Temperature monitoring device for suppression pools

Purpose: To ensure effective NPSH of after-heat removing system pumps thereby secure the fuel soundness upon abnormal reduction in the reactor water level. Constitution: Measured values from a temperature measuring and water level gages disposed in a suppression pool are inputted into a computation device during normal operation to calculate the heat capacitance of the suppression pool during normal operation. Upon occurrence of abnormality, the amount and the temperature of fluids flowing into the suppression pool are measured. Then, the increase in the heat capacitance, as well as the temperature and the temperature increase in the suppression pool are calculated by the computation device, whereby operators' attention is directed to CRT display or warning display before the trouble occurs in securing the effective NPSH of the after-heat removing system, as well as the suppression pool colling mode is automatically started. (Kamimura, M.)