ML072710013
| ML072710013 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 10/03/2007 |
| From: | Siva Lingam NRC/NRR/ADRO/DORL/LPLII-1 |
| To: | Christian D Virginia Electric & Power Co (VEPCO) |
| Lingam, Siva NRR/DORL 415-1564 | |
| References | |
| TAC MD5877, TAC MD5878 | |
| Download: ML072710013 (5) | |
Text
October 3, 2007 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:
SURRY POWER STATION, UNIT NOS. 1 AND 2, REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING THE PROPOSAL TO INCREASE MAXIMUM SERVICE WATER TEMPERATURE LIMIT (TAC NOS. MD5877 AND MD5878)
Dear Mr. Christian:
By letter dated June 25, 2007, Virginia Electric and Power Company (the licensee) proposed technical specification (TS) changes to increase the maximum service water temperature limit from 95 °F to 100 °F for Surry Power Station, Unit Nos. 1 and 2. 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 RAI is enclosed. The licensee is required to provide a response to the RAI within 30 days.
Sincerely,
/RA/
Siva P. Lingam, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-280 and 50-281
Enclosure:
RAI cc w/encl: See next page
- transmitted by memo dated OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA NRR/DSS/SBPB/BC NRR/DE/EMCB/BC NRR/LPL2-1/BC NAME SLingam MO=Brien DHarrison KManoly EMarinos DATE 10/1/07 10/1/07 9/19/07*
9/25/07*
10/3/07
Enclosure REQUEST FOR ADDITIONAL INFORMATION REGARDING REVISION OF TECHNICAL SPECIFICATION TO INCREASE MAXIMUM SERVICE WATER TEMPERATURE LIMIT SURRY POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-280 AND 50-281
- 1. The application states: AEquipment supported by the CC [component cooling] system will not be impacted by increasing the SW [service water] temperature to 100 °F due to the analytical restrictions imposed by this evaluation. In this evaluation the maximum CCHX [component cooling water heat exchanger] outlet temperature was constrained to the same value as in previous evaluations in which the SW temperature was 95 °F. The CC fluid outlet temperature of the CCHXs will be no more than the 120 °F currently supplied to the CC system loads.@
- a.
The only apparent analytical restriction described in the application is limiting the AYCCHX outlet temperatureY@ to the value used in previous evaluations. What other analytical restrictions have been imposed in the evaluation?
- b.
In constraining the CCHX outlet temperature to the same values as in previous evaluations, describe any changes in the way the CC or SW systems are operated or maintained?
- c.
UFSAR [Updated Final Safety Analysis Report] Table 9.4-1, AComponent Cooling Water System Component Design Data,@ indicates that with a service water temperature of 95 °F, the operating temperatures for the CC water CCHX inlet temperature is 119.7 °F and CCHX outlet temperature is 105.0 °F. With an increase in the SW temperature to 100 °F what will be the impact on these values and what impact will there be on the cooldown rates?
- 2. When the maximum SW temperature was increased from 92°F to 95°F in 1993, the application (Accession No. 9307230230) stated that the main control room (MCR) and emergency switchgear room (ESGR) air conditioning systems (ACS) AYare designed for service water temperatures up to 95 °F.@ The current application states that there will be a Asmall decrease@ in the capacity of the ACS chillers. Please provide a description of any analyses/evaluations that have been performed for the higher SW temperature. What is the projected reduction on the ACS chiller capacity and the basis for this reduction, and what are the resulting environmental conditions in the MCR and the ESGR with SW temperature of 100 °F and the most-limiting operating conditions?
- 3. The application states that the lube oil coolers and the intermediate seal coolers will continue to have Aadequate margin@ with a SW temperature of 100 °F. Please provide a description of the evaluation performed and the results of the evaluation that demonstrated adequate margin will be available with the increased SW temperature.
- 4. The application states the AEmergency Service Water Pumps (ESWP) diesels were evaluated and found to have no significant effects from an increase in the SW temperature limits.@
Please provide a description and the results of the evaluation performed that determined there were no significant effects from an increase in SW temperature limits to 100 °F.
- 5. Technical Specification 3.13.A.2 requires: AFor two unit operation, three component cooling water pumps and heat exchangers shall be OPERABLE.@ The Basis for this specification states: AEach of the component cooling water heat exchangers is designed to remove during normal operation the entire heat load from one unit plus one half of the heat load common to both units. Thus, one component cooling water pump and one component cooling water heat exchanger are required for each unit which is at POWER OPERATION.@ Therefore, having three pumps/heat exchangers operable will leave adequate component cooling water capability in the event of a single failure.
The application states: AFor the worst-case heat load (normal shutdown of two units following a loss of offsite power) and 100 °F SW temperature, three CCHXs have the capacity to support the CC design requirements.@ If three CCHXs are required to support the CC design requirements, four CCHXs should be required to be OPERABLE in TS 3.13 in order to maintain minimum required capability after a single failure. Please provide a proposed change to TS 3.13 or an explanation for maintaining TS 3.13 in its current form.
- 6. In Generic Letter (GL) 96-06, Assurance of Equipment Operability and Containment Integrity during Design-Basis Accident Conditions, licensees were requested to address a) cooling water system waterhammer and two-phase flow in the containment air cooler cooling water system, and b) thermal overpressurization of piping (fluid systems) that penetrates containment. Changes in the SW temperature limit could affect a nuclear plants analyses that address the GL 96-06 issues. The statement on page 11 of the subject license amendment request (LAR), in reference to GL 96-06, only addresses the impact the increase in SW temperature limit will have on the cooling water system, which is one of the two concerns of the GL. Table 1, page 18 of the LAR, states that in a loss-of-coolant accident increasing SW temperature will. increase containment pressures. Please explain how you have evaluated the second concern of the GL relative to the piping thermal overpressurization of fluid systems that penetrate containment due to the increase of the SW temperature limit to 100 °F and discuss the results of your evaluation.
- 7. In reference to the safety-related fiberglass piping, it is stated on page 11 of the LAR that this piping has the most-limiting stress margins of any of the piping at Surry 1 and 2 related to the increase in the maximum SW temperature limit to 100 °F. For the safety-related fiberglass piping, please provide a summary of the results of your evaluation showing current maximum stresses, maximum stresses due to SW temperature increase and compare it to the allowable stresses.
- 8. Describe the effect that the increase of the maximum SW temperature limit to 100 °F will have in the SW and SW-influenced piping and pipe supports. Also, indicate how the impact of the increased temperature was evaluated
Surry Power Station, Units 1 & 2 cc:
Mr. David A. Christian President and Chief Nuclear Officer Virginia Electrical and Power Company Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711 Ms. Lillian M. Cuoco, Esq.
Senior Counsel Dominion Resources Services, Inc.
Building 475, 5th Floor Rope Ferry Road Waterford, Connecticut 06385 Mr. Donald E. Jernigan Site Vice President Surry Power Station Virginia Electric and Power Company 5570 Hog Island Road Surry, Virginia 23883-0315 Senior Resident Inspector Surry Power Station U. S. Nuclear Regulatory Commission 5850 Hog Island Road Surry, Virginia 23883 Chairman Board of Supervisors of Surry County Surry County Courthouse Surry, Virginia 23683 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation Post Office Box 1197 Richmond, Virginia 23218 Dr. Robert B. Stroube, MD, MPH State Health Commissioner Office of the Commissioner Virginia Department of Health Post Office Box 2448 Richmond, Virginia 23218 Office of the Attorney General Commonwealth of Virginia 900 East Main Street Richmond, Virginia 23219 Mr. Chris L. Funderburk, Director Nuclear Licensing & Operations Support Dominion Resources Services, Inc.
Innsbrook Technical Center 5000 Dominion Blvd.
Glen Allen, Virginia 23060-6711