05000267/LER-1980-072, Forwards LER 80-072/03L-0

Forwards LER 80-072/03L-0

ML19354C400
Person / Time
Site:	Fort Saint Vrain
Issue date:	12/17/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19351F080	List: 05000267/LER-1980-072, Forwards LER 80-072/03L-0 05000267/LER-1980-072-03, /03L-0:on 801117,three Helium Circulator Seal Malfunction Pressure Differential Switch Units Discovered to Have Trip Point Outside Tech Spec Limits.Caused by Dirt Accumulation in Electrical Switches.Switches Readjusted
References
P-80432, NUDOCS 8012290435
Download: ML19354C400 (5)

LER-1980-072, Forwards LER 80-072/03L-0

Event date:
Report date:
2671980072R00 - NRC Website

text

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16805 ROAD 19%

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PLATTEVILLE, COLORADO 80651 December 17, 1980 Fort St. Vrain Unit No. 1 j

P-80432

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Mr. Karl V. Seyfrit, Director

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,3 Nuclear Regulatory Comission Region IV Office of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012

Reference:

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

Dear Mr. Seyfrit:

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

80-72, Preliminary, submitted per the requirements of Technical Specifica-tion 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.50-267/80-72.

Very truly yours, 4

W Don Warembourg Manager, Nuclear Production OW/sb Enclosure cc: Director, MIPC gY Y\\ \\ t Y-35~

Sill a o Qn

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REPORT DATE:

December 17, 1980 REPORTABLE OCCURRENCE 80-72

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ISSUE O OCCURRENCE DATE:

November 17. 1980 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE CCMPANY OF COLORADO 16805 WEID COUNTY RCAD 191/2 I

PLATTEVILLE, COLORADO 80651 REPORT No. 50-267/80-072/03-L-0 Preliminary P

IDENTIFICATION OF OCCURRENCE:

During the November performance of the monthly check of the helium circulator i

seal malfunction pressure differential switches, it was discovered that three 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

I While operating at 66% thermal power and 207 MWe, instrument personnel per-formed 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 under-taken 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.

j 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 f ound 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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REPORTABI.E OCCURRENCE 80-72 ISSUE O Page 2 o f 4

CAUSE

DESCRIPTION:

i Dirt buildup and accumulation in the electrical switches prevented them f rom 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 ? heck 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 OCCURRENCE 80-72 ISSUE O Page 3 of 4 TABLE 1 l

As Found Inches H2O As Left Inches H2O Increasing Decreasing Increasing Decreasing Trip Point Trip Point Trip Point Trip Point 1A Circulator PDIS-21149

+76

- 7

+76

- 7 I

PDIS-21151t

+74

- 5

+74

- 5 PDIS-21153

+75

- 6

+75

- 6 13 Circulator PDIS-21155_

+73

- 30(I)

+73 1

- 6 PDIS-21157

+75

- 20 @

+75

- 6 PDIS-21159

+77

- 5

+77

- 5 1C Circulator PDIS-21150 474

- 7

+74

- 7 PDIS-21152f

+73

- 4

+73

- 4 PDIS-21154

+77

- 6

+77

- 6 1D Circulator PDIS-21156

+75

- 25 O

+75

- 6 PDIS-21158

+77

- 6

+77

- 6 PDIS-21160

+77

- 7

+77

- 7

@ Denotes switches which were out of tolerance.

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REPORTABLE OCCURRENCE 80-72 ISSUE O Page 4 of 4 6

O Prepared By:

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Asa B. Reed Technical Services Technician i

Reviewed By:

.W sahm T. nical Services Supervisor Reviewed By:

Fra d M. Mathie Operations Manager Approved By:

Aa Mau M i

Don Warembourg

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Manager, Nuclear Production i

i b.