Magnox

Magnox is a type of nuclear power/production reactor that was designed to run on natural uranium with graphite as the moderator and carbon dioxide gas as the heat exchange coolant. The title, magnox, comes from the magnesium-aluminium alloy used to clad the fuel rods inside the reactor. In total it was constructed in the tens and sited primarily in Britain during the 1950-70s, with very few exported to other countries. The initial codename for the reactor design amongst the government agency which mandated it, the United Kingdom Atomic Energy Authority, was the Pressurised Pile Producing Power and Plutonium(PIPPA) and as this codename suggests, the reactor was designed as both a power plant and, when operated with low fuel "burnup"; as a producer of plutonium-239 for the nascent nuclear weapons program in Britain. This intentional dual-use approach to building electric power-reactors in the early Cold War era was also typical in other nations, now classified, "Generation I nuclear reactors".

In the specific case of the magnox design, the weapons-usable "burn-up" limitations, or plutonium-239 contamination limitations, were informed by the prior 1953 Operation Totem test series of nuclear detonations. The Low-to-interim burnup feature of the reactor design would also go on and become responsible for changes to US regulatory classifications after the, US-UK "Reactor-grade" plutonium detonation test of the 1960s.

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