Degmay Tailing Radioactive Wastes
Assessment of radioactive wastes impact from Degmay tailing on public health and environment
Tech Area / Field
- CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
3 Approved without Funding
Nuclear and Radiation Safety Agency (NRSA), Tajikistan, Dushanbe
- Wismuth GmbH, Germany, Chemnitz
Project summaryPurpose of the investigation under the Project – study and assessment of Degmai tailing’s radioactive wastes – uranium industry reprocessing wastes of the Northern Tajikistan on environment and health of public.
The subject of investigation is Degmai tailing.
Liquid radioactive wastes as a result of uranium extraction from different origin’s ores from SE ‘Vostokredmet’ as well as hydrometallurgical wastes are accommodated in the Degmai tailing, located not far from Chkalovsk.
Degmai tailing was intensively operated from 1963 to 1993. Location of Degmai tailing is aggrieved by the fact that it is surrounded by inhabited settlements with population more than 300 000 people in the radius from 1 till 10 km including regional center – Khujand city. This is one of the biggest tailings in Central Asia. Construction of pioneer dam within tailing played a role of natural block unit. The dam length is 1800 m, the main coating layer is bitumen (layer thickness is 0,08m). Pioneer dam is formed from seven river weirs in the process of their operation. Currently the height of dam is approximately 40 meters. Surface of tailing is more than 90 hectares, fullness – 83%, volume content – 36 million tons of hydrometallurgical wastes from Mining metallurgical plant located in Chkalovsk. Summary activity of radioactive wastes is approximately 150 TBq. No remediation works were carried out at all in Degmai tailing and it is considered as “operational”. Starting from 90th, planting with reed took place at the edges of tailing with the purpose of windy dusting prevention from its surface (distribution of radioactive dust). Volume reduce of uranic ores reprocessing dealt to volume reduce of liquid radioactive wastes transportation to the tailing which caused drying of the surface. In 2000 y. the surface of tailing was fully dried which dealt to cracks formation with very high concentrations of radon exhalation with depth up to 4 meters and width from 0,3 till 0,8 m.
In this regard, the issues of Degmai tailing’s radiation impact on public health and environment becomes very urgent and of high concern. Radiological assessment will be based on measurements of gamma-emission dose rate, gamma–emission spectrums on tailings’ and reprocessed uranium dumps areas, systematic measurements of Rn concentrations in dwellings, living spaces and environment, identification of basic natural radionuclides of uranium and thorium chain in ecological samples (materials of tailings, water, soil and air) as well as surface density contamination of territories by means of in-situ measurements. Measurements on underground water contamination will be also carried out around tailings.
It is planned to carry out assessment of radiation risks and threats due to tailings. The exact degree of radiation danger will be identified for public and environment and recommendations will be developed on exclusion of site’s radiation impact. Measurements on putting into safe condition of radioactive wastes will be typified in relation to conditions of Central Asia. For achieving these purposes, it is planned to carry out complex investigations including fulfillment of physical, chemical, hydrogeological, radiological works as well as social observations.
It is expected that during project implementation, the radiation danger of Degmai tailing on public health and environment will be evaluated on the basis of investigation results and priority for immediate tasks on ensuring radiation safety of this site will be identified.
Proposed project is in full compliance with ISTC goals and facilitates to involvement of scientists and specialists, particularly weapons scientists, to international scientific and technical cooperation for solution of ecological problems and their integration to international scientific community for solution of remediation of contaminated territories by radioactive wastes (legacy sites).
The volume of works under the project is calculated for two and half years (30 months), with use of modern methods of physical and chemical experiments, application of computer technique for carrying out theoretical calculations, reprocessing and experimental data analysis.
For successful implementation of the project, its expertise, quality assessment and works results, rendering assistance in fulfillment of scientific and research as well as technological works and etc, the involvement of foreign collaborators with leading role is foreseen in this project. The project implementation is not possible without participation and consultations of these collaborators. It is also planned to involve scientists from Scientific and research institution Institute of nuclear problems” of Byelorussian State University which has a rich experience from remediation of contaminated sites from Chernobyl accident.
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.