Non-radioactive scandium oxide receiving out of uranium ISR solutions

The task of the research was to study and determine an effective method for the preparation of non-radioactive scandium compounds from uranium In-Situ Recovery (ISR) solutions. The widespread use of scandium is restrained by the high price due to its small production volumes, low content in the raw materials (scandium is a scattered element and does not form its own deposits), as well as the complexity of technological schemes for its extraction. Scandium receiving out of uranium reverses ISR solutions technological scheme was experimental tested, including sorption on MTS 9580 (Purolite’s production) ion exchanger with recurrent ballast impurities desorption and receiving concentrate that contains scandium. New radiation cleaning technological sequencing based on different solubility of radioactive elements and scandium in carbonate solutions, that accompanied by insoluble macro components complex formation, that contains in deactivated scandium concentrate and allows to get scandium oxide with desired component maintenance more than 94 % and less than 0,3 kilobecquerels/kg specific activity level was developed. The developed technology is based on the ability to form soluble carbonate complexes of scandium and radioactive elements, while the main macro components of the concentrate - ferrum, aluminum, calcium, silicon and others under the conditions of carbonation of the concentrate are inert or form insoluble compounds. Optimal radioactive impurity removing from concentrate conditions and scandium leaching from deactivated residue of scandium and macro impurity were studied and identified in laboratory conditions and during pilot tests.

Simulation Approach in Forecasting Radioactive Situation in Case of Forest Fires in Radioactive Contaminated Zones

Purpose: The accident at the Chernobyl NPP caused radioactive contamination of large areas, including forestry. For the last decades forest fires in the RF tend to increase and, more alarmingly, their burnt-out area significantly expands. So, the risk of large-scale forest fires in the area of radioactive contamination increases. Effectiveness of the measures for radiation protection of population and personnel involved in fire response is directly related to existence of valid methods of radiation situation prognostication. The work is aimed to develop a method of prognostication of radiation situation at forest fire in the area of radioactive contamination, taking into account random nature of atmospheric turbulence and a convective column over the body of fire, and to estimate validity of this method. Material and methods: Methods of simulation modeling of mass transfer processes in the atmosphere (method of Bird) based on the molecular-kinetic theory and gas-dynamic theory were used when developing the prognostication method. Results: The simulation model of formation, spreading and fall-out of radioactive cloud taking into account random nature of atmospheric turbulence and presence of a convective column over the body of fire has been developed; the method of prognostication of radiation situation at forest fire in the area of radioactive contamination has been developed and verified based on data of European experiment E1. The relative error of received values in the control points of radiation situation parameters based on data of experiment E1 did not exceed 0.25. Conclusion: Use of modified method of Bird allowed developing 3D dynamic model of spreading of radioactive impurity into atmosphere at convective rising by heated air flow from underlying surface. This model takes into account random nature of atmospheric turbulence and presence of a convective column over the body of fire which significantly increases accuracy of the method of radiation situation prognostication.