What is "magnox"

n. an alloy of magnesium and aluminium used, with a non-oxidizing cover, as cladding for fuel rods in Magnox nuclear power stations

Magnox is a now-obsolete type of nuclear power reactor, which was designed in the United Kingdom and was exported to other countries, both as a power plant and, when operated accordingly, as a producer of plutonium for nuclear weapons. The name magnox comes from the magnesium- aluminium alloy used to clad the fuel rods inside the reactor.

Magnox can refer to:

• Magnox nuclear reactors.
• Magnox (alloy), an aluminium-magnesium alloy used for fuel cladding in Magnox type reactors.
• Magnox Ltd, a company that operates Magnox nuclear power stations in the United Kingdom.
• Magnox was the working title of an early draft of the film Edge of Darkness.

Magnox is an alloy—mainly of magnesium with small amounts of aluminium and other metals—used in cladding unenriched uranium metal fuel with a non-oxidising covering to contain fission products in nuclear reactors. Magnox is short for Magnesium non-oxidising. This material has the advantage of a low neutron capture cross section, but has two major disadvantages:

• It limits the maximum temperature (to about 360 Celsius), and hence the thermal efficiency, of the plant.
• It reacts with water, preventing long-term storage of spent fuel under water in spent fuel pools.

The magnox alloy Al80 has a composition of 0.8% aluminium and 0.004% beryllium.