05000400/LER-2003-003, For Shearon Harris, Unit 1, Regarding Manual Reactor Trip Due to Loss of B Main Feedwater Pump
| ML032270443 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 08/11/2003 |
| From: | Waldrep B Progress Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| EN 39938, HNP-03-086 LER 03-003-00 | |
| Download: ML032270443 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| 4002003003R00 - NRC Website | |
text
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i,> Progress Energy AUG I l1 23 U.S. Nuclear Regulatory Commission ATIN: NRC Document Control Desk Washington, DC 20555 Serial: HNP-03-086 10CFR50.73 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50400/LICENSE NO. NPF-63 LICENSEE EVENT REPORT 2003-003-00 Ladies and Gentlemen:
The enclosed Licensee Event Report 2003-003-00 is submitted in accordance with 10 CFR 50.73. This report describes a manual reactor trip due to a loss of the "B" main feedwater pump. Event notification EN 39938 previously reported this event in accordance with 10 CFR 50.72.
Please refer any questions regarding this submittal to Mr. John Caves, Supervisor -
LicensinglRegulatory Programs, at (919) 362-3137.
Sincerely, B. C. W61drep Plant General Manager Harris Nuclear Plant BCW/jpy Enclosure c:
Mr. R. A. Musser (HNP Senior NRC Resident)
Mr. C. P. Patel (NRC-NRR Project Manager)
Mr. L. A. Reyes (NRC Regional Administrator, Region II)
Progress Energy Carolinas. Inc.
Harris Nuclear Plant P.O. Box 165 New Hill, NC 27562
Abstract
On June 14, 2003 at 1053 EST with the reactor at 1 00%/6 power, the reactor was manually tripped In response to an automatic trip of one of two operating main feedwater pumps (MFPs). The O"8 MFP-tripped following the failure of a Westinghouse (NAL2) bistable comparator card associated with MFP feedwater flow control system. This card failure generated a spurious bw-flow alarm and low-flow trip signal to the "B" MFP. Both motor-driven auxiliary feedwater (AFW) pumps and the turbine-driven AFW pump auto-started due to lo-lo steam generator level. Safety systems
'functioned as required. The operations crew responded to the event In accordance with applicable plant procedures.
The cause of the unplanned trip of the *B" MFP was due to a failed T30 transistor on a NAL2 comparator card.
Immediate corrective action was to replace the failed card. In addition, HNP will modify the system by the end of the next refueling outage (Fall, 2004) such that failure of an NAL2 bistable comparator card in the MFP control system will not cause an unnecessary MFP trip.
NRC FORU 36 (7.2000)
(if more space Is requlred, use addiftnal copies of (ff more space Is required, use additional copies of NRC Form 366A)
IV.
CORRECTIVE ACTIONS
Immediate corrective action was to replace the failed card. In addition, HNP will modify the system by the end of the next refueling outage (Fall, 2004) such that failure of an NAL2 bistable comparator card in the MFP control system will not cause an unnecessary MFP trip leading to a reactor trip.
V.
PREVIOUS SIMILAR EVENTS
There have been no previous reactor trips at HNP caused by a failure of this type of transistor on this card type.
There are thousands of this type of transistor and hundreds of cards in service. Failures have occurred on a very small fraction of the Installed components where the cause Is either indeterminate or assumed to be age related. Age-based component replacement or refurbishment was considered but not implemented, consistent with vendor recommendations.
NHRC FOM J66(14!001j