ML19257B216
| ML19257B216 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 01/08/1980 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8001150378 | |
| Download: ML19257B216 (3) | |
Text
J BALTIMORE G AS AND ELECTRIC COMPANY P.O. BO X 147 5 B ALTIM O R E. M A R Y L A N D 2120 3 AnTHun E. LUNDVALL,JR.
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Supete January 8, 1980 Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Comission Washington, D.C.
20555 ATTENTION: Mr. Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2, Docket Nos. 50-317, 50-318 Adecuacy of the Offsite Power Systems of Nuclear Power
REFERENCE:
(a) Mr. Robert W. Reid to Mr. A. E. Lundvall, Jr.
Letter dated October 17, 1979, same subject Gentlemen:
In response to your letter dated October 17, 1979, requesting additional ir. formation concerning losses of offsite power at Calvert Cliffs, we are hereby submitting the infomation you requested concerning the adequacy of offsite power systems. The infomation is provided in the enclosure to this letter in the fom of answers to your questions.
If you have any questions regarding this infomation, we would be pleased to discuss them with you.
Very trul your,
1747 352 A=w q
A. E. Lundvall, Jr.
Vice President-Supply AEL/SMD/gla Enclosure fo/S S
ll 8001150 Mg 7
ENCLOSURE LOSS OF 0FFSITE POWER SURVEY A.
For losses of offsite power where less than all offsite power was lost:
1.
How many circuits to the offsite network are nomally available and how many were lost during the event?
2.
What was the cause of the event?
3.
Why did the other lines not fail when some did fail?
4.
Was any voltage increase or decrease experienced just prior to or during the outage? If so, please give details, voltages reached, effects, etc.
5.
Was any frequency decay experienced just prior to or during the outage?
If so, please give details, lowest frequency reached, decay rate, effects on equipment operation, etc.
6.
How long was power unavailable from the circuit?
7.
Date of Event.
Answers to Questions 1, 2, 3, 6, and 7:
FSAR, Chapter 8, Revision 45 describes in detail Calvert Cliffs' offsite power distribution network. LER's 76-5 (U-1), 76-19 (U-1), 76-24 (U-1), 76-50 (U-1),
76-53 (U-1), 78-26 (U-1), 79-40 (U-1), 79-71 (U-1) and 77-3 (U-2) describe which offsite power circuits were lost, the causes of the events, the reasons for the loss of oower, the length of time the circuits were unavailable, and the dates of the events.
Answers to Questions 4 and 5:
None of the events listed above experienced voltage or frequency var iations before or during the time of the circuit outage.
B.
For losses of all offsite power:
1.
How long was the power off? How long for partial recovery? Please give details.
2.
If turbine trip occurred, how soon af ter did loss of offsite power occur?
1747.53
4 ENCLOSURE LOSSOFUFFSITEPOWERSURVEY 3.
If power was recovered promptly (10 minutes or less), was it due to automatic or manual actions?
4 Was any voltage increase or decrease experienced just prior to or during the outage? If so, please give details, voltages reached, effects, etc.
5.
Was any frequency decay experienced just prior to or during the cutage?
If so, please give details, lowest frequency reached, decay rate, effects on equipment operation, etc.
6.
Date of Event Answers to Questions 1 - 6 LER 78-20 (U-1) describes a complete loss of all offsite power at Calvert Cliffs. The LER describes in detail how long power was lost, when power Wds restored, how long af ter the turbine trip occurred power was lost, the date and cause of the event. No voltage or frequency fluctuations were experienced prior to the outage, since the fault was associated with plant switchyard breakers; however, voltage and frecuency decayed to zero in the switchyard during the outage.
1747 354