JAFP-02-0195, Letter Regards 10 CFR Part 21 Notification EC-1 Overcurrent Sensors Failed Prematurely
| ML022890175 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 10/02/2002 |
| From: | Ted Sullivan Entergy Nuclear Northeast, Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| JAFP-02-0195 | |
| Download: ML022890175 (4) | |
Text
Entergy Nuclear Northeast Entergy Nuclear Operations, Inc.
________James A Fitzpatrick~ NPP Ent~i~yP0 Box 110
-nt gE A
comig NYx 1309 Tel 315 349 6024 Fax 315 349 6480 T.A. Sullivan Vice President. Operations-JAF October 2, 2002 JAFP-02-0195 United States Nuclear Regulatory Commission Attn: Document Control Desk Mail Station P1-137 Washington, D.C. 20555
Subject:
James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 10 CFR Part 21 Notification EC-1 Overcurrent Sensors Failed Prematurely
Dear Sir:
This report is being submitted in accordance with 1 OCFR21.21(d) to address a reportable defect. The defect deals with EC-1 overcurrent sensors for a safety related circuit breaker. The defect was discovered after two overcurrent sensors withdrawn from warehouse stock failed during bench testing in preparation for installation in the plant during the upcoming refueling outage. The failure mode was premature tripping of the magnetic (instantaneous) element of the device, such that the associated circuit breaker would have tripped early and the corresponding loads would not have remained energized to perform their required safety function.
The only application of these specific EC-1 overcurrent sensors would have been in a circuit breaker used in cubicle 71-11510, which is the emergency bus feeder breaker providing 600 VAC power to Motor Control Center (MCC)-151. Electrical loads powered from this MCC include various safety systems such as the Standby Gas Treatment System (SBGT), Residual Heat Removal System (RHR) and High Pressure Coolant Injection System (HPCI). The loss of the MCC could have resulted in the failure of SBGT to perform its safety function. See the Attachment for specific details.
There are no commitments contained in this report.
October 2, 2002 JAFP-02-0195 Questions concerning this report may be addressed to Mr. Timothy Page at (315) 349 6209.
TAS:TP:dmr Attachment cc:
USNRC, Region 1 USNRC, Project Directorate USNRC Resident Inspector INPO Records Center General Electric Nuclear
-I Attachment to JAFP-02-0195 Page 1 of 2 I. Name and Address Mr. T. A. Sullivan - Vice President, Operations Entergy Nuclear Operations, Inc.
James A. FitzPatrick Nuclear Power Plant P.O. Box 110 Lycoming, NY 13093 I1. Facility, Activity or Component James A. FitzPatrick Nuclear Power Plant (JAF)
The components in question are EC-1 overcurrent sensors for a safety related circuit breaker. Two overcurrent sensors removed from stock for bench testing tripped prematurely.
GE Model Type EC-1 Trip Device 225 Amp, 60 Cycle Sensor Trip, Characteristic 1B-2C GE P/N QEC10225ABCGlONOO Serial Nos. 77386-3A and 77386-3B I1l. Constructor or Supplier General Electric Nuclear M/C 397 175 Curtner Ave.
San Jose, CA 95125 IV. Defect and Safety Hazard A Condition Report (CR-JAF-2002-03255) identified that two new EC-1 overcurrent sensors withdrawn from warehouse stock failed during bench testing in preparation for installation in the plant during the upcoming refueling outage. The failure mode was premature tripping of the magnetic (instantaneous) element of the device, such that the associated circuit breaker would have tripped early. The only application of these specific EC-1 overcurrent sensors is in the circuit breaker used in cubicle 71-11510, which is the emergency bus feeder breaker providing 600 VAC power to Motor Control Center (MCC)-1 51. Electrical loads powered from this MCC include various safety systems such as the Standby Gas Treatment System (SBGT), Residual Heat Removal System (RHR) and High Pressure Coolant Injection System (HPCI).
Attachment to JAFP-02-0195 Page 2 of 2 IV. Defect and Safety Hazard (continued)
The test information indicates that the circuit breaker would have prematurely tripped based on the starting current of the 'A' SBGT Exhaust Fan and thus the associated MCC would not have remained energized. Assuming a concurrent single failure of the
'B' SBGT subsystem, this could have resulted in the loss of both subsystems and the failure of SBGT to perform its safety function. Therefore, a substantial safety hazard existed in that the potential existed for a major deficiency/major degradation of essential safety-related equipment.
No other safety functions would have been lost.
V. Date This defect was discovered on August 27, 2002.
VI. Location and Number of Defective Components The only application of these specific EC-1 overcurrent sensors would have been in a circuit breaker used in cubicle 71-11510, which is the emergency bus feeder breaker providing 600 VAC power to MCC-51. The spare overcurrent sensors that failed had been in parts inventory for approximately 2 years. There'are no other spares in the JAF stock system.
The overcurrent sensors currently installed in the plant were tested satisfactorily prior to installation and have not demonstrated the failure mechanism described in this letter (i.e., SBGT System testing which involves starting the 'A' SBGT Exhaust Fan has not resulted in breaker tripping).
VII. Corrective Action The defective components were placed in a "hold" status to prevent issuance in the plant. Corrective Action Request 02-111 was issued to General Electric for evaluation and corrective action, with a requested response date of October 21, 2002.
VIII. Advice-None.