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
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
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