ML19305C072

Forwards LER 80-007/03L-0

ML19305C072
Person / Time
Site:	Fort Saint Vrain
Issue date:	03/18/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19305C073	List: ML19305C072 ML19305C076
References
P-80052, NUDOCS 8003250552
Download: ML19305C072 (5)

Text

.-_____ _

. I

.R *: Public service company ae celleamrIe 16805 Veld County Road 191/2, Platteville, Colorado 80651 March 18, 1980 Fort S t. Vrain Unit No. 1 P-80052 Mr. Karl V. Seyfrit, Director Nuclear Regulatory Cossaission 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/

80-07, Pret tstnary, submitted per the requirements of Technical Specifi-cation AC 7.5.2(bIl and AC 7.5.2O)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/80-07.

Very truly'yours, hW Don f(arenbourg y Manager, Nuclear Production Du/cis Enclosure cc: Director, MIPC 9\\

1 l

g 8003250 5M

REPORT DATE: March 18,1980 REPORTABLE OCCURRENCE 80-07 ISSUE O OCCURRENCE DAIE: February 19, 1980 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION l PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATIEVILLE, COLORADO 80651 REPORT No. 50-267/80-07/03-L-0 PRELIMINARY IDENTIFICATION OF OCCURRENCE:

During performance of the acnthly check of the helium circulator seal mal-function 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:

While the reactor was in a shutdown condition, 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 Reportable Occurrence Report No. 50-267/79-56, Preliminary, Reportable Occurrence Report No. 50-267/79-32, Preliminary, and Reportable Occurrence Report No. 50-267/78-27, Preliminary, 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.

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.

, m - .- , - - , . - . - i-- -y%. , ,

REPORTABLE OCCURRENCE 80-07 ISSUE O Page 2 of 4 EVENT DESCRIPTION: (Cont'd)

The trip settings for the twelve switches are listed in Table 1.

The 13 circulator switch settings are included only to complete the table since the circulator was removed and not operating during the test interval.

See Reportable Occurrence 50-267/80-01.

CAUSE DESCRIPTION:

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

CORRECTIVE ACTION:

i The trip settings of the electrical switches were re-adjusted to the proper trip points.

Due to the continuing probleme 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 switcher.has been coupleted, and Public Secrice Company Nuclear Project Department is proceeding on a path to replace the existing equipment.

I l

REPORIABE OCCURRENCE 80-07 ISSUE O Page 3 of 4

! TABLE 1 I

As Found Inches H2O As Left Inches H2O Increasing Decreasing Increasing ' Decreasing Trip Point Trip Point Trip Point Trip Point 1A Circulator PDIS-21149 +75 -3 +75 -

5 PDIS-21151 +75 -4 +75 - 4 PDIS-21153 +73 -5 +73 -

5 13 Circulator PDIS-21155 +71 -8 +73 - 8 PDIS-21157 +90 -7 +78 - 7 PDIS-21159 +76 -25 +76 -

6 1C Circulator PDIS-21150 +77 -40 b +77 - 6 PDIS'-21152 +75 -35 @ +75 - 8 PDIS-21154 +77 -5 +77 -

5 1D Circulator PDIS-21156 +73 -5 +73 - 5 PDIS-21158 +76 -6 +76 - 6 PDIS-21160 +75 -8 +75 - 8 h Denotes switches which were out of tolerance.

l l

w-- m y w --,e -- -

-m- e - p py-, ~ -w

REPORTABLE OCCURRENCE 80-07 ISSUE O Page 4 of 4 Prepared By: h* A MictkelJ. Ferria( ;

Technical ServiceV Engineer Reviewed By: _

W. Gahm echnical Services Supervisor Reviewed By: d Frank M. Mathie Operations Manager Approved By: M7d Don Warembourg /

Manager, Nuclear Production