ENS Event | |
|---|---|
04:00 Jan 25, 2016 | |
| Title | Part 21 - Anomaly Related to Micro Switches |
| Event Description | {{#Wiki_filter:The following report was received via email:
Based on test data, Rotork believes an unsafe condition may exist as defined under 10 CFR 21. The adhesive formulation used for the construction of V12 and K5 safety related micro switches was altered by the switch maker's sub-supplier. K5 switches have no reported failures, but are affected because of construction. The altered adhesive formulation outgases an insulating material at elevated temperatures, which coats the switch contacts as it cools and can prevent the conduction of electricity.
This letter provides an update to the Rotork Controls Inc. Part 21 filing submitted May 4th 2016; documented in U.S.NRC Event Number 51907. Rotork have developed versions of the V12 & K5 switches that eliminate adhesive from the materials of construction. Evaluation of pre-production V12 switches, by thermal aging for 10 days at 125�C (257F), demonstrate the switch non-metallic housing and plunger also outgas materials that contributed to the accumulated contamination observed on switch electrical contacts as reported in Event 51907. The cause of the new outgassing sources and extent of condition is currently being investigated. For the moment suitable replacement switches remain unavailable that correct the issue reported in Event 51907. At this point in time, Rotork do not have grounds to believe the extent of condition is altered from that reported in Event Number 51907. Notified R1DO (Schroeder), R2DO (Guthrie), R3DO (Daley), R4DO (Vasquez) and PART 21/50.55 REACTORS via email. }} |
| Where | |
|---|---|
| Johnson Electric Rochester, New York (NRC Region 1) | |
| Organization: | Rotork Controls, Inc. |
| Reporting | |
| 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
| Time - Person (Reporting Time:+2411.93 h100.497 days <br />14.357 weeks <br />3.304 months <br />) | |
| Opened: | Patrick Shaw 14:56 May 4, 2016 |
| NRC Officer: | Dong Park |
| Last Updated: | Oct 31, 2016 |
| 51907 - NRC Website | |
Johnson Electric with 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | |
WEEKMONTHYEARENS 519072016-01-25T04:00:00025 January 2016 04:00:00
[Table view]10 CFR 21.21(d)(3)(i), Failure to Comply or Defect Part 21 - Anomaly Related to Micro Switches 2016-01-25T04:00:00 | |