ML20002A787

Forwards LER 80-058/03L-0

ML20002A787
Person / Time
Site:	Fort Saint Vrain
Issue date:	10/31/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20002A788	List: ML20002A787 ML20002A790
References
P-80385, NUDOCS 8011210575
Download: ML20002A787 (6)

Text

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/ puNie Service Company W OcDonale

( 16805 ROAD 19%

PLATTEVILLE, COLOR ADO 80651 b .s October 31, 1980 Fort St. Vrain Unit.No. 1 P-80385 -

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=.:?Q 2E l Mr. Karl V. Seyfrit, Director EgM -; g Nuclear Regulatory Commission j ~

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Region IV g  :

Office of Inspection and Enforcement G (4 .

611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012

Reference:

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

Dear !!r. Seyfrit:

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

80-58, Preliminary, submitted per ti e requirements of Technical Specifi-cation AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/80-58.

Very truly yours, j 7 Don Warembourg <

Itanager, Nuclear Production DW/cis Enclosure -

cc: Director, MIPC h

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.e OCCt'RRENCE REPORT DISTRIBUTION Number of Copies '

De p a r t ment o f E ne r gy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter)

San Francisco operatione of fice Atto: California Patent Groep 1333 Broadwer Oakland. California . 94612 De pa r tmen t o f E ne r gy - - - - = = = = = - - - - - - - - - = = - - - - - - - - - - 1 (p Legger) office of Nuclear Engineering Programe Vashington D.C. '20545 4

De p a r t men t o f Ene r gy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter)

Mr. Glen A. Newby. Chief HTR Branch ['

' Division of Nuclear Power Development

. Mail Station 5-107 l Washington D.C. 20545 Depa r tme nt o f Ene r gy - - - - - ~ - - - - - = = - - - - - - - - - - - - = = - - - - 1 (P Letter)

Atta Senior Program Coordinator ';

P. O. Box 81323-San Diego. California 92138 i

Mr. Karl V. Seyfrit. Director ------------------------- 1 (Original of P Letter 4 Region IV and Copy of LER)

! Of fice of Inspection and Enforcement Nuclear Regulatory Commisalon 611 Ryan Plata Drive Suite 1000 Arlington. Texas 76012 4

Director - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter. LER)

Of fice of Management Information and Program Control U. S. Nuclear Regulatory Commission Washington, D.C. 20$$$

M r . it ch a r d Phe lp e - J - - - - - - - - - - - - - - - - - - - = = = - - - - - 1 (Original of FPLG Letter PSV. GA. Site plus two Copies. One j . Rep resen tative . Copy of P Letter. One General Atonic Company Copy of LIR)

, . P. O. Sox 426 Platteville, Colorado 80631 - g Mr . B i l l La va lee - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1 (P Letter. LER)

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Nuclear Safety Analysis Canter 3412 Hillview Avenue P. O. Som 10412 Palo Alto. California 94303 NRC Resident Site Inspector --------------===--------- 1 (P Letter LER)

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REPORT DATE: October 31. 1980 REPORTABLE OCCURRENCE 80-58 ISSUE O OCCURRENCE DATE: October 9. 1980 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651 REPORT NO. 50-267/80-58/03-L-0 Preliminary IDENTIFICATION OF OCCURRENCE From 0830 to 1830 hours0.0212 days <br />0.508 hours <br />0.00303 weeks <br />6.96315e-4 months <br /> on October 9,1980, the plant was operated at power with the emergency feedwater header supply to Loop 1 circulators isolated.

This constitutes operation in a degraded mode of LCO 4.2.2a) and is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

EVENT DES CRIPTION:

Fort St. Vrain Technical Specification LCO 4.2.2 specifies the conditions which must be met for circulator operability. Item a) of LCC 4.2.2 requires that a supply of emergency feedwater be available to drive the circulator water turbines. This LCO f urther allows for isolation of the emergency feed-water supply for up to 24 houra without the affected helium circulators being considered inoperable.

A pressure control system is provided to control emergency feedwater flow in each loop under flow or' no-flow conditions. Refer to Figure 1 for simplified diagram of this system. Emergency feedwater is supplied to Loop 1 and Loop 2 he ium circulator water turbine drives via tw separa e flow paths ( CA and S ). The main pressure control valves ( 1 and 2 ) are designed to control feedwater upply p essure utier flow conditions. Additional pressure control valves ( 3 and 4 ) are provided to bleed off any lea *tage from the main valves to the turbine water drain tank under the no-flow conditions which normally exist.

On October 9,1980, graveyard shift, with the plant operating at 27% thermal power and approximately 65 MWe, Operations personnel performing routine rounds

. observed a leak a the line between PV-21243-1 and the turbine water drain tank (see point of Figure 1). The line was isolated at 0830 hours0.00961 days <br />0.231 hours <br />0.00137 weeks <br />3.15815e-4 months <br /> to begin repair wer on the line.

REPORTABLE OCCURRENCE 80-58 ISSUE O Page 2 of 4 EVENT DESCRIPTION: (Cont'd)

Separate valves ( h and h ) are provided for isolation o.f eacft loop. .

During isolation of tha. Loop 1 systam',5 a 1/2't pipa nipple was replaced.

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Repairs were completed by 1830. hours, and the system returned to service within the 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed.by the LCO.

Had it been necessary during this period, the Loop 1 circulators could have been operated on-water turbine drive at reduced speed utilizing a supply from the emergency condensate or firewater systems.

CAUSE DESCRIPTION:

Cause of line leakage was determined to be a result of erosion inside the line at a 90* elbow.

CORRECTIVE ACTION:

The system was isolated, a 1/2" pipe nipple was replaced in the eroded area of the line, and the -system was returned to service.

Because of problems which have been experienced in the past with erosion of valves and piping in this system, a request for design evaluation is being submitted to the Nuclear Projects Department to evaluate whether a design change is in order.

Results will be submitted in a future supplemental report.

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Emergency Feedwater To Backup Ile .dar Bearing Water

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@ @ n To Loop 1 llelium Circulator PV-2124 3 Water Turbine Drives x

oV-211615 x >

n PV-21243-1  !

Qh To Turbine Water

> Drain Tank l

C Location of Line Leakage O To Loop 2 IIelium circulator g V-211616 p

h p PV-21244 Water Turbine Drives ys

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O 5; i PV-21244-1 * '

Q To Turbine Water 8

> Drain Tank a

o Emergency Feedwater Pressure Control M -

8 FIGURE 1 &

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9 REPORTABLE OCCURRENCE 80-58 ISSUE O Page 4 of 4

.' 1 Prepared By: OX[g.@.

Cathy C/ Hirsch Technical Services Technician Reviewed By:

' W sahm echnical Services' Supervisor Reviewed By: L Frank M. Mathie / /

1 Operationd Manager i

Approved By: t

. f / h Don Warotabourg /

Managel, Nuclear Production I

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