Design of an on-line detection system for fuel rod failure in a pressurized water reactor

An on-line detection system for fuel rod failure of pressurized water reactor was designed to give a real-time indication of the activity concentrations of key radionuclides in the primary coolant. Tests were performed for the system in a PWR and the real-time monitoring data of the primary coolant was obtained. The tests showed that the system is sensitive to the activity concentrations of key radionuclides in the primary coolant and is able to detect the fuel rod failure. Minimum detectable concentrations for key radionuclides 135 Xe and 88 Kr are of the order of 3 and 10 kBq L −1 , respectively.