ML20195J064
| ML20195J064 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 11/22/1988 |
| From: | Chrzanowski R COMMONWEALTH EDISON CO. |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8812010228 | |
| Download: ML20195J064 (3) | |
Text
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Commonwealth Edison 8.**
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Address Reply to: Post Offc3 Box /67
' Chicago, Illinois 60690 0767 November 22, 1988 Dr. Thomas E. Murley, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory' Commission Washington, DC 20555
Subject:
Byron Station Units 1 and 2 Loss of Offsite Power Request for Additional Information NRC Docket Nos. 50-454/455 References (a): June 27, 1988, letter from L.N. Olshan to H.E. B11cs (b):
August 5, 1988, letter from F.G. Lentine to T.E. Murley
Dear Dr. Murley:
Reference (a) requested additional information concerning the design of the electrical distribution syste:n at Byron Station.
Reference 1
(b) contained the response to the request. The attached load summary answers an additional NRC question and shows that each 4160 V ESF bus and breaker feeding the ESF bus from the Startup transformer are rated to carry the Loss of Coolant Accident loads of one unit and the Safe Shutdown loads of the other. During the course of tabulating the loads for thase conditions, more accurate information was obtained for some of the loads submitted in reference (b).
This information is incorporated into the attached load sunnary.
Please direct any further questions on this matter to this office.
Very truly yours, 1
N R. A. /Chrzanows i Nuclear Licensing Administrator
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Att.
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cc:
Byron Resident Inspector Braidwood Resident Inspector i
i S. Sands Region III Office 8912010228 831122 PDR ADOCK 05000454 P
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SARGENT & LUNDY EN gNEERS Pa ge 1 of 2 Attachment The worst case load condition for the scenario verbally described by the NRC would be a LOCA on Unit 1 (Bus 141) and Safe Shutdewn on Unit 2 (Bus 241).
The load summary for this condition is as follows:
4160V Switchgear Bus 141 (LOCA)
Full Load Maximum Current Equi pment No.
Load Description Brake HP or kVA PF (%)
Eff. (%)
{ Amperes)
ISX01PA-M Essential Service 1247 HP 90.0
- 95. 0 151A Wa',er Pump 1A 15101PA Safety Injection 450 HP 93.0 93.0 54A Pump 1 A 1CV01PA Centrifugal Charging 480 HP 92.0
- 94. 0 57A Pump 1 A 1CS01PA-M Containment Spray 500 HP 93.0 93.0 60A Pump 1A 1AF01PA M Auxiliary Feedwater 1165 HP 89.0 94.0 144A Pump 1A OVA 01CA Auxiliary Building 314 HP 85.0
- 94. 0 41A Ventilation System Supply Fan 0A 1RH01PA Residual Heat Removal 400 HP 92.0 85.0 53A Pump 1 A 1CC01PA Component Cooling 390 HP 92.0 93.0 47A Pump 1 A OVA 02CA Auxiliary Building 478 HP 92.0 92.0 58A Ventilation System Exhaust Fan 0A 0W 001C A Control Room 345 HP 89.0
- 94. 0 43A' Refrigeration Unit 0A 480V Loads 1183 kVA 164 A Total Amperes =
872A
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SARGENTO LUNDY
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Attachment (cont'd) 4160V Switchgear Bus ?41 - Safe Shutdown Full Load Current Equi pment No.
Load Description Brake HP or kVA PF (%)
Eff. (%)
( Amperes )
dVA01CC Auxiliary Building 314 HP 85.0
- 94. 0 41A Ventilation System Supply Fan OC 2Cc01PA Component Cooling 300 HP 92.0 93.0 36A t
Pump 2A OVA 02CC Auxiliary Building 478 HP 92.0 92.0 58A Ventilation System Exhaust Fan OC 2CV01PA
' Centrifugal Charging 480 HP 92.0
- 94. 0 57A Pump 2A 480 V Loads 688 kVA 95A Total Amperes 287A I Based on the above, the maximum continuous load that will be seen by the 4160V Class 1E switchgear (Bus 241) and main breaker (2412) under this operating condition is 872A +
287A = 1,159 amperes.
This is below the switchgear bus and breaker continuous current rating of 1200A.
Therefore, "each 4160V ESF bus and breaker feeding the ESF bus from the startup transformer are also rated to carry the LOCA loads of one unit and the safe shutdown loads of the other unit."
ARN:saw 11/10/88 18AB-EP656
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