Uranium tailings of Tajikistan determine the overall environmental situation and ecological threat, in Sogdian oblast, in the north of the republic, and pose transboundary risk because they are located nearby Syrdary'a river. A Plant № 6 known as State Enterprise «Vostokkredmet» was created here in 1946 in Chkalovsk small town. The aim of this Plant is processing of uranium ores from Tajik, Uzbek and Kyrgyz minefields. Uranium mining was commenced in 4 minefields — Taboshar and Adrasman (Tajikistan), Mailuu-Suu (Kyrgyzstan) and Uigursai (Uzbekistan). The final ore processing was completed in Chkalovsk.
One of the tailings located in Gafurovo small town contains wastes of the pilot plant № 4 which was operated since 1945 — 1955. Initially the tailing was preserved but as per survey data this tailing was hazardous in terms of radium exhalation. In 1991 the tailing was deposited by extra soil that removed the radium leakage. The tailing occupies 4 hectares of area with 0,4 million tons of wastes. The capacity of exposure doze rate at surface is 20 micro-roentgen per hour. The tailing located nearby settlements an access to which of local population (in spite of fence) is open.
The major tailings related to Chkalovsk hydrometallurgical plant which commenced working since 1949. The capacity of this plant was 2000 tons per year as for uranium. This plant processed raw materials from the former USSR republic and foreign countries. Since 1995 — 1999 due to processing small quantity of raw materials the plant was closed. Operation of the plant resulted in 2 tailings:
- Tailing of the map 1−9 located 2 km from Chklavosk, the volume 3,03 million tons, area 18 hectare, capacity of exposure doze rate at surface — 40−45 micro-roentgen per hour
- Digmaisk tailing (acting) located 1,5 km from Gazen village, 9 km from Syrdar'a river. The quantity of wastes in tailing — 36 million tons, area 90 hectares, exposure doze rate at surface 250−300 — up to 1800 micro-roentgen per hour. The tailing was filled up 82% and 90% consist of wastes from raw materials transported from Uzbekistan and Kazakhstan. The surface is opened, exposed to wind erosion, drainage flow of ground water to Surdar'ya river
The overall quantity of radioactive wastes accrued during plant operating were 54,8 million tons, and located at area — 180 hectare.
The following group of minefields are located behind Taboshar village, where mining works were carried out from 1945 till 1965. Here were 2 hydrometallurgical plants and factory of base/poor ore. As a result of their activity the following tailings were created:
- tailing I-IV with the area 54 and 52 hectare with the quantity of wastes 7,62 million tone
- tailing with area 2,86 hectare and quantity of wastes 1,17 million tone
- wastes from base/poor factory ores with area 3,35 hectare and quantity of wastes 2,3 million tons
All of these tailings at surface have exposure doze rate — 40−60, and last — 30−350 micro-roentgen per hour. The tailing are not deposited, exposed to wind erosion and pollutes the environment.
Not far from Taboshar village, from 1945 till 1972 uranium was mined and processed at mining field Adrasman. Here, a hydrometallurgical plant has been created and resulted in creation of 6 tailings. In 1992 the materials of these tailings were shifted to tailing #2 and covered by macrofragmental soil. The area of tailing — 2,5 hectares, quantity of wastes — 0,4 million tons, exposure doze rate at surface — 60 micro-roentgen per hour. Currently, the tailing in the result of water erosion is split by «ravines» that lead to tailing' outcrop and pollution territories located below tailing. In the beginning of 2007 the tailing # 2, in the region of Adrasman village, was made into safety condition as for «ravines»: at the expenses of State Enterprise «Vostokkredmet» an off take dam was created in order to prevent the erosion of the dam in future.
Currently, no rehabilitation works at these tailings were made, they are continuing breaking down and pose a threat as well as in the territory Tajikistan and downstream of Syrdar'a of Uzbekistan and Kazakhstan.
Source: e-discussion "Uranium tailings: local problems, regional consequences, global solutions". Subject: «Risks and consequences of uranium tailings for Tajikistan»