05000267/LER-1982-043, Forwards LER 82-043/03L-0.Detailed Event Analysis Encl

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Forwards LER 82-043/03L-0.Detailed Event Analysis Encl
ML20070F227
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 11/24/1982
From: Warembourg D
PUBLIC SERVICE CO. OF COLORADO
To: Jay Collins
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20070F230 List:
References
P-82531, NUDOCS 8212200123
Download: ML20070F227 (5)
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LER-1982-043, Forwards LER 82-043/03L-0.Detailed Event Analysis Encl
Event date:
Report date:
2671982043R00 - NRC Website
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ptIniie service conipaniy e cenetniosa 16S05 Road 19 1/2, Platteville, Colorado 80651-9298 November 24, 1982 Fort St. Vrain Unit No. 1 P-82531 i

Mr. John T. Collins, Regional Administrator Region IV Nuclear Regulatory Commission 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011

Reference:

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

Dear Mr. Collins:

Enclosed please find a copy e'

Reportable Occurrence Report No. 50-267/82-043, Final, submitted par the requirements of Technical Specification AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/82-043.

V y truly yours, l

1D Don Warembourg Manager, Nuclear Production DW/cis Enclosure ce Director, MIPC h

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O 8212200123 821124 PDR ADOCK 05000267 S

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F REPORTABLE OCCURRENG DISTRIBUTIM mmbe r o f Coo t es Dep ar tmen t o f Ene r gy - - - - - - - - - - - - - - - - - - - - - - - - - - -

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San Francisco operations Of fice Attn: California Patent Group 1333 3 roadway Oakland, California 96612 De p a r t:e n t o f En e r gy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter)

Mr. Glen A. Newby, Chie f HTR 3 ranch Division of Nuclear Pcwer Development Mail Station 5-107 Washin gton, D.C.

20545 De p a r t :ne n t o f En e r gy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - a (P latter)

Attn : Project Manager P. O. Box S1608 San Diego, California 92138

!!r. John T. Collins, Regional Administrator 1 Original of P latter)

P4sien IV Nuclear Pegulatory Cornission 611 Ryan Plaza Drive S uite 1000 Arlin gt on, Te xas 76011 M r. Ge o r ge K uz:rr e z - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

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Nuclear Regulatorv Co-.is sion 7920 Norf olk Avenue Be thesda, Maryland 20034 Di r e c t o r - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Le t te r)

Of fice of Management Information sad Program Control Nuclear Regulatory Comission Washington, D.C.

20555 INPO Records Center 1 (P Letter)

Suite 1500 1100 circle 75 Parkvay Atlanta, GL 30339 Mr. Richa rd Phe lp s FS7, CA. S i te Rep re sen t ative - - - - - - - - - - - - - - - -

1 (P Letter)

General Atomic Cocoany 16864 Weld County Road 191/2 Platteville, Colorado 80651 NRC Resident Site Inspector 1 (P Letter)

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REPORT DRTE:

Noven6er 24,1982 REPORTABLE OCCURRENCE 82-043 ISSUE 0 OCCURRENCE DATE:

October 28, 1982 Page 1 of 3 FORT ST. VRAIN NUCLEAR GENERATING STATION i

PUBLIC SERVICE COMPANY OF COLORADO l

16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298 REPORT NO. 50-267/82-043/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

On October 27, 1982, and October 28, 1982, with the reactor shutdown, the average of the prestressed concrete reactor vessel cooling water system (System 46) inlet and outlet temperatures in both loops fell below 100 degrees fahrenheit. This constitutes a degraded mode of LCO 4.2.15(e) and is being reported per Fort St. Vrain Technical Speci fication AC 7.5.2(L,'2.

EVENT

DESCRIPTION

On October 25, 1982, with auxiliary boiler #2 already out of service, auxiliary boiler #1 was also taken out of service for maintenance.

Since a portion of the steam supply from these boilers is used to control water temperatures in the PCRV cooling water system (System 46) during shutdown conditions when reactor heat is insufficient to do so, the loss of the boilers caused the average of the System 46 inlet and outlet water temperatures to trend toward the 100 degrees fahrenheit minimum allowed by LCO 4.2.15(e).

This downward trend continued until Loop 2 of System 46 was manually shutdown at 2210 hours0.0256 days <br />0.614 hours <br />0.00365 weeks <br />8.40905e-4 months <br /> on October 26, 1982. The reduced heat removal rate that resulted from this action was sufficient to stabilize the Loop 1 average temperature at a value slightly above the 100 degrees fahrenheit limit.

Cooling water flow through Loop 2 of System 46 was re-established on October 27, 1982, at 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br /> with the idea that auxiliary boiler

  1. 1 was being returned to service. Due to the fact that the boiler was not returned to service until 1455 hours0.0168 days <br />0.404 hours <br />0.00241 weeks <br />5.536275e-4 months <br /> the same day, the average of the inlet and outlet water temperatures in Loop 2 of System 46 remained less than the 100 degrees fahrenheit minimum from the time that flow had been re-established. The presence of water in the line from the boiler to the System 46 surge tank further inhibited the supply of steam to the System 46 surge tanks. As a result, the average temperature in Loop 1 of System 46 also fell

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below the 100 degrees fahrenheit limit at 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br />.

Additional problems were experienced in the early morning hours of October 28, 1982, with malfunctioning auxiliary boiler feedpumps, and

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REPORTABLE OCCURRENCE 82-043 ISSUE O Page 2 of 3 consequently, heating of the System 46 surge tanks was not observed until approximately 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br />.

Loop 1 of System 46 returned to full compliance with LCO 4.2.15(e) at 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br />, and Loop 2 at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> on October 28, 1982.

The reactor remained in a cold shutdown condition throughout the event.

CAUSE

DESCRIPTION:

Equipment malfunction.

Operator error.

The residual decay heat production rate from the reactor was, by itself, insufficient to maintain the loop averages of the PCRV cooling water system inlet and outlet temperatures above the 100 degrees fahrenheit minimum specified in LCO 4.2.15(e) when both of the loops were in service. To maintain the loop averages above 100 degrees fahrenheit with more than one loop in service, auxiliary heat was required but was not immediately available due to equipment malfunctions. As a result of these malfunctions and the failure of the operating personnel to remove a System 46 loop from service, when it was apparent insufficient heat was available, the loop averages fell below the 100 degrees fahrenheit minimum.

CORRECTIVE ACTION:

Auxiliary boiler #2 was put in service to increase the heat input to the PCRV cooling water system.

Correct operation of the PCRV cooling water system during all conditions will be reviewed with all Licensed Operators by the Training De-e*-ent.

No further corrective action is anticipated or required.

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REPORTABLE OCCURRENCE 82-043 ISSUE O Page 3 of 3 i

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Prepared By:

v.u Pau? A/ Tramp Techafcal Services Technician Reviewed By:

<//[m C?iaries Fuller Technical Services Engineering Supervisor

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Reviewed By:

Edwin 0. Hill Station Manager Approved By:

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Manager, Nuclear *9roduction

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