抄録
Thermal powers of nuclear reactors are calculated by the enthalpy difference between reactor feed water and main steam. Improvement of the measurement accuracy in the flow rate measurements of reactor feed water enables us to uprate reactor thermal power, called MUR (Measurement Uncertainly Recapture) uprate. The ultrasonic pulse Doppler system is expected to be a suitable method featuring the capability o measuring the flow profile directly in a pipe. For the optimum measurements, ultrasound path from ultrasonic transducer into the fluid through steel pipe wall should be carefully predicted in high temperature water. This paper presents analytical results of ultrasound propagation using FEM simulation code and experimental results of pipe flow rate at high temperature thermal conditions.
