ML13275A094
| ML13275A094 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 10/04/2013 |
| From: | V Sreenivas Plant Licensing Branch II |
| To: | Division of Operating Reactor Licensing |
| Sreenivas V, NRR/DORL 415-2597 | |
| References | |
| TAC MF2721 | |
| Download: ML13275A094 (4) | |
Text
October 4, 2013 MEMORANDUM TO: Biweekly Notice Coordinator FROM: V. Sreenivas, Project Manager /RA/
Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
REQUEST FOR PUBLICATION IN BIWEEKLY FR NOTICE - NOTICE OF CONSIDERATION OF ISSUANCE OF AMENDMENTS TO FACILITY OPERATING LICENSES, PROPOSED NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION, AND OPPORTUNITY FOR A HEARING (TAC NO. MF2721)
Virginia Electric and Power Company, Docket No. 50-339, North Anna Power Station, Unit No.
2, Louisa County, Virginia Date of amendment request: September 10, 2013 Description of amendment request: The proposed license amendment (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13260A256) requests the changes to the Technical Specification (TS) 3.8.1, AC Sources-Operating. TS 3.8.1 contains Surveillance Requirement (SR) 3.8.1.8, which requires verification of the capability to manually transfer Unit 1 4.16 kV ESF bus AC power sources from the normal offsite circuit to the alternate required offsite circuit and this surveillance is only applicable to Unit 1. Dominion is developing a plant modification to install an alternate offsite power feed to each of the two 4.16 kV ESF buses for Unit 2, such that it will be similar to the Unit 1 design.
Therefore, the proposed change would delete Note 1 to SR 3.8.1.8 to remove the limitation that excludes Unit 2 and will be consistent with the verification currently performed for Unit 1.
Basis for proposed no significant hazards consideration determination: As required by 10 CFR 50.91(a), the licensee has provided its analysis of the issue of no significant hazards consideration, which is presented below:
Biweekly Notice Coordinator 1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No The previously evaluated accident that could be affected is a complete loss of offsite power (LOOP). Analyses have been performed to confirm that power distribution system voltages and currents with both of the new Unit 2 alternate normal to emergency bus ties in service are adequate during a unit trip scenario.
The conditions under which the Unit 2 manual transfer capability is verified are the same as Unit 1. The verification test may only be performed under conditions that will not challenge steady state operation or challenge the safety of the unit.
Therefore, the Unit 2 verification test (manual transfer between Unit 2 normal offsite circuit and alternate required offsite circuit) will not significantly increase the probability of a LOOP.
Should a LOOP occur, the consequences are unaffected by availability of offsite power (normal offsite circuit and alternate required offsite circuit). Therefore, the Unit 2 verification test (normal offsite circuit and alternate required offsite circuit) will not affect the consequences of an accident previously evaluated.
- 2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No The purpose of the surveillance test is to verify the capability to manually transfer AC power sources from the normal offsite circuit to the alternate required offsite circuit.
The only effect of the change is to permit the new Unit 2 required offsite circuits to be tested in the same manner and frequency as the corresponding Unit 1 circuits. Since the Unit 2 circuits are similar to the Unit 1 circuits, and the Unit 1 test is a required TS Surveillance to demonstrate operability of the alternate offsite circuits, permitting the Unit 2 circuits to undergo the same surveillance test will not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3. Does the proposed change involve a significant reduction in a margin of safety?
Response: No
Biweekly Notice Coordinator The proposed change enables SR testing of the new Unit 2 alternate offsite AC circuits to verify the capability to manually transfer AC power sources from the normal offsite circuit to the alternate required offsite circuit as is performed in Unit 1.
The margin of safety is related to the confidence in the ability of the fission product barriers to perform their design functions during and following an accident situation and the ability of the ECCS to provide adequate core cooling.
These barriers include the fuel cladding, the reactor coolant system, and the containment system. The proposed change does not directly affect these barriers, nor does it involve any adverse impact on the Class 1E circuits or SSCs supplied by Class 1E power. In fact, it enhances the ability to power the required ECCS equipment during accident conditions. Therefore, the proposed change will not involve a significant reduction in a margin of safety.
The NRC staff has reviewed the licensee's analysis and, based on this review, it appears that the three standards of 50.92(c) are satisfied. Therefore, the NRC staff proposes to determine that the amendment request involves no significant hazards consideration.
Attorney for licensee: Lillian M. Cuoco, Senior Counsel, Dominion Resources Services, Inc.,
120 Tredegar Street, RS-2, Richmond, VA 23219 NRC Branch Chief: Robert Pascarelli.
Biweekly Notice Coordinator The proposed change enables SR testing of the new Unit 2 alternate offsite AC circuits to verify the capability to manually transfer AC power sources from the normal offsite circuit to the alternate required offsite circuit as is performed in Unit 1.
The margin of safety is related to the confidence in the ability of the fission product barriers to perform their design functions during and following an accident situation and the ability of the ECCS to provide adequate core cooling.
These barriers include the fuel cladding, the reactor coolant system, and the containment system. The proposed change does not directly affect these barriers, nor does it involve any adverse impact on the Class 1E circuits or SSCs supplied by Class 1E power. In fact, it enhances the ability to power the required ECCS equipment during accident conditions. Therefore, the proposed change will not involve a significant reduction in a margin of safety.
The NRC staff has reviewed the licensee's analysis and, based on this review, it appears that the three standards of 50.92(c) are satisfied. Therefore, the NRC staff proposes to determine that the amendment request involves no significant hazards consideration.
Attorney for licensee: Lillian M. Cuoco, Senior Counsel, Dominion Resources Services, Inc.,
120 Tredegar Street, RS-2, Richmond, VA 23219 NRC Branch Chief: Robert Pascarelli.
DISTRIBUTION:
Nonpublic LPL2-1 R/F RidsNrrDorlLpl2-1 RidsNrrPMNorthanna (hard copy)
RidsNrrLASFigueroa Resource ADAMS Accession Number: ML13275A094 OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA NRRLPL2-1/BC NRR/LPL2-1/PM NAME VSreenivas SFigueroa RPascarelli VSreenivas DATE 10/2/13 10/2/13 10/3/13 10/4/13 OFFICIAL RECORD COPY