ENS 55223
ENS Event | |
|---|---|
05:00 Mar 29, 2021 | |
| Title | Part 21 - Failure of Size 1 and 2 Freedom Series Full Voltage Reversing Starters |
| Event Description | The following is a summary of information received from Paragon Energy Solutions:
On 3/29/2021, Dominion - North Anna Station has identified instances where size 1 and 2 starters have failed to function as expected in assemblies that were originally supplied by Nuclear Logistics LLC (NLI). The mechanical interlock exhibited binding that prevented the contactor from closing when energized. The identified failed starters are utilized in an application of operating Motor Operated Valves (MOV). This is an intermittent duty application. The issue was identified on Eaton Starter Model AN56DN*, AN56GN*, CN55DN*, CN55GN* style starters and contactors with supplied date codes T4514 (week 45 of year 2014) and T4215 (week 42 of year 2015). Paragon is in the process of identifying the date codes to provide the specific information to the identified plants. The following plants were supplied starters from September 2014 through October 2018: Beaver Valley, Columbia, Ergytech, Harris, Millstone, NEK KRSKO, North Anna, Prairie Island. The component design that exhibited the failure was revised by the original equipment manufacturer (Eaton) in October 2018. There have been no reported failures of the interlock mechanism in vintages manufactured before September 2014 or after October 2018. These recommendations are based on the specific application: The reversing starters and reversing contactors are typically wired in a configuration that will electrically lock out one of the contactors when the other one is being energized to prevent both contactors from being energized at the same time. Therefore, the mechanical interlock is not required to prevent both contactors from being closed at the same time when the electrical interlock configuration is being implemented. In this scenario, the mechanical interlocks are not required and can be removed. The motor control centers that contain the mechanical interlock should be monitored to ensure that there is no binding during operation. The evaluation being performed by Paragon is expected to be completed by May 29, 2021. Tracy Bolt Chief Nuclear Officer, CNO 817-284-0077 Paragon Energy Solutions, LLC 7410 Pebble Drive Ft. Worth, TX 76118
The following revision was received from Paragon Energy Solutions via email and corrects the identified date code and includes the size and serial number of the starter that failed: The issue was identified on supplied Size 1, 73262-025-00028 (Date Code: T4515 - 45th week of 2015) and Size 2, 73262-028-00001 (Date Code: T4215 - 42nd week of 2015). Notified R1DO (Young), R2DO (Miller), R3DO (Orlikowski), R4DO (Deese), NMSS Events Notification, and Part 21 Group via email.
The following update (Interim Report) was received from Paragon Energy Solutions via email: Paragon is submitting this Interim Report since this condition is currently under evaluation but will not be completed within 60 days. Paragon is in communication with EATON, the OEM for the starters/contactors to determine the extent of condition. The evaluation is expected to be completed by June 30, 2021. It was determined that Dominion - Millstone should not be included in the list of affected plants. Millstone will be removed from the list in the final revision of P21-03302021. Notified R1DO (Bower), R2DO (Miller), R3DO (Feliz-Adorno), R4DO (Gepford), NMSS Events Notification, and Part 21 Group via email.
The following is a synopsis of an update (completion of the evaluation) received from Paragon Energy Solutions via email: Paragon has identified the date codes of the supplied starters and contactors to provide the specific information to the identified plants. This information has been provided directly to the specific plant." [Millstone was removed from the list of plants.] The component design that exhibited the failure was revised by the original equipment manufacturer (EATON) in September of 2014. The failed units were from Date Codes T4215 and T4515 which are in the 42nd and 45th weeks of 2015. In September 2018 the drawing was revised again. In discussions with the OEM the revision of the drawing was due to a change in material type and was not a result of binding issues. This condition has not been identified on assemblies manufactured after September 2018. Due to the number of starters that have been installed and in service without issue, it is highly unlikely that there is a defect within all the supplied starters in the date range of September 2014 through September 2018. To date, Paragon has been unable to obtain any conclusive information from EATON regarding the potential cause of the binding issue. One of the failed starters along with samples of binding and non-binding interlocks have been provided to EATON for them to perform their own analysis on the potential causes of the binding issue. Until more information is gathered from the OEM (EATON) Paragon recommends the following: The reversing starters and reversing contactors are typically wired in a configuration that will electrically lock out one of the contactors when the other one is being energized to prevent both contactors from being energized at the same time. Therefore, the mechanical interlock is not required to prevent both contactors from being closed at the same time when the electrical interlock configuration is being implemented. In this scenario, the mechanical interlocks are not required and can be removed at the plant's discretion. Replacement mechanical interlocks may be ordered to replace the existing interlocks from the affected date code range if the plant application will not allow for removal. The motor control center cubicles or starter assemblies with date codes within the September 2014 through September 2018 range should be monitored to ensure that there is no binding during operation. It is possible that if the starter is found to bind during operation, the bound condition could be released by cycling the power to the starter. This action may release the bound condition and will allow the starter to operate. Notified R1DO (Lilliendahl), R2DO (Miller), R3DO (Stone), R4DO (Werner), NMSS Events Notification, and Part 21 Group via email. |
| Where | |
|---|---|
| Paragon Energy Solutions Fort Worth, Texas (NRC Region 4) | |
| Organization: | Paragon Energy Solutions |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+758.87 h31.62 days <br />4.517 weeks <br />1.04 months <br />) | |
| Opened: | Tracy Bolt 19:52 Apr 29, 2021 |
| NRC Officer: | Joanna Bridge |
| Last Updated: | Jun 29, 2021 |
| 55223 - NRC Website | |
Paragon Energy Solutions with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 571432024-05-09T04:00:0009 May 2024 04:00:00
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