Just before the end of 2015, on December 30, the last operating Magnox reactor anywhere in the world was shut down for the final time, which ended a history for this type dating all the way back to 1956.
In 1956, the first reactor of the Magnox type — one of an eventual eight at Calder Hall — was dedicated by Queen Elizabeth II and placed in service. “Magnox” stands for Magnesium Non-Oxidizing, a term that describes the magnesium alloy cladding used on the carbon dioxide cooled, graphite moderated reactors of this type. Eventually very much larger units were built, optimized for commercial power service (instead of dual power production and plutonium production as initially envisaged) and the type went on to have a long and successful history in the UK.
The Wylfa power station, combining two Magnox reactors and four turbine generators, was the last to operate — and nearly didn’t operate this long. The plant was originally scheduled to shut down permanently in 2010, but an incredible effort was made to transfer partly spent fuel from one reactor to the other, enabling the single remaining reactor to operate until the end of 2015.
Magnox Ltd. has provided a short video showing the historic final shutdown of the last unit, which fittingly is this week’s ANS Friday Matinee feature.