ML12324A167
| ML12324A167 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 11/14/2012 |
| From: | Gatlin T South Carolina Electric & Gas Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RC-12-0173, TAC ME8997 | |
| Download: ML12324A167 (3) | |
Text
Thomas D. Gatlin Vice President, Nuclear Operations 803.345.4342 dob! MS
,November 14, 2012 A SCANA COMPANY RC-12-0173 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555
Dear Sir / Madam:
Subject:
VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT 1 DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 RELIEF REQUEST RR-III-09 REQUEST FOR INFORMATION
Reference:
- 1. WCAP-1 5987-P-A Revision 2, "Technical Basis for the Embedded Flaw Process for Repair of Reactor Vessel Head Penetrations"
[ML040290246]
- 2. Letter from H. N. Berkow (U. S. NRC) to H. A. Sepp (Westinghouse Electric Company), "Acceptance for Referencing - Topical Report WCAP-1 5987-P, Revision 2, 'Technical Basis for the Embedded Flaw Process for Repair of Reactor Vessel Head Penetrations,' (TAC NO.
MB8997)," dated July 3, 2003 [ML031840237]
- 3. Letter from T. D. Gatlin (VCSNS) to Document Control Desk (NRC),
"Reactor Vessel Head Penetration Weld Repair Under WCAP-1 5987,"
dated October 22, 2012 [ML12306A530]
- 4. Letter from T. D. Gatlin (VCSNS) to Document Control Desk (NRC),
"Relief Request RR-III-09 Alternative Weld Repair For Reactor Vessel Head Penetration," dated October 30, 2012
- 5. Letter from T. D. Gatlin (VCSNS) to Document Control Desk (NRC),
"Relief Request RR-111-09 Supplemental Information," dated November 5, 2012 South Carolina Electric & Gas Company (SCE&G), acting for itself and as an agent for South Carolina Public Service Authority, hereby submits a response to the Request for Additional Information (RAI). VCSNS is providing the technical basis for the Embedded Flaw Process for repair of the reactor vessel head penetrations. During teleconference between NRC, Westinghouse and SCE&G on November 7, 2012, the NRC identified that additional information was needed to support review of the relief request.
Virgil C. Summer Station. Post Office Box 88. lenkinsville, SC. 29065. F (803) 345-5209 P
Document Control Desk CR-12-04775 RC-12-0173 Page 2 of 2 This letter contains no commitments.
In the future, SCE&G may propose a method of monitoring flaw growth during subsequent refueling outage inspections and provide a basis for extending the service life of the repairs.
Should you have any questions, please call Bruce L. Thompson at 803-931-5042.
Very truly yours, Thomas D. Gatlin JG/TDG/bj
Enclosure:
VCSNS Relief Request RR-III-09, Request for Additional Information LTR-PAFM-12-137-NP, Revision 2 c:
K. B. Marsh S. A. Byrne J. B. Archie N. S. Cams J. H. Hamilton R. J. White W. M. Cherry V. M. McCree R. E. Martin NRC Resident Inspector K. M. Sutton NSRC RTS (CR-12-04775, LTD 1331)
File (810.19-2)
PRSF (RC-12-0173)
Document Control Desk Enclosure CR-12-04775 RC-12-0173 Page 1 of 1 VIRGIL C. SUMMER NUCLEAR STATION UNIT 1 REQUEST FOR ADDITIONAL INFORMATION Relief Request RR-III-09 Alternative Weld Repair For Reactor Vessel Head Penetration Request for Additional Information, During a teleconference between NRC, Westinghouse and SCE&G on November 7, 2012, additional information was requested to support the review of the subject relief request. VCSNS submittals have identified the flaws as being contained within the tube material only. Since the flaw indications extend above the toe of the weld, the technical basis for the flaw repair should conservatively assume the flaw extends radially over the entire depth of the J-Groove weld cross-section.
The following request was developed as a result of discussions during the teleconference.
- 1. VCSNS has identified the flaw as limited to the penetration tube material and that it is located below the J-Groove Weld. The UT results indicate some of the flaws extend above the toe of the J-Groove weld. Since the weld itself cannot be interrogated, conservative analysis assuming a flaw in the J-Groove weld that extends radially over the entire depth is required.
[VCSNS Response]
Westinghouse has conducted the reanalysis for VCSNS that conservatively assumes postulated axial flaw near the penetration nozzle that encompasses the entire J-Groove weld region. The results of this analysis are provided as Attachment 1.
In the future, SCE&G may propose a method of monitoring flaw growth and provide bases for extending the service life of the repairs.