IRIS AND SHIVA: PROCESSES FOR THE INCINERATION VITRIFICATION OF HAZARDOUS ORGANIC WASTES

摘要

Incineration represents a promising weight and volume reduction technique for hazardous organic waste and its application is very useful in proper disposal of radioactive wastes. Two ways, depending on the final use of the ashes, can be chosen. Either it is necessary to recover some valuable elements (noble metals, actinides,…) from the ashes, or it is better to immobilize them in a long-lasting matrix. With the production of high quality ashes having very low carbon content, the IRIS (Installation de Recherche en Incineration de Solides) process meets with the goal of the first way. For the second one, the SHIVA process (the French acronym for Advanced Hybrid System for Incineration and Vitrification) is an attractive tool to perform an incineration of the burnable part of the waste followed by a vitrification of the mineral charge. The two steps take place in the same vessel using two means of heating: direct induction through a cold crucible in the lower part and plasma torch in the upper part. The plasma is dedicated to the glass melting and the incineration of the burnable waste and the glass is maintained molten in the cold crucible that also leads to the minimisation of the corrosion problem at this place. Based on the SHIVA technology, studies concerning the treatment of old bituminized wastes stored in Marcoule were performed. The interests of such treatment are to stabilise the radioactive charge in an inert matrix and to reduce the volume of wastes in order to appreciably diminish the cost of their storage.