all pressurizer Alloy 600/82/182 butt weld locations. Following the initiation of a shutdown, the plant must be in Hot Standby in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown in the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

3. If the increase in unidentified RCS leakage rate is not maintained for 3 days, the requirement in Section 2.c for shutdown and/or pressurizer Alloy 600/82/182 butt weld bare metal examinations shall not apply.

4. If FPL Energy Seabrook determines that the unidentified leakage did not come from the pressurizer, the requirement in Section 2.c for shutdown and/or pressurizer Alloy 600/82/182 butt weld bare metal examination shall not apply.

5. If FPL Energy Seabrook determines that a quantity of the RCS leakage is attributable to a source other than the pressurizer and that quantity decreases the unidentified leakage below the thresholds set forth in Section 2.a or 2.b, the requirement in Section 2.c for shutdown and/or pressurizer Alloy 600/82/182 butt weld bare metal examination shall not apply.

6. FPL Energy Seabrook shall report results of any bare metal visual inspections required to NRC 60 days after plant start up.

Seabrook Station, Docket No. 50-443 L-2007-025, Page 3 of 3 FPL Energy will fully implement these leakage monitoring program enhancements, including operator training, by March 1, 2007.

Acceleration of April 2008 outage into 2007 Commitment FPL Energy Seabrook will accelerate the outage currently scheduled for April 2008 into 2007 if the calculations being developed by NEI and MRP do not demonstrate an adequate level of safety. This schedule could also be accelerated if new information is obtained during upcoming inspections at other plants that challenge current industry assumptions.

If you have any questions concerning this submittal, please contact Rudy Gil at (561) 694-3370.

Sincerely yours, Senior Vice President, Nuclear and Chief Nuclear Officer cc: Regional Administrator, Region I USNRC Project Manager, Seabrook Station Senior Resident Inspector, Seabrook Station