Residue-free nuclear fuel production at IPEN, Brazil

Abstract

The Nuclear Fuel Center (CECON) at IPEN (Instituto de Pesquisas Energeticas e Nucleares), Brazil, will scale up the production of nuclear fuel elements based on uranium silicide in the coming years to ensure a future supply for the planned Brazilian Multipurpose Reactor (RMB). This expansion is expected to generate significant amounts of liquid radioactive waste (LRW) containing low enriched uranium (LEU). However, a portion of this LRW currently lacks a defined procedure for reutilization, resulting in their accumulation at the facility or their transfer as waste to the Institute’s Radioactive Waste Management Department, in compliance with safeguards, safety, and security regulations. The increasing volumes of LRW present a significant challenge due to the difficulties associated with long-term storage of radioactive material in liquid matrix, which requires stringent containment measures to prevent leaks and contamination. In this study, LRW from the UF4 production process were treated with biochar (BC) and covalent organic framework membrane (COF) to reduce uranium concentrations. The results indicate that uranium levels could be lowered to below 0.22 mgꞏL-1, which meets the Brazilian standard for discharge as regular sewage.