A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. When a fissile nucleus like uranium-235 or plutonium-239 absorbs a neutron, it splits into lighter nuclei, releasing energy, gamma radiation, and free neutrons, which can induce further fission in a self-sustaining chain reaction. The process is carefully controlled using control rods and neutron moderators to regulate the number of neutrons that continue the reaction, ensuring the reactor operates safely, although inherent control by means of delayed neutrons also plays an important role in reactor output control. The efficiency of nuclear fuel is much higher than fossil fuels; the 5% enriched uranium used in the newest reactors has an energy density 120,000 times higher than coal.
Mixed oxide fuel, commonly referred to as MOX fuel, is nuclear fuel that contains more than one oxide of fissile material, usually consisting of plutonium blended with natural uranium, reprocessed uranium, or depleted uranium. MOX fuel is an alternative to the low-enriched uranium fuel used in the light-water reactors that predominate nuclear power generation.
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. These reactors can be fueled with more-commonly available isotopes of uranium and thorium, such as uranium-238 and thorium-232, as opposed to the rare uranium-235 which is used in conventional reactors. These materials are called fertile materials since they can be bred into fuel by these breeder reactors.
A fast-neutron reactor (FNR) or fast-spectrum reactor or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons, as opposed to slow thermal neutrons used in thermal-neutron reactors. Such a fast reactor needs no neutron moderator, but requires fuel that is relatively rich in fissile material when compared to that required for a thermal-neutron reactor. Around 20 land based fast reactors have been built, accumulating over 400 reactor years of operation globally. The largest was the Superphénix sodium cooled fast reactor in France that was designed to deliver 1,242 MWe. Fast reactors have been studied since the 1950s, as they provide certain advantages over the existing fleet of water-cooled and water-moderated reactors. These are:
The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator; furthermore a solid form of fissile elements is used as fuel. Thermal-neutron reactors are the most common type of nuclear reactor, and light-water reactors are the most common type of thermal-neutron reactor.
The integral fast reactor (IFR), originally the advancedliquid-metal reactor (ALMR), is a design for a nuclear reactor using fast neutrons and no neutron moderator. IFRs can breed more fuel and are distinguished by a nuclear fuel cycle that uses reprocessing via electrorefining at the reactor site.
State Atomic Energy Corporation Rosatom, also known as Rosatom State Nuclear Energy Corporation,, or Rosatom State Corporation, is a Russian state corporation headquartered in Moscow that specializes in nuclear energy, nuclear non-energy goods and high-tech products. It was established in 2007 and comprises more than 350 enterprises, including scientific research organizations, a nuclear weapons complex, and the world's only nuclear icebreaker fleet.
Generation IVreactors are nuclear reactor design technologies that are envisioned as successors of generation III reactors. The Generation IV International Forum (GIF) – an international organization that coordinates the development of generation IV reactors – specifically selected six reactor technologies as candidates for generation IV reactors. The designs target improved safety, sustainability, efficiency, and cost. The World Nuclear Association in 2015 suggested that some might enter commercial operation before 2030.
The lead-cooled fast reactor is a nuclear reactor design that uses molten lead or lead-bismuth eutectic coolant. These materials can be used as the primary coolant because they have low neutron absorption and relatively low melting points. Neutrons are slowed less by interaction with these heavy nuclei so these reactors operate with fast neutrons.
A sodium-cooled fast reactor is a fast neutron reactor cooled by liquid sodium.
The water-water energetic reactor (WWER), or VVER is a series of pressurized water reactor designs originally developed in the Soviet Union, and now Russia, by OKB Gidropress. The idea of such a reactor was proposed at the Kurchatov Institute by Savely Moiseevich Feinberg. VVER were originally developed before the 1970s, and have been continually updated. They were one of the initial reactors developed by the USSR, the other being the infamous RBMK. As a result, the name VVER is associated with a wide variety of reactor designs spanning from generation I reactors to modern generation III+ reactor designs. Power output ranges from 70 to 1300 MWe, with designs of up to 1700 MWe in development. The first prototype VVER-210 was built at the Novovoronezh Nuclear Power Plant.
The BN-600 reactor is a sodium-cooled fast breeder reactor, built at the Beloyarsk Nuclear Power Station, in Zarechny, Sverdlovsk Oblast, Russia. It has a 600 MWe gross capacity and a 560 MWe net capacity, provided to the Middle Urals power grid. It has been in operation since 1980 and represents an improvement to the preceding BN-350 reactor. In 2014, its larger sister reactor, the BN-800 reactor, began operation.
The Beloyarsk Nuclear Power Station was the third of the Soviet Union's nuclear plants. It is situated by Zarechny in Sverdlovsk Oblast, Russia. Zarechny township was created to service the station, which is named after the Beloyarsky District. The closest city is Yekaterinburg.
The BN-350 was a sodium-cooled, fast reactor located at the Mangyshlak Nuclear Power Plant, located in Aktau, Kazakhstan, on the shore of the Caspian Sea.
A liquid metal cooled nuclear reactor, or LMR is a type of nuclear reactor where the primary coolant is a liquid metal. Liquid metal cooled reactors were first adapted for breeder reactor power generation. They have also been used to power nuclear submarines.
The Prototype Fast Breeder Reactor (PFBR) is a 500 MWe sodium-cooled, fast breeder reactor that is being constructed at Kokkilamedu, near Kalpakkam, in Tamil Nadu state, India. The Indira Gandhi Centre for Atomic Research (IGCAR) is responsible for the design of this reactor, the Advanced Fuel Fabrication Facility at the Bhabha Atomic Research Centre in Tarapur is responsible for MOX fuel fabrication and BHEL is providing technology and equipment for construction of the reactor. The facility builds on the decades of experience gained from operating the lower power Fast Breeder Test Reactor (FBTR). At first, the reactor's construction was supposed to be completed in September 2010, but there were several delays. The Prototype Fast Breeder Reactor is scheduled to be put into service in December 2024, which is more than 20 years after construction began and 14 years after the original commissioning date, as of December 2023. The project's cost has doubled from ₹3,500 crore to ₹7,700 crore due to the multiple delays. The construction was completed on 4th March 2024 with commencement of core loading of the reactor hence paving the way for the eventual full utilization of India’s abundant thorium reserves.
The BN-800 reactor is a sodium-cooled fast breeder reactor, built at the Beloyarsk Nuclear Power Station, in Zarechny, Sverdlovsk Oblast, Russia. The reactor is designed to generate 880 MW of electrical power. The plant was considered part of the weapons-grade Plutonium Management and Disposition Agreement signed between the United States and Russia. The reactor is part of the final step for a plutonium-burner core The plant reached its full power production in August 2016. According to Russian business journal Kommersant, the BN-800 project cost 140.6 billion rubles.
Igor Ivanovich Afrikantov was a Soviet designer and manager of building nuclear reactors and components for the Russian nuclear industry, civil fleet, and navy.
The BN-reactor is a type of sodium-cooled fast breeder reactor built in Russia from the company OKBM Afrikantov. Two BN-reactors are to date (2015) the only commercial fast breeder reactors in operation worldwide.
The BREST reactor is a Russian conceptual design for a lead-cooled fast reactor based on a generation IV reactor. Two designs are planned, the BREST-300 and the BREST-1200. The main characteristics of the BREST reactor are passive safety and a closed fuel cycle.
