ML20003B107

Forwards LER 81-006/03L-0

ML20003B107
Person / Time
Site:	Fort Saint Vrain
Issue date:	02/03/1981
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20003B109	List: ML20003B107 ML20003B115
References
P-81037, NUDOCS 8102100358
Download: ML20003B107 (5)

Text

pubue service company o2 ccacenz 16805 ROAD 19%

PLATTEVILLE, COLOR ADO 80651 February 3, 1981 Fort St. Vrain Unit No. 1 P-81037 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Comission 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/

81-006, 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. 50-267/81-006.

Very truly yours,

-- WY Don Warenbourg Manager, Nuclear Production DW/cis Enclosure cc: Director, MIPC S0'V+,1 i

i 81021003 Q

_. _ _ _ _ . _ . . _ _ _ _ _ _ ._ -- - -. . ._. ._ _m__ -._ _ . _ _ . . _ _ . . .

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REPORT DATE: Februarv 3,1981 REPORTABLE OCCURRE'ICZ 81-006 ISSUE O OCCURRENCE DATE: January 7,1981 Page 1 of 4 I FORT ST. VRAIN NUCLEAR GENERATING STATION 1

PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLATTEVILLE, COLORADO 80651 l REPORT No. 50-267/ 81-006/03-L-0 P reliminary IDENTIFICATION OF OCCURRENCE:

During the annual performance of the circulator seal malfunction calibration and check of the switch trip points, it was discovered that six 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, instrument personnel performed the annual circulator seal malfunction calibration and checked the switch trip poin ts.

The switches are normally calibrated on an annual basis; hcwever, due to the problems cited in the previous reports as listed on the LER, a check of the 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-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 of j water (positive buffer-mid-buf fer) 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 OCCURRCiCE 81-006 ISSUE O Page 2 of 4 CAUSE DES CRIPTION:

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

CORRECTIVE ACTION:

The trip settings of the electrical switches were re-adjusted to the proper trip points, and the Surveillance Test satisfactorily completed.

Due to the continuing problems being experianced 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 cocpleted, and Public Service Company Nuclear Project Department is proceeding on a path to replace the existing equipment.

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REPORTABLE OCCURRENCE 81-006 ISSUE O Page 3 of 4 TABLE 1 i

As Found Inches H2O As left Inches H?O Incriasing! Decreasing Increasing Decreasing TripPoint!TripPoint Trip Point Trip Point I I l' 1A Circulator PDIS-21149' +77 3 -7 +77 - -7 PDIS-21151 +76 -9 +76 -7 PDIS-2115 3 +77 -25 b +77 -7 13 Circulator PDIS-21155 +82 b -7 +74 -7 PDIS-21157 +75 -24 b +75 -6 PDIS-21159 +92 b -5 +74 -5 1C Circulator PDIS-21150 +74 -42 b +74 -6 PDIS-21152 +75 _

-9 _

+75 -7 PDIS-21154 +84 b -5 +75 -5 1D Circulator PDIS-21156 +74 -5 +74 -5 PDIS-21158 +73 -6 +73 -6 PDIS-21160 +75 -5 +75 -5

@ Denotes switches which were out of tolerance.

O

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REPORTABLE OCCURRENCE 81-006 ISSUE O Page 4 of 4 t f

1 Prepared By: a f Asa B. Reed Technical Services Technician Reviewed By: . / / ,g echn Services Supervisor Reviewed By:

Frank M. Mathie Operations Manager 1

Approved By: ~ M 4,4_ _ ..b Don Warembourg ,

f Manager, Nuclear Production i

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