Fuel-clad heat transfer coefficient of a defected fuel rod. Transfer coefficient fuel-clad in the presence of water steam

Using a special rod built with a stack of UO2 pellets inside a thick Zircaloy clad, the authors report the measurement of the fuel-clad heat transfer coefficient when water vapour in intentionally introduced in the fuel rod at the beginning of its life. They describe the irradiation device, the measurement method (acquired data and mathematical determination of various values: temperature of the inner surface of the cladding, integrated thermal conductivity, fuel surface temperature, fuel-cladding heat transfer coefficient, thermal expansion of the cladding inner radius, UO2 thermal expansion). They finally report the experiment