ML20059D989
| ML20059D989 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 01/03/1994 |
| From: | Feigenbaum T PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NYN-94001, NUDOCS 9401100176 | |
| Download: ML20059D989 (3) | |
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Seab NH 03874
. Telephone (603)474-9521
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Facsimile (603)474 2987
. Energy Service Corporation Ted C. Felgenbaum Senior Vbe President and Chief Nuclear Officer NYN 94001 January 3,1994 United States Nuclear Regulatory Commission
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Washington, D.C. 20555 Attention:
Document Control Desk
Reference:
Facility Operating License No. NPF-86, Docket No. 50-443
Subject:
Diesel Generator Special Report Gentlemen:
The following Diesel Generator Special Report documents diesel generator failures which occurred during the month of December 1993 and are being reported pursuant to Technical Specification 4.8.1.1.3.
I 1.
On December 1,'1993, while perfonning the Train B Emergency Diesel Generator _(EDG) monthly.
surveillance, an alarm indicated that the EDG auxiliary coolant pump was running. The associated alann response procedure recommended shutting down the EDG in non-emergency situations.
The Train B EDG was shutdown approximately 12 minutes after starting the engine and prior to loading.
Each EDG is equipped with an electric powered auxiliary coolant pump which supplies engine coolant in the event either engine driven coolant pump fails. The auxiliary coolant pump is automatically started when a low pressure is sensed in the engine coolant system. A failure in the air cooler pressure control loop caused the auxiliary coolant pump to start. - The pressure control loop was repaired.
2.
On December 1,1993, while conducting post maintenance testing on the Train B EDG the auxiliary coolant pump automatically started. This was due to oscillations in thejacket coolant a
pressure control loop. The pressure control loop was repaired.
I 3.
On December 2,1993, the Train B EDG was started for post maintenance operability testing.
The auxiliary coolant pump started approximately 26 minutes following the EDG start and after.
the EDG was loaded. The EDG was unloaded and the output breaker opened 22 minutes afler the auxiliary coolant pump started. The EDG was shutdown 12 minutes later.. Additional adjustment on the air cooler pressure control loop was performed. Following successful post maintenance and post maintenance operability testing, the Train B EDG was returned to operable status.
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9401100176 940103 PDR. ADOCK 05000443.y
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United States Nuclear Regulatory Commission January 3,1994 Attention:
Document Control Desk Page two In accordance with Regulatory Position C.2.c.(6) of Regulatory Guide 1.108, Revision I, August
-l 1977, the above events are considered to be valid tests. Ilowever, these events are considered to be non-valid failures. The auxiliary coolant pump starting during nonnal or emergency conditions would not have resulted in EDG damage or failure. Previous to these non-valid failures, the Train B EDG has had 3 valid a
failures in the last 100 starts. Because the above events are non-valid failuress the number of valid failures in the last 100 starts remains unchanged. Pursuant to Technical Specification Table 4.8.1, the required test schedule for the Train B EDG is at least once per 31 days. As a result of these events, the Train B -
EDG was inoperable for approximately 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br />.
4.
On December 16,1993, while performing the Train A EDG monthly surveillance, the EDG output breaker opened and the engine automatically shutdown after the EDG had been successfully started and loaded fbr approximately 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />. The cause of the automatic breaker trip and engine shutdown was actuation of a reverse power relay. This relay is designed to protect the generator from a reverse power condition when the EDG is paralleled to an offsite power supply. The reverse power relay actuation was caused by malfunction in the EDG speed / load control circuitry.
The EDG speed / load control circuit was repaired.
in accordance with Regulatory Position C.2.e.(2) of Regulatory Guide 1.108, Revision 1,' August 1977, this event is considered to be a valid test. However, the speed control malfunction wouki not have prevented the EDG from operating in the emergency mode. Therefore, this event is~
~i considered a non-valid faibire.
5.
On December 18, 1993, while performing post maintenance operability testing on the Train A -
.l EDG, the test was terminated prior to loading the engine. ' The test was terminated because a temporary recorder installed only during testing to measure EDG voltage and frequency q
malfunctioned. In accordance with Regulatory Position C.2.e.(2) of Regulatory Guide 1.108, _
Revision 1, August 1977, this event is considered to be a valid test. Ilowever, because the '
y recorder is not part of the plant design and is only installed when testing the EDG, this event is i
a non. valid failure. The recorder malfunction was repaired and the test successfully completed.
Previous to these non-valid failures (events 4 and 5), the Train A EDG had 2 valid failures in the last 100 starts. Liecause the above events are non-valid failures, the number of valid failures in the last l
100 starts remains unchanged. Pursuant to Technical Specification Table 4.8-1, the required test schedule for the Train A EDG is at least once per 31 days. As a result of these events, the Train A EDG was inoperable for approximately 42 hours4.861111e-4 days <br />0.0117 hours <br />6.944444e-5 weeks <br />1.5981e-5 months <br />.
6.
On December 29,1993, while performing the Train B EDG monthly surveillance, the auxiliary
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coolant pump automatically stated. The EDG was shutdown and the air cooler pressure control loop was repaired. In accordance with Regulatory Position C.2.e.(6) of Regulatory Guide 1.108, l
Revision 1, August 1977, this event is considered to be a valid test. Ilowever, this event is l
considered to be a non-valid failure because the auxiliary coolant pump starting during normal or emergency operating conditions would not have resulted in EDG damage or failurec At the time
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of this event :he plant was in Mode 1 at 100% power.
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i United States Nuclear Regulatory Commission January 3,1994
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. Document Control Desk Page three.
Previous to this failure, the Train 13 EDG had 3 valid failures in the last 100 Jtarts. Because the above event is considered a non-valid failure, the number of valid failures in the last 100 stans is_
. unchanged. Pursuant to Technical Specification Table 4.8-1, the required test schedule for the Train B EDG is at least once per 31 days. As a result of this event, the Train B EDG was inoperable for approximately 27 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br />.
Should you require further infonnation regarding this matter, please contact Mr. James M. Peschel, Regulatory Compliance Manager, at (603) 474-9521 extension 3772.
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Very tru y',yours, n "s ab
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Ted C. Feigenbantu TCF:MDO/act cc:
Mr. Thomas T. Martin
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. Regional Administrator j
U.S. Nuclear Regulatory Commission i
Region I l
475 Allendale Road King of Prussia, PA.19406 Mr. Albert W. De Agazio, Sr. Project Manager Project Directorate 1-4 Division of Reactor Projects M
U.S. Nuclear Regulatory Commission Washington, DC 20555 l
1 Mr. Noel Dudley NRC Senior Resident inspector P.O. Box 1149 1
Seabrook, Nil 03874 i
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