The engine house with the steam turbine is usually structurally separated from the main reactor building. The purpose of the steam turbine is to convert the heat contained in steam into mechanical energy. In addition, many reactors are equipped with a dome of concrete to protect the reactor against both internal casualties and external impacts. This containment absorbs radiation and prevents radioactive material from being released into the environment. Since nuclear fission creates radioactivity, the reactor core is surrounded by a protective shield. This also means that U-238 is less radioactive than U-235. U-238 has a longer half-life than U-235, so it takes longer to decay over time. Different isotopes also have different half-lives.
On the other hand, U-238 does not have that property despite it being the same element. For instance, U-235 is fissile which means that it is easily split and gives off a lot of energy making it ideal for nuclear energy. U-238 has 146 neutrons and U-235 has 143 neutrons.ĭifferent isotopes have different behaviors. Naturally occurring uranium is found in two different isotopes: uranium-238 (U-238), accounting for 99.3% and uranium-235 (U-235) accounting for about 0.7%. Uranium is a very heavy metal that is abundant on Earth and is found in sea water as well as most rocks. Nuclear reactors usually rely on uranium to fuel the chain reaction. The heat from nuclear fission is used to raise steam, which runs through turbines, which in turn power the electrical generators. With this heat, a coolant is heated as it is pumped through the reactor and thereby removes the energy from the reactor. In its central part, the reactor's core produces heat due to nuclear fission. The nuclear reactor is the heart of the station. The water-steam cycle corresponds to the Rankine cycle.
WHICH REACTION TAKES PLACE IN A NUCLEAR FISSION REACTOR GENERATOR
The water is then pumped back into the steam generator and the cycle begins again. The condenser is a heat exchanger which is connected to a secondary side such as a river or a cooling tower. After the steam turbine has expanded and partially condensed the steam, the remaining vapor is condensed in a condenser. The pressurized steam is then usually fed to a multi-stage steam turbine. The reactor coolant then goes to a steam generator and heats water to produce steam. The coolant may be water or gas, or even liquid metal, depending on the type of reactor. The fission in a nuclear reactor heats the reactor coolant. The conversion to electrical energy takes place indirectly, as in conventional thermal power stations. Despite some spectacular catastrophes, nuclear power plants are among the safest mode of electricity generation, comparable to solar and wind power plants. Nuclear power plants have a carbon footprint comparable to that of renewable energy such as solar farms and wind farms, and much lower than fossil fuels such as natural gas and brown coal. However, building a nuclear power plant often spans five to ten years, which can accrue to significant financial costs, depending on how the initial investments are financed. Nuclear plants are very often used for base load since their operations, maintenance, and fuel costs are at the lower end of the spectrum of costs.
As of 2022, the International Atomic Energy Agency reported there were 439 nuclear power reactors in operation in 32 countries around the world. 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. Flanked by cooling towers, a PWR nuclear reactor is contained inside a spherical containment buildingĪ nuclear power plant (sometimes abbreviated as NPP) is a thermal power station in which the heat source is a nuclear reactor.
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