Development of a Novel GANEX Process
Paper in proceedings, 2010
The waste from nuclear power plants has to be isolated from man and his environment for about 100,000 years to be considered safe. It has been suggested that if the long-lived actinides could be separated from the spent fuel and transmuted, the isolation time could be shortened to about 1,000 years. This, however, requires selective separation of parts of the waste. The partitioning for transmutation research in Europe has for the major part taken place within several European Union Framework Programmes. Within the projects NEWPART, PARTNEW and EUROPART a process scheme for the partitioning of nuclear waste from the PUREX process was developed. The scheme includes the DIAMEX, SANEX and SESAME-processes among which both the DIAMEX and SANEX process has been successfully tested on genuine spent fuel. However, in the latest EU Project ACSEPT, which started in 2008, another approach towards partitioning is being investigated. This is the so called GANEX (Group ActiNide EXtraction) process. In the GANEX process all the actinides in the dissolved spent fuel are extracted as a group and hence separated from the lanthanides as well as the rest of the fission and corrosion/activation products. A novel GANEX process has been developed at Chalmers university of Technology in Sweden. This new process utilizes the properties of already well known extractants by combining BTBP and TBP into one solvent. The system is able to extract U, Np, Pu and Am from strong nitric acid and simultaneously separate these elements from the lanthanides. This is done with sufficiently high distribution ratios and separation factors without the need for any redox control.