ML15030A033

Letter from James Thigpen Notification of Potential Part 21 Nuclear Nonconformance Event Number 50703

ML15030A033
Person / Time
Site:	Susquehanna
Issue date:	01/20/2015
From:	Thigpen J Baldor Electric Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
50703
Download: ML15030A033 (4)

Text

Baldor Electric Company

,,I ,I=,P. 0. Box 250, 4349 Avery Drive

..................... _Flowery Branch, GA 30542 USA A MEMBER OF THE ABB GROUP Tel 678.947.7350 January 20, 2015 To: Document Control Desk United States Nuclear Regulatory Commission Washington, DC 20555

Dear Sir or Madam:

In accordance with Title 10, Code of Federal Regulations, Part 21, Baldor Electric is making Written and Final Notification as required by 10CFR21.21 for event #50703.

A. Name and address of the individual informing the NRC.

James Thigpen Quality Assurance Manager Baldor Electric/Gainesville Motor Plant 4349 Avery Drive Flowery Branch, Georgia 30506 B. Identification of Basic Component being Supplied.

AC Motor C. Name of firm supplying basic component.

Baldor Electric/Gainesville Motor Plant 4349 Avery Drive Flowery Branch, Georgia 30542 D. Nature of the defect, deviation, or failure to comply.

Subject:

Nuclear Nonconformance Event Number 50703 This is a reportable 10CFR21 notification because we believe it is possible that the 9 identified lE motors shipped by Baldor Electric, contain a design where the buildup of tolerances between the shaft journal, bearing cap and bracket could potentially allow the bearing cap to cock in the bracket causing a 0.001" interference fit on one side of the cap in a worst case scenario.

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..... Baldor Electric Company 9A LID O0 P. 0. Box 250, 4349 Avery Drive Flowery Branch, GA 30542 USA A MEMBER OF THE ABB GROUP Tel 678.947.7350 STEPS TAKEN TO PREVENT FUTURE OCCURRENCES A review was completed by design engineering to determine this design issue has only occurred for the Baldor Specification ID #'s associated with Howden Part Number 600287-28R, *of which Baldor has only shipped the 10 motors identified below of which 9 remain in the customers possession. Baldor has the remaining motor in our possession and it is being replaced with one using the revised design developed as our corrective action response.

Baldor has notified Howden North America Inc. Company's Quality Assurance of our findings. They have in turn contacted their customer, PPL Susquehanna, and determined all 9 motors in their possession have been in service for over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with no problems.

The design of the shaft/bearing cap radial clearance has been increased to correct the potential safety issue. Motor Bill of materials for the effected Baldor designs have been revised to call for bearing cap part number 603295-74B on any future shipment.

CONCLUSION The one motor that failed during initial customer testing is in process of being repaired or replaced with the new designed bearing cap.

The revision of the design for Spec. ID's B505968, B656588, B782464, B952117 and B1092454 has been implemented and verified to be correct.

The end user PPL Susquehanna has confirmed to Howden North America Inc. that the remaining 9 motors have been in service for over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with no problems, and therefore do not require any alteration to the bearing cap in order to perform their intended use safely.

D. The Discovery Date.

October 29, 2014.

Baldor Electric Company P. 0. Box 250, 4349 Avery Drive Flowery Branch, GA 30542 USA A MEMBER OF THE ABB GROUP Tel 678.947.7350 E. The Quantity and Location of Motors Affected.

PART/COMPONENT NUMBER:

Customer Customer Motor Serial # End User / Location Status Name PO #

Howden 39679 B505968-010 T1 PPL Susquehanna Contacted North 44617 B656588-010 T1 PPL Susquehanna Todd.Gunvalson@Ho America Inc. B656588-010 T1 PPL Susquehanna wden.com and 48105 B782464-010 T1 PPL Susquehanna confirmed all 9 motors B782464-010 T2 PPL Susquehanna have been running in 012747 LIl 1 B952117-010 T1 PPL Susquehanna service for over 24 B952117-010 T2 PPL Susquehanna hours with no B952117-010 T3 PPL Susquehanna problems.

022355 B1092454-010 T1 PPL Susquehanna B1092454-010 T2 Baldor Electric Motor will ship to Howden with new design, new serial number F. The Corrective Action which has been completed.

Baldor has notified Howden North America's Quality Assurance

.of our findings on the motor returned to Baldor for 10CFR21 evaluation. A review was completed by design engineering to determine this failure was due to a collection of events that occurred simultaneously, and if were to happen again, would result in failure within hours of the motor being powered.

Baldor's solution to this worst case scenario is to open the clearances of the shaft bore in the cap up from a 0.008" radial clearance by design, to the maximum 0.012" radial clearance for 1.5" fit length for UL XP standards. This would eliminate any possibility of a rub while the cap is mounted in the cap journal of the bracket. All motors that have been in service for more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> do not require alteration of the bearing cap. Any others that have not been placed into service should have the opposite drive end bearing cap replaced to ensure this failure will not occur. The corrective action CAR-00451 Howden: Request for 10CFR21 Evaluation for bearing lockdown was completed and closed on 12/23/14.

Baldor initiated corrective action per Baldor CAR-00451 on December 15, 2014 which was completed and received final approval by James Thigpen QA manager Baldor. Final verification of actions will be and verified for effectiveness by 3/23/2015.

Baldor Electric Company P. 0. Box 250, 4349 Avery Drive Flowery Branch, GA 30542 USA Tel 678.947.7350 A MEMBER OF THE ABB GROUP G. Other Information.

All motors that have been in service for more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> do not require alteration of the bearing cap. Any others that have not been placed into service should have the opposite drive end bearing cap replaced with a newly designed cap (603295-74B) to ensure this failure could not occur.

Sincerely, mre~s Tge~n Quality Assurance Manager, Gainesville Motor Plant Baldor Electric Co.