TheBREST is ageneration IVlead-cooledfast nuclear reactor. BREST-300 model is under construction since 2021 inSeversk.
The main characteristics of the BREST reactor arepassive safety and aclosed fuel cycle.[1] The reactor uses nitride uranium-plutonium fuel, is abreeder reactor and can burn long-termradioactive waste.[2] Lead is chosen as a coolant for being high-boiling, radiation-resistant, low-activated and at atmospheric pressure.[3]
In a traditional nuclear reactor design, the fuel is only able to reachcriticality when the neutrons produced in the fission reactions are slowed down using a "neutron moderator". The most common neutron moderator is water, although other concepts have been used by some designs. The resulting moderated neutrons no longer have enough energy to cause fission in the238
U that makes up the majority ofnatural uranium, and even with a moderator, natural uranium is generally not able to maintain achain reaction. Instead, the fuel isenriched to increase the amount of235
U, which increases the chance that the moderated neutrons will strike another235
U and maintain the reaction, and well as the removal of more of the238
U which would lower the overall reactivity.[4]
In the typical fast breeder design, the fuel is further enriched to the point where there is enough235
U to keep the reaction going even without a moderator. The result is that some of the neutrons exit the core area with high energy. This is only possible if the core is cooled using a fluid that is not also a moderator, and typically coolants like helium or liquid sodium metal are used for this purpose. The core is then surrounded by abreeding blanket, typically containingdepleted uranium of almost entirely238
U. The high-energy neutrons exiting the core cause some of these238
U nuclei to be converted toplutonium239
Pu, which can be separated using chemical processes and fed back into the reactor as fuel. At some point, enough plutonium has been created that no new enriched uranium is needed, and from that point the system can be run on natural uranium ore and the bred plutonium.[5]
In a traditional fast reactor design, a small core operating at higher neutron energies results in a number of issues, related mostly toprompt neutron reactorpower excursions which require the addition of more layers of control systems. They have also proven to be uneconomical compared to traditionallight water reactors in practice, as the expected high cost ofuranium ore never materialized and it is generally cheaper to simply buy new fuel than attempt to breed fuel and then separate it from the highly radioactive used fuel. The high energy neutrons also cause fission in some of the other materials in the blanket, which can be used to convertnuclear waste materials into less dangerous forms. The idea of using fast neutron reactors as "burners" instead of breeders, with the specific role of burning off nuclear waste, has also been raised on many occasions but has not, as of 2025[update], produced a commercial system.[5]
The BREST design is based on a new core design that addresses some of the issues seen in the earlier designs. In contrast to the earlier solid-core concepts, which were generally designed using traditional fuel rods, BREST is based on the use of fuel encapsulated in heat-conducting nitride elements. The design results in the plutonium breeding taking place entirely inside the core, without the separate blanket section.Lead coolant is used, instead of sodium, both for safety reasons as well as the Soviet practical experience using this coolant innuclear submarines. The result is an overallneutron economy that is similar to traditional reactors, with the denser fuel and breeding elements reduced into individual fuel elements.
The construction of the BREST-300-OD inSeversk (nearTomsk) was approved in August 2016.[6][7] The preparatory construction work commenced in May 2020.[8] Construction started in8 June 2021.[9][10]
By the end of 2024, thecooling tower has been built, the walls of the reactorcontainment building have been erected, the reactor shaft has been installed.
In November 2024, installation work has begun for thecondenser in theturbine hall.
Installation of the turbine and generator is planned to start in 2025. The target for starting operation is 2026. The first BREST-300 will be a demonstration unit over the next decade. If it is successful, the 1200 MWe (2800 MWt) BREST-1200 will be developed.[11]
In January 2025, the facility for fabrication of nuclear fuel for BREST-OD-300 has started producing prototype fuel assemblies withdepleteduranium nitride fuel pellets. It will have around 250 people working in it.[12]
In September 2025 key large parts were delivered to the construction site such as a metal shell for the central cavity, an internal casing for the core basket, the first shell of the peripheral cavity (there are four such shells in total). It took two months to transport this equipment along rivers and the northern sea route.[13]
| Reactors |
| ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Reactor types |
| ||||||||||
| Research locations | |||||||||||
| Companies | |||||||||||
