Uranium and its decay products in radioactive anomalies of oxidized brown coals (western part of Kansko-Achinsk brown coal basin)

Vertical distribution of uranium and its decay products (226Ra and 210Pb) in the uppermost layers of the oxidised brown coals was studied for some deposits and natural outcrops of the Western part of the Kansko-Achinsk brown-coal basin. Abnormal accumulation of the mentioned radioactive elements is observed in all studied sites. Several types of radioactive anomalies are differed by the ratio of activities of 238U and 226Ra: 1) Equilibrium; 2) Radium; 3) Uranium. The depletion of 210Pb in the radioactive horizons of some sites indicates an active emanation of 222Rn in the underlying coal layers. Uranium besides the form sorbed on coal is presented in poral solutions. It says about its potential mobility and is confirmed experimentally. Radium is actively absorbed by the plants growing on radioactive coals

Assessment of contamination of the Issyk-Kul' valley natural waters with uranium mine wastes

The Lake Issyk-Kul' of the central Tyan-Shan is characterized by increased natural uranium content. Uranium-carbon deposit situated on the southern bank of the Lake can be the reason of chemical and radioactive contamination of this unique basin by exploitation wastes. ln order to estimate possible danger, a project “Assessment and prognosis of environmental changes in Lake Issyk-Kul' (Kyrghyzstan)” was developed and supported by the Program ofthe European Commission “Copernicus-2” (2001-2003). According to this project the water assays were sampled from different depths near the banks of the Lake and from low-debit sources draining the dumping grounds of the uranium-carbon deposit. Elemental and isotopic examinations of these water samples were performed using an ELEMENT HR-ICP-MS (Finnigan Mat). The results obtained are the evidence that the ecological status of the Lake Issyk-Kul'is not damaged at present. Wastewaters from the uranium-carbon mine do not make decisive contribution into the natural radioactive background