ML18152A711

LER 87-037-00:on 871203,emergency Diesel Generator 3 Automatically Started.Caused by Blown Fuse & Failed Relay. Undervoltage Relay 59 ABC-1J1 & Dc Control Fuse Replaced.W/ 871222 Ltr

ML18152A711
Person / Time
Site:	Surry
Issue date:	12/22/1987
From:	Benson D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
87-041, 87-41, LER-87-037, LER-87-37, NUDOCS 8712310232
Download: ML18152A711 (4)

Text

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NRC Form 386 19,831 e e POW 28-06-01 U.S. NUCLEAR REGULATORY COMMISSION APPROVED 0MB NO. 3150-0104 LICENSEE EVENT REPORT (LERI EXPIRES: 8/31/88 FACILITY NAME 11 l I DOCKET NUMBER 121 I PAGE 131 Surry Power Station, Unit 1 and Unit 2 o I s I o I o I o 12 18 1 ol , loF nl~

TITLE 141 Emergency Diesel Generator Auto-Start Due to Failed Relay and Blown Fuse EVENT DATE ISi LER NUMBER 161 REPORT DATE 171 OTHER FACILITIES INVOLVED 181 MONTH DAY YEAR YEAR 1:::::/ SEQUENTIAL NUMBER kt REVISION NUMBER MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERISI 01s1010,0 1 I I 1 I2 013 8 7 81 7 - o I 3'7 - o I o 1 I 2 212 81 7 o,s,o,o,o, I I OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: /CMci< ono o, more of rhe follow,ngJ 1111 POWER MOOE 191 I 11 N

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20.405111!1lliv) l50.7311112lliil II0.7311) (Z)(viii) 1Bl 20.405111(1 )Iv) 50.7311ll2lliii) 50.73(1)(211*1 LICENSEE CONTACT FOR THIS LER 1121 NAME TELEPHONE NUMBER AREA CODE David L. Benson, Station Manager 81 o, 4 3 15 I 7 1-13 I 11814 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 1131 MANUFAC- REPORTABLE  :*.::::: :::::::,:.:: ::::::::: :.,.:/}: MANUFAC. REPORTABLE CAUSE SYSTEM COMPONENT TURER TO NPRDS  :.:,:.,.:,: *:-:;::: :;:::,:,:::::: CAUSE SYSTEM COMPONENT TURER rnr***:***tt:::::::*  :::::::::::::::::

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SUPPLEMENTAL REPORT EXPECTED 1141 MONTH DAY YEAR EXPECTED Fxi SUBMISSION h YES (If yo,. compllro EXPECrED SUBMISSION DArEt NO DATE 1151 I I I ABSTRACT (Umir ro 1400 s,,.c*s. i., .. *ppro1tim*r11y fifrHn singl1-spact1 rvp1wrirtt1n lint1s} 1161 On December 3, 1987, at 0928 hours0.0107 days <br />0.258 hours <br />0.00153 weeks <br />3.53104e-4 months <br />, with Unit 1 and Unit 2 at 100% power, Bus lJ undervoltage alarm (EIIS-ANN) and Bus lJ overvoltage alarm (EIIS-ANN) were received, Operations personnel observed that the main station battery (EIIS-BTRY) ground lights flickered. Emergency Diesel Generat*or #3 (EDG) (EIIS-DG) automatically started, which is an engineered safety feature actuation. At 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br />, the alarms cleared. At 0946 hours0.0109 days <br />0.263 hours <br />0.00156 weeks <br />3.59953e-4 months <br />, EDG #3 was placed in its cooldown cycle, At 0950 hours0.011 days <br />0.264 hours <br />0.00157 weeks <br />3.61475e-4 months <br />, it was returned to the automatic mode. At 0954 hours0.011 days <br />0.265 hours <br />0.00158 weeks <br />3.62997e-4 months <br />, the alarm for Bus lJ undervoltage was received, and the #3 EDG auto-started again and was manually loaded onto lJ Bus. The cause of the auto-start of 113 EDG was a blown DC fuse (EIIS-FU) in the degraded voltage circuit. Relay (EIIS-59) 59 ABC-lJl, the overvoltage relay surge capacitor, failed and shorted to the relay case. This caused the positive DC fuse in the degraded voltage circuit to blow. The first auto-start of #3 EDG at 0928 hours0.0107 days <br />0.258 hours <br />0.00153 weeks <br />3.53104e-4 months <br /> was due to the arcing of the surge capacitor with the relay case. When the surge capacitor failed and flashed to ground, DC power was lost, causing the undervoltage signal and the auto-start of the diesel at 0954 hours0.011 days <br />0.265 hours <br />0.00158 weeks <br />3.62997e-4 months <br />. The undervoltage relay 59 ABC-lJl and the DC control fuse were replaced, and the circuit was returned to normal, The #3 EDG was stopped and placed in automatic at 1655 hours0.0192 days <br />0.46 hours <br />0.00274 weeks <br />6.297275e-4 months <br />.

8712310232 871222 PIIR AIIOCK 05000280 -_j s DCII

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U.I INCLIAII IIIOULATOIIY COIIM. . 10,W LICENSEE EVENT REPORT ILERI TEXT CONTINUATION All'PIIIOYIO Otill OfO JI IO..OIC>*

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• • en.in - 111 DOCKI T INIIIIII 111 LIii ._.._Ill Ill ,ao1 111 Surry Power Station, Units l & 2 o 11 1o Io Io 12 I SI o a 17 - o 13 I 7 - 01 o o 12 oF o I 3 TIXT,, _ -

• _... - - . . IIIIIC ,,.,_ _.'al 1171 1.0 Description of the Event On December 3, 1987, at 0928 hours0.0107 days <br />0.258 hours <br />0.00153 weeks <br />3.53104e-4 months <br />, with Units 1 and Unit 2 at 100\ power, Bus lJ undervoltage alarm

{EIIS-ANN} and Bus lJ overvoltage alarm {EIIS-ANN}

were received. Operations personnel observed that the main station battery {EIIS-BTRY} ground *lights flickered. Emergency Diesel Generator 43 (EDG)

{EIIS-DG} automatically started, which is an engineered safety feature actuation. At 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br />, the alarms cleared. At 0946 hours0.0109 days <br />0.263 hours <br />0.00156 weeks <br />3.59953e-4 months <br />, EOG 43 was placed in its cooldown cycle. At 0950 hours0.011 days <br />0.264 hours <br />0.00157 weeks <br />3.61475e-4 months <br />, it was returned to the automatic mode. At 0954 hours0.011 days <br />0.265 hours <br />0.00158 weeks <br />3.62997e-4 months <br />, the alarm for Bus lJ undervoltage was received and the 43 EOG auto-started again and was manually.loaded onto lJ Bus.

2.0 Safety Consequences and Implications The i3 EOG is designed to supply power to either the Unit 1 (lJ) emergency bus or the Unit 2 (2J) emergency bus. During this event, the *3 EOG was paralleled and loaded tn the lJ emergency bus.

During this time, *3 EI)(:, remained capable of supplying power to Unit 2 (2J) emergency bus. Therefore, the health and safety of the public were not affected.

3.0 cause The cause of the auto-start of i3 EOG was a blown DC fuse {EIIS-FU} in the degraded voltage_circuit.

Relay {EIIS-59} 59 ABC-lJl, the overvoltage relay surge capacitor, failed and shorted to the relay case. This caused the positive DC fuse in the degraded voltage circuit to blow. The first auto-start of 13 EDG at 0928 hours0.0107 days <br />0.258 hours <br />0.00153 weeks <br />3.53104e-4 months <br /> was due to the arcing of the surge capacitor with the relay case. When the surge capacitor failed and flashed to ground, DC power was lost, causing the undervoltage signal and the auto-start of the diesel at 0954 hours0.011 days <br />0.265 hours <br />0.00158 weeks <br />3.62997e-4 months <br />.

4.0 Immediate Corrective Action The inunediate corrective actions included paralleling EOG 13 with lJ emergency bus's normal supply and loading the diesel onto the bus.

POW 28-06-01

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5. 0 Additional Corrective Ac ti.on ( s)

The overvoltage relay 59 .ABC~lJl, and the DC control fuse were replaced and the circuit was returned to normal. The *3 EDG was stopped and placed in automatic at 1655 hours0.0192 days <br />0.46 hours <br />0.00274 weeks <br />6.297275e-4 months <br />.

6.0 Action(s) Taken to Prevent Recurrence

• None required.

7.0 Similar Events None.

8.0 Manufacturer/Model Number General Electric/125LV llAlA.

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e VIRGINIA ELECTRIC AND POWER COMPANY Surry Power Station P.O. Box 316 Surry, Virginie 23883 December 22, 1987 U.S. Nuclear Regulatory Commission Serial No.: 87-041 Document Control Desk Docket No.: 50-280 016 Phillips Building 50-281 Washington, D.C. 20555 Licensee No.: DPR-32 DPR-37 Gentlemen:

Pursuant to Surry Power Station Technical Specifications, Virginia Electric and Power Company hereby submits the following Licensee Event Report for Surry Unit 1 and Unit 2.

REPORT NUMBER 87-037-00 This report has been reviewed by*the Station Nuclear Safety and Operating Committee and will be reviewed by Safety Evaluation and Control.

Very truly yours, David L. Benson Station Manager Enclosure cc: Dr. J. Nelson Grace Regional Administrator Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323