05000311/LER-1982-049, Forwards LER 82-049/03L-0.Detailed Event Analysis Encl

Forwards LER 82-049/03L-0.Detailed Event Analysis Encl

ML20055A948
Person / Time
Site:	Salem
Issue date:	06/30/1982
From:	Midura H Public Service Enterprise Group
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20055A949	List: 05000311/LER-1982-049, Forwards LER 82-049/03L-0.Detailed Event Analysis Encl
References
NUDOCS 8207200164
Download: ML20055A948 (4)

LER-2082-049, Forwards LER 82-049/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3112082049R00 - NRC Website

text

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O PSIEG Public Service Electric and Gas Company P.O. Box E Hancoch Bridge, New Jersey 08038 Salem Generating Station June 30, 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 82-049/03L 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 82-049/03L. This report is required within thirty (30) days of the occurrence.

Sincerely yours, g ,%zh ls- __ >

H. J. Midura General Manager -

Salem Operations RF:ks CC: Distribution 8207200164 820630 PDR ADOCK 05000311 g PDR The Energy People I t,annoom n m

m Report Number: 82-049/03L Report Date: 06-30-82 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 and 25 Containment Fan Coil Units - Inoperable.

This report was initiated by Incident Reports82-150 and 82-151.

CONDITIONS PRIOR TO OCCURRENCE:

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

DESCRIPTION OF OCCURRENCE:

At 0130 hours0.0015 days <br />0.0361 hours <br />2.149471e-4 weeks <br />4.9465e-5 months <br />, June 17, 1982, during performance of Surveillance Procedure SP (O) 4. 6. 2. 3 A, the Control Room Operator observed that the service water flow to No. 21 Containment Fan Coil Unit (CFCU) was less than the 2500 GPM required by the Technical Specification for the low speed mode of operation. The group containing the CFCU was declared inoperable, and Technical Specification Action Statement 3.6.2.3.a was entered, retroactive to the time of discovery.

La ter that day, at 0545 hours0.00631 days <br />0.151 hours <br />9.011243e-4 weeks <br />2.073725e-4 months <br />, during further surveillance, the operator discovered that No. 25 CFCU also failed to meet specification limits, due to low service water flow in the low speed mode. A second fan group was declared inoperable, and Action Statement 3.6.2.3.b was entered. The containment spray systems were operable in both instances.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

The low service water flow to No. 21 CFCU was apparently caused by American oysters (Crassostrea virginica) plugging Back Pressure Control Valve 21SW57. 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 bundle and accumulate on the bundle face, thereby restricting flow.

LER 82-049/03L a n DESIGNATION OF APPARENT CAUSE OF OCCURRENCE: (continued)

The low flow to No. 25 CFCU resulted from the failure of the square root extractor board in the back pressure flow control circuit. High temperatures in the environment of the square root extractor module causec a solder joint on the board to crack; the resultant control signal caused Back Pressure Control Valve 25SW57 to throttle service water flow excessively.

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 spray systems is necessary to insure offsite radiation dose is maintained within the limits of 10 CFR100. These occurrences, therefore, constituted operation in a degraded mode permitted 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, and both con sinment spray systems operable, 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, and both containment spray systems operable, 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 />.

CORRECTIVE ACTION In the first case, Valve 21SW57 was stroked to dislodge and eliminate the oysters. The flow velocities involved are sufficient to break-up or erode away larger shells. Flow was returned to within specification, and the surveillance procedure was satisfactorily completed. No. 21 CFCU was declared operable at 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br />, June 17, 1982, and Action Statement 3.6.2.3.b 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 Specifications 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.

LER 82-049/03L

• 4 CORRECTIVE ACTION: (continued)

In the instance involving No. 25 CFCU, the failed circuit board was repaired; all solder joints subject to stress from high temperature were resoldered to preclude further failure. No. 25 CFCU was returned to service and the surveillance satisfactorily completed. The unit was declared operable,-and at 1825 hours0.0211 days <br />0.507 hours <br />0.00302 weeks <br />6.944125e-4 months <br />, June 17, 1982, Action Statement 3.6.2.3.a was terminated. The square root extractor modules will be moved to a location with a lower ambient temperature, as part of a service water valve control modification scheduled for installation during the next refueling outage.

FAILURE DATA:

Fischer and Porter Co.

Square Root Extractor Series 50ES3000 Prepared By R. Frahm ,

k d ^/g -

General' Manager -

Salem Operations SORC Meeting No. 82-65

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