ML19323H665

Forwards LER 80-024/03L-0

ML19323H665
Person / Time
Site:	Fort Saint Vrain
Issue date:	06/06/1980
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19323H666	List: ML19323H665 ML19323H667
References
P-80145, NUDOCS 8006160030
Download: ML19323H665 (5)

Text

.- _.

l l

F puhuc service company of cdondo 16805 ROAD 19%

)- PLATTEVILLE, COLORADO 80651 June 6, 1980 Fort St. Vrain Unit No. 1 P-80145 Mr. Karl V. Seyf rit, Director Nuclear Regulatory Cocnission Region IV Of fice of Inspection and Enforcement 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76012 Re ference: 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/

80-24, Final, submitted per the requirements of Technical Specification AC 7.5.2(b) 2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/80-24.

Very truly yours, Wa.

n Warembourg #

Manager, Nuclear Production DW/cis Enclosure cc: Director, MIPC 8006160 Mg S

REPORT DATE: June 6, 1980 REPORTABLE OCCURRENCE 80-24 ISSUE O OCCURRENCE DATE: May 12, 1980 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651 REPORT No. 50-267/80-24/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

During normal plant operation, it was determined that the 1C helium circulator seal malfunction differential pressure switches could have tripped outside the limits of LCO 4.4.1, Table 4.4-3.

This is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

EVENT DESCRIPTION:

On May 12, 1980, with the plant at 47% reactor power and 140 MW electrical power, operations personnel observed that the 1C circulator seal differential pressure decreased significantly. The circulator seal differential pressure had been lower than normal for several days. The personnel investigating the problem found that the equaliaing valve on PDT-21390,1C circulator seal differential pressure transmitter, was open about one turn (see Figure 1).

With this equalizing valve open, PDT-21390 would give an erroneous indication.

The circulator seal malfunction switches, PDIS-21150, PDIS-21152, and PDIS-21154, would not sense the actual differential pressure across the buffer-mid-buf fer area of the circulator, but would sense a much lower differential pressure. Thus, if a circulator seal malfunction occurred, the trip could occur at a value less conservative than required by the LCO.

When the equaliaing valve was closed, the 1C circulator seal differential pressure returned to normal. Plant operation was not affected, and no circu-lator upsets occurred during this period.

CAUSE DESCRIPTION:

The cause of the equaliaing valve being open is not known, and no particular activity can account for the condition. ,

REPORTABLE OCCURRENCE 80-24 ISSLT 0 Page 2 of 4 I CORRECTIVE ACTION:

! The PDT-21390 equalizing valve was clos ~ed, and the 1C circulator buffer helium ,

i differential pressure returned to normal.

No further corrective action is anticipated or required.

i i

)

i 1

1 J

5 1

4 l

= . - , . :. .

A REPORTABLE OCCURRENCE 80-24 ISSUE O Page 3 of 4 C-2103 HELIUM CIRCULATOR 1C Circulator Seal Malfunction Switches

( >

C I Trip Settings V-21890

~ ~ ~

High

< 80" H2O )

IS P IS PDIS Equalizing

-> - 0" H 2O 21150 21152 21134 l 21390 I Valve l V

V-21433 V-21435 V-21437 l

A r A Circulator Seal AP Transmitter FIGURE 1 -

j- - .

' REPORTABLE OCCURRENCE 80-24

< . ISSUE O Page 4 of 4 i

r l

I Prepared By:

Asa B. Reed

/*&

Technical Services Technician i

4 a

Reviewed By: s_ h y_b J. Wh Gahm i Technical Services S ervisor Reviewed By: [ N \

Frafik M. Ifathie i Operations !!anager i

i 1

Approved By: YuAa4  %

Don Warembourg f.

Manager, Nuclear Production I

i 4

J l

4 1

4 9

b D

g ~~ - - -

g- e . *e, re + v - m =