ML20072L207

ROs83-063 & 83-039:on 830621,motor-driven Auxiliary Feedwater Pumps 2P-141 & 3P-504 Failed to Complete 48 H Endurance Test Successfully.Initially Reported on 830624. Caused by Improperly Machined Oil Grooves.Lers Forthcoming

ML20072L207
Person / Time
Site:	San Onofre
Issue date:	06/27/1983
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
RO-83-039, RO-83-063, RO-83-39, RO-83-63, NUDOCS 8307130096
Download: ML20072L207 (2)

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RECElvio imc Southern California Edison Company g .gCE l S AN ONOF RE NUC LE A R GENER A TENG ST A TION + [}

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June 27, 1983 U.S. Nuclear Regulatory Commission Region V Office of Inspection and Enforcement 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention: Mr. J. B. Martin, Regional Administrator

Dear Sir:

J

Subject:

Docket Nos. 50-361 and 50-362 Prompt Reports Licensee Event Report No.83-063 (Docket No. 50-361)

Licensee Event Report No.83-039 (Docket No. 50-362)

San Onofre Nuclear Generating Station, Units 2 and 3 Pursuant to Sections 6.9.1.12.1 of Appendix A, Technical Speci-fications to Facility Operating Licenses NPF-10 and NPF-15 for San _Onofre Units 2 and 3, respectively, this submittal provides the written confirmation of our prompt notification to the NRC on June 24, 1983, at 1600 of a reportable occurrence involving the motor bearings of the Auxiliary Feedwater (AFW) system.

On June 21, 1983, while Unit 2 and Unit 3 were in Mode 5, the Unit 3 motor-driven AFW pump 3P-504 was declared inoperable when it failed to successfully complete its 48-hour endurance run. The outboard bearing on the motor failed and the pump was secured. The bearings (both outboard and inboard) were replaced and during installation of the replacement bearings, it was determined that the dimensions of the oil gr, oves were not consistent with the vendor drawings. The repla: 9 ment bearings were removed, re-machined, and re-installed. The bearings on the other AFW pump motor 3P-141 were examined and '

found to have the same dimensional defect. A preliminary investigation was completed on June 24, 1983, which concluded that the improperly machined oil grooves may have contributed to the failure of the motor bearings of AFW pump 3P-504. This defect does not affect the third AFW pump 3P-140 since it is driven by a steam turbine and its design does not include a motor with these bearings.

8307130096 830627 PDR ADOCK 05000361 S PDR 7)0 ][8dSU'

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• Mr. J. B. Martin June 27, 1983 1

.One of the two motor-driven.AFW pumps at Unit 2 (2P-141) was

{ found to have motor bearings with oil grooves machined within proper tolerances and the other AFW pump (EP-504) has been determined to have improperly machined oil grooves. We are i

, investigating the effect of the improperly machined oil grooves on pump operability.

The 14-day follow-up reports and copies of Licensee Event l Reports (LER's) No.80-063 (Docket No. 50-361) No.83-039 (Docket No. 50-362) will be submitted by July 8, 1983, to address this event including the cause and corrective action.

If there are any questions, please contact me.

Sincerely, M/

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occ: A.E. Chaffee (USNRC Resident Inspector, Units 2 and 3) j, R.J. Pate (USNRC Resident Inspector, Units 2 and 3)

] J.P. Stewart (USNRC Resident Inspector, Units 2 and 3) 4 1

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