Comparison assessment of the potential radiation hazard of tailing dumps in the Sughd region of Tajikistan

The global environmental changes have been observed since the nineties of the twentieth century. The current environmental situation is caused mainly due to the intensive human activity. During 46 years, from 1945 to 1991, radioactive waste from uranium processing was accumulated in the Sughd region in Tajikistan, the former USSR Republic. According to various estimates the total amount of accumulated radioactivity varies from 240 to 285 TBq. The tailings are the major sources of environmental pollution, they contain emanating gas, aerosols, dust and filterable solutions. The purpose of the work is to conduct comparison assessment of the potential radiation hazard of “Digmai” and “Adrasman” tailing dumps and Istiklol-city in the Sughd region and to estimate radiological risks to the population living near the tailing dumps. For radon monitoring both integral and instantaneous measurements were used. For instant measurements of radon volumetric activity the PPA-01M-03 LLC “HTM-Protection” (Russia) raidometer was used. The background radiation in the area under study was measured with Dosimeters DKS-96 “Dose” (Russia), DKS-AT1123 “Atomtech” (Belarus), MKS-AT6130 “Atomtech” (Belarus) and PackEye FHT complex-1377 “Thermo” (Germany). The paper presents data on comparison assessment of potential hazard of radioactive tailing dumps in the Sughd area. The impact of uranium tailing dumps on radioecological situation in the Sughd region, as well as in cities and districts of the Sughd region was assessed. The most unfavorable radioecological situation in the Sughd region is in areas with the ambient dose equivalent power (MAED)>0.35-0.40 μSv/h. The coordinates of the areas location coincide with coordinates of the radioactive tailing dumps Istiklol-city and Gaziyeon (“Digmai”) location, and their adjacent territories. According to comparison assessment, the tailing dumps “Digmai” and “Factory of Poor Ores” (Istiklol-city) are potentially the most hazardous facilities. It means that for radioecological safety of the environment and the population, it is recommended to carry out cleaning and remediation of the tailing dumps as a priority: «Digmai» and «Factory of poor ores».