05000267/LER-1979-051, Forwards LER 79-051/03L-0

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Forwards LER 79-051/03L-0
ML19210E327
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 11/16/1979
From: Warembourg D
PUBLIC SERVICE CO. OF COLORADO
To: Seyfrit K
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19210E328 List:
References
P-79274, NUDOCS 7912040337
Download: ML19210E327 (5)


LER-1979-051, Forwards LER 79-051/03L-0
Event date:
Report date:
2671979051R00 - NRC Website

text

.

I public Service Company W CcHendo

(,

16805 Weld County Road 19 1/2, Platteville, Colorado 80651 w. _.._:.

November 16, 1979 Fort S t.

Vrain Unit No. 1 P-79274 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commission Region IV Office of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012 REF:

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

Dear Mr. Seyfrit:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/79-51/03-L-0, Final, submitted per the requirements of Technical Specification AC 7.5.2(b)4.

Also, please find enclosed one copy of the Licensee Event Repert for Reportable Occurrence Report No. 50-267/79-51/03-L-0.

Very truly yours,

A Don Warembourg Manager, Nuclear Production DW/cls cc: Director, MIPC Aoo3.

1472 351 3

t//

791204 0 337

REPORT DATE:

November 16, 1979 REPORTABLE OCCURRENCE 79-51 ISSUE O OCCURRENCE DATE:

October 17, 1979 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLATIEVILLE, COLORADO 80651 REPORT NO. 50-2 67/ 79-51/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

On October 17, 1979, while operating at 5% reactor power, System 21 Loop 1 surge tank level decreased to the low level trip setpoint, which tripped the Loop 1 bearing water purps, making Loop 1 circulators inoperable per Fort St.

Vrain Technical Specification LCO 4.2.1.

This is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)3.

EVENT

DESCRIPTION

On October 17, 1979, reactor power was at 5% and being increased in preparation to put the turbine generator on lina.

A clearance had been returned on the emergency feedwater system and it. cc charged to approximately 1,700 psig. However, the backup bearing water systec had not been returned to service, as it is not put in service until approximate?v 11% power.

See Figure 1.

With the backup bearing water system not in service, the makeup water for the bearing water surge tank, T-2104, comes from the bearing water makeup pump, P-2105, which is run intermittently to maintain proper surge tank level.

The rezetor operator turned P-2105 off and had became involved in an evolution at control panel I-05, when the surge tank low level alarm was received.

It was acknowledged but P-2105 was not started iumediately as the reactor operator returned to the evolution at I-05.

Before he returned to the surge tank level situation, the level had decreased to the low level trip setpoint and tripped Loop 1 bearing water pumps resulting in Loop 1 being automatically shutdown.

The plant protective circuits functioned as expected during this occurrence.

CAUSE

DESCRIPTION:

The procedures that cover operation of System 21 surge tank makeup allowed the situation to develop where the surge tank level was low and the reactor operator

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REPORTABLE OCCURRENCE 79-51 ISSUE O Page 2 of 4

CAUSE

DESCRIPTION:

(Cont'd) was occupied with another matcer.

The reactor operator's response to the bearing water surge tank level low alarm was inadequate as the recommended operator action was not carried out af ter the alarm was acknowledged. This allowed the bearing water surge tank level to decrease to the low level trip setpoint.

The procedure does not adequately address the current operating conditions of System 21 and allows intermittent operation when the bearing water system is re-quired to be operable, and the backup bearing water system is not available to supply makeup.

CORRECTIVE ACTIr*'

The surge tank was filled to the proper level and Loop I returned to service.

The operating procedure has been revised to use backup bearing water (when available) as the normal surge tank makeup. If the bearing water system is required to be operable and the backup bearing water system is not available, either the bearing water makeup pump, P-2105, or the emergency bearing water makeup pump, P-2108, shall be in continuous operation. Personnel involved have been reinstructed in the proper response to control panel alarms. No further corrective action is anticipated or required.

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I T-2104 i

Loop 1 Bearing Water Surg ank

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LV-2135-1 g

Level Control Valve PDV-2191 I -PT1 IN g

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A P V-21105

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P-2105 - Bearina h

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,j Water Makeup Pui 5

Emergency Bearing WatH A

yi Makeup Pump P-2108 I

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FIGURE 1 g

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REPORTABLE OCCURRENCE 79-51 ISSUE O Page 4 of 4

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Prepared by:

g Tsa B. Ree'd

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Technical Ser41ces Technician Reviewed by:

ack W. Gahm Te d cal Services Supervisor Reviewed by: _M[

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frank M Math % /

Operati ns Mahage'r Approved by:

h k df Lod '4are ourg' /

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Manager Nuclear 4'roduction 1472 355

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