Rosatom said that scientists from its Fuel Division and the Proryv, or Breakthrough, project area have developed the new technology, which will be implemented at the facility for reprocessing irradiated uranium-plutonium (SNUP) fuel as part of the pilot energy complex (ODEK) being built at the Siberian Chemical Combine's site in Seversk, Tomsk Region.

Rosatom's Proryv project aims to enable a closed nuclear fuel cycle, ultimately eliminating production of radioactive waste from nuclear power generation. The ODEK complex comprises a fuel production/refabrication module for production of dense uranium plutonium (nitride) fuel for fast reactors; a nuclear power plant with a BREST-OD-300 lead-cooled fast-neutron reactor; and a used fuel retreatment module.

The crystallisation technology is expected to become the final technological stage in the process of purification of nuclear materials isolated from irradiated SNUP fuel - uranium, plutonium and neptunium, the company said.

"Crystallisation refining technology will ensure a high level of safety during used nuclear fuel reprocessing," Rosatom said. "The technological process will make it possible to jointly purify and isolate uranium, plutonium and neptunium, eliminating the possibility of isolating plutonium as a separate product. Thus, the technology fully complies with the nuclear non-proliferation regime."

It noted that, unlike extraction technologies for purification of nuclear materials, crystallisation is accompanied by the production of a smaller volume of secondary waste, including due to the use of only nitric acid solutions as reagents. "This technology will improve the environmental safety of the used fuel reprocessing process," Rosatom said.

Technologies for reprocessing irradiated fuel are of particular importance for closing the nuclear fuel cycle at ODEK, the company noted. Materials separated from used fuel, after reprocessing, will be sent for fabrication of fresh fuel. "Thus, this system will gradually become practically autonomous and independent of external energy supplies," Rosatom said.