An approach towards enhancing the role of microwave heating in low-level radioactive waste management

Nuclear industries, medical industries, and nuclear research establishments generate a considerable amount of low-level radioactive waste (LLW). The paper presents the application of microwave energy for the processing of low-level radioactive wastes (volume reduction). A temperature-based study of these kinds of wastes has been performed using the COMSOL multiphysics software package. The simulated results agree well with experiments performed on a commercially available microwave oven at a frequency of 2.450 GHz. The main focus of this paper involves a detailed study of the effectiveness of microwave heating for treatment of LLW based on their dielectric loss tangent data. The study is carried out by recording the temperature rise in the corresponding waste materials, which is basically representation of the conversion of the applied electromagnetic energy into heat. Various shapes such as cubical, cylindrical, and cuboid of low-level radioactive test objects have been incorporated in the treating environment (Oven). Further, measurement of electromagnetic and heat transfer properties of the test objects has been performed to improve the accuracy of the simulation and experimental results. Many combinations of test objects with different shapes and dielectric properties have been studied for microwave heat treatment. The study suggests that radioactive waste treatment using microwave heating will be more effective after categorizing the wastes concerning their dielectric loss tangent.