Perspective of exploitation of new sandstone type deposits by ISL method and environmental impact from uranium deposits mined out by in situ leaching in Ukraine

In Ukraine, two uranium deposits, Devladivske and Bratske, were mined using acid in-situ leach method during the seventies-eighties. No restoration of the affected aquifer was made after mining. More than ten years after the end of mining, no displacement of the contaminated aquifer has been observed. In contrast, a process of self-restoration has been observed, with a significant decrease of U, Th, Ra, sulphates content. pH increased from 3.9 to 6.2. Self-restoration of the aquifer may be attributed to significant content in coal and clay minerals in the leached formation, that promote self-neutralization of the affected aquifer. (author)