ML19318C457

Forwards LER 80-020/03X-1

ML19318C457
Person / Time
Site:	Fort Saint Vrain
Issue date:	06/23/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19318C458	List: ML19318C457 ML19318C467
References
P-80171, NUDOCS 8007010496
Download: ML19318C457 (5)

Text

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PLATTEVILLE, COLORADO 80651 June 23, 1980 Fort St. Vrain Unit No.1 P-80171 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. 50-257/

80-20, Preliminary, submitted per the requirements of Technical Speci-fication 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. 50-267/80-20.

Very truly yours, hbu Don Warembourg /

Manager, Nuclear Production DW/cls Enclosure ec: Director, MIPC Doc >2 5

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800702o (pg 3 1

4 REPORT DATE: June 23, 1980 REPORTABLE OCCURRENCE 80-20 ISSUE 1 OCCURRENCE DATE: April 18.1980 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. 50-267/80-20/03-X-1 Preliminary IDENTIFICATION OF OCCURRENCE:

During performance of the monthly check of the helium circulator seal malfunction 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. -.

Since reactor operation had taken place during the test interval, this is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)1 and AC 7.5.2(b)2.

EVENT DESCRIPTION:

During normal plant operation, instrument personnel performed the circu-lator 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 element 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. i 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.

REPORTABLE OCCURRENCE 80-20 ISSUE 1 Page 2 of 4 CAUSE DESCRIPTION:

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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REPORTABLE OCCURREICE 80-20 ISSUE 1-Page 3 of 4 TABLE 1 As Found Inches H2O As left Inches H2O Increasing l Decreasing Increasing Decreasing Trip Pointi Trip Point Trip Point Trip Point 1A Circulator PDIS-21149 +77 -5 +77 PDIS-21151 +74 -7 +74 -7 PDIS-21153 +75 -5 +75 -5 13 Circulator PDIS-21155 +77 -5 +77 -5 PDIS-21157 +90 b - -7 +73 -7 PDIS-21159 +73 -9 +73 -9 1C Circulator PDIS-21150 +76 -7 +76 -7 PDIS-21152 +82 h -21h +74 -7 PDIS-21154 +76 -5 +76 -5 i ,

i 1D Circulator PDIS-21156 +74 -8 +74 -8 PDIS-21158 +77 -5 +77 -5 i PDIS-21160 +75 -5 +75 -5 h Denotes switches which were out of tolerance.

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REPORTABLE OCCURRENCE 80-20 ISSUE 1 Page 4 of 4 Prepared By:

Asa B. Reed Technical Serv 1ces Technician Reviewed By: ~

f W. a Iec cal Services Supervisor M

Reviewed By:

Frank M. Mathie

Operations hanager Approved By: Ymb_

Don Warembourg /

Manager, Nuclear Production i

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