Estimation of Radionuclides Migration by the Data from²⁰⁶Pb/²³⁸U-²⁰⁷Pb/²³⁵U and²³⁴U-²³⁸U Systems Studies

Abstract

Taking into account the fact that pitchblende, the main uranium mineral of uranium deposits, has similar properties to synthetic uraninite, which constitutes 96% of spent nuclear fuel (SNF), uranium deposits of pitchblende ores can rightly be considered as natural analogues of underground SNF disposal and long-term storage facilities.Stability and disturbance of U-Pb and 234 U-238 U isotopic systems at the sites of uranium mineralization development were investigated with the purpose of quantitative estimation of original uranium ores preservation degree.For this purpose a profile was selected through the ore zone in trachydacites of Streltsovskoe deposit (Western Transbaikalia, Russia) [1].The profile is a typical cross section of a mineralized zone at a mining level at a depth of approximately 230 m from the surface.The profile was started near a fault, passed through a zone of stockwork-vein U mineralization ~2.5 m thick, and was ended in the host rocks at about 1.5 m from the interval with visible U mineralization (Fig. 1).