A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nuclear fission is passed to a working fluid, which in turn runs through steam turbines. These either drive a ship's propellers or turn electrical generators' shafts. Nuclear generated steam in principle can be used for industrial process heat or for district heating. Some reactors are used to produce isotopes for medical and industrial use, or for production of weapons-grade plutonium. As of 2022, the International Atomic Energy Agency reports there are 422 nuclear power reactors and 223 nuclear research reactors in operation around the world.
A nuclear power plant (NPP) is a thermal power station in which the heat source is a nuclear reactor. As is typical of thermal power stations, heat is used to generate steam that drives a steam turbine connected to a generator that produces electricity. As of September 2023, the International Atomic Energy Agency reported there were 410 nuclear power reactors in operation in 31 countries around the world, and 57 nuclear power reactors under construction.
Sellafield, formerly known as Windscale, is a large multi-function nuclear site close to Seascale on the coast of Cumbria, England. As of August 2022, primary activities are nuclear waste processing and storage and nuclear decommissioning. Former activities included nuclear power generation from 1956 to 2003, and nuclear fuel reprocessing from 1952 to 2022.
A propellant is a mass that is expelled or expanded in such a way as to create a thrust or another motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the engine that expels the propellant is called a reaction engine. Although technically a propellant is the reaction mass used to create thrust, the term "propellant" is often used to describe a substance which contains both the reaction mass and the fuel that holds the energy used to accelerate the reaction mass. For example, the term "propellant" is often used in chemical rocket design to describe a combined fuel/propellant, although the propellants should not be confused with the fuel that is used by an engine to produce the energy that expels the propellant. Even though the byproducts of substances used as fuel are also often used as a reaction mass to create the thrust, such as with a chemical rocket engine, propellant and fuel are two distinct concepts.
The hydrogen economy is an umbrella term that draws together the roles hydrogen can play alongside renewable electricity to decarbonize specific economic sectors, sub-sectors and activities which may be technically difficult to decarbonize through other means, or where cheaper and more energy-efficient clean solutions are not available. In this context, hydrogen economy encompasses hydrogen’s production through to end-uses in ways that substantively contribute to avoiding the use of fossil fuels and mitigating greenhouse gas emissions.
Nuclear marine propulsion is propulsion of a ship or submarine with heat provided by a nuclear reactor. The power plant heats water to produce steam for a turbine used to turn the ship's propeller through a gearbox or through an electric generator and motor. Nuclear propulsion is used primarily within naval warships such as nuclear submarines and supercarriers. A small number of experimental civil nuclear ships have been built.
Grid energy storage is a collection of methods used for energy storage on a large scale within an electrical power grid. Electrical energy is stored during times when electricity is plentiful and inexpensive or when demand is low, and later returned to the grid when demand is high, and electricity prices tend to be higher.
Nuclear power in the United Kingdom generated 16.1% of the country's electricity in 2020. As of August 2022, the UK has 9 operational nuclear reactors at five locations, producing 5.9 GWe. It also has nuclear reprocessing plants at Sellafield and the Tails Management Facility (TMF) operated by Urenco in Capenhurst.
Hydrogen production is the family of industrial methods for generating hydrogen gas. There are four main sources for the commercial production of hydrogen: natural gas, oil, coal, and electrolysis of water; which account for 48%, 30%, 18% and 4% of the world's hydrogen production respectively. Fossil fuels are the dominant source of industrial hydrogen. As of 2020, the majority of hydrogen (~95%) is produced by steam reforming of natural gas and other light hydrocarbons, partial oxidation of heavier hydrocarbons, and coal gasification. Other methods of hydrogen production include biomass gasification and methane pyrolysis. Methane pyrolysis and water electrolysis can use any source of electricity including renewable energy.
Scotland has a long history of nuclear research and electricity generation. Nuclear energy consistently accounts for 20-80% of the electric supply in Scotland depending on weather conditions for wind power generation and electricity demand. As of 2022, there is only one remaining operating nuclear power station in Scotland (Torness).
Between 2007 and 2009, 13 companies applied to the Nuclear Regulatory Commission (NRC) for construction and operating licenses to build 31 new nuclear power reactors in the United States. However, the case for widespread nuclear plant construction has been hampered due to inexpensive natural gas, slow electricity demand growth in a weak US economy, lack of financing, and safety concerns following the Fukushima nuclear accident at a plant built in the early 1970s which occurred in 2011.
NuScale Power Corporation is a publicly traded American company that designs and markets small modular reactors (SMRs). It is headquartered in Portland, Oregon. A 50 MWe version of the design was certified by the US Nuclear Regulatory Commission (NRC) in January 2023. NuScale has agreements to build reactors in Idaho in 2029 and 2030.
Small modular reactors (SMRs) are a proposed class of nuclear fission reactors, smaller than conventional nuclear reactors, which can be built in one location, then shipped, commissioned, and operated at a separate site. The term SMR refers to the size, capacity and modular construction only, not to the reactor type and the nuclear process which is applied. Designs range from scaled down versions of existing designs to generation IV designs. Both thermal-neutron reactors and fast-neutron reactors have been proposed, along with molten salt and gas cooled reactor models.
NuGeneration (NuGen) was a company that planned to build a new nuclear power station nearby the Sellafield nuclear site in the United Kingdom. The proposed site was called Moorside, and is to the north and west of Sellafield. On 8 November 2018, Toshiba announced their withdrawal from the project and intent to liquidate NuGen.
Moorside nuclear power station is proposed for a site near Sellafield, in Cumbria, England. The original plan by NuGeneration, a British subsidiary of Toshiba-owned Westinghouse Electric Company, had the station coming online from 2024 with 3.4 GW of new nuclear capacity, from three AP1000 reactors. Work up to 2018 would include acquiring the site licence, the development consent order, and other required permits and permissions to start work. Site preparation was to take two years, up to 2020.
The Integral Molten Salt Reactor (IMSR) is a nuclear power plant design targeted at developing a commercial product for the small modular reactor (SMR) market. It employs molten salt reactor technology which is being developed by the Canadian company Terrestrial Energy. It is based closely on the denatured molten salt reactor (DMSR), a reactor design from Oak Ridge National Laboratory. It also incorporates elements found in the SmAHTR, a later design from the same laboratory. The IMSR belongs to the DMSR class of molten salt reactors (MSR) and hence is a "burner" reactor that employs a liquid fuel rather than a conventional solid fuel; this liquid contains the nuclear fuel and also serves as primary coolant.
The Stable Salt Reactor (SSR) is a nuclear reactor design under development by Moltex Energy Canada Inc. and its subsidiary Moltex Energy USA LLC, based in Canada, the United States, and the United Kingdom, as well as MoltexFLEX Ltd., based in the United Kingdom.
The Rolls-Royce SMR, also known as the UK SMR, is a small modular reactor (SMR) being developed by the Rolls-Royce (RR) company in the United Kingdom.
A nuclear microreactor is a plug-and-play type of nuclear reactor which can be easily assembled and transported by road, rail or air. Microreactors are 100 to 1,000 times smaller than conventional nuclear reactors, and when compared with small modular reactors (SMRs), their capacity is between 1 and 20 megawatts whereas SMRs comes in the range from 20 to 300 megawatts. Due to their size, they can be deployed to locations such as isolated military bases or communities affected by natural disasters. It can operate as part of the grid, independent of the grid, or as part of a small grid for electricity generation and heat treatment. They are designed to provide resilient, non-carbon emitting, and independent power in challenging environments. The nuclear fuel source for the majority of the designs is "High-Assay Low-Enriched Uranium", or HALEU.
