Glossary
Megawatt (MW)
A unit of power, = 106 watts. MWe refers to electric output from a generator, MWt to thermal output from a reactor or heat source (eg the gross heat output of a reactor itself, typically around three times the MWe figure).
Metal fuels
Fuels using natural uranium metal, as used in a gas-cooled reactor.
Micro
one millionth of a unit (eg microsievert is 10-6 Sv).
Mixed oxide fuel (MOX)
Reactor fuel which consists of both uranium and plutonium oxides, usually about 5% Pu, which is the main fissile component.
Moderator
A material such as light or heavy water or graphite used in a reactor to slow down fast neutrons by collision with lighter nuclei so as to expedite further fission.