Early fault detection systems in experimental fast reactor 'JOYO' introduction of primary coolant main pump start-up and stop sequence trigger recording system, pipe thermal displacement measuring system and detection of sodium leakage with infrared thermography

For operating the plant of the experimental fast reactor 'JOYO' safely and stably, it is important to promptly detect and respond to the anomaly of facilities and equipment. As the devices to detect the plant anomaly of 'JOYO,' there are primary coolant main circulation pump state recording system, pipe thermal displacement measuring system, and portable compact infrared thermography. This paper reports the devices that promptly detect the anomaly of the plant. In the primary coolant main circulation pump state recording system, it has become possible to grasp in detail the control state and the behaviors during operation of the primary coolant main circulation pump, and to easily identify the cause at the time of anomaly. In the pipe thermal displacement measuring system, it can be confirmed from the measurement data that the structure (pipe) is sound since there is no sticking in the piping support device and the thermal displacement of each part is within allowable values. The portable compact infrared thermography was found to be effective for on-site monitoring of the environment where a room was full of smoke at a fire site or during sodium leak. 'JOYO' is currently in a long-term shutdown state, but with these devices, it is possible to promptly detect anomaly in the plant during reactor operation as well as during reactor shutdown. (A.O.)