New Technologies and Innovation Development in Russia #2

The safety of the reactor is also enhanced by placing the systems and equipment containing radioactive sodium inside the reactor tank. The autonomous heat exchangers of the emergency heat removal system, which are also installed inside the tank, along with the natural coolant circulation through the circuits, contribute to reducing the likelihood of severe damage to the core. The capacity of the BN‑1200 in-vessel storage has been increased in order to unload fuel assemblies from the reactor directly into the spent fuel pool, eliminating the need for a sodium drum.

Compared to the BN‑600 and BN‑800, the power density of the BN‑1200 core is almost twice as low, which significantly extends the refueling interval. The use of larger fuel rods and fuel assemblies, mixed uranium-plutonium fuel, and new structural steels with increased radiation resistance ensures deeper burnup and reduced consumption of fuel assemblies. The use of expansion bellows to compensate for thermal expansion of the pipes has led to a reduction in their length. With the implementation of these new technical solutions, the length of sodium systems has been reduced considerably; radioactive sodium leaks and contact with air have been eliminated.

Due to its physical properties, the fast neutron reactor can be operated on different plutonium isotopes extracted from the spent fuel of both fast and thermal neutron reactors. It can also ‘burn’ minor actinides to produce fresh plutonium for fuel and fabricate desirable isotopes.

The service life of the BN‑1200M reactor unit is at least 60 years. As Sergey Shepelev notes, there is potential to extend its lifespan to 80 years, increase the utilization factor from 0.9 to 0.91, extend the service life of steam generators from 30 to 60 years, and lengthen the refueling interval.

there is potential to extend its lifespan to 80 years