Rosatom Establishes New Laboratory to Test Molten Salt Reactor Spent Fuel Reprocessing Technology

The first production site of the Khlopin Radium Institute, part of Rosatom's research division, is completing the construction of a new laboratory that will be dedicated to testing the processing and reprocessing technology for spent nuclear fuel (SNF) from molten salt reactors (JSR/MSR). In the first phase of facility testing, it is planned to synthesize simulated fuel compositions based on lithium fluoride and beryllium fluoride, with added simulants of fission products and plutonium; subsequently, the technology will be validated on models, and ultimately practical application will be carried out on the basis of the research molten salt reactor (IZHSR) being built in Zheleznogorsk. The related construction, installation, and commissioning work is planned for completion by the end of 2026, and to prepare for the first research.

Oleg Volkov, Acting General Director of the Khlopin Radium Institute, stated that the institute is currently carrying out laboratory construction and equipment commissioning work. According to the research plan, the developed technology will be tested in 2027. If operational validation is successful, it will become a prerequisite for establishing the foundational spent nuclear fuel processing and reprocessing technology for industrial-scale molten salt reactors.

Molten salt reactors are an important element of the closed nuclear fuel cycle (FC NFC) concept. Their main role is to incinerate (transmute) minor actinides, thereby improving the environmental safety of Russia's domestic nuclear energy. The proposed spent fuel reprocessing technology is based on continuous high-temperature metallurgical/liquid metal reductive extraction of nuclear materials and neutron poisons (fission products) from the fuel composition, followed by back-extraction of nuclear materials into the fuel salt for reuse in the reactor.

Ilya Skrigan, Head of the Radioactive Waste Solidification Technology and Process Laboratory at the Khlopin Radium Institute, pointed out that the main stage of the process is the mixing of two melts under intense hydrodynamic conditions——fuel salt and lithium bismuthide. During this process, lithium enters the fuel salt, while neutron poisons extracted from the salt enter the bismuth. The uniqueness of this technology and equipment lies in the need to operate at high temperatures of approximately 700 degrees Celsius and in highly corrosive media, to transport melts between equipment, and to maintain an inert atmosphere with oxygen content not exceeding 100 ppm. Currently, there is no comparable equipment anywhere in the world.

The testing of industrial-scale molten salt reactor technology will also be carried out in conjunction with the construction of the research molten salt reactor (IZHSR), which is planned to be built in Zheleznogorsk in the Krasnoyarsk Krai. Rosatom is implementing this project jointly with the Kurchatov Institute, and the technical design of the research molten salt reactor facility is currently in its final stage.

Molten salt reactors belong to fourth-generation nuclear energy technology. In the future, such facilities will reduce the volume and radioactivity of nuclear waste by orders of magnitude and eliminate dependence on costly deep geological disposal. Molten salt reactor technology is regarded as one of the effective tools for solving Russia's minor actinide (primarily curium) problem, and also as an extension measure to provide services to foreign partners interested in spent fuel reprocessing with minimal high-level waste output.

The Khlopin Radium Institute is Russia's oldest research institution and the country's first scientific research organization in the field of nuclear science and technology. The institute holds a leading position in research on nuclear physics, radiochemistry, geochemistry, and ecology, as well as in the fields of nuclear energy, radiation ecology, and isotope production, and is also a major supplier of radionuclides and radionuclide sources (including radiopharmaceuticals) for domestic and international markets.