Troubleshooting and Modification of the class 1E Speed Sensor for Reactor Coolant Pump IN NPP

The reactor coolant pump is called the heart of the reactor. It is Safety Class-1 components [1]. Speed is an important parameter for reactor coolant pump operation. The structure and principle of the Class 1E speed sensor for reactor coolant pump in Nuclear Power Plant (NPP) is introduced. During the commissioning and operation of the reactor coolant pump, the Class 1E speed sensor has encountered many problems, including loss of signal and output error. To solve these problems, the authors analyze the waveform to identify the problem and then, according to the fault types, adjust the on-site installation mode or improve the signal processing unit. This paper presents the symptoms of the problem, the way to find the problem, and the final resolution, hoping to provide some solutions for peer workers to solve similar problems.