Annealing of Mineral-Like Host Matrices for High-Level Waste Immobilization

Inorganic Materials - We have studied the effect of annealing on the chemical and physical properties of mineral-like host matrices for immobilization of the rare-earth–actinide fraction from...     

Liquid Deactivation of Equipment Units in Solutions with Complexing Agents by Electrochemical and Combined Process Intensification

Radiochemistry - Experiments on liquid decontamination of simulators of radiation-contaminated metal equipment with ultrasonic and electrochemical intensification of the process were carried out....     

Electrochemical properties and solubility of URh<Subscript>3</Subscript> in nitric acid solutions

Electrochemical properties of the intermetallic compound URh₃ in 0.5–8 M HNO₃ solutions were studied by linear voltammetry. The electrochemical characteristics of URh₃ in nitric acid solution were determined for the first time using the Tafel equation. URh₃ is highly resistant to both chemical and anodic dissolution, which is due to formation of passive films on the electrode surface. All the anodic oxidation processes observed on the electrode led to secondary passivation of the alloy and not to its dissolution. The conclusions based on the electrochemical data were confirmed by experiments in 8 M HNO₃.     

Matrices for immobilization of the rare earth–actinide waste fraction,synthesized by cold crucible induction melting

The structure of eight samples containing simulated rare earth–actinide fraction of high-level waste was studied. Samples of weight from 0.2 to 6 kg were prepared by cold crucible induction melting followed by crystallization of the melt. The target phases (britholite, pyrochlore, zirconolite, rhombic and monoclinic rare earth titanates) prevail in all the matrices; glass, zirconolite, and rutile were detected as impurities, sometimes in significant amounts. These phases do not contain waste components (rutile) or are stable in solutions (zirconolite); therefore, their presence should not impair the properties of the matrix. The possibility of controlling the phase composition of the matrix by introducing zirconium or aluminum oxide into the charge was demonstrated.     

Radiation and Chemical Stability of a Magnesium-Phosphate Matrix for 14C Immobilization

Radiochemistry - The results of manufacturing, studying the radiation and hydrolytic stability of a magnesium-potassium phosphate (MPP) matrix, are presented, which is being developed for the...     

Reducibility of Linear Time-Varying Systems of Special Form with Control and Measurements

Journal of Computer and Systems Sciences International - This paper considers some classes of linear time-varying systems with control and output vectors that can be reduced to time-invarint...