05000311/LER-1982-050, Forwards LER 82-050/03L-0.Detailed Event Analysis Encl

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Forwards LER 82-050/03L-0.Detailed Event Analysis Encl
ML20058D278
Person / Time
Site: Salem 
Issue date: 07/07/1982
From: Midura H
Public Service Enterprise Group
To: Haynes R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20058D282 List:
References
NUDOCS 8207270068
Download: ML20058D278 (4)
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LER-1982-050, Forwards LER 82-050/03L-0.Detailed Event Analysis Encl
Event date:
Report date:
3111982050R00 - NRC Website
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> S L4 G Public Service Electric and Gas Company P.O. Box E Hancocks Bridge, New Jersey 08038 Salem Generating Station July 7, 1982 Mr.

R. C.

Haynes Regional Administrator USNRC Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Haynes:

LICENSE NO. DPR-75 DOCKET NO. 50-311 REPORTABLE OCCURRENCE 82-050/03L Pursuant to the requirements of Salem Generating Station Unit No.

2, Technical Specifications, Section 6.9.1.9.b, we are submitting Licensee Event Report for Reportable Occurrence 82-050/03L.

This report is required within thirty (30) days of the occurrence.

Sincerely yours,

,if.

%f$[w w H. J.

Midura General Manager -

Salem Operations RF:ks CC:

Distribution 8207270068 820707 PDR ADOCK 05000311 i

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The Energy People g6 21?'S?..

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Report Number:

82-050/03L Report Date:

07-07-82 Occurrence Date:

06-17-82 Facility:

Salem Generating Station, Unit 2 Public Service Electric & Gas Company Hancocks Bridge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:

Nos. 21, 22 and 23 Containment Fan Coil Units - Inoperable.

This report was initiated by Incident Reports82-152, 82-153 and 82-154.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 1 - Rx Power 100% - Unit Load 1140 MWe.

DESCRIPTION OF OCCURRENCE:

At 1830 hours0.0212 days <br />0.508 hours <br />0.00303 weeks <br />6.96315e-4 months <br />, June 17, 1982, during routine operation, the Control Room Operator observed that the service water flow to No. 22 Contain-ment Fan Coil Unit (CFCU) was 500 GPM, and attempts to increase flow by shifting to low speed failed.

The fan coil group containing the CFCU was declared inoperable, and Technical Specification Action Statement 3.6.2.3.a was entered, retroactive to the time of the discovery.

The following day, June 18, 1982, at 0315 hours0.00365 days <br />0.0875 hours <br />5.208333e-4 weeks <br />1.198575e-4 months <br /> during the performance of Surveillance Procedure SP (O) 4. 6. 2. 3A, the Control Room Operator discovered that No. 21 CFCU failed to meet specification limits, due to low service water flow in low speed.

The fan coil group was declared inoperable, and Action Statement 3.6.2.3.b was entered.

Shortly after, at 0330 hours0.00382 days <br />0.0917 hours <br />5.456349e-4 weeks <br />1.25565e-4 months <br />, service water flow to No. 23 CFCU was found to be less than specification, and the third fan coil group was declared inoperable.

The containment spray systems were operable throughout the occurrences.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

The low service water flow to the CFCU's was apparently caused by American oysters (Crassostrea virginica) plugging the back pressure control valves.

It appears that earlier this year oyster scat were drawn into the Service Water System, and were able to pass through the strainers.

The scat attached themselves in colonies, to piping walls in low flow portions of the system, where they grew in size.

The oysters are released from their points of attachment during system operational events (pump shifts, lineup changes, etc.) and periodic chlorination.

The larger oysters cannot pass through the valve tube bundles and accumulate on the bundle face, thereby restricting flow.

r LER 82-050/03L -

ANALYSIS OF OCCURRENCE:

The CFCU's operate in conjunction with the containment spray systems to remove heat and radioactive contamination from the containment atmosphere in the event of a design basis accident.

Operability of either all fan coil groups or of both containment spray systems is necessary to insure offsite radiation dose is maintained within the limits of 10CFR100.

These occurrences therefore constitute conditions leading to a plant shutdown required by a limiting condition for operation, and are reportable in accordance with Technical Specification 6.9.1.9.b.

Because redundant cooling capability was provided by the containment spray system, no risk to the health or safety of the public was involved.

Action Statement 3.6.2.3.a requires:

With one group of containment cooling fans inoperable, restore the inoperable group of cooling fans to operable status within the next 7 days, or be in hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Action Statement 3.6.2.3.b requires:

With two groups of containment cooling fans inoperable, restore at least one group of cooling fans to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or be in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Technical Specification Limiting Condition for Operation 3.0.3 requires:

When a limiting condition for operation cannot be met, within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> action shall be initiated to place the unit in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, in at least hot shutdown within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in at least cold shutdown within the subsequent 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

CORRECTIVE ACTION

l The back pressure control valves on Nos. 21 and 23 CFCU's were cycled to dislodge and eliminate the oysters.

The flow velocities involved are sufficient to break up or erode away the larger shells.

Flow was returned to within specification, and the surveillance procedure t

l was satisfactorily completed.

The units were declared operable at 0400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />, June 18, 1982, meeting the requirements of Action State-ment 3.6.2.3.b, and consequently terminating the applicability of Limiting Condition for Operation 3.0.3.

I

LER 82-050/03L -

==CORRECTIVE ACTION==Back Pressure Control Valve 22SW57 was cycled in an attempt to dislodge the oysters.

Due to the extremely low flow, however, the attempt failed.

The valve was disassembled and the oysters were removed.

Reassembly and surveillance testing were satisfactorily completed, No. 22 CFCU was declared operable, and at 1437 hours0.0166 days <br />0.399 hours <br />0.00238 weeks <br />5.467785e-4 months <br />, June 19, 1982, Action Statement 3.6.2.3.a was terminated.

Development of a chlorination program to fully eliminate the oysters from the Service Water System, and to prevent recurrence of colony development, is in progress.

Limits in the Environmental Technical Specification presently restrict chlorination to concentrations and durations which are ineffective.

A commitment to submit a Supplemental Report upon resolution of the problem was made in LER 82-041.

FAILURE DATA:

Not Applicable.

Prepared By R. Frahm

/

Generaf Manager -

Salem Operations SORC Meeting No.82-67B r

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