ML12135A217
| ML12135A217 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 05/08/2012 |
| From: | Price J Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 12-235 | |
| Download: ML12135A217 (6) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 May 8, 2012 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Serial No.:
12-235 NL&OS/ETS R2 Docket Nos.:
50-338 50-339 License Nos.: NPF-4 NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)
NORTH ANNA POWER STATION UNITS I AND 2 CONFIRMATORY ACTION LETTER STATUS UPDATE By letter dated November 7, 2011 (Serial No. 11-520D), Dominion submitted a compilation of long-term actions to be performed in addressing the August 23, 2011 earthquake.
These long-term actions were reviewed and confirmed by the NRC in a Confirmatory Action Letter (CAL) dated November 11, 2011. As discussed with the NRC staff after the CAL was issued, Dominion agreed to provide periodic status updates for the long-term actions identified in CAL. Enclosed is the status of the long-term action commitment list that had actions due by April 30, 2012.
If you have any questions or require Mr. Thomas Shaub at (804) 273-2763.
additional information, please contact Sincerely, J..Pr e Vge Pr sident - Nuclear Engineering
Attachment:
Status Update for Long-Term Action Commitments ot) 1 04,9-
Serial Number 12-235 Docket Nos. 50-338/339 Page 2 of 2 cc:
Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Senior Resident Inspector North Anna Power Station Ms. M. Khanna Branch Chief - Division of Operating Reactor Licensing U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 B1A 11555 Rockville Pike Rockville, MD 20852-2738 Ms. N. L. Salgado Branch Chief - Division of Operating Reactor Licensing U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 C2A 11555 Rockville Pike Rockville, MD 20852-2738 Dr. V. Sreenivas NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, MD 20852-2738 J. E. Reasor, Jr.
Old Dominion Electric Cooperative Innsbrook Corporate Center 4201 Dominion Blvd.
Glen Allen, Virginia 23060
Serial No.12-235 Docket Nos. 50-338/339 Attachment Status Update for Long-Term Action Commitments Virginia Electric and Power Company (Dominion)
North Anna Power Station Units I and 2
Serial No.12-235 Docket Nos. 50-338/339 Attachment Page 1 of 3 Long-Term Action Commitment List North Anna Power Station Units 1 and 2 Item Commitment Scheduled No.
Completion Date 1
Dominion will perform long-term evaluations of plant structures, systems and components in accordance with RG 1.167/EPRI NP-6695, Section 6.3. Any April 30, 2013 anomalies identified during the evaluations will be entered into the corrective action system and evaluated for extent of condition.
2 Dominion will develop a plan to characterize the seismic source and any special ground motion effects due to the relative locations of the fault and the site and will update the NRC accordingly.
Status: The action item for plan development has been completed.
(Ongoing activities to implement the plan will be completed as indicated below.)
The Dominion plan to characterize the seismic source and any special ground motion effects due to the relative locations of the fault and site is presented below.
The earthquake catalog contained within the Central and Eastern US Seismic Source Characterization (CEUS-SSC) model and database has been updated to include the last three years of seismicity data (through mid-December 2011). This update includes the Mw 5.8 earthquake in Louisa County Virginia.
The updated earthquake catalog was issued March 8, 2012.
Dominion has obtained data from the USGS and the Virginia Seismologic Observatory at Virginia Tech on the main shock and aftershocks resulting from the earthquake. The aftershocks define a planar feature in the subsurface that appears to be a previously unknown fault.
- 1. Dominion is conducting a geologic reconnaissance of the relatively linear projection of the aftershock hypocenters to the ground surface and other features of significance that may be identified through review of LiDAR imagery obtained for a defined area of interest and field work. The objective of the LiDAR imagery review and field work is to document the presence or absence of any evidence for surface faulting due to the earthquake. The LiDAR survey review was completed during December 2011 and February 2012, and data evaluation is in progress. The field reconnaissance was guided by using maps that combine geologic data with LiDAR imagery. The field reconnaissance was completed on April 23, 2012. The final report is scheduled to be completed by May 30, 2012.
- 2. Separately, the USGS has indicated plans to perform a geophysical survey for the August 23, 2011 event during the spring of 2012.
Dominion will review the data obtained from that survey and incorporate any new findings into our overall evaluation of the event.
March 31, 2012 (Complete) 3 Dominion will revise the North Anna Updated Final Safety Analysis Report to document:
- a.
The recorded August 23, 2011 seismic event.
Status: Complete April 30, 2012 Section 2.7 of the UFSAR has been revised to include a description of (Complete) the August 23, 2011 seismic event.
- b.
A summary of the evaluation and results of the seismic analysis of the April 30, 2013 recorded event completed per RG 1.167/EPRI NP-6695.
Serial No.12-235 Docket Nos. 50-338/339 Attachment Page 2 of 3 Long-Term Action Commitment List North Anna Power Station Units I and 2 Item Commitment Scheduled No.
Completion Date
- c.
Design controls on seismic margin management (i.e., the Seismic Margin Management Plan).
April 30, 2012 Status: Complete Section 3.7 of the UFSAR has been revised to include a description of (Complete) the Seismic Margin Management Plan.
- d.
Incorporation of Regulatory Guide (RG) 1.166, "Pre-Earthquake Planning and Immediate Nuclear Power Plant Operator Post-Earthquake Actions,"
December 31, 2012 and RG 1.167, "Restart of a Nuclear Power Plant Shut Down by a Seismic Event," into the North Anna licensing basis.
4 Dominion will implement a design change to replace the existing seismic equipment and Main Control Room indication with upgraded and enhanced seismic monitoring instrumentation equipment, which includes installation of a permanent, free field seismic monitor. Permanent, seismically qualified backup power to a new Seismic Monitoring Panel will also be installed including a backup battery power supply. The seismic instrumentation will be installed and maintained in accordance with RG 1.12, Rev 2, Nuclear Power December 31, 2012 Plant Instrumentation for Earthquakes. The project will also install seismic (subject to receipt recording instrumentation at the station Independent Spent Fuel Storage of seismic Installation (ISFSI) pad.
monitoring Status: Ongoing equipment)
New seismic instruments and associated controls/indication were installed in the Unit I containment and main control room during the spring 2012 refueling outage. This equipment was declared functional April 24, 2012. The remainder of the instruments (auxiliary building, ISFS/ and free field) will be installed by December 31, 2012. The instrumentation and monitoring panel include seismically qualified backup power supplies.
5 Dominion will perform a re-evaluation of the plant equipment identified in the IPEEE review with HCLPF capacity <0.3g, which will include an assessment of March 31, 2013 potential improvements.
6 Dominion will develop a plan with the NSSS vendor consisting of additional evaluations or inspections, as warranted, to assure long term reliability of the reactor internals.
Status: Complete Dominion Engineering performed a systematic review of the previous evaluations, NRC correspondence, and inspections of the reactor vessel intemals (RVI) that were performed following the August 23, 2011 earthquake.
Data and rationale for future planned programmatic inspections were considered and included input from Westinghouse, the NSSS vendor. Results February 29, 2012 of the prior activities were summarized and evaluated regarding their (Complete) demonstration of RVI integrity. As a result of the evaluation, the RVI remain capable of reliably performing their function in. the future. Furthermore, RVI inspections performed during the spring 2012 Unit 1 refueling outage did not identify any seismically induced issues. Therefore, it was concluded that developing a plan consisting of additional inspections and evaluations of the RVI beyond those already required by existing programs is not warranted for assuring the long term reliability of the RVI.
Serial No.12-235 Docket Nos. 50-338/339 Attachment Page 3 of 3 Long-Term Action Commitment List North Anna Power Station Units I and 2 Item Commitment Scheduled No.
Completion Date 7
Dominion will perform a comparison of the calculated load from the August 23, 2011 earthquake and the existing leak-before-break (LBB) analysis and submit March 31, 2013 the results.
8 Dominion will perform inspections at North Anna Power Station in accordance In accordance with with the latest MRP-227 revision approved by the NRC.
the MRP-227 inspection plan, which will be provided by March 31, 2013 9
Dominion will re-evaluate the Time-Limiting Aging Analyses (TLAAs) that include seismic inputs to either: 1) quantitatively demonstrate that the TLAAs March 31, 2013 are still bounding, or 2) re-analyze the TLAAs, based on the August 23, 2011 earthquake.
10 Dominion will implement a long term Seismic Margin Management Plan to address the impact of the August 23, 2011 earthquake. Specifically, to ensure adequate seismic margins are maintained for plant SSCs, Dominion will revise the design change process for North Anna Power Station to require explicit evaluation of plant modifications for the effects of the August 23, 2011 earthquake using In-Structure Response Spectra (ISRS) for the event for the Containment, Auxiliary Building, and other buildings containing safety related SSCs developed based on actual time-histories recorded during the event. In support of future plant design changes, the evaluation of plant SSCs will December 31, 2011 require design verification and code compliance with the stresses, loads, (Complete) accelerations, and displacements generated from the analysis with the design basis ISRS and the analysis with the ISRS for the August 23, 2011 earthquake, whichever are higher.
Status: Complete The Nuclear Design Control Program has been revised to incorporate controls that will ensure that seismic margin is maintained at North Anna Power Station for plant modifications performed after the August 23, 2011 earthquake.
Dominion will provide 30-days prior written notification to the NRC if it determines the Seismic Margin Management Plan is no longer required based on the implementation of comparable actions as part of the resolution of the N/A NRC's recommendations emanating from the Fukushima Daiichi Task Force and/or Generic Issue (GI)-1 99.