Nitride fuel developed for Russia’s BREST-OD-300 fast neutron reactor


Russian state atomic energy corporation Rosatom’s fuel arm TVEL has developed a fuel rod design based on nitride uranium-plutonium (MNUP) fuel for the BREST-OD-300 fast neutron reactor, Rosatom announced last week. In a statement, Rosatom said that the fuel rod project being undertaken by TVEL’s research facility, the Bochvar Institute, will be applied for commercial manufacturing of nitride fuel to be launched as part of the Pilot Demonstration Energy Complex that is under construction in the Seversk, Tomsk, region of Russia.

The Pilot Demonstration Energy Complex is underway as part of the strategic “Proryv” (“Breakthrough”) project. It will include three linked facilities, making up a closed nuclear fuel cycle at one site — the fuel fabrication/re-fabrication unit (FRU), the 300 MW nuclear power plant with the fast neutron BREST-OD-300 reactor, and the unit for spent fuel reprocessing.

“At the same time, Rosatom’s Nuclear Fuel Division continues development of the second-generation fuel rods for the BREST-OD-300 with a higher burnout level, which will be used when the MNUP fabrication will shift to the re-fabrication stage (meaning that irradiated fuel of the first load after irradiation and reprocessing will be used for fresh fuel fabrication)”, the statement said.

“Pilot fuel assemblies with nitride fuel have been irradiated in the BN-600 reactor at the Beloyarsk NPP since 2014. Though the sufficient validated fuel burnout for the BREST initial load is 6 percent, in the course of the testing we have already achieved the 9 percent level. These results give us the grounds for the fuel rod endurance tests with 9-10 percent burnout”, said Mikhail Skupov, Deputy Director General of the Bochvar Institute.

According to the TVEL Vice President (Research, Development and Quality) Alexander Ugryumov, “the research results related to nitride fuel for the BREST reactor will significantly accelerate fuel development for the nitride core version of the next generation BN-1200M fast reactor. In 2022, experimental fuel assemblies with fuel rods of BN-1200M type are scheduled to be loaded in the BN-600 for endurance tests”.

Rosatom announced last year that the 789 MW BN-800 fast neutron reactor powering the fourth unit of the Beloyarsk nuclear power plant (NPP) in Russia will be completely switched to uranium-plutonium MOX fuel in 2022. This BN-800 reactor of 789 MW capacity is currently fuelled by a “hybrid core” consisting of a mix of uranium and plutonium oxides arranged to produce new fuel material as it burns. World Nuclear News reported that the transition to MOX fuel assemblies will start in the first half of 2021. The BN-800 fast neutron reactor is designed to use the MOX fuel as one of the stages on to the development of a closed nuclear fuel cycle. The capacity of the Beloyarsk Unit 4 exceeds that of the world’s second most powerful fast reactor – the 560 MW BN-600 Beloyarsk Unit 3.

The “Breakthrough” project targets creation of a new technology platform for the industry with the closed nuclear fuel cycle, as well as tackling the issues of spent nuclear fuel and radioactive waste. One of the project components is the construction of a lead-cooled BREST-OD-300 fast neutron reactor facility with an on-site closed nuclear fuel cycle.

Rosatom has said that unlike NPPs with light-water VVER reactors, where refueling is performed at the ‘cooled’ reactor, the BREST-OD-300 project provides that these operations will be carried out at the temperature of the liquid-lead coolant of the primary circuit over 400° C. Before loading into the core, the fuel assemblies will be heated up in a special chamber and then placed into the core filled with a melt of lead coolant”.

In addition to the 300 MW BREST-OD power unit, the Pilot Demonstration Energy Complex in Seversk will include the on-site closed nuclear fuel cycle embracing the unit for refabrication of mixed nitride uranium-plutonium fuel, as well as the unit for irradiated fuel reprocessing.

According to TVEL, the production of equipment for the reactor facility at Seversk, being constructed by its subsidiary Siberian Chemical Combine (SCC), is supposed to take between three to five years, while installation of the main equipment is expected to be completed in 2025. The “Breakthrough” project is aimed at development of the new technological platform of the nuclear power industry capable of solving the current issues of handling and storage of spent nuclear fuel and waste.