United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for October 7, 2003

Headquarters Daily Report

To top of page

N/A

Part 21 - Woodward governor trouble at Oyster Creek

Licensee/Facility:

OYSTER CREEK
ENGINE SYSTEMS
Rocky Mount, North Carolina
Dockets:

License No:
Notification:

MR Number: H-2003-0027
Date: 06/19/2003


Source Document: Letter

Reviewer: MARKLEY, ANTHONY W

Discussion:

The vendor, Engine Systems, Inc. (ESI) reported to the NRC that they have concluded an investigation of a condition reported with an EMD electric start motor manufactured in 1999. Oyster Creek Generating Station purchased four of these electric start motors which was part of the emergency diesel generators system, from the vendor in 1999. One of these starters was returned to the vendor for failure analysis. The vendor has reported that the starter, having been in the site's inventory since receipt, was bench tested and the results showed that the starter drive or "Bendix" did not extend properly from rest upon application of voltage to the solenoid. The vendor performed functional testing and inspection of the starter.

The vendor contacted the manufacturer, Delco Remy, to discuss the findings. The representative reviewed photos of the material found and determined it was a room temperature vulcanizing (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.

The vendor has reported that only one plant, Oyster Creek, was affected and the vendor has contacted Oyster Creek concerning the problem. Any further information can be found in ADAMS under Accession No. ML031690386.

Accession Numbers:

Accession No Accession Date
ML031690386 06/11/2003

Contacts:

Name Office Abbrev Phone No E-Mail
MARKLEY, ANTHONY W NRR (301) 415-3165 AWM@nrc.gov
Page Last Reviewed/Updated Thursday, March 29, 2012