ENS 56322
ENS Event | |
|---|---|
05:00 May 23, 2022 | |
| Title | Part 21 - Medium Voltage Circuit Breakers |
| Event Description | The following information is a synopsis of information provided by the licensee via fax and phone:
On May 23, 2022, Framatome informed Tennessee Valley Authority (TVA) of a deviation of breakers purchased under contract. On January 23, 2023, TVA determined that a defect of the basic component could create a substantial safety hazard. Framatome Inc. identified a deviation in the Siemens medium voltage vacuum circuit breaker where a failure to electrically charge or electrically close could occur. Framatome Inc. identified this as a departure from the technical requirements included in the procurement document. It is noted that the ability to electrically trip the circuit breaker would not be affected by the condition. TVA was notified by Framatome under 10 CFR 21.21(b) to evaluate the application of the breaker for a substantial safety hazard. The TVA evaluation identified these breakers as intended for use in safety related Class 1E applications where a loss of the closure function would impact mitigation of design basis accidents and transients. During the Framatome dedication testing/inspection of Siemens medium voltage vacuum breakers, a hi-pot test failure on one circuit breaker was encountered. Troubleshooting and inspection found damage to charging motor wiring. It was determined that the cause of the damage was due to the manner in which control wiring was routed and connected to the internal bracket in close proximity to a bracket edge. This edge caused damage to wiring after significant number of cycles were applied to the breaker prior to dedication testing. TVA received nine medium voltage vacuum circuit breakers at an offsite warehouse facility. While located at that facility, TVA, with assistance from Framatome, examined the affected breakers for the wire routing condition. The wiring harnesses of certain breakers were corrected. Framatome is to examine medium voltage vacuum circuit breakers that may be purchased under this contract for the wiring condition and correct as necessary before delivery. The NRC Senior Resident Inspector has been notified. This is a non-emergency notification required by 10 CFR 21.21(d)(3)(i). |
| Where | |
|---|---|
Sequoyah  Tennessee (NRC Region 2) | |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+5935.37 h247.307 days <br />35.33 weeks <br />8.13 months <br />) | |
| Opened: | Jeffery Blaine 13:22 Jan 25, 2023 |
| NRC Officer: | Ian Howard |
| Last Updated: | Jan 25, 2023 |
| 56322 - NRC Website
Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 56322\u003C/a\u003E - \u003Ca href=\"/Sequoyah\" title=\"Sequoyah\"\u003ESequoyah\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EPart 21 - Medium Voltage Circuit Breakers\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 56322 - Sequoyah\n","link":"","lat":35.22651944444444,"lon":-85.09192777777778,"icon":"/w/images/c/ce/Tennessee_Valley_Authority_icon.png"}],"imageoverlays":null} | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 568882023-12-11T18:32:00011 December 2023 18:32:00
[Table view]10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Circuit Breaker Defects ENS 563222022-05-23T05:00:00023 May 2022 05:00:00 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Medium Voltage Circuit Breakers 2023-12-11T18:32:00 | |