Sorption of 90Sr and 137Cs on clays used to build safety barriers in radioactive waste storage facilities

Sorption of 90Sr and 137Cs on clays used to build safety barriers in radioactive waste storage facilities

The purpose of the work was to investigate the sorptive capacity of natural clay samples with respect to 90 Sr and 137 Cs to assess the possibility of using these as components of protective barriers at radioactive waste isolation facilities. Bentonite clays of the Zyryanskoye and Desyaty Khutor dep...

Full description

Saved in:
Bibliographic Details
Published in:Nuclear energy and technology Vol. 7; no. 2; pp. 151 - 156
Main Authors: Volkov, Ilya N., Zharkova, Viktoriya O., Karaseva, Yana Yu, Lysakova, Еlena I., Zakharova, Еlena V.
Format: Journal Article
Language:English
Published: Sofia Pensoft Publishers 24-06-2021
National Research Nuclear University (MEPhI)
Subjects:
Aqueous solutions
Bentonite
Cation exchange
Cation exchanging
Cesium
Cesium 137
Cesium isotopes
Cesium radioisotopes
Clay
clays
Ions
Melting
Montmorillonite
Radioactive wastes
Radioisotopes
Safety barriers
Sorption
Storage facilities
Strontium
Strontium 90
Strontium radioisotopes
Waste storage
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The purpose of the work was to investigate the sorptive capacity of natural clay samples with respect to 90 Sr and 137 Cs to assess the possibility of using these as components of protective barriers at radioactive waste isolation facilities. Bentonite clays of the Zyryanskoye and Desyaty Khutor deposits and high-melting clay of the Kampanovskoye deposit were selected for the investigation. The capacity of clays for sorption through ionic exchange is characterized by the value of the cation exchange capacity (CEC). In the process of sorption experiments, all of the test clays displayed a high rate of extracting strontium and cesium radionuclides from aqueous solutions. It was shown that the sorption of 90 Sr is affected by the content of montmorillonite in the samples: bentonite clays absorb up to 98–99% of the initial radionuclide content in the solution, while about 80% of strontium is sorbed by high-melting clay. Cesium is practically fully sorbed by the tested samples and the degree of sorption amounts to over 99%, the highest value of the distribution coefficient having been recorded for the Kampanovskoye sample ( K d = 5.0×10 3 cm 3 /g). The method of sorbed radionuclides fixation on the clay samples were identified by selective desorption using the modified Tessier methodology. It was shown that strontium ions are more mobile than ions of cesium up to 97% of which is retained by clays.
ISSN:2452-3038
2452-3038
DOI:10.3897/nucet.7.69930