Magnox power stations were powered by fuel rods containing uranium. Inside the reactor, nuclear fission took place causing the uranium fuel to becomes very hot. This heated carbon dioxide gas which, in turn, heated water in the boilers. This hot, high-pressure steam was used to spin large turbines. The turbines turn the generators to make electricity.

Wylfa is located on the north coast of Anglesey between Amlwch and Holyhead. Commissioned in 1971, it was the last and biggest of the Magnox stations to be built. After nearly 45 years of successful and safe operations, on 30 December 2015, Wylfa Nuclear Power Station closed down, marking the conclusion of Magnox reactor generation in the UK. During its generating life, Wylfa produced 232 terawatt-hours of electricity.

The site is now in the defuelling phase, following which work will then be undertaken to take the site into Care and Maintenance.

Wylfa is also responsible for the 30MW Maentwrog hydroelectric station near Blaenau Ffestiniog.