ENS 46072
ENS Event | |
|---|---|
04:00 May 25, 2010 | |
| Title | Part 21 Report Concerning Failure of Oil-Filled Capacitor |
| Event Description | The information below is a summary of a report received via facsimile from Trentec dated July 6, 2010.
Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect: The basic component containing the defect is a Ronken oil filled capacitor with a rating of 70 micro Farad-660 VAC @ 60 Hz. The part number is P91D23706H05 with a 06-06 date code (manufactured in 2006). The capacitor is commercially dedicated by Trentec for use in safety related applications. The associated Trentec part number is 7T20701 with a 06-06 date code. Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect: Trentec, Business Unit of Curtiss Wright Flow Control Corporation, 4600 East Tech Drive, Cincinnati, OH 45245 Nature of the defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply: The defect pertains to 70 micro Farad capacitors that failed in the inverter circuitry for the uninterruptible power supply (UPS) for the turbine driven auxiliary feedwater pump (TDAFWP). The failure of the capacitors was determined by an independent testing lab to be a manufacturing defect in which the internal spot-welded (no solder used) connection points on the capacitors were inadequate and resulted in poor/high resistance connection points which culminated in internal arcing at several of the connection points. The Auxiliary Feedwater (AFW) system for each unit consists of two motor driven pumps and one turbine driven pump. The TDAFWP UPS for each unit has an A and B section for system redundancy, with two 70 micro Farad capacitors used in each section. The capacitors currently installed in the Farley 1 TDAFWP UPS B section and Farley 2 TDAFWP UPS B section have the suspect date code (total of four). Given a loss of a TDAFWP UPS due to the capacitor failures, together with a single failure of one of the motor driven AFW pumps leaves the one remaining motor driven AFW pump to ensure the reactor coolant system is properly cooled via the steam generators during emergency conditions. However, two of the three AFW pumps are required to satisfy the flow demand for the most limiting associated design basis accidents and transients, i.e., feedwater line break, main steam line break, and loss of main feedwater. Accordingly, the flow demand is needed to mitigate the consequences of these events which can result in over pressurization of the reactor coolant pressure boundary, and to prevent uncovering the reactor core and potential radiological releases. Additionally, credit for operation of the TDAFWP is needed for coping with a station blackout event during which the TDAFWP is the only source of AFW. The date on which the information of such defect or failure to comply was obtained: Farley Condition Report 2010107145 was written on May 25, 2010 to determine 10 CFR 21 reportability of the capacitor failures. Trentec Failure Evaluation Plan was written on 6/7/10. Trentec's capacitor evaluation and report was completed 6/30/10. In the case of a basic component which contains a defect or fails to comply, the number and location of these components in use at, supplied for, being supplied for, or may be supplied for, manufactured, or being manufactured for one or more facilities or activities subject to the regulations in this part: The Ronken 70 micro Farad capacitors with 06-06 date code have only been supplied to the Farley Plant on PO number QP070496 for a quantity of 8 each, shipped 5/11/2007 with Trentec tag number 7T20701. The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action: Corrective actions have been scheduled for Farley Maintenance to replace the suspect 06-06 date code capacitors by July 30, 2010. Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees: Perform a failure analysis of any recently failed Trentec qualified Ronken 70 micro Farad capacitor to determine proper corrective action. Replace any Trentec qualified Ronken 70 micro Farad capacitor with a date code of 06-06. They should also be removed from stock to prevent their future use. In the case of an early site permit, the entities to whom an early site permit was transferred Not applicable. |
| Where | |
|---|---|
| Ronken Industries Inc Cincinnati, Ohio (NRC Region 3) | |
| Organization: | Trentec |
| Reporting | |
| 10 CFR 21.21 | |
| Time - Person (Reporting Time:+1016.68 h42.362 days <br />6.052 weeks <br />1.393 months <br />) | |
| Opened: | Marion Mitchell 12:41 Jul 6, 2010 |
| NRC Officer: | Dong Park |
| Last Updated: | Jul 6, 2010 |
| 46072 - NRC Website | |
Ronken Industries Inc with 10 CFR 21.21 | |
WEEKMONTHYEARENS 460722010-05-25T04:00:00025 May 2010 04:00:00
[Table view]10 CFR 21.21 Part 21 Report Concerning Failure of Oil-Filled Capacitor 2010-05-25T04:00:00 | |