Pollutants around Uranium Industrial Objects
Forecasting of Technological Migration Components and Radionuclides in Uranic Objects of Production and Developing the Ways of Protecting Environment
Tech Area / Field
- CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
- CHE-THE/Physical and Theoretical Chemistry/Chemistry
3 Approved without Funding
Institute of Chemistry named after V.I.Nikitin, Academy of Sciences, Republic of Tajikistan, Tajikistan, Dushanbe
- State Enterprise "Oriental Industrial Complex of Rare Metals", Tajikistan, Chkalovsk
- Lawrence Livermore National Laboratory, USA, CA, Livermore\nSouthwest Research and Information Center, USA, NM, Albuquerque
Project summaryThe Project purpose is the creation of a scientific basis of localization radioactive and technological pollutants around of industrial objects of uranium production through studying of physico-chemical processes of components – pollutants migration at the industry district and ore tailings in conditions of a filtration heterogeneity of water bearing horizons and regimens varying in time of their function.
The utilization of nuclear energy is coupled to harmful affecting of separate stages, in particular production activity and waste-handling of uranium ores on the environment. The ground mass of a wastage of uranium ores is shaped as mining dump of grocery waters, and the task of reduction of severe affecting them on an environment demands a solution of series of complex engineering, scientific, design and manufacturing problems. It is necessary to note, that GE "Vostokredmet" within many years was leading plant a former USSR on heap and underground leaching of uranium. One of acting objects located in territory of Republic of Tajikistan is Digmay mining dump, which one of earlier experimental burial metallurgical workshop, represents potential hazard to vegetation, underground waters, food products etc. The security problem of underground waters has got a significant urgency in connection with substantial hazard of impurity of acting and projecting water intakes as a result of filtering technological components pollutants, which contaminate drains and solutions of mining dump at the industrial objects, at the effluent burial place and underground leaching. For the implementation of the Project purpose the following tasks should be solved:
- development of contamination criteria of layer waters in an area of acting objects and area distribution of toxic and radio nuclide elements;
- forecasting of a geofiltration stock solution, formation of the objects condition map for the fixed period, character of an objects interaction with water intakes, substantiation of methods for recultivation and protection of underground waters;
- determination of the radio nuclide content and heavy metals in flora and soil, the study of radon migration through different materials.
These tasks may be resolved by determination the contents of radioactive and heavy metals around of burial place, eliciting of their distribution influences in soil, plants, underground waters by compiling of a corresponding maps. The development effective, indispensable physicochemical methods of analysis such as polarography, potentiometry, spectroscopy is potential for the sratum areas. The advantages of electrochemical methods of analysis over others is: the large nomenclature of determined chemical elements and organic compounds, wide range of determination (from 10 up to n. 10-8 %) at high reproducibility (standard deviation in the majority of methods is ±0.3 %, and at coulometer analysis ±03 and less), the opportunity of carrying out of multi element analysis, determination the total contents and forms of presence impurities in tested medium, accessibility of instrumentation and low cost of analysis. It is necessary to note, the Chemistry Institute of AS RT jointly with GE “Vostoredmet” has been accumulated a wide experience on use of a well polarography in two alternatives - dot and continuously on shaft of well. It has allowed to lower distortings for account of stirring of solution at move of the well instrument and to provide maximal drainage exchange around sensors. The experience of work on bore-hole surveying by electrochemical methods has shown, that the control of results of well measurements by chemical analysis of samples in many respects depend from quality of sampling. Within the framework of the first task the samplers of electromechanical and piston types allowing to make sampling from selected depth will be designed.
In close contact with the first task there is an analysis of radio nuclides contents and heavy elements in the ground and vegetation at the Digmai zone within the framework of the third task. For this purpose will be determined X-ray intensity, which may be determined by portable radiometers and radio nuclides by the X-ray methods. The selection of biogeochemical hallmarks was carried out on biogeochemical profiles crossing slopes of different expositions in various parts of stocks. For definition of radon diffusion through various materials the appropriate model will be developed.
Being based on first task results, the second task is solved, which one are main in the present proposal. The second task include the study of polyelement ores distribution in bearing horizon, simulation of geofiltering of local waters and technological solutions, determination of a field of filtration rates of a stream in water reservoir and pathway of particle migration, calculation of current links and tubes, construction of the hydrodynamical schemas, cross-sections, counting of reserves of useful components in underground waters involved in treating, and also the study of sulphatic acid leaching kinetics of polyelement ores.
All these tasks are assembled around of a solution of an overall objective of the Project, namely, forecasting of geotechnological and ecological parameters of occurrences polyelements ores, including protection of water intakes from affecting objects of a underground leaching, ore tailings and development of ways for the safety of underground waters, and also, development of the software engineering both for geotechnology and ecology of underground waters.
The proposed Project wholly corresponds to the ISTC purposes and tasks. It allows the large group of the highly skilled "defensive" scientific and engineering workers -11 men (58,6 % from total of man-days), have been working in the field of uranium extraction and concentration, working on solution of the relevant humanitarian tasks, connected with development of environment protection measures and population security against negative affect of the radioactive contamination.
The basic researches will be focused on development of the method for determination of radionuclides and heavy metals transferring rates constants values from a solid phase to solutions, the elucidation of the complex formation mechanism of this elements in waters. The applicable algorithms and model programs forecasting levels of withdrawal, residual contents of this bond at the moment from a beginning of improvement of objects or period of observation will be generated.
The quantitative data about a radiation, of radio nuclides and heavy metal contents in an environment of the mining dump and dynamics of their diffusion, may be utilized at:
- the development of environmental protection measures and security of the population against negative affect of the radioactive factors.
- the regularity of the radon transferring through various materials and quantitative data’s on determination of diffusivities can be utilized for more effective burial of radioactive objects.
- the quantitative data’s about the iron, oxygen and sulphate ions contents, and also oxidation-reduction potential in technological and observational wells can be used for optimizations of technological process and prevention of environmental problems.
The mathematical model describing the physicochemical processes occurring in entrails at a underground leaching, geofiltering technological solutions, migration of components - pollutants can be used at processing of objects of a underground leaching, mining dump, their subsequent recultivation and development of methods for safety of the underground waters.
The results, obtained on the present project, are relevant for radioactive control and ecological situation on huge region, including territory of Republics of Tajikistan, Kyrgyzstan and Uzbekistan. The competence of the participants of the project is highest. The designed methods and preliminary results related to the project objectives are published in different international scientific journals and are well known.
The present project essentially will support basic researches in Tajikistan directed to ecological study of underground waters, soils, flora and will encourage federating of scientist of Tajikistan in the international scientific community.
The role of foreign collaborators within the framework of the tendered project is following: (а) in information exchange during work on project; (b) in representation of the commentaries to the technical reports sent by the participants of the project in ISTC; (c) carrying out of joint seminars and meetings; and (d) joint contribution for publication of results.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.