SORPTION AND SPATIAL DISTRIBUTION OF RADIONUCLIDES ON FRACTURED ROCK MINERALS AT THE “YENISEISKIY” SITE

The paper presents data on the distribution coefficients (K_a ) ¹³⁷Cs, ⁹⁰Sr/ ⁹⁰Y, ²⁴¹Am on a fractured rock sample taken from the exocontact zone of the Nizhnekanskiy granitoid massif. The study focuses on the micro distribution of radionuclides on mineral phases of the fractured sample. Based on the comparative analysis of radiograms and SEMimages, the data on relative sorption efficiency (RSE) were obtained, which allowed to evaluate the contribution of ann individual mineral phase of the fractured rock sample to the sorption of the studied radionuclides. It was noted that in terms of cesium and strontium retention, the secondary mineral, namely, the chlorite filling the fractured zones in the sample (RSE = 2) should be considered as the most effective mineral phase. Cesium and strontium sorption on zeolite and feldspars was less effective with RSE parameters ~ 1. Americium sorbed uniformly on the surface of the fractured sample, which was confirmed by similar RSE values on the mineral phases of the sample.

 

Keywords: radioactive waste, sorption, micro-distribution of radionuclides, fractured rocks, Nizhnekanskiy granitoid massif, digital autoradiography.