How a nuclear reactor makes electricity A nuclear reactor
produces and controls the release of energy from splitting the
atoms of uranium. Uranium-fuelled nuclear power is a clean and
efficient way of boiling water to make steam which drives
turbine generators. Except for the reactor itself, a nuclear
power station works like most coal or gas-fired power stations.
The Reactor Core Several hundred fuel assemblies containing
thousands of small pellets of ceramic uranium oxide fuel make up
the core of a reactor. For a reactor with an output of 1000
megawatts (MWe), the core would contain about 75 tonnes of
enriched In the reactor core the U-235 isotope fissions or
splits, producing a lot of heat in a continuous process called a
chain reaction. The process depends on the presence of a
moderator such as water or graphite, and is fully controlled.
The moderator slows down the neutrons produced by fission of the
uranium nuclei so that they go on to produce more fissions. Some
of the U-238 in the reactor core is turn