The Siberian Chemical Combine (an enterprise of TVEL Fuel Company of Rosatom in Seversk, Tomsk Region) has launched an experimental shop-floor for fabrication of trial REMIX fuel bundles for VVER-1000.
The production chain of the first REMIX fuel fabrication has been established in cooperation with the Mining and Chemical Combine (an enterprise of Rosatom in Zheleznogorsk, Krasnoyarsk region), where production of uranium-plutonium fuel pellets has started (the first batch of pellets has been already delivered from Zheleznogorsk to Seversk and successfully passed the acceptance). The experimental REMIX fuel will be manufacture in TVS-2M design, one of the basic models of VVER-1000 fuel.
REMIX (regenerated mixture) fuel is Russian innovative product for thermal light-water reactors, which make-up the back-bone of the modern nuclear power industry. Its fuel matrix is made from a mixture of reprocessed uranium and plutonium, extracted from spent nuclear fuel, with addition of small volumes of enriched uranium. Distinct from uranium-plutonium fuels for fast reactors (such as MNUP and MOX fuel), REMIX fuel has low plutonium content (up to 1.5%). 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.
Since 2016, three TVS-2M fuel assemblies, each containing six experimental REMIX fuel rods (among the total 312 rods in one fuel bundle), have been undergoing pilot operation program at unit No. 3 of Balakovo NPP in Russia. In 2020, the third 18-month cycle of their irradiation started.
“The shop-floor for VVER-1000 fabrication in Seversk has been established in a record-breaking short time, as the work started in the third quarter of 2020. In 2021, we plan to manufacture several full-fledged TVS-2M bundles with REMIX fuel. The first cycles of REMIX fuel rods irradiation at Balakovo NPP showed good results, while testing of complete REMIX bundles will be an important milestone for commercial implementation of this technology. And in the case of confirmed market demand, we will need to establish a large-scale facility for REMIX fuel fabrication at one of Rosatom's enterprises”, commented Alexander Ugryumov, Vice-President for research, development and quality at TVEL JSC.