ML20085M565

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AO 50-267/74/23A:on 741211,engine a of Standby Diesel Generator 1A Declutched During 2 H Surveillance Run & No Alarm Annunciated.Caused by Dirt Under Seat of Solenoid Valve.Plant Change Notice 12 Initiated
ML20085M565
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 12/22/1975
From: Hillyard H, Mathie F, Swart F
PUBLIC SERVICE CO. OF COLORADO
To: Howard E
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20085M570 List:
References
AO-50-267-74-23, P-75036, NUDOCS 8311090009
Download: ML20085M565 (4)


Text

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r.ecember ??. 1975 ABNOR!taidCC!!RRE: ICE 71./23A-Tage 1 of 3 GCCURRENCE DATE:

Dece-i.IOUBolU361,. Plattev111e, Colorado 80651

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December 22, 1975 Fort St. Vrain

/f Unit No. 1

, 'T P-75036 10tN?IFIC.T'ON OF

.s Td d 'F2 Horris.Howard, Director Nuclear Regulatory Commission EnFRegion'IV.x

/ di:.:n.wne.ator 1.A declutched durin3 a two hour sur-ve officg of4Insp~ect'16n'a~nd Edfoice'me'n't "

I Suite 1000 C' Arlington, Texas 76012

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Stcady State Powe

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Raft FacilityOperatingLi[ense Hot Shuwown No. DPR-34

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X Cold ShutdowrDocket No. 50 267_

cthor (specify)

Dear Mr. Howard:

Refueling S utdoen

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Enclosed please find-a-copy-of Ab' norm %....,al Oc' urrence Report Nor.-501267/

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c 74/23A Fina Tt4gge,gg,,,,,...l, submitted p_er. the. requirements. of the. Technica. (Speci-

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Power m

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Secondary Coolant Freddde"~E;-- Sum si8

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Superintendent, Nuclear Production Fort' St. ' Vrain--Nucles/

Gen,arating Station 0

f/hr.

FES/alk 4t.ury Coolant Pressure N/n.

poig cct Mr. Roger S. Boyd Tenc rature N/A

  • F Core Inlet

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  • F Core Outlet Flov 0

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. REPORT DATE:

December 22. 1975 ABNORMAL OCCURRENCE 74/23A Page 1 of 3 OCCURRENCE DATE:

December 11, 1974 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO P. O. BOX 361 PIATTEVILLE, COLORADO 80651 REPORT No. 50-267/74/23A Final

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IDENTIFICATION OF OCCURRENCE:

i Engine A of standby diesel generator lA declutched during a two hour sur-veillance run and no alarms annunciated.

CONDITIONS PRIOR TO OCCURRENCE:

Steady State Power Routine Shutdown Hot Shutdown Routine Load Change X

Cold Shutdown Other (specify)

Refueling Shutdown Plant out of service to change Routine Startup circulator pelton wheele.

The major plant parameters at the time of the event were as follows:

Power ITR O

Weh ELECT 0

We Secondary Coolant Pressure O

psig Temperature 0

'F Flow 0

f/hr.

s Primary Coolant Pressure N/A psig 7

l Temperature N/A

'F Core Inlet N/A

'F Core Outlet

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Flow 0

  1. /hr.

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ABNOMfAL OCCURRENCE 74/23A Page 2 of 3 VESCRIPTION OF OCCURRENCE:

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.During the two hour weekly surveillance test at 1/2 load, engine A of standby generator 1A declutched.

No alarms annunciated.

i On a second attempt the engine again declutched as soon as the unit was started.

Again no alarms annunciated.

i APPARENT CAUSE OF OCCURRENCE:

Design Unusual Service Cond Including Environ.

Manufacture Component Failure Installation /Conse.

X Other (specify)

Operator See below.

l Procedure Dirt under the seat of the solenoid valve to the clutch operating cylinder

-allowed the cylinder air pressure to decay, and the unit to declutch.

No alarms came on because the valve had not operated and because the alarm actuating switch had not been made up when the clutch was engaged, due to an improper adjustment.

ANALYSIS OF 7

OCCURRENCE:

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The air line to the solenoid contains sufficient small foreign particles to cause leakage through the solenoid valve when these particles become lodged under the seat.

CORRECTIVE ACTION:

l It has been recognized for some time that this occurrence was a possibility.

Accordingly Plant Change Notice No. 12 was initiated some time ago and was approved in December, 1974. This change notice provides in-line filters in the air lines to the solenoid valves, to remove any foreign material which I

might interfere with solenoid valve operation.

1 The position of the alarm limit switch relative to the clutch operating cy-linder is now checked periodically and cyclinder adjustments are made as re-quired to ensure alarm actuation on declutching.

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ABNORMAL OCCURRENCE 74/23A Page 3 of 3 FAILURE DATA /SIMILAR REPORTED OCCURRENCES:

None PROGRAMMATIC IMPACT:

None

[,0DE IMPACT:

.s None Submitted by:

t H. 9.' Hil/fard, Jr./

Technical Services Supervisor N

Reviewed by:

Francis M. Mathie Superintendent, Maintenance Approved by:

2 Ffederic E. Swart

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j Superintendent, Nuclear Production e

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