ML19338F024

Forwards LER 80-051/03L-0

ML19338F024
Person / Time
Site:	Fort Saint Vrain
Issue date:	10/01/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19338F025	List: ML19338F024 ML19338F027
References
P-80348, NUDOCS 8010070401
Download: ML19338F024 (5)

Text

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i public servlee company *e Cchnab 16805 ROAD 19%

, . . . _ . PLATTEVILLE, COLOR ADO 80651 October 1,1980 Fort St. Vrain Unit No. 1 P-80348 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

Dear Mr. Seyfrit:

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

80-51, 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 i Reportable Gecurrence Report No. 50-267/80-51.

Very truly yours, YM W Don Warembourg Manager, Nuclear Production DW/cis Enclosure _

cc: Director, MIPC

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8010070D/ s

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REPORT DATE: October 1, 1980 REPORTABLE OCCURRENCE 80-51 ISSUE O OCCURRENCE DATE: September 22, 1980 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLATTEVILLE, COLORADO 80651 REPORT No. 50-267/80-51/03-L-0 Preliminary IDENTIFICATION OF OCCURRENCE:

During the September performance of the monthly check of the helium circulator seal malfunction pressure differential switches, it was discovered that five of the twelve switch units tripped outside the limits specified in LCO 4.4.1, Table 4.4-3.

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

EVENT DESCRIPTION:

During a maintenance shutdown period, instrunent 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 the sensing ele-mec- is from (-) 100 inches of water to zero to (+) 100 inchas 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 of 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 j of the functional requirements of the system.

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, REPORTABLE OCCURRENCE 80-51 ISSUE O Page 2 of 4 CAUSE DESCRIPTION:

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

CORRECTIVE ACTIO:1:

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, i

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 eq uipment.

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,. 0 REPORTABLE OCCURRE :CE 8'b51 ISSUE O Page 3 of 4 TABLE 1 l

As Found Inches H2O As left Inches H2O _

Increasing Decreasing Increasing ' Decrearing Trip Point Trip Point Trip Point Trip Point 1A Circulator PDIS-21149 74 - 6 74 -6 PDIS-21151 75 - 6 75 -6 PDIS-21153 76 -5 76 -5 IB Circulator _PDIS-21155 77 - 7 77 -7 PDIS-21157 75

- 24 h 75 -6 PDIS-21159 75 -100 b 75 -6 1C Circulator PDIS-21150 76

- 20 h 76 -9 PDIS-21152 _

77 - 17 b 77 -9 l l PDIS-21154I 76 -- 5 76 -5 I

1D Circulator PDIS-21156 73 - 7 73 -7 I

PDIS-21158 t 73 -7 73 -7 PDIS-21160 75 -100 h 75 -6 h Denotes switches which were out of tolerance.

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' REPORTABLE OCCURRENCE 80-51 ISSUE O Page 4 of 4 4

! Prepared By:

' Asa B. Reed /

Technical Servic4s Supervisor Reviewed By: a M M & aho

1. fechnical Services Supervisor Reviewed By: M.,_ \

Frank M. Mathie

,- Operations Manager 1

Approved By: N

% d'th.

Don Warembourg y' Manager, Nuclear Production i

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