ML20024B986

LER 83-020/03L-0:on 830604,emergency Feedwater Header Supply to Loop I Helium Circulator Turbine Water Drive Isolated & Bearing Water Make Up Pump Taken Out of Svc.Caused by Flexitallic Gasket Failure Due to Normal wear.W/830701 Ltr

ML20024B986
Person / Time
Site:	Fort Saint Vrain
Issue date:	07/01/1983
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
LER-83-020-03L, LER-83-20-3L, P-83232, NUDOCS 8307120087
Download: ML20024B986 (5)

Text

NRC FORM 36L U. S. NUCLEAR REGULATORY COMMISSION j7 77),

LICENSEE EVENT REPORT (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

CONTROL BLOCK: l 1

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l o l t6 l9 l C lLICENSEE 7

0 l F CODEl S l V 14l 1 l@l 0 l 0 l - l LICENSE lb 0 l 0 NUMBER l 0 l 0 l 0 l - l 0 26l 0 l@l 4LICENSE 2t> l 1 l ]TYPE l2l0l@l JO l

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SIRc 60l L l@l 0l 5 DOCKET l0l0 l0l2l6 68 l 769 l@lEVENT 0 lDATE 610 l 4 l 8 l 3 l@l 74 75 REPORT0 l 7 l 080l 1 l 8 l 3 D ATE 6 61 NUMDER EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h tol2l l The emergency feedwater header supply to the Loop I helium circulator turbine water l drives was is laced, and the bearing water make up pump was taken out of service on l Lo i 3 I I l o l 41 l June 4,1983, with the plant plant ooerating at power. This constitutes operation in I f,o,3, ga degraded mode of Fort St. Vrain Technical Specifications LCO 4.2.2(a) and (d), and l

.I I o l e l l is reportable per AC 7.5.2(b)2. No accompanying occurrences. No affect on public l

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g a ; ; ; ; health or safety. Related reports: RO 78-06, 79-26, 80-15, 80-23, 80-32, 80-58, l

, o ,, , , 80-77,81-019, 81-046,81-052, 81-054,81-060, 82-028,82-029, 82-031,82-034, 82-036.l 7 8 P C DE CODE SUSC E COMPONFNT CODE SUSC DE S E

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!1 1 6) ! The flexf tallic nuket feVyIf was attributed to normal vear. The casket serlire I L

li 11 1 I surfaces were cleaned and inspected, the gasket replaced, and the emergency feedwater I

, ,, ,7, l supply header was returned to service. The check valve internal components were l i

repaired using qualified replacements or fabricated parts. The valve was leak I

{ g l checked and the bearing water make up pump (P-2105) was returned to service.

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Redundant systems were available and operable. No further corrective action is I

L'_L l I anticipated or reauired . 80 7 8 9 STA  % POWER OTHER STATUS ISC RY DISCOVERY DESCRIPTION N/A' Operator Observation l1 l L' l l Cl@ l 0 l 1 l 0 l@l l lAl@l l l A TIVITY CO TENT RELE ASED OF RELE ASE AMOUNT OF ACTIVITY LOCATION OF RELE ASE

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, PERSONNEL INJURIES

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NA l lTT 1 7 8 9 10 "I"5lo l@l 11 12 i 80 LOSS OF OR DAMAGE TO FACILITY TYPE DE SCRIPTl N 1 9 (_Zj@l N[A k k l

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NRC USE ONLY j

DESCRIPTION @PDR ADOCK 05000267 l @ (N_jhl N/A , ., .

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\ PHONE:

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NAME OF PREPARER ,p

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@ CCEGIf8DdG 16805 Road 19 1/2, Platteville, Colorado 80651-9298 p-? 7 July 1, 1983 Fort St. Vrain Unit No. 1 P-83232

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Mr. John T. Collins, Regional Administrator Region IV .

Nuclear Regulatory Commission 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011

Reference:

Facility Operating Licente No. CPR-34 Docket No. 50-267

Dear Mr Collins:

Enclosed please find a copy of Reportable Occurrence Repert No. 50-267/83-020, Final, submitted per tne requirements of Techt.icel Specification AC 7.5.2(b)2. -

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/83-0#. ,

1 Very truly yours, l N et SM Don Warembourg Manager, Nuclear Production DW/cis Enclosure

, cc: Director, MIPC D

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REPORT DATE: July 1, 1983 REPORTABLE OCCURRENCE 83-020 ISSUE O OCCURRENCE DATE: June 4. 1983 Page 1 of 3 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY. ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298

. REPORT NO. 50-267/83-020/03-L-0 5-

! Final IDENTIFICATION OF OCCURRENCE:

During power operatien, on June 4, 1983, the emergency feedwater supply header to the Loop I helium circulator water turbine drives was isolated, and approximately one hour and fifty minutes later, the bearing water make up pump (P-2105) was taken out of service. These events constitute operation in degraded mcdes of Fort St. Vrain Technical Specifications LCO 4.2.2(a) and (d), respectively, and are reportable per AC 7.5.2.(b).2.

EVENT DESCRIPTION _;

Event No. 1:

At approximately 0450 hours0.00521 days <br />0.125 hours <br />7.440476e-4 weeks <br />1.71225e-4 months <br /> on Jun: 4, 1983, with the plarit operating at 10% power, a flange gasket failed on the inlet piping to emergency feedwater header relief valve, V-21522. The external water leakage necessitated the isolation of the emergency feedwater header to the Loop I helium circulator water turbine drives until repairs could be accomplished. j If necessary, the affected helium circulators could have been operated on the water turbine drives at a reduced speed utilizing the

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water supplied from the emergency condensate or the firewater system.

I Event No. 2:

At approximately 0645 hours0.00747 days <br />0.179 hours <br />0.00107 weeks <br />2.454225e-4 months <br /> on June 4, 1983, with the plant operating l

at 10% power, the bearing water make up pump, P-2105, was taken out of service. This action was necessary to allow an internal, visual

. inspection of check valve, V-21843, for operability. This check valve is located in the discharge piping of P-2105. Had it become necessary, the emergency bearing water make up pump, P-2108, was cvailable and operational to supply make up bearing water to the helium circulator bearing water surge tanks.

V" REPORTABLE OCCURRENCE S3-020 ISSUE O Page 2 of 3 CAUSE DESCRIPTION:

Component Failure Event No. 1:

I The flexitallic flange gasket on V-21522 was found deformed and the L

gasket surfaces washed out. This condition is attributed to normal t wear and operating conditions.

Event No. 2:

The inspection of the check valve (V-21843) internal components revealed that the disc hinge pin and bushing were missing. Corrosion of the set screw holding the hinge pin to the valve body allowed the hinge pin to become dislodged resulting in the faulty operation of the check valve.

The check valve (V-21843) was manufactured by the Crane Company, and is a 3 inch, ccrbon steel, cast, check, model no. Ib73.

CORRECTIVE ACTION:

Event No. 1:

T'e n flange sealing surfaces were inspected for wear, surfaces were cleaned, and a new flexitallic gasket was installed.

The emergency feedwater header was returned to service at 1430 hours0.0166 days <br />0.397 hours <br />0.00236 weeks <br />5.44115e-4 months <br /> on June 4, 1983.

Event No. 2:

A new disc hinge pin was fabricated and installed. The seal ring, lock nuts, and set screws were replaced with the set screws tack welded in place. The valve was ' reassembled and leak checked.

Following repair of the check valve, the bearing water make up pump was returned to service at 1615-hours on June 4, 1983.

. The total duration of both events was 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> and 25 minutes, within the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period allowed by LCO 4.2.2. No further corrective

. action is anticipated or required.

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REPORTABLE OCCURRENCE 83-020 ISSUE 0 Page 3 of 3 i

Prepared By: EsmI . [tr Robert A. Dickerdf6n Senior Technical Services Technician

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Reviewed By: [ '

Frank Q A o'vachek b Technical Services Engineering Supervisor Reviewed By: 7M 1 97d 4 L. Milt 6n McBride '

Station Manager Approved By: MuJM, Don Warembourg /

Manager, Nuclear ProdGetion E