ML20004D710

Forwards LER 81-031/03L-0

ML20004D710
Person / Time
Site:	Fort Saint Vrain
Issue date:	05/27/1981
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20004D711	List: ML20004D710 ML20004D717
References
P-81153, NUDOCS 8106090673
Download: ML20004D710 (4)

Text

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Q[,';s, l ^ L3 PLATTEVILLE, COLORADO 80651 ,.3, e A May 27, 1981 ut

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Fort St. Vrain Unit No. 1

,E JW 0 81981 * . i P-81153 M u h%sT C Y /J N .

m Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commission Region IV Office of. Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012

Reference:

Facility Operating License No. DPR-34 Docket No. 50-267

Dear Mr. Seyfrit:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/

81-031, Final, submitted per the requirements of Technical Specification AC 7.5.2 (b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/81-031.

Very truly yours, 7Y A on Waremuourg 47 Manager, Nuclear Production DW/cis Enclosure .

l cc: Director, MIPC

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t REPORT DATE: May 27. 1981 REPORTABLE OCCURRENCE 81-031 ISSUE O OCCURRENCE DATE: Aoril 27, 1981 Page 1 of 3 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROA0 19 1/2

.. PLATTEVILLE, COLORADO 80651 REPORT NO. 267/81-031/03-L-0 ,

Final e

i IDENTIFICATION OF OCCURRENCE:  ;

Ouring normal surveillance testing, "B" diesel engine of "A" diesel generator set tripped and declutched on starting. This is operation .

in a degraded mode per LCO 4.6.1(d) and is reportable per Fort St.  !

Vrain Technical Specification AC 7.5.2(b)2.

EVENT DESCRIPTION:

• On April 27, 1981, with the plant operating at 30% thermal power and 70 MWe, Operations personnel began the weekly surveillance test on >

"A" diesel generator set. Shortly after starting the test, the "B" l diesel engine tripped and declutched, reducing the available output of "A" diesel generator set. The diesel generator set was cleared for repair at 1315 hours0.0152 days <br />0.365 hours <br />0.00217 weeks <br />5.003575e-4 months <br />, and returned to service at 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br />.

"B" diesel generator set was operable during this occurrence, and if necessary, "A" diesel generator was available at a reduced output.

CAUSE DESCRIPTION:

- The cause of "B" engine trip and declutch was improcer load balance between the "A" and "B" diesel engines which resulted in "A" engine carrying more load than "B" engine. Thermocouples in. the exhaust ,

manifolds of each engine detect the outlet exhaust temperature and send a signal to an associated temperature indicating switch. If the individual engine exhaust temperature does not increase to i 175 degrees fahrenheit within 30 seconds, indicative of an engine ,

failure to start or an imbalance between the engines, a trip circuit J is energized which trips and declutches the affected engine.

The improper load balance between "A" and "B" is attributed to normal j wear of the linkage between the -governor terminal shaft and the diesel fuel rack of "B" diesel engine. I 1

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s REPORTABLE OCCURRENCE 81-031 ISSUE O

'Page 2 of 3 CORRECTIVE ACTION:

The linkage between the governor terminal shaft and the fuel rack of "B" diesel engine was adjusted to attain balanced loads between "A" and "B" diesel engine.

The weekly surveillanca on "A" diesel generator was completed successfully. ,

No further corrective action is anticipated or required.  ;

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a REPORTA8LE OCCURRENCE 81-031 ISSUE O Page 3 of 3 r

t-Prepared By: M Paul Moore  !

Technical Services Technician E i

s Reviewed By: [/ . #

g. W'Ganm i

1. Technical Services Supervisor  ;

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Reviewed By:

Frank .y. Matr/e Mb [

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l i Approved By: Mw d '

Con Waremcourg Manager, Nuclear Pro uction )

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