ENS Event | |
|---|---|
11:00 Sep 28, 2011 | |
| Title | Part 21 Report - Diode Failures Due to Deterioration |
| Event Description | The following was received via fax:
Component Description: International Rectifier (IR) and Vishay 150 amp clamp diodes with either forward or reverse bias These are Ametek Solid-state Controls part numbers 07-600150-00 and 07-600151-00. Diodes can be either installed in Ametek Solid-state Controls UPS equipment or provided as a spare part. The diode failures due to this suspected defect have occurred generally at around the third or fourth year of operating life of the device. There are no warning signs that a failure is imminent, or detection method for predicting an approaching failure. The investigation has revealed that the diode failures were due to voltage transients or punch through. A failure analysis by Southwest Research concluded that the device having an 'alloy junction' can deteriorate after three to four years of operation resulting in a 'punch through' condition within the device causing the diode to short. The actual cause has not been determined; however it is suspected that the alloy junction type device may have sensitivity to age or voltages causing the device to more rapidly degrade. The failures described above, could result in loss of output voltage and transfer of the static switch to the bypass source which could result in a potential damage to the load. We have only two known failures in systems at this voltage level. We feel the failure rate has been extremely low and the risk is minimal. Each operating facility will need to evaluate the potential risk to their operation. The licensee did not indicate which NRC licensees, if any, are affected by this notice. |
| Where | |
|---|---|
| Ametek Columbus, Ohio (NRC Region 3) | |
| Organization: | Ametek |
| Reporting | |
| 10 CFR 21.21 | |
| Time - Person (Reporting Time:+6.38 h0.266 days <br />0.038 weeks <br />0.00874 months <br />) | |
| Opened: | Robert George 17:23 Sep 28, 2011 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Sep 28, 2011 |
| 47301 - NRC Website
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Ametek with 10 CFR 21.21 | |
WEEKMONTHYEARENS 473012011-09-28T11:00:00028 September 2011 11:00:00
[Table view]10 CFR 21.21 Part 21 Report - Diode Failures Due to Deterioration ENS 448052009-01-26T05:00:00026 January 2009 05:00:00 10 CFR 21.21 Ametek Part 21 Report on Tyco/Potter & Brumfield Relays 2011-09-28T11:00:00 | |