A team of scientists at Rusia’s Mining and Chemical Combine (GKhK – Gorno Khimicheskii Kombinat), in Zheleznogorsk, Krasnoyarsk, (part of Rosatom’s Environmental Solutions Division) have completed research confirming the feasibility using fast and molten salt reactors (MSRs) in two-component nuclear energy. The results make it possible to justify the use of MSRs for the transmutation of curium – one of the most difficult minor actinides to handle in the long-lived wastes from reprocessing used fuel.
Minor actinides are transuranium elements formed in nuclear fuel during reactor operation. The major minor actinides include neptunium, americium, and curium. These elements do not occur in nature. They are highly radioactive and toxic, and have isotopes with long half-lives, making them hazardous components of radioactive waste.
While fast reactors (such as Rosatom’s sodium-cooled BN series or lead-cooled BREST-OD-300) can burn solid mixed oxide fuel containing minor actinides such as americium and neptunium, the MSR acts as a specialised “clean-up” component designed specifically for the most volatile or chemically difficult actinides such as curium.
The work was carried out as part of the development of closed nuclear fuel cycle technologies. GKhK acts as the coordinator of the project to develop a research MSR and the site for its future location. During the research, experts showed that the MSR is capable of transmuting curium in volumes corresponding to the predicted formation of this element during the processing of used fuel.
“Until now, fast and molten salt reactors have been viewed by the nuclear industry as alternatives. Now calculations show that their joint work will give the best effect – now we are not talking about competition, but about synergy. Each type of reactor effectively closes its segment of the task of afterburning the most dangerous radioactive waste – minor actinides,” explained Rosatom’s Director of State Policy in the field of radioactive waste, used fuel and decommissioning of nuclear and radiation hazardous facilities, Vasily Tinin.
He added: “This approach will systematically reduce the volume of long-lived waste and at the same time increase the efficiency of the fuel cycle. The results obtained will help formulate proposals for a new strategy in terms of closing the nuclear fuel cycle and working with minor actinides. I am convinced that the pooling of the competences of Rosatom’s enterprises, scientific organisations and research centres will allow us to continue to confidently move along the path of creating a new generation of energy systems – resource-saving and even more environmentally friendly.”
