ML20008E939

Forwards LER 81-016/03L-0

ML20008E939
Person / Time
Site:	Fort Saint Vrain
Issue date:	03/03/1981
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20008E940	List: ML20008E939 ML20008E941
References
P-81079, NUDOCS 8103100579
Download: ML20008E939 (5)

Text

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'I  ! 16805 ROAD 19%

'd _ j PLATTEVILLE, COLORADO 80651 March 3, 1981 Fort St. Vrain Unit No. 1 P-81079 Q /.5 ,

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Mr. Karl V. Seyfrit, Director '

Nuclear Regulatory Cocunission [ ,pca' Region IV -

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Office of f aspection and Enforcement  % , ,d 611 Ryan Plaza Drive v. f ' ,' '

Suite 1000 4/ ,/ ;,3. di ,

Arlington, Texas 76012

Reference:

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

Dear Mr. Seyfrit:

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

81-016, 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. 50-267/81-016.

Very truly yours, b WAm Don 'a'arembourg #

Manager, Nuclear Production DW/cis Enclosure ec: Director, MIPC I

- i 81 031005-79

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REPORT DATE: March 3, 1981 REPORTABLE OCCURRENCE 81-016 ISSCE O OCCURRENCE DATE: Feb ruarv 13. 1981 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICF COMPANY OF COLORADO 16805 WELD COUNTY ROAD 191/2 PLA!TEVILLE,. COLORADO 80651 REPORT NO. 50-267/81-016/03-L-0 Prelimina ry IDENTIFICATION OF OCCURRENCE: ___

During the February performance of the monthly check of the helium circulator seal malfunction pressure differential switches, it was discovered that three of the twelve switch units tripped outside the limits specified in LCO 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:

4 During normal power operation, instrument personnel performad the circulator seal malfunction (buffer-mid-buffer) switch operability che-... 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 buf fer-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 water (positive buf fer-mid-buffer) per Table 4.4-3.

The trip settings for the cuelve 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.

CAUSE.

EESCRIPTION:

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

_-. -_. - . __--_ .- - . - .= .

REPORTABLE OCCURRENCE 81-016 ISSLT 0 Page 2 of 4 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 metfunction 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 OCCURRENCE 81-016 ISSUE O Page 3 of a TABLE 1 As Found Inches H2O As Lef t Inches H2O Increasing Decreasing Increasing Decreasing Trip Point Trip Point 1 Trip Point Trip Point 1A Circulator PDIS-21149 +75 -5 +75 -5 PDIS-21151 +77 -9 +77 -9 PDIS-21153 +75 -4 +75 -4 1B Circulator PDIS-21155 +72 -6 +72 -6 PDIS-21157 +70 -20([) +73 -4 PDIS-21159 +76 -3 +76 -3 6

1C Cire'ulator PDIS-21150 i +74 -25 (5) ' +74 -3 PDIS-21152 +76 -20 (1) 1 +76 -5 PDIS-21154 +78 -4 +78 -4' 1D Circulator PDIS-21156 +73 -3 +73 -3

? DIS-21158 +74 -3 +74 -3 PDIS-21160 +75 -5 +75 -5

(3) Denotes switches which were out of tolerance.

i REPORTABLE OCCL"ARENCE 81-016 ISSUE O l Page 4 of 4 1

Prepared By: b Asa B. Reed Technical Services Technician 1

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Reviewed By: [

J. R. Ga>& '

hnical Services Supervisor Reviewed By: [M M8b I IO;*V Frank M. Mathie rf Operations Manager Approved By: - Maum[-1 Don Warembourg g Manager, Nuclear Production S

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