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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 55950 | 16 June 2022 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Report - Failure of an Arnold Magnetics Power Supply | The following is a synopsis of information received via facsimile: On June 16, 2022, vendor Nutherm International, Inc. was informed that a defect caused the failure of Arnold Magnetics power supply PBM-24-106. The unit had been supplied by Nutherm to a nuclear power plant. The unit failed on or before March 15, 2022 during a 24-hour burn in period and was returned to Nutherm which did an inspection and analysis. Nutherm then returned the unit to Arnold Magnetics, the manufacturer, which completed further analysis. The manufacturer determined the unit failed due to the EMI filter assembly not functioning as designed as a result of the manufacturer's assembler not installing no-mex paper and thus not in accordance with manufacturer's procedure. Both the manufacturer and Nutherm have initiated corrective actions to prevent recurrence. One facility is listed as being affected: TVA - Browns Ferry. Nutherm notified the affected facility on June 17, 2022. If you have any questions or wish to discuss this matter or this report, please contact: Adrienne Smith at adrienne.smith@nutherm.com or at (618) 244-6000 x3034. | ||
| ENS 54914 | 25 September 2020 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Report - Continuously Energized Eaton D26 Relays | The following is a summary of the report provided by the notifier: Pursuant to 10 CFR 21.21(d)(3)(ii), Nutherm International, Inc. is providing written notification of the identification of a potential defect found in Eaton D26 relays. On July 23, 2019, Eaton Corporation released a letter, 'Update on Reports of Size 1 & 2 AC Contactors that Failed to Open When Deenergized'. This letter described a condition observed on AC contactors after being energized for a long period of time without being 'cycled'. Eaton also stated that this would occur in only a few isolated cases in continuously energized applications. The cause of the problem is the coating on each of the steel laminations in the cores of these devices. This steel is coated with an organic insulating varnish classified as C3. This coating, when heated for a long time period, can migrate from the lamination surfaces to the edges at the area between the separate core pieces (referred to as armatures and magnets). This substance is sticky and can potentially hold the core pieces together with enough strength to overcome the forces of the device's return springs. Potentially impacted components may include: Freedom contactors NEMA Size 00 through 5 A200 contactors NEMA Size 00 through 4 D15 Relays D26Relays AR Relays (AC Only) BF Relays (AC Only and including NBF relays) Vacuum contactors NEMA Size 4 Nutherm identified that they had supplied the Eaton relays to the following facilities: Dresden Nuclear Station Quad Cities Nuclear Station Palisades Nuclear Power Plant HB Robinson Steam Electric Plant Point Beach Nuclear Plant If you have any questions please contact Adrienne Smith at 618-244-6000, extension 3034, email adrienne.smith@nutherm.com or Kyle Mitchell at 618-244-6000, extension 3097 email kyle.mitchell@nutherm.com. | ||
| ENS 52938 | 29 August 2017 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 Report - Relay Failure Nutherm Model 700Dc | The following excerpted report was received via fax: On the basis of our evaluation, it is determined that Nutherm lnternational, Inc. does not have sufficient information to determine if the subject condition would, or has, created a Substantial Safety Hazard or would have created a Technical Specification Safety Limit violation as it relates to the subject plant applications. On 8/28/2017 Cooper notified the NRC of a reportable condition under 10CFR Part 21. An Allen Bradley relay base model 700DC exhibited early failure after 133 hours of service. This relay, model 700DC, has been dedicated/qualified for multiple applications for various plants. The Allen Bradley 700DC series relay coil failed after 133 hours of service. This failure was determined by Cooper Nuclear Station to have been a component infant mortality likely caused by a manufacturing flaw that likely occurred due to a tensioning issue at the start of the coil wire winding process. Failure of the coil will result in failure of the relay, which could result in a safety hazard. Nutherm International, Inc. has concluded its review of all procurements of the 700DC series relays that use the coil in question and have found forty-nine (49) units shipped to customers which could potentially have this defect: Nebraska Public Power Cooper Nuclear Station and Indiana Michigan Power Company Donald C. Cook Nuclear Plant. Initial actions of determining the units affected were completed 8/30/2017. The impacted customers were notified of this condition 8/30/2017. Nutherm International, Inc. does not have sufficient information to determine this condition would, or has, created a Substantial Safety Hazard or would have created a Technical Specification Safety Limit violation as it relates to the subject plant applications. Nutherm has no current orders for these units and has no units in stock. No further actions will be taken at this time. This issue has been identified as a 'component infant mortality' failure caused by a manufacturing flaw. The manufacturing flaw appears to be a random failure and was identified by Cooper Nuclear Station as likely to have occurred due to a tensioning issue at the start of the coil wire winding process. Failure of the coil would be expected to occur within a few days of operation. The units that have been installed and in operation for more than two months could be considered to not contain this random manufacturing flaw. Point of Contact: Thomas Sterbis - 618-244-6000 See also NRC event: 52934 | ||
| ENS 51612 | 18 December 2015 06:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Potential Part 21 Involving Rtd Transmitter | The following is excerpted from a report submitted by Nutherm International, Inc.: The wire insulation in T2 transformer on the Moores Industry RTD transmitter, Part Number: RBT/3W20-40/4-20MA/117AC/-EZ84.06-LNP-VTD (EX) was damaged during assembly. This damage reduced the insulation resistance and dielectric breakdown between the windings of the transformer. This resulted in early, catastrophic failure of the RTD transmitter. It has been determined that no visual inspection of the transformer or testing after the transformer is installed will discover this defect. This defect can only be found by performing testing on the transformer prior to installation. Two of these transmitters were sent to Entergy Operations - Fitzpatrick. | ||
| ENS 51123 | 4 June 2015 05:00:00 | 10 CFR 21.21(d)(3)(i), Failure to Comply or Defect | Part 21 - Potential Failure of a Time Relay | The following was received via facsimile: Allen Bradley relay base model 700RTC contains an unevaluated CPLD (Complex Programmable Logic Device). This was an unpublished design change that did not result in a part number change from Allen Bradley. There was no change to the appearance of the relay that would identify any design changes made to the relay configuration. Allen Bradley has indicated that the change occurred in mid-2009 and that it was a rolling change with no specific manufacturing date to distinguish between the old and new configuration. Based on this information, all units manufactured during 2009 and later are suspect. Nutherm International, Inc. has concluded its review of all procurements of the 700RTC series relays and have found two (2) units manufactured during or after 2009 dedicated and shipped to customers. The following facility was determined to be impacted by this condition: Utility: Exelon Plant: Quad Cities Purchase Order: 00447625 Part Number: 700-RTC11110U1 Nutherm Traceability Number: 11340-02R01 1/01, 11340-02R01 1/02. In a separate 10CFR Part 21 notification, Event Number 51095, reported to the NRC (on) 5/28/2015 indicated that the CPLD can be affected by electrical noise from operation of nearby relays which can reset the timing of the relay. The plant should evaluate whether the installed relays are subjected to unevaluated EMI/RFI (electromagnetic interference/radio-frequency interference) conditions when installed in the plant. |