Authors:G. Panneerselvam, R. Venkata Krishnan, K. Nagarajan, and M. Antony
Dysprosium hafnate is a candidate material for as control rods in nuclear reactor because dysprosium (Dy) and hafnium (Hf)
have very high absorption cross-sections for neutrons. Dysprosium hafnate (Dy2O3·2HfO2-fluorite phase solid solution) was prepared by solid-state as well as wet chemical routes. The fluorite phase of the compound
was characterized by using X-ray diffraction (XRD). Thermal expansion characteristics were studied using high temperature
X-ray diffraction (HTXRD) in the temperature range 298–1973 K. Heat capacity measurements of dysprosium hafnate were carried
out using differential scanning calorimetry (DSC) in the temperature range 298–800 K. The room temperature lattice parameter
and the coefficient of thermal expansion are 0.5194 nm and 7.69 × 10−6 K−1, respectively. The heat capacity value at 298 K is 232 J mol−1 K−1.
Authors:K. Venkatesan, V. Sukumaran, M. Antony, and T. Srinivasan
The commercially available crystalline silicotitanate inorganic ion exchanger, IONSIV IE-911, and its parent precursor, TAM-5,
have been evaluated for the removal of 137Cs from nitric acid medium and simulated high-level liquid waste. The distribution coefficient (Kd) of cesium decreased with increasing nitric acid concentration and at 3.0 M nitric acid, a distribution coefficient of 1150
mL/g and 2600 mL/g were obtained for IONSIV IE-911 and TAM-5, respectively. Rapid uptake of cesium followed by the establishment
of equilibrium occurring within three hours. Loading of cesium in ion exchangers increased with the increase in the concentration
of cesium in aqueous phase and from Langmuir adsorption model the apparent capacity of cesium was 69 mg/g and 82 mg/g for
IONSIV IE-911 and TAM-5, respectively. The performance of the sorbent under dynamic conditions was assessed by following a
breakthrough (BT) curve up to C/Co = 1, where C and Co are the concentrations of cesium in the effluent and feed, respectively.