ENS 46760
ENS Event | |
|---|---|
04:00 Apr 15, 2011 | |
| Title | Potential Defect in Magnetrol Level Switch from Engine Systems Incorporated |
| Event Description | Engine Systems, Incorporated (ESI) began an evaluation of a level switch on February 16, 2011. Monticello Nuclear Plant returned a level switch for failure evaluation. The reported condition was that the switch mechanism would not actuate throughout the entire level range. ESI supplied the level switch in July, 2008. The switch was functionally tested prior to shipment and it worked properly at that time. It remained in customer inventory until recently when it was tested and the problem was identified.
This level switch is used in the fuel oil day tank of some EMD 999 emergency diesel generators and controls the fuel transfer pump. Malfunctioning of this switch could prevent the fuel transfer pump from operating and therefore the diesel generator could shut down due to insufficient fuel supply; thus preventing the diesel generator from performing its safety related function. The EMD 999 fuel system also incorporates a backup fuel transfer pump that is controlled by the level alarm switch within the day tank. The backup transfer pump turns on when the low level alarm is actuated and turns off when the high level alarm actuates. ESI has been conducting tests and inspections of the returned level switch and will be coordinating with the manufacturer (Magnetrol) to complete our evaluation. To date, no other similar failures with this Magnetrol level switch have been reported to ESI. Component: Magnetrol level switch, ESI P/N: 8277780-ESI, Magnetrol type A10 Report No: 10CFR21-0101-INT
The following information was received by facsimile: COMPONENT: Magnetrol level switch ESI P/N: 8277780-ESI Magnetrol type A 10 PURPOSE: This report is a follow-up to an interim report (10CFR21-0101-INT) issued by Engine Systems, Inc. (ESI) on 04/15/11 which identified a deviation with a Magnetrol level switch. The interim report was issued because ESI was not able to complete the evaluation within the 60 day requirement of 10CFR21. SUMMARY: Evaluation of the level switch failure at Monticello was completed on 5/12/11 and it has been determined that the deviation is not a reportable defect as by defined by 10CFR21. Based on the data collected by ESI and through evaluation by and discussion with Magnetrol (manufacturer of the level switch), it is ESI's conclusion that the level switch was delivered to the customer in working order and that it must have been damaged subsequent to ESI's involvement. Furthermore, within the fuel oil system in which the level switch is installed, there is an inherent redundancy whereby the high/low level alarm switch will actuate to turn on or turn off a secondary fuel transfer pump in the event this level switch (or its associated fuel transfer pump) does not function properly. Therefore, ESI does not consider this as a reportable defect. Notified R2DO (Guthrie), R3DO (Passehl), and Part 21 group via email. |
| Where | |
|---|---|
| Engine Systems, Inc Rocky Mount, North Carolina (NRC Region 1) | |
| Organization: | Engine Systems, Inc |
| Reporting | |
| 10 CFR 21.21 | |
| Time - Person (Reporting Time:+13.48 h0.562 days <br />0.0802 weeks <br />0.0185 months <br />) | |
| Opened: | Tom Horner 17:29 Apr 15, 2011 |
| NRC Officer: | John Knoke |
| Last Updated: | May 13, 2011 |
| 46760 - NRC Website | |
Engine Systems, Inc with 10 CFR 21.21 | |
WEEKMONTHYEARENS 473472011-10-11T04:00:00011 October 2011 04:00:00
[Table view]10 CFR 21.21 Part 21 Notification - Emergency Diesel Generator Piston Delamination ENS 471122011-06-16T16:00:00016 June 2011 16:00:00 10 CFR 21.21 Part 21 - Emergency Diesel Generator Failed Air Start Motor ENS 467602011-04-15T04:00:00015 April 2011 04:00:00 10 CFR 21.21 Potential Defect in Magnetrol Level Switch from Engine Systems Incorporated 2011-06-16T16:00:00 | |