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The following is a synopsis of information … The following is a synopsis of information provided by Curtiss-Wright (CW) via email:</br>On 5/21/2025, Xcel Energy notified Curtiss-Wright about the failure of two NAMCO limit switches provided under CW project CJ21087 (tag number CJ2108701, serial numbers 01 and 04). The limit switches were dedicated by CW and shipped on 2/28/2025 to Xcel Energy. The switches failed a bench test performed by Xcel Energy, which aimed to verify that the contacts properly revert to their original state during spring return. Xcel Energy found that the contacts reverted to their original state prior to the audible click/snap, which is supposed to indicate contact changeover.</br>The two units were returned to Curtiss-Wright on 5/29/2025. The test result was fully duplicated on one of the switches. For the other switch (serial number 04), the switch contacts intermittently failed to return to the original state at all, requiring manual assistance to do so.</br>On 6/26/2025, CW sent the parts to NAMCO for repair. CW retested the parts after the repair. Part 04 still had the same issue with failing to reset as noted earlier. That limit switch was returned to NAMCO for a full evaluation. </br>CW anticipates an update to this notification with final results on 9/23/2025.</br>Potentially affected U.S. nuclear power plants: unknown at the time of the notification.</br>Contact Information:</br>Mark Papke</br>Quality Assurance Manager</br>Curtiss-Wright</br>4600 East Tech Drive</br>Cincinnati, OH 45245 </br>mpapke@curtisswright.com </br>* * * UPDATE ON 9/23/25 AT 0850 EDT FROM MARGIE HOVER TO KAREN COTTON * * *</br>The following information was provided by Curtiss-Wright (CW) via email:</br>On 6/26/2025 CW sent the relays to NAMCO for repair and the parts were returned to CW on June 26. CW retested the limit switches and one failed for the same issue as noted earlier, the failed limit switch was returned to NAMCO for a full evaluation.</br>The failure is still under investigation and CW has been in communication with NAMCO, the manufacturer.</br>Once the evaluation is complete this report will be updated. CW anticipates an update to this notification with final results on 11/24/2025.</br>Notified R3DO (Szwarc) and the Part 21/50.55 Reactors group</br>* * * UPDATE ON 11/21/25 AT 1635 EDT FROM MARGIE HOVER TO JORDAN WINGATE * * *</br>The following information was provided by Curtiss-Wright (CW) via email:</br>The NAMCO evaluation/report issued to CW on September 4, 2025, concluded that the failure was caused by improper sizing of the hub on the top of the shuttle/slide assembly. The hub was too small which prevented proper fit with the latch and, therefore, the switch could not open or close as intended.</br>NAMCO confirmed that this failure was only reported on PN: EA700-80926, Date Code: 0425 and also confirmed that the design of PN: EA700-80926 nor supplier of the shuttle/slide assembly has not changed in many years. NAMCO has changed their supplier for the shuttle/slide assembly since the manufacture of PN: EA700-80926, Date Code: 0425. It should also be noted that NAMCO now performs the slow latch test as stated above on all limit switches, not just the E700 series.</br>To address this issue, CW will be revising all affected NAMCO limit switches' dedication plans to incorporate the slow latch test. CW recommends that end users should perform slow latch testing as a part of their bench or field test procedures upon receiving any Namco limit switches. These actions should preclude a possible recurrence of this failure mechanism.</br>Please note that CW has not supplied P/N: EA700-80926 of the impacted date code 0425 to any other end users.</br>Notified R3DO (Orlikowski) and the Part 21/50.55 Reactors groupwski) and the Part 21/50.55 Reactors group
04:00:00, 21 May 2025 +
57,827 +
09:47:00, 25 July 2025 +
04:00:00, 21 May 2025 +
The following is a synopsis of information … The following is a synopsis of information provided by Curtiss-Wright (CW) via email:</br>On 5/21/2025, Xcel Energy notified Curtiss-Wright about the failure of two NAMCO limit switches provided under CW project CJ21087 (tag number CJ2108701, serial numbers 01 and 04). The limit switches were dedicated by CW and shipped on 2/28/2025 to Xcel Energy. The switches failed a bench test performed by Xcel Energy, which aimed to verify that the contacts properly revert to their original state during spring return. Xcel Energy found that the contacts reverted to their original state prior to the audible click/snap, which is supposed to indicate contact changeover.</br>The two units were returned to Curtiss-Wright on 5/29/2025. The test result was fully duplicated on one of the switches. For the other switch (serial number 04), the switch contacts intermittently failed to return to the original state at all, requiring manual assistance to do so.</br>On 6/26/2025, CW sent the parts to NAMCO for repair. CW retested the parts after the repair. Part 04 still had the same issue with failing to reset as noted earlier. That limit switch was returned to NAMCO for a full evaluation. </br>CW anticipates an update to this notification with final results on 9/23/2025.</br>Potentially affected U.S. nuclear power plants: unknown at the time of the notification.</br>Contact Information:</br>Mark Papke</br>Quality Assurance Manager</br>Curtiss-Wright</br>4600 East Tech Drive</br>Cincinnati, OH 45245 </br>mpapke@curtisswright.com </br>* * * UPDATE ON 9/23/25 AT 0850 EDT FROM MARGIE HOVER TO KAREN COTTON * * *</br>The following information was provided by Curtiss-Wright (CW) via email:</br>On 6/26/2025 CW sent the relays to NAMCO for repair and the parts were returned to CW on June 26. CW retested the limit switches and one failed for the same issue as noted earlier, the failed limit switch was returned to NAMCO for a full evaluation.</br>The failure is still under investigation and CW has been in communication with NAMCO, the manufacturer.</br>Once the evaluation is complete this report will be updated. CW anticipates an update to this notification with final results on 11/24/2025.</br>Notified R3DO (Szwarc) and the Part 21/50.55 Reactors group</br>* * * UPDATE ON 11/21/25 AT 1635 EDT FROM MARGIE HOVER TO JORDAN WINGATE * * *</br>The following information was provided by Curtiss-Wright (CW) via email:</br>The NAMCO evaluation/report issued to CW on September 4, 2025, concluded that the failure was caused by improper sizing of the hub on the top of the shuttle/slide assembly. The hub was too small which prevented proper fit with the latch and, therefore, the switch could not open or close as intended.</br>NAMCO confirmed that this failure was only reported on PN: EA700-80926, Date Code: 0425 and also confirmed that the design of PN: EA700-80926 nor supplier of the shuttle/slide assembly has not changed in many years. NAMCO has changed their supplier for the shuttle/slide assembly since the manufacture of PN: EA700-80926, Date Code: 0425. It should also be noted that NAMCO now performs the slow latch test as stated above on all limit switches, not just the E700 series.</br>To address this issue, CW will be revising all affected NAMCO limit switches' dedication plans to incorporate the slow latch test. CW recommends that end users should perform slow latch testing as a part of their bench or field test procedures upon receiving any Namco limit switches. These actions should preclude a possible recurrence of this failure mechanism.</br>Please note that CW has not supplied P/N: EA700-80926 of the impacted date code 0425 to any other end users.</br>Notified R3DO (Orlikowski) and the Part 21/50.55 Reactors groupwski) and the Part 21/50.55 Reactors group
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