05000270/LER-1981-003, Forwards LER 81-003/03L-0.Detailed Event Analysis Encl

Forwards LER 81-003/03L-0.Detailed Event Analysis Encl

ML20032B506
Person / Time
Site:	Oconee
Issue date:	04/01/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20032B507	List: 05000270/LER-1981-003, Forwards LER 81-003/03L-0.Detailed Event Analysis Encl 05000270/LER-1981-003-03, /03L-0:on 810302,alarm Sounded to Indicate High Temp on Reactor Bldg Cooling Unit.Caused by Grease Starvation.Reactor Bldg Cooling Unit 2C Was Secured & Grease Added to Motor Bearings.Cooling Unit Restarted
References
NUDOCS 8111050613
Download: ML20032B506 (2)

LER-1981-003, Forwards LER 81-003/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2701981003R00 - NRC Website

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Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report RO-27 /81-0 This report is submitted pursuant to Oconee Nuclear Station Technicc.1 pecification 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 considered to be of no signi-ficance with respect to its effect on the health and safety of the public.

Very truly yours, f

o William O. Parker, Jr.

7 JLJ:ls Attachment cc: Director Mr. Bill Lavallee Office of Management & Program Analysis Nuclear Safety Analysis Center U. S. Nuclear Regulatory Commission P.O. Box 10412 Washington, D. C.

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DUKE POWER COMPANY OCONEE UNIT 2 Report Number:

R0-270/81-03 Report Date_: April 1, 1981 Occurrence Date: March 2, 1981 Facility: Oconee Unit 2, Seneca, South Carolina Identification of Occurrence: High Outboard Bearing Temperature on RBCU 2C Conditions Prior to Occurrence:

73% FP Description of Occurrence: At 1315 hours0.0152 days <br />0.365 hours <br />0.00217 weeks <br />5.003575e-4 months <br /> on March 2, 1981, an alarm sounded in the Unit I and 2 Control Room indicating a high temperaturc on Reactor building Cooling Unit (RBCU) 2C.

RBCU 2C was declared inoperable and secured. This cou-stitutes operation in a degraded mode per Technical Specification 3.3.5.C.2(b) and is thus reportable pursuant to Technical Specification 6.6.2.1.b(2).

Apparent Cause of Occurrence: The high temperature in the bearing was apparently caused by grease starvation.

These motors have grease lubricated ball bearings which require the addition of grease once every six months as specified by Joy and Reliance.

The Oconee Units are presently on an annual lubrication schedule.

Analysis of Occurrence: The securing of the RBCU, after the high temperature alarm, was verified to have prevented the further degradation of the RB Cooling Systems by verifying operation of the two remaining RBCU's and verifying that the RB Spray System was operable due to the fact that it had passed its most recent performance test.

The operability of RBCU 2C after adding grease was verified by running the unit and monitoring the bearing temperatures until they stabilized at an acceptable temperature.

Technical Specification 3.3.5.C(2)(b) allows one RB cooling trai-to be out of service for no more than seven days, provided both RB Spray trains are operable.

During the 46 hour5.324074e-4 days <br />0.0128 hours <br />7.60582e-5 weeks <br />1.7503e-5 months <br /> period that RBCU 2C was out of service, the requirements of the above Technical Specification were met.

Thus this incident was of no signifi-cance with respect to safe operation and the health and safety of the public were not affected.

Corrective Action

The immediate corrective action was to secure RBCU 2C which lef t RBCU 2A and 2B as the remaining operable RBCU's on Unit 2.

Subsequent corrective action consisted of adding grease to the motor bearings of RBCU 2C and restarting the cooling unit, thus restoring its operability. The current frequency of lubri-cation of the RBCU will be re-evaluated against the manufacture's recommendations.