05000269/LER-1982-014, Forwards LER 82-014/03L-0.Detailed Event Analysis Encl

Forwards LER 82-014/03L-0.Detailed Event Analysis Encl

ML20065R882
Person / Time
Site:	Oconee
Issue date:	10/14/1982
From:	Tucker H DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20065R885	List: 05000269/LER-1982-014, Forwards LER 82-014/03L-0.Detailed Event Analysis Encl
References
NUDOCS 8210290355
Download: ML20065R882 (3)

LER-2082-014, Forwards LER 82-014/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2692082014R00 - NRC Website

text

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DUKE POWER GOMPANY P.O. IM)x 33180 CitAHLOTTE. N.C. 28242 ilALILTUCKEH TELEPItONE vu r==.-- October 14, 1982 (*) Nn mm. -m-

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c -r Mr. James P. O'Reilly, Regional Administrator ea y

U. S. Nuclear Regulatory Commission 'ft o Region II 101 Marietta Street, Suite 3100

'co 73m Atlanta, Georgia 30303 3 .$9 f

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Re: Oconce Nuclear Station Docket No. 50-269 -

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-269/82-14. This report is submitted pursuant to Oconee Nuclear Station Technical Specification 6.6.2.1.b(2) which concerns operation in a degraded mode permitted by a

. limiting condition for operation, and describes an incident which is con-sidered to be of no significance with respect to its effect on the health and safety of the public.

Very truly yours, fg &rba.

Hal B. Tucker JCP:scs Attachment cc: Document Control Desk Mr. W. T. Orders U. S. Nuclear Regulatory Commission NRC Resident Inspector Washington, D. C. 20555 Oconee Nuclear Station INPO Records Center Mr. P. C. Wagner Suite 1500 Office of Nuclear Reactor Regulation 1100 Circle 75 Parkway U. S. Nuclear Regulatory Commission Atlanta, Georgia 30339 Washington, D. C. 20555 ggc1M> COW A '

F210290355 821014 s-f~g' JLM PDR ADOCK 05000269 O PDR

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DUKE POWER COMPANY OCONEE NUCLEAR STATION Report Number: R0-269/82-14 Report Date: October 14, 1982 Occurrence Date: September 14, 1982 Facility: Oconee Unit 1. Seneca, South Carolina Identification of Occurrence:

Unit 1 Reactor Building cooling unit fan lA was declared inoperable when it tripped out on low speed thermal overloads.

Conditions Prior to Occurrence: 100% Full Power Description of Occurrence:

On September 14, 1932 at 2120 hours0.0245 days <br />0.589 hours <br />0.00351 weeks <br />8.0666e-4 months <br />, Unit 1 Reactor Building Cooling Unit.(RBCU) fan lA was declared inoperable when it tripped out on low speed thermal overloads.

Previously, RCBU fan lA had tripped out on low speed thermal overload August 16th and 23rd. September 10th, it tripped again, at the time the smoke detector alarm located above the fan, and vibration alarm, went off. That day the inboard and outboard bearings were greased. Each time a trip oc..urred, the thermal overloads were reset. September lith, the RCBU fan lA was shut off so the motor could be inspected. No cause for the trips was found. September 12th, 13th, 14th, and 20th the RCBU fan lA tripped out on low speed thermal overload and each time was reset.

Ever since the reset on September 20th, the fan has been running without a trip.

There has been no further problems with high vibration or any smoke alarms since the bearings were greased. New overloads were put in the motor starter on September 27, 1982 to see if the old overloads were bad, but nothing has been found out due'to this change. ..

Apparent Cause of Occurrence:

The cause of the repeated trips is unknown. At present, the fan is running at about 10 amps above its normal low speed running current.

Analysis of Occurrence:

The problems with the RBCU fan lA did not jeopardize any equipment or systems in Unit 1. Since there are no overloads in the Engineered Safeguards (E.S.)

circuitry for this fan, it would have performed its E.S. function. Also, the other two fans and the Reactor Building Spray systems were operable as required by Technical Specifications 3.3.5. If fan lA had not been operable and if the worst design basis LOCA had occurred, the Reactor Building design pressure would not have been exceeded. Therefore, the health and safety of the public was not endangersd.

r Corrective Action:

In each case the immediate corrective action was to check bearing temperature, to check the breaker and thermal overloads. After resetting of the overloads, the fan was restarted and a check was made of the running current. Although the current had been higher than usual, it had not been above the rated range of the overloads.

Unit 1 Operating Engineering would like the fan motor to be replaced next refueling outage. Station personnel is keeping a check on the fan and may request that the fan motor be changed if no other reason can be found to cause the trips.

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