ML20238E312
| ML20238E312 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 12/22/1987 |
| From: | Nauman D SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20238E314 | List: |
| References | |
| NUDOCS 8801050093 | |
| Download: ML20238E312 (3) | |
Text
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10 CFR 50.36 th na Electric & Gas Company n
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December 22, 1987 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555 l
SUBJECT:
Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 Technical Specification Change l
Gentlemen:
l South Carolina Electric & Gas Company (SCE&G) hereby requests a revision to the Technical Specifications for the Virgil C. Summer Nuclear Station.
This proposed change revises Table 3.7-7, " Area Temperature Monitoring" to increase the temperature limit for Item 25, " Service Water Pump / Screen Room" from 102*F to 118*F. Attachment I provides a copy of the marked-up Technical Specification page and Attachment II provides the No Significant Hazards Determination for the request.
The purpose of Technical Specifications Section 3/4.7.11, " Area Temperature Monitoring" is to ensure that safety-related equipment is maintained in an environment which will not degrade the equipment and result in a loss of its operability. Two relevant pieces of equipment pertain to Item 25 " Service Water Pump / Screen Room" in Table 3.7-7 of Section 3/4.7.11 - the Service Water Pump Motors and the Traveling Screen Drive Motors. Qualification programs for both of these pieces of equipment support the proposed temperature increase. The original Technical Specification value was an overly conservative figure based on the most limiting equipment in the Service Water Pumphouse Building. This equipment was located in the Service Water Switchgear Rooms and is limited to 102"F; however, increasing the allowable temperature limit for the pump room would not affect the limits in other rooms.
According to qualification test reports for the Service Water Pump Motors, these motors have a measured temperature rise above ambient of 37.2*C.
The motors are rated at 115"C above ambient. Assuming original ambient conditions of 40*C, the total temperature allowable for the motor is 155"C l
(115*C + 40*C). Therefore the motor has an approximate 77'C margin in the ambient rise motor temperature (115'C - 37.2*C = 77"C).
Increasing the allowable ambient temperature limit to approximately 48"C (=118'F) from 40*C I
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Technical Specification Change Page 2 December 22, 1987 (104*F) has negligible impact on the service life of the motors. This assumption was verified by SCE&G by extrapolating the service life versus
-temperature curve found in the qualification report for the pump motors and reading that the service life is significantly greater than 40 years even at a temperature of 50*C.
The Traveling Screen Drive Motors are also located in the Service Water Pump Room. Qualification program reports indicate the maximum temperature for these motors is 130*C. Qualification programs were based on area ambient temperatures from -20*F to 120*F to support the maximum qualification number.
Increasing the Technical Specification limit to 118'F continues to support-the qualification reports and also allows for instrumerit inaccuracies.
As described in Attachment II SCE&G has determined that a finding of No Significant Hazards is appropriate. This letter and the proposed change have been reviewed and approved by both the Plant Safety Review Committee and the Nuclear Safety Review Committee. The application fee of $150.00 as required by 10 CFR 170 is enclosed.
If you should have any questions, please advise.
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a AMM/ DAN:bjh Attachment pc:
- 0. W. Dixon, Jr./T. C. Nichols, Jr.
R. M. Campbell, Jr.
E. C. Roberts K. E. Nodland
- 0. S. Bradham J. C. Snelson D. R. Moore G. O. Percival W. A. Williams, Jr.
R. L. Prevatte J. Nelson Grace J. B. Knotts, Jr.
Group Managers INP0 Records Center W. R. Baehr Marsh & McLennan W. R. Higgins ANI Library R. B. Clary Surveillance Systems G. G. Soult RTS C. A. Price NPCF T. L. Matlosz File C. L. Ligon (NSRC)
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ATTACHMENT II NO SIGNIFICANT HAZARDS DETERMINATION The proposed change does not involve a significant hazards consideration because operation of the Virgil C. Summer Nuclear Station in accordance with the proposed change would not:
1.
involve a significant increase in the probability or consequences of.an accident previously evaluated. The proposed temperature increase does not significantly decrease the margin of service life of the motors.
Th.e service life of the motors will still exceed the-licensed 40 years of plant life and therefore accident evaluations will not be affected by the proposed change.
2.
create the possibility of a new or different kind of accident from any previously analyzed. Since the service life of the motors will still exceed 40 years, and the equipment will continue to be available for the licensed life of the plant, no new or different kinds of accidents are created.
3.
involve a significant reduction in a margin of safety. The proposed-allowable temperature. increase may slightly' decrease the overall service lives of the motors in the-area; however. the motors will continue to remain environmentally qualified for at least 40 years.
'Therefore, no margins of safety are reduced.
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