05000400/LER-2003-001, Turbine Trip - Reactor Trip
| ML032030350 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 07/16/2003 |
| From: | Waldrep B Progress Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| HNP-03-071 LER 03-001-00 | |
| Download: ML032030350 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| 4002003001R00 - NRC Website | |
text
@ Progress Energy JUL 1 6 2003 U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 Serial: HNP-03-071 10CFR50.73 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400/LICENSE NO. NPF-63 LICENSEE EVENT REPORT 2003-001-00 Ladies and Gentlemen:
The enclosed Licensee Event Report 2003-001-00 is submitted in accordance with 10 CFR 50.73. This report describes an automatic turbine trip - reactor trip. Event notification EN 39856 previously reported this event in accordance with 10 CFR 50.72.
Please refer any questions regarding this submittal to Mr. John Caves, Supervisor -
Licensing/Regulatory Programs, at (919) 362-3137.
Sincerely, B. C. W rep 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.0 Box 165 New Hill, NC 27562 1
- 3:69
Abstract
On May 18,2003, with the reactor at approximately 27% power following a refueling outage (RFO-1 1), the reactor was automatically tripped from a turbine trip-reactor trip signal. Plant equipment functioned as required. The operations staff responded to the event in accordance with applicable plant procedures. The plant stabilized at normal operating no-load reactor coolant system (RCS) temperature and pressure following the reactor trip.
The most likely failure mode is an electrical failure of the turbine overspeed sensing probe that resulted in generation of a spurious turbine overspeed signal. This spurious signal subsequently resulted in the reactor trip. An installed spare turbine overspeed sensing probe has been placed in service. The sensing probe that was in service at the time of the trip remains installed in the system and is unavailable for forensic analysis until the next refueling outage (RFO-12).
The root cause is a design vulnerability in which a single component failure can result in a spurious turbine overspeed signal and subsequently cause a reactor trip. Corrective action includes modifying the electrical turbine overspeed circuit to remove single-point vulnerability for turbine overspeed sensing probe failures.
NRC FORM 366 (7-2000)
(If more space is required, use additional copies of (if more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A)
V.
PREVIOUS SIMILAR EVENTS
No previous HNP events or conditions are known related to an electrical failure of the turbine overspeed sensing probe that caused a turbine trip-reactor trip.