РАСЧЕТНО-ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ ГИДРОДИНАМИЧЕСКИХ УСЛОВИЙ РАБОТЫ ФИЛЬТРОВ-КОНТЕЙНЕРОВ ДЛЯ ИОНОСЕЛЕКТИВНОЙ ОЧИСТКИ

Abstract

The generation of radioactive waste (RW) is a specific feature of NPP operation. Liquid radioactive waste (LRW) is generated during the operation of reactor facilities, decontamination of equipment, premises and overalls. The main radionuclides in the distillation residues are 134,137Cs in the form of ions and isotopes 60Co, 54Mn in the form of complexons with substances that are used to decontaminate equipment. Among the known methods of conditioning, the largest reduction in the volume of LRW occurs with selective sorption. It is possible to increase the efficiency of using the volume of the filtering material by supplying the medium to be purified simultaneously into several layers of the sorbent. In the work, computer simulation of three proposed variants of improved designs of the filter container for ion-selective purification was carried out, which differ both in the ways of separating the flows of purified water and in the methods of their supply to the sorbent layers. All versions of the filter containers had the same cross-sectional area and height of the sorbent layers. Evaluation of the increase in the efficiency of sorption processes in the proposed designs was carried out using computer simulation in SolidWorks Flow Simulation. Three sorbents of NPP Eksorb were used. To determine the hydraulic resistance of the samples under study, a series of experimental studies of the flow through the sorbent layer was carried out. Experiments have shown that the hydraulic resistance of the layer increases in a quadratic dependence on the flow velocity, which is consistent with the Ergun equation. The obtained experimental data was added to the SolidWorks Flow Simulation engineering database to simulate the previously presented structures. Based on the simulation results, the characteristic parameters of the flow in the cavity of the filter containers were obtained. Modeling showed that, in all variants, the flow rate of the medium was distributed approximately equally among the layers. It was revealed that the third design option has the least hydraulic resistance. The chemical interaction of the filtered medium with the sorbent was not considered in the calculations. © 2022 Obninsk Institute for Nuclear Power Engineering, National Research Nuclear University 'MEPhI'. All rights reserved.