ML102810247
| ML102810247 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/01/2010 |
| From: | Gratton C Plant Licensing Branch III |
| To: | Pacilio M Exelon Nuclear |
| Gratton C, NRR/DORL/LPL3-2, 415-1055 | |
| References | |
| TAC ME2604 | |
| Download: ML102810247 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 rtlvenl".:er 1, 201 0 Mr. Michael J. Pacilio President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555
SUBJECT:
DRESDEN NUCLEAR POWER STATION, UNIT 2 - REQUEST FOR APPROVAL OF FLAW EVALUATION REPORT FOR RECIRCULATION PUMP A TEE-TO-VALVE WELD PS2-TEE/202-4B (TAC NO. ME2604)
Dear Mr. Pacilio:
By letter dated December 7, 2009, Exelon Generation Company, LLC (EGC, or the licensee),
(Agencywide Documents Access and Management System Accession No. ML093420189),
submitted for Nuclear Regulatory Commission (NRC) staff review and approval an updated flaw evaluation report for a weld in the reactor recirculation system piping at Dresden Nuclear Power Station (DNPS), Unit 2. The licensee's request stated that the updated flaw evaluation report was being submitted in accordance with Generic Letter (GL) 88-01 "NRC Position in Integranular Stress Corrosion Cracking (lGSCC) in BWR Austenitic Stainless Steel Piping," which requires licensees to reexamine known flaws each outage and apply the flaw evaluation method to the results of the re-examination to determine if any actions are needed. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code)Section XI, 1995 Edition with 1996 Addenda is the DNPS Unit 2 Section XI Code for record for the current fourth inspection interval and for continued operation without repair/replacement or flaw evaluation.
The updated flaw evaluation report addresses two circumferential flaw indications which are located on the tee side of Recirculation Pump A Tee-to-Valve Weld PS2-TEE/202-4B. Based on the results of the evaluation conducted during refuelillg outage D2R21 in November 2009, EGC proposed to leave the two flaws as-is without repair.
The two indications were first identified in 1995, and have been re-evaluated periodically in accordance with GL 88-01. During refueling outage D2R21, the NRC staff reviewed the original flaw evaluation and questioned the fact that neither the evaluation (documented in a letter from Mr. R. Rybak of Commonwealth Edison Company to the NRC dated October 16, 1995), nor the NRC staffs safety evaluation (documented in a letter from the NRC staff to Mr. D. Farrar of Commonwealth Edison Company, dated February 15, 1996), discussed the examination limitations. During a subsequent telephone call between the NRC staff and the licensee to discuss the status of the flaws, it was agreed that the original flaw evaluation should be updated to the current ASME Code edition and addenda, and revised to clearly identify and justify the examination limitations, and that the licensee should request that the NRC staff review the revised flaw evaluation for approval.
During the subsequent review of the revised flaw evaluation by the NRC staff, the staff determined that there is no NRC requirement explicitly requiring the licensee to obtain NRC review and approval in order to update the licensee's flaw evaluation report. However, the
- 2 M. Pacilio licensee should determine whether the existing flaw evaluation is set forth in the licensee's Final Safety Analysis Report (FSAR), or affects the accuracy of any statements in the FSAR, in which case the licensee should determine whether NRC staff review and approval of the revised flaw evaluation or a change to the FSAR is required under Title 10 of the Code of Federal Regulations, Section 50.59. Finally, the licensee should determine if the revised flaw evaluation requires a change in a technical specification or its bases, in which case a change to the technical specification must be accomplished through a license amendment.
The NRC staff will close TAC No. ME2604. If you have any questions regarding this matter, please contact Christopher Gratton at 301-415-1055, or christopher.gratton@nrc.gov.
Sincerely,
~hA--~
Christopher Gratton, Senior Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-237 cc w/encls: Distribution via Listserv
-2 M. Pacilio licensee should determine whether the existing flaw evaluation is set forth in the licensee's Final Safety Analysis Report (FSAR). or affects the accuracy of any statements in the FSAR, in which case the licensee should determine whether NRC staff review and approval of the revised flaw evaluation or a change to the FSAR is required under Title 10 of the Code of Federal Regulations, Section 50.59. Finally, the licensee should determine if the revised flaw evaluation requires a change in a technical specification or its bases, in which case a change to the technical specification must be accomplished through a license amendment.
The NRC staff will close TAC No. ME2604. If you have any questions regarding this matter, please contact Christopher Gratton at 301-415-1055, or christopher.gratton@nrc.gov.
Sincerely, IRA!
Christopher Gratton, Senior Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-237 cc w/encls: Distribution via Listserv DISTRIBUTION:
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