ML19321A516

Forwards LER 80-034/03L-0

ML19321A516
Person / Time
Site:	Fort Saint Vrain
Issue date:	07/15/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19321A517	List: ML19321A516 ML19321A522
References
P-80213, NUDOCS 8007230548
Download: ML19321A516 (5)

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public Servlee Company & CoHoemTo i

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16805 ROAD 19%

PLATTEVILLE, COLORADO 80651 l

July 15, 1980 Fort St. Vrain Unit No. 1 P-80213 ,

1 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Commission Region IV Office of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012

Reference:

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

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Dear Mr. Seyfrit:

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

80-34, Preliminary, submitted per the requirements of Technical Specifi-cation AC 7.5.2(b)1 and AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/80-34.

Very truly yours, A- w%

Don Warembourg Manager, Nuclear Production DW/cis Enclosure

• cc: Director, MIPC I

8007230 3

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REPORT DATE: July 15, 1980 REPORTABLE OCCURRENCE 80-34 ISSUE O OCCURRENCE DATE: June 19, 1980 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATIEVILLE, COLORADO 80651 REPORT No. 50-267/80-34/03-L--O Preliminary IDENTIFICATION OF OCCURRENCE:

During performance of the monthly check of the helium circulator seal mal-function pressure differential switches, it was discovered that two of

. twelve switch units tripped outside the limits specified in LCO 4.4.1, Table 4.4-3.

This is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)1 and AC 7.5.2(b)2.

EVENT DESCRIPTION:

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During normal plant operation, instrument personnel performed the circulator seal malfunction (buffer-mid-buffer) switch operability check. The switches are normally calibrated on an annual basis; however, due to the problems cited in the previous reports as listed on the LER, a check of buffer-mid-buffer trip settings on a monthly basis has been undertaken as an interim measure to test operability.

There are twelve buffer-mid-buffer switch units, three per circulator. Each

. switch unit contains two electrical switches. The range of c:te sensing ele-ment is from (-) 100 inches of water to zero to (+) 100 inches of water.

One of the electrical switches in each unit must operate at greater than or equal to .(-) 10 inches water (negative buffer-mid-buffer), and the other electrical switch must operate at less than or equal to (+) 80 inches water (positive buffer-mid-buffer) per Table 4.4-3.

The trip settings for the twelve switches are listed in Table 1.

The switch settings, which were found to be less conservative than~those established by the Technical Specification did not prevent the fulfillment ,

of the functional requirements of the system.

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REPORTABLE OCCURRENCE 80-34 ISSUE O Page 2 of 4 CAUSE DESCRIPTION:

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Dirt buildup and accumulation in the electrical switches prevented them from making proper contact.

CORRECTIVE ACTION:

The trip settings of the electrical switches were re-adjusted to the proper trip points.

Due to the continuing problems being experienced with the electrical switches, the interim check of the trip settings is being conducted on a monthly basis.

The investigation of the problem associated with the helium circulator seal malfunction trip switches has been completed, and Public Service Company Nuclear Project Department is proceeding on a path to replace the existing equipment.

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REPOR".ABLE OCCURRENCE 80-34 ISSUE O Page 3 of 4 TABLE 1 As Found Inches H2O As Lef t Inches H90 Increasing Decreasing Increasing Decreasing Trip Point Trip Point Trip Point Trip Point lA Circulator PDIS-21149 75 -31 O 75 -4 PDIS-21151 76 -8 76 -8 PDIS-21173 73 -6 73 -6 1B Circulator PDIS-21155 78 -10 78 -4 ,

PDIS-21157 75 -4 ,

75 -8 PDIS-21159 72 -8 72 -8 1C Circulator PDIS-21150 78 -5 78 -5 PDIS-21152 77 -7 77 -7 PDIS-21154 78 78

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-11 @ -5 1D Circulator PDIS-21156 73 -4 73 -4 PDIS-21158 73 -7 73 -7 PDIS-21160 75 -8 75 -8 h Denotes switches which were out of tolerance.

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REPORTABLE OCCURRENCE 80-34 ISSUE O Page 4 of 4

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Prepared By: 44, < jf.gt[ ,

Asa H. Reed Technical Services Technician Reviewed By: /

. WAahm echnical Services Supervisor Reviewed By:

Frank M. Ifathie Operations Manager i

Approved By: /k My;dw Don Warembourg (/ j Manager, Nuclear Production I

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