SCIENTIFIC RESEARCH ACTIVITIES
The Agency for Nuclear and Radiation Safety was created as an integral part of the National Academy of Sciences of Tajikistan, therefore one of its main tasks is to conduct research work (R&D, Research and development work). Such work will be carried out in the research sector. The Agency conducts research work on scientific topics "Physicochemical foundations of uranium mining from uranium ores and mineral waters" (RKD 01115 TJ 00470) and "Physicochemical foundations of radiation ecology, development of regional radioecological maps and radiation monitoring of bioecology in Tajikistan" (RKD 01115 TJ 00471).
The coordination of research work is carried out by the chief researcher - Academician of the National Academy of Sciences of Tajikistan, Doctor of Chemical Sciences, Professor Ulmas Mirsaidov. The scientific topics of the agency are headed by doctors of sciences and professors - Badalov Abulkhair, Salomov Abdujabor, Nazarov Kholmurod and Mirsaidov Ilkhom. Several scientists, including 9 candidates of sciences, are working on the implementation of scientific tasks at the Agency.
The researches were done in the course of the study of characteristics of mineral water and technical waste from the uranium industry. It was found that the water content of the Taboshar tunnel is 10 mg per liter, the inflow of water is 40 m3 / h, and the water of the Kiik-Tal deposit contains 25-30 mg of uranium per liter, pH is 7.0-7.5 and the inflow of water is 4.0- 4.5 m3 / hour. These values show that uranium can be extracted from the mineral and industrial waters of Taboshar and Kiik-Tal. The kinetics of the sorption (absorption) process of uranium separation from uranium industrial waste has already been studied. The high sorption capacity of the apricot shell was revealed in comparison with other sorbents. The optimal absorption parameters have been determined. The basic technological scheme of uranium extraction from mine waters and industrial waste waters of the uranium industry, which consists of the stages of acidification, absorption, cooking, leaching, settling, refining and drying have been already presented. A basic technological scheme was proposed and the optimal conditions for the process of handling uranium wastes were determined based on the research results.
In this case, the process of dehydration of hexahydrauranyl nitrate, which takes place in the temperature range of 310-420 K and consists of three stages, is carried out with water separation at each stage. The possibility of obtaining U3O8 from hexahydratiuranyl nitrate and trihydratiuranyl sulfate has been shown.
The thermal decomposition of UO2 (NO3) 2, which takes place in the temperature range of 430-750 K, consists of two stages. The process of dehydration of uranium sulfate trihydrate takes place in two stages in the temperature range of 320-420 ° C, where one washing takes place at the first stage of the process, and the process takes place in two washes at the second stage. The process of thermal decomposition of uranium sulfate occurs in one stage at a temperature range of 480-710K.
The chemical schemes of individual (separate) stages of the process of dehydration and destruction of uranium compounds and the thermal characteristics of these stages have been determined by the methods of X-ray phase, spectroscopic and tensometric analysis.
There has been obtained more detailed information on the thermal and thermodynamic characteristics of crystalline hydrates, nitrate and sulfate uranium.
A study of the radioecological situation in the regions of Tajikistan, including radioactive waste dumps in the north of Tajikistan, was carried out, as well as radiological map was succesfully compiled.