ML082670670
| ML082670670 | |
| Person / Time | |
|---|---|
| Site: | North Anna  (NPF-004, NPF-007) |
| Issue date: | 09/24/2008 |
| From: | Stang J Plant Licensing Branch II |
| To: | Christian D Virginia Electric & Power Co (VEPCO) |
| Stang J, NRR/DORL, 415-1345 | |
| References | |
| TAC MD8354, TAC MD8355 | |
| Download: ML082670670 (5) | |
Text
September 24, 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 REGARDING PROPOSED LICENSE AMENDMENT REQUEST TO CHANGE TECHNICAL SPECIFICATION:
DELETION OF TS 3.7.13 - MAIN CONTROL ROOM (MCR)/EMERGENCY SWITCHGEAR ROOM (ESGR) BOTTLED AIR SYSTEM (TAC NOS. MD8354 AND MD8355)
Dear Mr. Christian:
By letter dated March 19, 2008, Virginia Electric and Power Company submitted an amendment request in the form of changes to the technical specifications (TSs) to Facility Operating License Nos. NPF-4 and NPF-7 for North Anna Power Station, Unit Nos. 1 and 2, respectively. The proposed TS changes include: 1) Delete TS 3.7.13, "Main Control Room(MCR)/Emergency Switchgear Room (ESGR) Bottled Air System, 2) Add TS 3.3.6, "MCR/ESGR Envelope Isolation Actuation Instrumentation," to establish operability requirements for the MCR/ESGR envelope isolation function; and 3) Incorporate TS 3.7.14, "MCR/ESGR Emergency Ventilation System during Movement of Recently Irradiated Fuel Assemblies," into 3.7.10, "MCR/ESGR Emergency Ventilation System," which will contain the requirements for all applicable Modes or conditions consistent with Improved Technical Specifications. The Nuclear Regulatory Commission (NRC) staff is reviewing the submittal and has determined that additional information is required to complete its evaluation.
The NRC staffs request for additional information (RAI) is enclosed. The licensee is required to provide a response to the RAI by October 14, 2008.
Sincerely,
/RA/
John Stang, Senior 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
- transmitted by memo dated OFFICE NRR/LPL2-1 NRR/LPD2-1/LA NRR/DE/SCVB/BC* NRR/LPL2-1/BC NAME DWright MOBrien RDennig MWong DATE 09 / 24 /08 09/ 24 /08 08/26/08*
09 / 24 /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. Eric Hendrixson, Director Nuclear Safety & Licensing Virginia Electric and Power Company North Anna Power Station P.O. Box 402 Mineral, VA 23117
REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED TECHNICAL SPECIFICATION (TS) CHANGE:
DELETION OF TS 3.7.13, MAIN CONTROL ROOM (MCR)/EMERGENCY SWITCHGEAR ROOM (ESGR) BOTTLED AIR SYSTEM NORTH ANNA POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-338 AND 50-339 By letter dated March 19, 2008, (Agencywide Document and Management System (ADAMS)
No. ML080800364), Virginia Electric and Power Company (Dominion), the licensee, proposed to delete TS 3.7.13, "Main Control Room (MCR)/Emergency Switchgear Room (ESGR) Bottled Air System." Dominion further stated that operation of the Bottled Air System will be controlled by a licensee-controlled document (e.g., the Updated Final Safety Evaluation Report (UFSAR) and Title 10 of the Code of Federal Regulations (10 CFR), Section 50.59).
North Anna Power Station, Unit Nos. 1 and 2, Amendments 240 and 221 respectively, approved by letter dated June 15, 2005, permitted implementation of the alternative source term (AST) methodology in compliance with 10 CFR 50.67. The AST dose assessment modified the assumptions in the analysis of record (AOR), which in turn permitted a change to the operability requirements of the emergency habitability systems (EHSs). However, Dominion chose not to significantly alter the operability requirements for the MCR/ESGR EHS at that time.
After reviewing the Dominion submittal, the U.S. Nuclear Regulatory Commission (NRC) staff determined that a request for additional information (RAI) is needed to complete its review as described below:
RAI Question 1:
Regulatory Position C.1.1.1, Safety Margins, to Regulatory Guide 1.183, Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors, states:
The proposed uses of an AST and the associated proposed facility modifications and changes to procedures should be evaluated to determine whether the proposed changes are consistent with the principle that sufficient safety margins are maintained, including a margin to account for analysis uncertainties The bottled air system is an engineered-safety-feature (ESF) system. Dominion proposed to eliminate TS 3.7.13, "MCR/ESGR Bottled Air System." The NRC staff requests that Dominion provide justification determining, with the requested change, how conformance with the guidance of Regulatory Guide (RG) 1.183 is maintained regarding Regulatory Position C.1.1.1, Safety Margins. This justification will be used to determine whether the proposed removal of TS 3.7.13 is consistent with the principle that sufficient safety margin, including margin to account for analysis uncertainties, is maintained.
RAI Question 2:
Regulatory Position C.1.1.2, Defense in Depth, to RG 1.183, Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors, states:
The proposed uses of an AST and the associated proposed facility modifications and changes to procedures should be evaluated to determine whether the proposed changes are consistent with the principle that adequate defense in depth is maintained to compensate for uncertainties in accident progression and analysis data. Consistency with the defense-in-depth philosophy is maintained if system redundancy, independence, and diversity are preserved commensurate with the expected frequency, consequences of challenges to the system, and uncertainties. In all cases, compliance with the General Design Criteria in Appendix A to 10 CFR Part 50 is essential.
Modifications proposed for the facility generally should not create a need for compensatory programmatic activities, such as reliance on manual operator actions.
Proposed modifications that seek to downgrade or remove required engineered safeguards equipment should be evaluated to be sure that the modification does not invalidate assumptions made in facility PRAs and does not adversely impact the facilitys severe accident management program.
The bottled air system is an ESF system. Dominion proposed to eliminate TS 3.7.13, "MCR/ESGR Bottled Air System." The NRC staff requests that Dominion provide justification that demonstrates conformance with the guidance of RG 1.183, Regulatory Position C.1.1.2, Defense in Depth, is maintained. This justification will be used to determine that the proposed removal of TS 3.7.13 does not invalidate assumptions made in facility Probabilistic Risk Assessments and does not adversely impact the facilitys severe accident management program.
RAI Question 3:
In the letter dated March 19, 2008, on Page 7 of 18 of Attachment 1, Dominion stated in one of the mitigative actions in the dose analysis (in the Operational Assessment and Readiness) that:
For the MSLB [main steamline break], SGTR [steam generator tube rupture], RCP
[reactor coolant pump] Locked Rotor, the MCR/ESGR envelope is assumed operating with normal ventilation flow and 500 cfm of additional inleakage.
If normal ventilation is required, explain why the MCR/ESGR emergency ventilation system is not relied upon.