Rare-Earth Waste Transport with Natural Waters
Study of Possible Thorium and Other Rare-Earth Waste Transport with Natural Waters (Case Study of Kyrgyz Chemical-Metallurgical Plant)
Tech Area / Field
- CHE-RAD/Photo and Radiation Chemistry/Chemistry
- ENV-WDS/Waste Disposal/Environment
- ENV-WPC/Water Pollution and Control/Environment
3 Approved without Funding
Institute of Physics, Kyrgyzstan, Bishkek
- VNIITF, Russia, Chelyabinsk reg., Snezhinsk
- University of California / Department of Nuclear Engineering, USA, CA, Berkeley
Project summaryExtraction and processing of rare-earth raw materials at former Ak-Tyuz enterprises of Kyrgyz Mining and Smelting complex and Kyrgyz Chemical-Metallurgical plant brought to formation of tailing dumps and pits containing radioactive and accompanying toxic metals, which create potential hazard. So, for example, in 1964 an accident happened at one of the tailings. After destruction of a dam the sand with high thorium content got into the Kichikemin and the Chu rivers. Examination of soils in 2002 nearby the Chu river in Kazakhstan showed an increased content of thorium, its decay products, and other toxins, which are peculiar to rare-earth production. Potentially hazardous are also industrial waste ponds of Kyrgyz Chemical-Metallurgical plant (outskirts of Orlovka village) and other enterprises of radioactive raw materials processing, located close to the river Chu.
There is a conventional opinion that the thorium has a low chemical solubility, tendency to form low-soluble compounds in conditions of natural environment, and a high selective sorption by soils with contrast physico-chemical properties and mechanical composition, and does not migrate with natural waters, mudflows, and flood water. However the earlier researches (see a collection “Investigation on chemistry of rare and accompanying them elements”. – AS of Kyrgyz SSR, Frunze, 1966, the article of R.T Yakovenko and A.K Mustaev “Study of systems Th(NO3)4 – K2P2O7 – H2O at temperature 26”, - p. 82) showed that thorium in a process of its acid and soda-nitrate release from natural raw materials and its further storage in tailing dumps and pits forms well-soluble double salts with alkaline metals. These double salts as well as soluble salts of thorium, rare-earth elements, and heavy metals formed at interaction with precipitation, natural waters, biota of containing rocks and products of their vital functions and metabolism can migrate and pollute the environment.
Goal of the project:
Main goal of the project is investigation of possibility and space regularities of water migration of thorium, its decay products, and other toxins, characteristic to enterprises of rare-earth and radioactive raw materials processing; prognosis of these processes development, formulation of recommendations for reduction of radio-ecological, radiation-sanitary, and toxic hazard for the environment of entities under study.
Technical approach and methodology:
In the framework of project, the samples of water (wells, springs, rivers, etc.), bottom sediments, and near-shore soils of the Chu river basin will be selected and analyzed for chemical, element, and radionuclide composition. Besides, the samples will be selected in control points not connected with activities of enterprises on rare-earth raw materials processing for determination of the same components “background” contents. For solution of project tasks the authors offer the following methods:
- optical spectral and other methods of analysis for determination of heavy metal, arsenic, and other toxins contents;
- γ-spectrometry methods of analysis, which allow carrying out both general analysis on radionuclides, which decay is accompanied by γ-radiation, and determination of basic isotopes content of thorium series: 228Th by γ-radiation of 212Pb and 228Ra by γ-radiation of 228Ac;
- the developed during implementation of the ISTC projects # KR-072-97 and # KR-715 method, based on discovery of V.V. Cherdyntsev and P.I. Chalov “Phenomenon of natural separation of 234U and 238U” (# 163 in State register of discoveries of the USSR) allowing determination a share of man-caused uranium in natural waters;
- respective standard and developed during the project implementation mathematical programs.
- Check of proposed methodology and development of practical processes and methods for tracing radioactive and rare-earth production waste migration with natural waters.
- Mapping of radionuclides and accompanying toxins space distribution on adjacent territories in consequence of their water migration from tailing dumps and ponds.
- Assessment of their radio-ecological, sanitary-radiation, and toxic hazard.
- Development of recommendations for reduction of radio-ecological, sanitary-radiation, and toxic hazard of monitoring objects.
- Creation of mathematical models of migration of thorium, its decay products, and other toxins characteristic for rare-earth production.
- Mathematical prognoses of thorium, its decay products, and other toxins distribution in natural objects of the environment.
- Creation of a WEB-node in the INTERNET network with information of ecological situation around Kyrgyz Chemical-Metallurgical plant.
Role of collaborators:
- Participation in organization of meetings, in planning and establishing contacts with organizations in project’s interest;
- Assistance in equipment procurement for project purposes;
- Participation in analytical work of inter-laboratory matching;
- Assistance in database creation;
- Information exchange during the project performance, holding joint workshops, participation in International meetings and publications.
- Large-scale researches of ecological situation in area under study.
- The retrospective review and critical analysis of activities and natural phenomena influencing ecological and radio-ecological situation of territories adjacent to the Aktyuz enterprises of Kyrgyz Mining and Smelting complex and Kyrgyz Chemical-Metallurgical plant.
- Choice of locations of sampling.
- Field sampling.
- Development and upgrading of analytical methods and equipment for analyses implementation.
- Carrying out laboratory analytical researches.
- Detailed study and outlining of ecologically problematic sites and objects.
- Study of radionuclides, heavy and rare-earth metals forms and their migratory properties.
- Assessment of potential hazard of the examined sites and objects.
The planned researches agree with the ISTC goals because the project provides for researches connected with the assessment and consequent development of recommendations for prevention of negative aftermaths from chemical technologies impacting the environment.
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.