ML090150378
| ML090150378 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/15/2009 |
| From: | Matthews W Dominion, Dominion Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 09-010, GL-08-001 | |
| Download: ML090150378 (3) | |
Text
Dominion Nuclear Connecticut, Inc.
';000 Dominion Boulevard, Glen Allen, Virginia 2.\\060 Web Address: www.dom.corn January 15, 2009 U.S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike~
Rockville, MD 20852-2738 Serial No.
NLOS/GAW Docket No.
License No.09-010 RO 50-423 NPF-49 DOMINION NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION UNIT 3 SUPPLEMENTAL RESPONSE TO THE NRC GENERIC LETTER 2008-01, MANAGING GAS ACCUMULATION IN EMERGENCY CORE COOLING, DECAY HEAT REMOVAL, AND CONTAINMENT SPRAY SYSTEMS This letter supplements the nine-month response to Generic Letter (GL) 2008-01 for Millstone Power Station Unit 3 (MPS3) that was provided in Dominion Nuclear Connecticut, Inc. (DNC) letter dated October 14, 2008 (ADAMS Accession ML082890266). Specitically, this letter completes an alternative course of action for responding to the Gl. that was approved in Nuclear Regulatory Commission (NRC) letter dated July 23, :2008 (ADAMS Accession ML081980640), which allowed DNC to acquire confirmatory system information during the MPS3 fall 2008 refueling outage (3R12).
The DNC nine-month response to the GL contained a description of a technical evaluation of the Emergency Core Cooling System (ECCS), Residual Heat Removal system (RHS), and Containment Spray (CS) system, which was performed to assure DNC's capability to maintain gas voiding less than the amount that challenges operability of these systems. The nine-month report summarized the corrective actions to be completed for the gas accumulation management plans, assuring compliance with design, licensing bases and quality assurance criteria in Sections III, V, XI, XVI, and XVII of Appendix B to 10 CFR Part 50.
During 3R12 which ended on November 24,2008, DNC completed the required GL 2008-01 system walkdowns at MPS3. Subsequently, planned gas accumulation management improvements were refined and the technical evaluation was updated accordingly. The ballance of this letter provides additional information relative to the nine-month response for MPS3. The corrective actions and the associated schedule previously discussed in the nine-month response to the GL are not changed. DNC confirms the gas accumulation management plans currently in place at MPS3, augmented by planned corrective actions described in the nine-month letter, are in compliance with appllicable quality assurance criteria, design and licensing bases.
Serial No.09-010 Docket No. 50-423 Page 2 of 3 Walkdowns previously described in the nine-month response and scheduled for 3R12 are complete, except for High Pressure Safety Injection (HPSI) inside containment piping from penetration (51) to the reactor coolant system (RCS) cold legs. Further review of these HPSI lines determined flow rates during surveillance testing were adequate to fully sweep the piping. Returning systems to service during 3R12 included numerous confirmatory ultrasonic testing (UT) inspections to verify piping was adequately filled. The corrective action process is being used to identify improvements to the system restoration process to ensure the systems are full. A corrective action plan is in place as described by the nine-month response to the GL, which will improve the fill and vent processes and procedures and address lessons learned from system restoration deficiencies encountered during 3R12. This plan will use the insights gained from GL 2008-01 evaluations including walkdowns, slope measurement, and UT information obtained during 3R12. The walkdowns, identification of local void locations from planned UT inspections, and planned system enhancements resulted in the following modifications implemented during 3R12 as well as Licensee Event Report 2008-004-00, Gas Void Discovered in the Emergency Core Cooling System Suction Line, dated December 19, 2008:
New vent valve 3SIL*V817 was installed in the 24-inch suction line entering the Auxiliary Building from the refueling water storage tank.
New vent valve 3SIL*V816 was installed in an 8-inch line, upstream of Penetration 95 and 3SIL*MV8840 in the RHS pumps discharge to hot legs loops 2 and 4.
New vent valve 3SIH*V791 was installed outside of containment at Penetration 98 in the HPSI discharge piping.
Vent valve 3SIH*V993 in HPSI common suction piping was relocated to the high point.
Please contact Mr. Geoffrey A. Wertz at (804) 273-3572 if you have any questions or require additional information.
Serial No.09-010 Docket No. 50-423 Page 3 of 3 Sincerely, e..v £ t.-IQJ t..ea. ~
William R. Matthews Senior Vice President - Nuclear Operations COMMONWEALTH OF VIRGINIA VICKI L. HULL
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Notary Public Commonwealth of Virginia 140542
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My Commission Expires May 31. 2010
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Notary Public cc:
U. S. Nuclear Regulatory Commission Region I Regional Administrator 475 Allendale Road King of Prussia, PA 19406-1415 Commitments made in this letter: None Attachments: None My Commission Expires:
COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by William R. Matthews, who is Senior Vice President - Nuclear Operations of Dominion Nuclear Connecticut, Inc. He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.
- W Acknowledged before me this /5 ;; day of
,2009.
NRC Senior Resident Inspector Millstone Power Station Ms. C. J. Sanders NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08-83 11555 Rockville Pike Rockville, MD 20852-2738