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| Entered date | Event description | |
|---|---|---|
| ENS 56252 | 1 December 2022 14:45:00 | The following is a summary of information provided by Flowserve - Limitorque via email: Entergy Waterford 3 informed Flowserve - Limitorque on 10/5/2022 that it discovered that a Peerless 125 volt, 25ft-lb, 56 frame direct current (DC) motor had two fasteners securing the brush holder ring assembly to the motor frame. However, the DC motor assembly used in the qualification test program was assembled with 4 fasteners. Therefore, the use of two fasteners is a deviation to the qualified design. Flowserve is submitting this report as an interim report and is evaluating this deviation to determine whether this condition could potentially affect the safety related function of DC powered Limitorque actuators. Flowserve is continuing to work with the motor original equipment manufacturer (OEM) to refine the scope of potentially affected motors. Limitorque actuators equipped with Peerless - Winsmith DC electric motors with start torque ratings of 40 ft-lb and larger are not affected by this issue. Limitorque actuators equipped with alternating current (AC) powered electric motors are not affected by this issue. The evaluation is expected to be completed by 01/27/2023. If there are questions, or addition information is required, please contact Chris Shaffer, Quality Assurance Manager, Flowserve Corporation, Ph: (434) 522-4136. Known affected plant: Waterford 3 Nuclear Generating Station
Flowserve provided an update to notify that the final evaluation of the safety consequence and reportability, primarily involving seismic qualification, will be delayed until 02/24/2023. Notified R4DO (Agrawal) via phone and the Part 21 group via email.
Flowserve has completed the evaluation of the deviation described in the initial notification. Flowserve has concluded that the deviation has no substantial impact to the safety function of the component and/or the associated actuator. Notified R4DO (Vossmar) via phone and the Part 21 group via email. |
| ENS 55505 | 4 October 2021 12:04:00 | The following is a summary of the report provided by Flowserve: Flowserve - Limitorque was notified by Framatome Nuclear Parts Center that TVA Browns Ferry Nuclear (BFN) plant reported that a Limitorque SMB actuator had failed to operate electrically. It was noted by TVA that the actuator failure was discovered following a recent steam leak in the vicinity of the actuator. Investigation at BFN identified the failed component as the DC electric motor. The motor was removed from the actuator and disassembled by BFN personnel. Subsequently the motor was returned to Flowserve - Limitorque for evaluation. The subject motor is designated as a safety related basic component. Flowserve' s investigation, in conjunction with the motor original equipment manufacturer (OEM), has concluded that during manufacture, the subject motor sustained mechanical damage to the stator assembly field coil which led to the failure. As the dedicating entity, Flowserve is reporting this deviation in the assembly of the motor as a defect per the requirements of 10 CFR 21. Flowserve's investigation has concluded that this manufacturing defect is an isolated occurrence. No other instances of similar mechanical damage to the stator field coil insulation of Peerless DC motors have been observed or reported. The defect is specific to a quantity of one motor originally supplied to Framatome NPC on Limitorque Order Number 164879.001. This motor was subsequently supplied to the TVA Browns Ferry Nuclear Plant. Identification of Component: Limitorque part # P-140-851-18F0 Description: Peerless 7.5 ft-lb, 250 volt DC motor Serial Number: E18-99091-2 manufactured in August 2018 Corrective Actions to Date: The motor OEM is implementing additional assembly controls and quality control verification concerning the installation and final appearance of the coil support rod that damaged the stator field coil. This action, to be completed by October 15, 2021 will supplement the existing inspection checks on fully assembled motors, which includes insulation resistance tests and high potential tests which verify the integrity of the motor insulation system. Technical questions concerning this notification can be directed to Kyle Ramsey, Engineering Specialist, Flowserve - Limitorque Actuation Systems: kramsey@flowserve.com |