Vitrocerus: An Alternative for Processing MTR Spent Fuel from Research Reactors

Abstract

Research reactors spent fuels disposal is a problematic area that conduces to the quest of feasible solutions for garantee the safe destiny of the spent fuels. In this work, a new method for processing spent fuel from MTR reactors is presented. The main objective of this process is the immobilization of principal radioactive elements present in the spent fuel in order to achieve a suitable material which could be temporally stored safely. The Vitrocerus method involves simple physical procedures performed in a hot cell. It differs from conventional vitrification because there is a reduction in volume of glass material added. The process consists of the ceramization of a mixture of milled and calcined spent fuel plates with natural uranium oxide (U3O8) to obtain the desired isotopic dilution (to low the U235 enrichment). At the same time, a small fraction of vg98/12 glass [1] is added to enhance low temperature sintering. The treatment and conditioning tasks proposed in Vitrocerus were tested on MTR fuel miniplates that simulate a real U3Si2 dispersed in Al fuel, which were successfully transformed into ceramic sintered pellets [2,3] with low enrichment, structural integrity, good mechanical properties and water corrosion resistance. Eventually these pellets could be stored safely in an interim dry storage facility.