Characterization and decontamination of a lubricant waste from CONUAR S.A

Full text: An oil waste compounded by several lubricants and a suspended solid was received in the Radioactive Wastes Management Activity Unit to be treated. This waste is produced by the company CONUAR S.A., during the natural uranium oxide pellets production, which are used in the power reactor fuel fabrication.At the moment, the waste is stored in 50 containers with 20 litres each. So a work to characterize and to develop a process to let the waste decontaminated, has been started. As a result of this work, it has found that the waste has produced a chemical combination between the uranium and the oil phase, giving an uranium concentration of about 200 mg./ l. An other component of this waste is the solid phase, which contains about 20 % of uranium oxide that can be easily separated by filtering. It is possible to take the uranium off from the oil by means of basic or acid washes in aqueous , followed by decanting, since the content of uranium can drop 10 or 20 times in a single contact stage. It was found a higher coalescence velocity in case of acid washes, so it can be finally used as a continue or batch process