nojayuk writes: The world's last operating Magnox nuclear reactor, Wylfa 1 in Anglesey, Wales was closed yesterday after providing carbon-free power for over 40 years. Wylfa1 was originally scheduled to shut in 2012 along with the adjacent Wylfa 2 reactor but it was kept operating for another three years with the innovative use of partially-burnt fuel from Wylfa 2 and remaining stocks of fresh Magnox fuel. The reactor will be defuelled and move into its decommissioning phase over the next year. The Magnox design used gas-cooling and a carbon moderator with the capability to produce weapons-grade plutonium depending on how it was fuelled and operated. Its design fed into the next-generation AGRs which provide about 6GW of Britain's electricity supply today.