United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for May 3, 2004

Headquarters Daily Report

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Part 21 - 2004-0007-00 - Fairbanks Morse Engine has determined a potential safety hazard with the Woodward Digital Reference Unit

Licensee/Facility:


FAIRBANKS MORSE ENGINE

Dockets:

License No:
Notification:

MR Number: H-2004-0011
Date: 04/23/2004


Source Document: Call / Fax from Licensee

Discussion:

Part 21 - 2004-0007-00 - Fairbanks Morse Engine has determined a potential safety hazard with the Woodward Digital Reference Unit

On April 21, 2004, Fairbanks Morse (FM) Engine, a vendor of emergency diesel engines, determined that a potential safety hazard exists for Woodward Digital Reference Units (DRUs). The FM Part Number is 12998236 and the Woodward Part Number is 9903-439.

The defect causes an erratic ramp-up of speed and an inability to reach rated revolutions per minute along with an inability to apply load to the engine. The cause of this issue has been traced to a random contamination problem of an integrated circuit (IC) in DRUs manufactured by Woodward between November 2000 and January 2002.

The rate of occurrence is less than 10 in the United States and approximately 20 worldwide out of approximately 38,000 Woodward units worldwide that use this IC. Only one U.S. nuclear utility has experienced this failure, and the failure occurred during testing prior to the declaration of operability. In all cases, the failure has occurred within the first few hours of operation. Therefore, the vendor believes that if a DRU has been installed and has been operating for many hours/years, it is not at risk for this failure.

Affected nuclear power plants include Seabrook and Wolf Creek. Both utilities received this component in 2001. These utilities are being notified, and any affected DRUs will have ICs replaced as necessary.

Information for this issue as well as other Part 21s is available at the NRC's Operating Experience web page at:
http://www.nrc.gov/reading-rm/doc-collections/event-status/part21/.

Contacts:

Name Office Abbrev Phone No E-Mail
RINI, BRETT A NRR (301) 415-3931 BAR3@nrc.gov


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REGION II

STEAM GENERATOR TUBES DEGRADED

Licensee/Facility:

SOUTHERN NUCLEAR OPERATING CO., INC.
Vogtle 2
WAYNESBORO, Georgia
Dockets: 05000425
[2] W-4-LP
License No:
Notification:

MR Number: 2-2004-0005
Date: 05/03/2004

Discussion:

This Morning Report provides information concerning confirmed outer diameter circumferential cracks in Unit 2 steam generator (SG) tubes. Unit 2 is currently in a scheduled refueling outage. The SGs are Westinghouse Model F with thermally treated alloy 600 tubes. During eddy current testing (ECT) of SG hot leg tubes in SGs 2 and 3, the licensee identified three tubes in SG 2 and three tubes in SG 3 with indications of circumferential cracking. At least one tube in SG 2 has been confirmed to have circumferential cracking by ultrasonic testing. The licensee determined the crack indications were at the transition area just above the tube sheet. The licensee is continuing their ECT of all tubes in SGs 2 and 3 at the tube sheet and ultrasonic testing of the remaining 5 tubes with circumferential crack indications. Due to the confirmed the circumferential crack, the licensee will expand their examination to include at least 20% of the hot leg tubes in SGs 1 and 4.

All Unit 2 SGs were examined during previous refueling outages and no indications of outer diameter circumferential cracks were identified. In addition, there were no indications of primary-to-secondary leakage during the recently completed operating cycle.

This information is current as of 12:00 p.m. 5/3/2004.


Accession Numbers:

Accession No Accession Date
ML041240281 05/03/2004

Contacts:

Name Office Abbrev Phone No E-Mail
BONSER, BRIAN R R2 (404) 562-4540 BRB1@nrc.gov
Page Last Reviewed/Updated Thursday, March 29, 2012