ML080380108
| ML080380108 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/19/2008 |
| From: | Richard Jervey NRC/NRR/ADRO/DORL/LPLII-1 |
| To: | Christian D Virginia Electric & Power Co (VEPCO) |
| Jervey, Richard 301-415-2728 | |
| References | |
| TAC MD7490, TAC MD7491 | |
| Download: ML080380108 (4) | |
Text
February 19, 2008 Mr. David A. Christian President and Chief Nuclear Officer Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711
SUBJECT:
NORTH ANNA POWER STATION, UNIT NOS. 1 AND 2, REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING STEAM GENERATOR TUBE INSERVICE INSPECTION REPORTS (MD7490 AND MD7491)
Dear Mr. Christian:
By letters dated November 15, 2007 (ML073200234), and October 9, 2007 (ML072820576),
Virginia Electric and Power Company, Inc. submitted steam generator tube inservice inspection reports for the North Anna Unit 1, Fall 2007 refueling outage (RFO), and the North Anna Unit 2, Spring 2007 RFO. This was in accordance with the plants technical specifications.
The NRC staff has reviewed the reports and has determined that additional information is required in order to complete their evaluation of the information provided. The NRC staffs request is enclosed.
You are asked to provide a response to the RAI within 30 days.
Sincerely,
/RA/
R. A. Jervey, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-338 and 50-339
Enclosure:
RAI cc w/encl: See next page
ML080380108 OFFICE NRR/LPL2-1/PM NRR/LPD2-1/LA NRR/LPL2-1/BC NAME RJervey MOBrien MWong DATE 02/19 /08 02/ 19/08 02/ 19/08
North Anna Power Station, Units 1 & 2 cc:
Mr. David A. Christian President and Chief Nuclear Officer Virginia Electric and Power Company Innsbrooks Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711 Mr. C. Lee Lintecum County Administrator Louisa County Post Office Box 160 Louisa, Virginia 23093 Ms. Lillian M. Cuoco, Esq.
Senior Counsel Dominion Resources Services, Inc.
120 Tredegar Street, RS-2 Richmond, VA 23219 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation Post Office Box 1197 Richmond, Virginia 23218 Old Dominion Electric Cooperative 4201 Dominion Blvd.
Glen Allen, Virginia 23060 Mr. Chris L. Funderburk, Director Nuclear Licensing & Operations Support Dominion Resources Services, Inc.
Innsbrook Technical Center 5000 Dominion Blvd.
Glen Allen, Virginia 23060-6711 Office of the Attorney General Commonwealth of Virginia 900 East Main Street Richmond, Virginia 23219 Senior Resident Inspector North Anna Power Station U. S. Nuclear Regulatory Commission P. O. Box 490 Mineral, Virginia 23117 Mr. Daniel G. Stoddard Site Vice President North Anna Power Station Virginia Electric and Power Company Post Office Box 402 Mineral, Virginia 23117-0402 Dr. Robert B. Stroube, MD, MPH State Health Commissioner Office of the Commissioner Virginia Department of Health Post Office Box 2448 Richmond, Virginia 23218 Mr. Mark D. Sartain, Director Nuclear Safety & Licensing Virginia Electric and Power Company North Anna Power Station P.O. Box 402 Mineral, VA 23117
Enclosure REQUEST FOR ADDITIONAL INFORMATION STEAM GENERATOR TUBE INSERVICE INSPECTION REPORTS NORTH ANNA POWER STATION, UNIT NOS. 1 AND 2 (NORTH ANNA 1 AND 2)
DOCKET NOS. 50-338 AND 50-339 By letters dated November 15, 2007 (ML073200234), and October 9, 2007 (ML072820576),
Virginia Electric and Power Company, Inc. (the licensee), submitted steam generator (SG) inspection reports for the North Anna 1 fall 2007 refueling outage (RFO) and the North Anna 2 spring 2007 RFO in accordance with the plants technical specifications.
Question pertaining to North Anna 1:
- 1. One tube was plugged in Unit 1 since a permeability indication rendered a significant portion of the tube uninspectable. Please discuss how the integrity of this tube was assessed (i.e., did the tube satisfy the performance criteria) if it could not be fully inspected. For example, was an in-situ pressure test performed?
Questions pertaining to North Anna 1 and 2:
- 2. For each RFO and SG tube inspection since installation of the SGs, please provide the cumulative effective full power months that the SGs have operated.
- 3. It was indicated that the secondary-side inspections did not reveal any component degradation that would compromise tube integrity. Please discuss the results of the inspections of the secondary-side internals (e.g., any degradation/deterioration observed, any extensive deposits observed at the tube support plate openings).
- 4. Tube wear was listed as a potential degradation mechanism for the straight-leg and anti-vibration bar tangent points for Rows 8, 14, and 26. Please clarify why the only rows considered susceptible to this degradation mechanism are Rows 8, 14, and 26.
- 5. With respect to the design of your SGs, please confirm that the tubes are arranged in a square pitch/pattern and they were manufactured by Sandvik. In addition, please provide the radius of the Row 1 tubes and the tubesheet thickness (with and without clad).
- 6. It was indicated that the rotating coil probe was used to inspect freespan dents/bulges in Unit 1 and dents/dings/bulges in Unit 2 that measured greater than 2-volts (as determined by the bobbin coil). Please provide the information in Table 1 of the reports for these locations (e.g., these locations are potentially susceptible to primary water stress corrosion cracking and outside diameter stress corrosion cracking). Please discuss why freespan dings were not inspected in Unit 1. In addition, please discuss whether there are any dents/dings/bulges at non-freespan locations and whether these locations are susceptible to degradation (potential, relevant, existing). If so, discuss what examinations, if any, were performed at these locations.