ENS 47567
ENS Event | |
|---|---|
12:00 Jan 2, 2012 | |
| Title | Part 21 Report - Defective 48 Volt Dc Safety Related Power Supplies |
| Event Description | The following was received via fax:
ATC Nuclear has identified a design defect associated with power supplies provided through ATC Nuclear, Schenectady, NY. The defect was identified during Failure Mode Analysis following return of one of the units from the customer. The 48 VDC Power Supplies, PIN DA265A1879P00/ST were provided as safety related components to Entergy's Pilgrim Station under Purchase Orders 10240621, 10282296 and 10308991. Entergy's Pilgrim Station is currently the only station in possession of these items. The failures are exhibited as a spurious overvoltage shutdown condition when power is applied or a spurious overvoltage shutdown condition if the overvoltage circuit becomes contaminated with particulate or other material. The design defect is related to the specific silicon control rectifier used in the over voltage protection circuit. An extent of condition review is ongoing to determine if other power supplies provided under these three purchase orders are affected. Currently none of the other power supplies provided have exhibited this condition. The affected serial numbers are: 90922-1, 90922-2, 90922-3, 91013-1, 91013-2, 91013-3 under purchase orders 10240621 and 10282296. The affected serial numbers are: 110512-1, 110512-2, 110512-3, 110512-4, 110512-5 under purchase orders 10308991. ATC does not have sufficient information to evaluate the safety significance of the defect because the quantities and locations of the power supplies currently in use is not known. Information Contact: Ray Chalifoux ATC Nuclear (865) 384-0124.
ATC Nuclear has identified an additional defective lot of power supplies provided through ATC Nuclear, Schenectady, NY to Xcel Energy's Monticello Station under Purchase Order #00037345. The defects were identified during Failure Mode Analysis following return of twelve units from the customer. The additional affected 115 VDC Power Supplies, P/N DA265A1313P001/ST, Serial Numbers 110713-1 through 110713-12 also were found to contain design flaws in the overvoltage protection circuitry similar to the 48 VDC power supplies. A design change was implemented to resolve the defective overvoltage protection circuit and the defects were resolved. No other additional customers are affected. The customer had not placed the power supplies into service. Notified the R3DO (Stone) and the Part 21 Reactor Group via email. |
| Where | |
|---|---|
| Atc Nuclear Oak Ridge, Tennessee (NRC Region 1) | |
| Organization: | Atc Nuclear |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+28.32 h1.18 days <br />0.169 weeks <br />0.0388 months <br />) | |
| Opened: | R.A.Chalifoux 16:19 Jan 3, 2012 |
| NRC Officer: | Joe O'Hara |
| Last Updated: | Mar 26, 2012 |
| 47567 - NRC Website | |
Atc Nuclear with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 540952019-05-29T04:00:00029 May 2019 04:00:00
[Table view]10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 Notification - Introl Positioners Potential Latent Defect ENS 524032015-12-08T05:00:0008 December 2015 05:00:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Pawl Fasteners Failed to Provide Sufficient Structural Support ENS 475672012-01-02T12:00:0002 January 2012 12:00:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 Report - Defective 48 Volt Dc Safety Related Power Supplies 2019-05-29T04:00:00 | |