ML031690386

10CFR21 Reporting of Defects and Non-Compliance - Engine Systems, Inc., Report No. 10CFR21-0087, Rev 0, Emd Electric Start Motors at Oyster Creek

ML031690386
Person / Time
Site:	Oyster Creek
Issue date:	06/11/2003
From:	Woolard S Engine Systems
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
10CFR21-0087, Rev 0
Download: ML031690386 (7)

Text

XJj~J1 ENGINE SYSTEMS, INC.

J 1220 S. Washingtn St., Rocky Mount, NC 27801 Telephone: 252/977-2720

_, - P.O. Box 1928, Rocky Mount, NC 27802-1928 Fax: 252/446-1134 June 11, 2003 U.S. Nuclear Regulator Commission Document Control Desk Mail Stop OPI-17 Washington, DC 20555

Subject:

I OCFR21 Reporting of Defects and Non-Compliance -

Engine Systems, Inc. Report No. 10CFR21-0087, Rev. 0 EMD Electric Start Motors at Oyster Creek

Dear Sir:

The enclosed report addresses a reportable notification about EMD electnc start motors at Oyster Creek (manufactured in 1999) - P/N 10478830.

A copy of the report has also been sent to the NRC.

Please sign below, acknowledging receipt of this report, and return a copy to the attention of Document Control at the address above (or, fax to number 252/446-1134) within 10 working days after receipt.

Yours very truly, ENGINE SYSTEMS, INC.

Susan Woolard Document Control Please let us know if ANY of your mailing Information changes - name of recipient, name of company/facility, address, etc. Mark the changes on this acknowledgment form and send to us by mall or FAX to the number above.

RECEIVED:

(93)

DATE:

Quality Performance With Pride

( ENGINE SYSTEMS INI 1220 S. Washington St. Rocky Mount, NC 270 01 Telephone: 2521977-2720 P.O. Box 1928, Rocky Mount, NC 27802-1928 Fax: 2521446-1134 Report No. IOCFR21-0087 Rev. 0: 06/11/03 IOCFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: EMD Electric Start Motors at Oyster Creek (manufactured in 1999).

P/N 10478830 SYSTEM: EMD diesel generators at Oyster Creek CONCLUSION: Reportable in accordance with 10CFR21.

Prepared By: Date: 6_/___

/ Engineering Manager Reviewed By: Date:

Quality Assdrance Manager Quality Performance With Pride

Report No. 10CFR21-0087 Record of Revisions Page: 1 of 1 REV DATE PAGE DESCRIPTION

Report No. IOCFR21-0087 Revision: 0 Date: 06/11/03 Page: 1 of 4 COMPONENT:

EMD electric start motors, P/N 10478830 manufactured in 1999.

SUMMARY

Engine Systems Inc. (ESI) has concluded an investigation of a condition reported with an EMD electric start motor. Oyster Creek Generating Station purchased 4 electric start motors from ESI on their PO 0744183 in 1999. One of these starters, p/n 10478830, s/n 05D99 was retumed to ESI for failure analysis. Reportedly the starter, having been in the site's inventory since receipt, was bench tested and the starter drive or "Bendix" did not extend properly from rest upon application of voltage to the solenoid. ESI performed functional testing and inspection of the starter. Inspection revealed that the starter drive brake washer had adhesive applied to both sides (normally, only one side has adhesive). This caused the brake washer and starter drive to astick" to the lever housing; thus preventing the starter drive from operating properly.

DISCUSSION:

Upon removal of the Bendix assembly from the starter, a white opaque ring of material was found adhered to the lever housing. This material was in a position such that the Bendix assembly would rest against it in the de-energized state.

Internal view of lever housing, Bendix removed

Report No. 10CFR21-0087 Revision: 0 Date: 06111/03 Page: 2 of 4 White material removed from lever housing Non-drive end of Bendix assembly, brake washer surface

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Report No. 10CFR21-0087 Revision: 0 Date: 06111/03 Page: 4 of 4 The function of the brake washer is to slow down the starter's armature after the engine starts and the pinion disengages. This reduces the starter's coast down time and conserves brush life.

ESI contacted the manufacturer, Delco Remy, to discuss the findings. The representative reviewed photos of the material found and determined it was an RTV adhesive formerly used to adhere the brake washer. Delco Remy's practice is to either adhere the brake washer to the lever housing or to the Bendix assembly. In the early 1980's, RTV was used exclusively to adhere the brake washer. In 1986, their sub-supplier applied a mastic type adhesive on the brake washer.

Sometimes the pre-applied adhesive did not provide sufficient bond strength, so RTV was used occasionally as a supplemental adhesive. At some point in 1999, the manufacturer stated that they had a process problem in which the brake washer was installed in the standard manner, but RTV was applied to the opposite side also. Delco Remy could not confirm the exact dates of this problem, but they estimate that it occurred only over a 2 week period. In April, 2001 a stronger adhesive was applied by the brake washer sub-supplier and the use of RTV was eliminated.

Because the process problem date could not be obtained from the manufacturer, all starters with 1999 serial numbers are considered suspect.

CONCLUSION:

Improper operation of the starter's drive assembly was caused by the presence of silicone RTV adhesive on the face of the lever housing. In this starter assembly, the brake washer was apparently adhered to the Bendix assembly using the pre-applied adhesive while RTV was applied to the lever housing and/or to the opposite face of the brake washer. The RTV surface maintained a sticky finish relative to the face of the brake washer, and this led to higher than normal required forces to separate the two. Therefore, with normal test voltage applied to the starter's solenoid, the Bendix would not engage.

After removal of the improperly applied RTV, the Bendix assembly operated properly.

CUSTOMERS AFFECTED:

ESI has searched its historical data and has determined that only one (1) customer is affected.

All other EMD users have air start motors.

CUSTOMER SITE PIN SIN or Date Code ESI ORDER I GPU Oyster Creek Nuclear Station 10478830 99 05D99 61790 l Note: One of "05D99" starters has already been corrected by ESI as part of the failure analysis.

CORRECTIVE ACTION:

1. Inspect starters with serial numbers containing "99" for a "sticking" starter drive. Two (2) starting motors are required for the engine. The solenoids of each motor are connected in series; therefore, the starter drive must engage at % of the minimum system voltage.

2. Starters with sticking drives should be disassembled and the RTV removed; or, returned to ESI for evaluation and repair.