Assessment of prospects for using mixed nitride fuel enriched with 15N in fast reactors of a closed nuclear fuel cycle

The present paper considers two options for the core of the BR-1200 reactor to reduce the fuel loading. The effect of changing the isotopic composition of nitrogen in the fuel on the required launch loading is assessed for each concept. A fuel cycle is assumed closed if irradiated nuclear fuel is reprocessed to recover valuable fissile material for return to the cycle. The introduction of ¹⁵N into the composition of nitride fuel demonstrates reducing the consumption of uranium and plutonium. Prospective isotope separation methods for tonnage production of ¹⁵N are considered. The conventional nitric acid method appears disadvantageous due to the lack of a back flushing necessary for large-scale production. Therefore, we propose the ammonia complex method as a possible option for organizing ¹⁵N production.