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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 54206 | 5 August 2019 22:19:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Notification - Spectrum Technologies Control Power Transformer | Pursuant to 10 CFR 21.21(d)(3)(i), this is a non-emergency notification by Energy Northwest concerning a defect on a control power transformer (CPT) resulting in a failed starter coil while in service at Columbia Generating Station. The defect was associated with a CPT provided by Spectrum Technologies (model Micron B150-2957-1). On June 14, 2019, a failure analysis was completed that determined that the failure of the coil occurred because the starter coil was exposed to chronic elevated temperatures. These elevated temperatures were caused by the associated control power transformer (CPT) secondary voltage being maintained outside the coil's rated voltage range. Previously on June 10, 2019, it was determined that the CPT installed in the Spectrum Technologies motor starter assembly did not meet procurement specifications resulting in a turns ratio that produced higher voltages on the motor starter coil than its rated voltage. This led to overheating and breakdown of the coil insulation that created a short between two windings. On August 5, 2019, Energy Northwest completed a Part 21 evaluation in accordance with 10 CFR 21.21(a)(1) and determined that this deviation could create a substantial safety hazard as defined in 10 CFR 21.3. The NRC Resident Inspector has been notified. The licensee has 14 Spectrum transformers that are continuously energized that could be affected. The one transformer that experienced the failure was out of service for maintenance at the time of discovery. Four other coils were inspected for extent of condition and no more failures were found. | ||
| ENS 44504 | 15 September 2008 04:00:00 | 10 CFR 21.21 | Part 21 - Siemens Model 353 Process Controller Transformer Failure | The following information was received via facsimile. The defect concerns a decreased reliability of the transformer within the controller. The failure of the transformer can cause the controller to not power up when energized or to unexpectedly shut down during normal operation. This notification is for the following controller models shipped between 2/21/2007 and 4/21/2008: 353A, Kit A TGX:353A, Kit B 16353-68 Controller Board Kits for Design Level A TGX:16353-302 Controller Board Kit for Design Level B Affected licensees are Florida Power and Light (Duane Arnold) and Duke Energy (Oconee). | ||
| ENS 41610 | 18 April 2005 05:00:00 | 10 CFR 21.21 | Part 21 Notification Concerning Cutler-Hammer A200 Nema Size 1 Starters | In March 2002, Spectrum Technologies provided 20 Class 1 E safety related Cutler-Hammer A2001 NEMA Size 1 starters to Rochester Gas & Electric Company - Ginna Station. Spectrum Technologies had purchased the starters as commercial grade items from Cutler-Hammer, and dedicated them per EPRI NP5652, method 1, Special Tests and Inspections. Ginna Station advised Spectrum Technologies that they had installed one of these starters in the circuit for their Boric Acid Storage Tank (BAST) Heaters. Approximately eight (8) weeks later they received an alarm for low BAST temperature. Investigation found an open coil on the starter and replaced the starter. The failed starter was sent to the Ginna Materials Laboratory for analysis. This analysis indicates that a manufacturing defect caused the failure. The Ginna Materials Laboratory examined the starter using a low power binocular microscope for signs of defects, overheating, or cracks. Resistance measurements between the two coils in the starter were taken and they were then subjected to X-ray radiography. Subsequent to this, the coils were disassembled and sectioned to reveal the defect. The failed coil wire was also examined using scanning electron microscopy for signs of overheating or melting. It was determined that the failure is the result of a manufacturing defect in the epoxy surrounding the coil. The open circuit was caused when the epoxy cracked at the defect and broke a wire running through the epoxy. This wire connected the two coils and this failure caused the open circuit. Spectrum Technologies has provided the above information, including all figures, to Cutler-Hammer for them to investigate/evaluate the situation. Spectrum Technologies has requested that they provide a formal report addressing what caused the condition and whether it is unique or a common problem, what other components may be affected, and what will be done to prevent recurrence. |