Microwave process employed to study the immobilization feasibility of spent ion exhange resins polymeric matrices

Abstract

Nuclear activities generate radioactive wastes in several physical states, radioactive levels and kinds of radioactive emission. Hence, a lot of techniques have been developed and optimized to do the immobilization of these materials, according to local and international regulations to protect human being and environment. Another great concern is the indiscriminate disposal of used polymeric materials (such as plastic and rubber) or production leftovers in landfills, which remain for many years before they are naturally decomposed. In this work, it was studied the possibility of carrying out the immobilization of spent ion exchange resins (contaminated with ionising radiation), by using polymeric matrices of bitumen and rubber (as solidification materials for the storage of low level radioactive waste). The samples were mixed at different percentages and were heated in a microwave device (2,450MHz) at IPEN/CNEN-SP, varying the irradiation time and power. The objective of the immobilization is converting the wastes into forms that are leach resistant and physically and chemically stable for disposal. Characterizations of these materials have been performed according to ABNT-NBR standards. The results indicated the previous idea of the necessary minimum temperature to keep the matrix for future embedding of radioactive waste, in solid state.