Dysprosium hafnate as absorbing material for control rods

Dysprosium hafnate is proposed as a promising absorbing material for control rods of thermal nuclear reactors. The properties of dysprosium hafnate pellets with different Dy and Hf contents are presented in this article. The fluorite phase is characterized by the density range 6.8–7.8 g/cm3 and; the thermal diffusivity achieves 0.58–0.83 mm2/s at 20 °C, thermal conductivity of 1.5–2.0 W/(K m) and TLEC of (8.4–8.6) × 10−6 K−1 at 20 °C. The temperature dependence of the thermophysical properties of dysprosium hafnate are presented. The neutron absorption efficiency of dysprosium hafnate was estimated in comparison with boron carbide. The radiation resistance of pellets after irradiation in the BOR-60 reactor is presented as well.