ENS 56603
ENS Event | |
|---|---|
04:00 May 17, 2023 | |
| Title | Part 21 - Emergency Diesel Generator - Incorrect Bus BAR Installation |
| Event Description | The following is a summary of the information provided by Engine Systems, Inc. (ESI) via fax:
Copper bus bars are used at rectifier diode pigtail connections CR1, CR2, CR3, CR4, and CR7 to provide a common connection point for associated wiring to minimize the number of conductors on a single fastener. It is intended for the conductors to clamp directly to the bus bar, thereby maintaining a low resistance conduction path between components. ESI has determined the bus bars were installed incorrectly whereby the conductors are not clamped in direct contact, resulting in current now passing through the stainless steel fasteners. This configuration is undesired and will result in unnecessary heat generation which may lead to failure of the connection and therefore failure of the automatic voltage regulator (AVR) assembly. The AVR is relied upon to automatically regulate emergency diesel generator (EDG) terminal voltage. Failure of the AVR would impact the ability of the EDG to perform its safety-related function and therefore may impact the nuclear plant's ability to manage safety-related loads during an emergency event. This Part 21 applies to the bus bar installation for part numbers 72-12300-100-ESI, 72-14200-100-ESI, and 72-14000-100-6020. These part numbers impact Constellation Energy - Nine Mile Point, Avaltec/CFE - Laguna Verde (Div III), and Avaltec/CFE - Laguna Verde (Div II), respectively. Corrective Actions: Voltage regulator installed: Bus bar installation should be corrected immediately by restacking the components to ensure direct contact with all conductors. Voltage regulators in inventory (not installed): The bus bar installation should be corrected prior to installation. If desired, the customer may perform on site or the voltage regulator chassis may be returned to ESI for rework. |
| Where | |
|---|---|
| Engine Systems, Inc. Rocky Mount, North Carolina (NRC Region 1) | |
| Organization: | Engine Systems, Inc. |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+1069.15 h44.548 days <br />6.364 weeks <br />1.465 months <br />) | |
| Opened: | Dan Roberts 17:09 Jun 30, 2023 |
| NRC Officer: | Eric Simpson |
| Last Updated: | Jun 30, 2023 |
| 56603 - NRC Website | |
Engine Systems, Inc. with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 569132023-11-27T05:00:00027 November 2023 05:00:00
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