ML20085M565

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
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: ML20085M565 ML20085M571
References
AO-50-267-74-23, P-75036, NUDOCS 8311090009
Download: ML20085M565 (4)

Text

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.5EPCRT T/ ATE: r.ecember ??. 1975 --

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

Dece-i.IOUBolU361,. Plattev111e, Colorado 80651

'3 4 10RT ST. VRAIN 'n 8 C STAT!ON PUBLIC SER'! ... gI(4 DADO

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s December 22, 1975 RCPC. p< U. .-

Fort St. Vrain

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Unit No. 1

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.s 10tN?IFIC.T'ON OF 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'tI " .

Suite 1000 C' Arlington, UTexas 76012 ~

10 c;.ca.%.:  : Stcady State Powe .o

r. ut ins. Sh u '.down

, Hot Shuwown Raft FacilityOperatingLi[ense """","

No. DPR-34 ~

X Cold Shutdowr cthor (specify)

Docket No. 50 267_

Dear Mr. Howard:

Refueling S utdoen - pjaar out of we/f ce to ch ;n:

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

74/23A Fina Tt4gge,gg,,,,, .. .l,,-asubmitted

_a x. a u 6 p_er. 25 the.u- requirements. ~6 ..--mg of the.- - Technica.

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(Speci-Power m O Wth Very truly yours, ELECI O  %'e \

Secondary Coolant ~

Freddde"~E;-- Sum si8 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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N/A *F Core Outlet Flov 0 9/hr.

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. REPORT DATE: December 22. 1975 ABNORMAL OCCURRENCE 74/23A Page 1 of 3 OCCURRENCE DATE: December 11, 1974 l

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

^

Flow 0 #/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 i generator 1A declutched. No alarms annunciated.

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: t l

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 ,

Reviewed by: N Francis M. Mathie Superintendent, Maintenance Approved by: 2 ~

Ffederic E. Swart j Superintendent, Nuclear Production e

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