MOSCOW, Oct. 30 — The Research Institute of Nuclear Reactors, a facility under the auspices of Rosatom located in Dimitrovgrad, has commenced testing VVER-type fuel rods containing uranium-plutonium MOX fuel in the MIR research reactor. These tests are essential to assess the efficiency and reliability of MOX fuel operation in VVER reactor units, which constitute the backbone of Russia’s nuclear power sector and are also widely deployed in Russian-designed nuclear power plants in other countries.
This marks a significant milestone for the Russian nuclear industry in terms of closing the nuclear fuel cycle. Currently, Rosatom exclusively produces MOX fuel for fast-neutron reactors, particularly the world’s most powerful BN-800 fast reactor at the Beloyarsk Nuclear Power Plant. For light-water thermal neutron VVER reactors, Rosatom has developed uranium-plutonium REMIX fuel, which has successfully completed the full lead-test rods program in a commercial VVER-1000 reactor and is currently undergoing lead-test assemblies operation.
The REMIX fuel contains up to 1.5% plutonium and is based on a mixture of regenerated uranium and plutonium bred in the reactor. In contrast, MOX (mixed oxide fuel) consists of a blend of plutonium oxides and depleted uranium oxides. The MOX fuel designed for VVERs is anticipated to contain approximately 5.5-7.5% plutonium. This increased plutonium content enhances the flexibility and efficiency of utilizing regenerated nuclear materials in the VVER fuel cycle, thereby optimizing the fabrication costs of uranium-plutonium fuel before its full-scale implementation.
Alexander Ugryumov, Senior Vice President for Research and Development at TVEL JSC, highlighted the potential shift in fuel matrix options for VVER reactors, depending on nuclear power plant (NPP) requirements and fuel cycle strategies. This flexibility is expected to extend the resource base of light-water thermal reactors, promote the reprocessing of irradiated fuel instead of storage, and significantly reduce the volume of nuclear waste.
In the MIR reactor, 21 MOX fuel rods with plutonium content ranging from 5-12% were manufactured through collaborative efforts involving TVEL Fuel Company of Rosatom, including the Bochvar Institute, Novosibirsk Chemical Concentrates Plant, and Siberian Chemical Combine. The experimental fuel assembly loaded into the research reactor loop consists of twelve fuel rods, with nine fresh fuel rods gradually replacing irradiated ones during the test, allowing for post-irradiation studies at various burnup levels.
Russia’s nuclear power development strategy aims to establish a dual-component nuclear power system featuring both thermal and fast-neutron reactors while widely adopting closed nuclear fuel cycle technologies. This approach is founded on the fabrication of fresh uranium-plutonium fuel from spent fuel. As fast-neutron reactors become more prevalent, it is expected to achieve a balance in the circulation of nuclear fuel materials between fast and thermal reactors.
Innovation is pivotal in improving manufacturability within the nuclear power industry, with VVER reactors benefiting from advanced materials, enhanced designs, and improved manufacturing processes. These advancements enhance the efficiency, reliability, and economics of VVER reactors. Their design allows for optimal heat transfer and energy conversion, resulting in higher electricity generation per unit of fuel. VVER reactors are renowned for their durability, designed to have an operational life of up to 60 years with proper maintenance and refurbishment, ensuring a reliable and continuous source of electricity.
Moreover, VVER reactors have a lower environmental impact compared to traditional energy sources like coal or natural gas. They produce no greenhouse gas emissions during operation, contributing significantly to the reduction of carbon dioxide emissions and the fight against climate change. These advantages make VVER reactors an attractive choice for countries seeking sustainable and secure energy solutions.
Notably, a VVER-1200 reactor is currently under construction on the African continent at the El-Dabaa Nuclear Power Plant in Egypt. It is estimated that this NPP will generate approximately 2.4 trillion kilowatt-hours over its operational lifetime, making the initial construction costs highly worthwhile.
