The first batch of uranium-plutonium REMIX nuclear fuel for VVER-1000 reactor has been manufactured and successfully passed acceptance at Siberian Chemical Combine, an enterprise of Rosatom’s TVEL Fuel company in Seversk, Tomsk region.

Each of the six fuel bundles of the standard TVS-2M model fully consists of REMIX fuel rods with uranium-plutonium pellets instead of the traditional enriched uranium dioxide (one standard VVER-1000 fuel assembly contains 312 rods). The fuel pellets had been manufactured at Mining and Chemical Combine, Rosatom’s facility in Zheleznogorsk, Krasnoyarsk region.

The complete REMIX fuel bundles will undergo a full operation cycle in one of the Russia’s VVER-1000 reactors. Earlier, in 2021, three fuel bundles, each containing six REMIX fuel rods, completed the irradiation programme at the Balakovo NPP.

Such approach fully complies with the international practice of innovative nuclear fuel introduction. At first, a reactor core is loaded with several bundles, each containing a few rods with the new fuel among the standard ones (the so called Lead Test Rods, or LTR programme). The next stage is loading several assemblies, fully consisting of the new type rods (Lead Test Assemblies, or LTA programme).

“The LTR programme at the Balakovo NPP was sussessfully completed in 2021, now we are looking forward to the post-irradiation studies. Meanwhile, the full cycle of the six lead test assemblies operation will give us more information about REMIX fuel behavior in the core and its influence on reactor physics. Thus, we would obtain the necessary data for licensing full refueling of the core with REMIX assemblies, as well as a reference experience for commercialization and introduction of such fuel”, Alexander Ugryumov, Vice President for Research, Development and Quality at TVEL Fuel Company, commented.

REMIX (regenerated mixture) fuel is a Russian innovative product for thermal light-water reactors, which make up the basis of the modern nuclear power industry. Its fuel matrix is made from a mixture of reprocessed uranium and plutonium, extracted from spent nuclear fuel. Distinct from uranium-plutonium fuels for fast reactors (such as MNUP and MOX fuel), REMIX fuel has low plutonium content. Its neutron spectrum does not vary from common LWR fuel with enriched uranium, therefore, fuel assemblies behavior in the reactor core and the amount of plutonium bred from uranium due to irradiation are generally similar. For NPP operators, this means that, in perspective, REMIX fuel may be introduced without any changes in reactor design or additional safety measures.

Introduction of such fuel would enable to boost exponentially the feedstock for nuclear power plants due to closing the nuclear fuel cycle, and also to recycle spent nuclear fuel instead of its storage.