Migration and sorption of Cs-137 and Eu-152,Eu-154 in crushed crystalline rocks under dynamic conditions

摘要

In migration experiments, sorption of Cs-137 and Eu-152,Eu-154 in the columns of crushed crystalline rocks of 0.25-0.8 mm grain size under dynamic flow conditions from the synthetic groundwater (SGW) has been studied. Five samples of crystalline rocks from Cavernous Gas Reservoir near P angstrom (TM) ibram were taken. Plastic syringes of 8.8 cm length and 2.1 cm in diameter were used as columns. The water phase was pumped downward through the columns, using a multi-head peristaltic pump, with a seepage velocity of about 0.2 cm/min. The radioactive nuclides, containing chemical carriers, were added into the water stream individually in the form of a short pulse. Desorption experiments were carried out with 2:1 (v/v) mixture of H2SO4 and HNO3. In the columns the longitudinal distribution of the residual Cs-137 and Eu-152,Eu-154 activities was also determined. By the evaluation of respective breakthrough and displacement curves, the experimental and theoretical retardation factors, distribution coefficients and hydrodynamic dispersion coefficients were determined using the integrated analytical form of a simple advection-dispersion equation (ADE). Dynamic sorption experiments were also compared with the results of static sorption experiments.