05000373/LER-1982-034, Forwards LER 82-034/03L-0.Detailed Event Analysis Encl

Forwards LER 82-034/03L-0.Detailed Event Analysis Encl

ML20054L150
Person / Time
Site:	LaSalle
Issue date:	06/23/1982
From:	Holyoak R COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20054L151	List: 05000373/LER-1982-034, Forwards LER 82-034/03L-0.Detailed Event Analysis Encl 05000373/LER-1982-034-03, /03L-0:on 820605,RHR Shutdown Cooling Isolation Valve 1E12-F009 Would Not Open Due to Isolated RHR Pump Suction Flow Switch 1E31-N012B.Caused by Flow Switch Left Isolated During Personnel Reassignment
References
NUDOCS 8207070194
Download: ML20054L150 (2)

LER-1982-034, Forwards LER 82-034/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3731982034R00 - NRC Website

text

-.

O Commonwitith Edison s

) Rural Route #1, Box 220 LaSalle County Nuclear Station e

mv Marseilles, Illinois 61341 Telephone 815/357 6761 s

I i

June 23, 1982 James G. Keppler Regional Administrator Directorate of Regulatory Operations, Region lil U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Dear Si r:

Reportable Occurrence Report #82-034/03L-0 Docket #050-373 is being submitted to your office in accordance with LaSalle County Nuclear 3

Power Station Technical Specification 6.6.B.2. (c), observed inade-quacies in the implementation of administrative or procedural controls which threaten to cause reduction of degree of redundancy provided in reactor protection systems or engineered safety feature systems.

1 l

kt

<u R. H. Holy superintendent N

)

LaSalle County ation

]

RHH/GW/djp Enclosure cc: Director of Inspection & Enforcement Director of Management Information & Program Control U. S. NRC Document Management Branch inpo-Records Center File /NRC I207070194 820623

{DRADOCK 05000373 g30 M

4 1.

LER NUMBER:

82-034/03L-0 11.

LA SALLE COUNTY STATION: UNIT 1 111. DOCKET NUMBER:

050-373 IV.

EVENT DESCRIPTION

The RHR System was being lined up for the shutdown cooling mode of operat1~on per LOP-RH-07 The RHR Shutdown Cooling Suction Header isolation Valve (IE12-F009) would not open.

Subsequent investigation found RHR Pump Suction flow switch 1E31-N0128 isolated.

V.

PROBABLE CONSEQUENCES OF THE OCCURRENCE The plant was in Condi tion 3, Hot Shutdown, at approximately 225 F reactor coolant temperature.

Tech. Spec. 3 3 2. requires one channel per trip system to be operable.

A redundant channel from RHR pump suction flow switch 1E31-N012A was operable.

Technical Specification 3.4.9.1 requires that shutdown cooling flow be established as soon as possible.

The RWCU non-regenerative heat exchanger was operable and in service for heat removal.

There is no irradiated fuel generating decay heat at this time.

Safe operation of the plant was maintained at all times.

VI.

CAUSE

l The last documentated operation the RHR pump suction flow switch IE31-N012B was on 6/5/82, the date of the Deviation Report.

The Instrument Maintenance Department was performing LIS-RH-12 (RHR, Shutdown Cooling Mode, High Suction flow isolation and Functional Test). The Instrument Mechanic contacted

~1 related he cut the lockwires on RHR pump suction flow switch 1E31-N012B, isolated the instrument, repaired a leak on the manifold block, completed the Inst. Calibra tion Check, then went on break.

After break he was reassigned to a higher priority job.

It can not be determined with certainty the status (inservice or isolated) of instrument 1E31-N012B when the instrument mechanic was reassigned.

Vll. CORRECTIVE ACTION:

i l

RHR pump suction flow switch 1E31-N012B was immediately unisolated and returned to service.

Shutdown cooling was established'dithin one hour.

AIR 1-82-312 has beer. issued to the Instrument Maintenance Department to re-emphasis the importance of LAP-24E1, step f.6.

This item refers to informing the shif t engineer of system status if a test is stopped or delayed.

Prepared by:

A. C. Settles