Sizewell: 72% say no to nuclear power
Plutonium is formed in a nuclear reactor during operations. It was first created in 1942 as part of the Manhattan project.
In the reactor, fission converts enriched Uranium 235 into Uranium 238 and other radioactive isotopes including Plutonium 239.
Spent nuclear fuel is then reprocessed and plutonium is extracted - at Sellafield�s THORP reprocessing plant.
This reprocessed plutonium is mixed with freshly enriched uranium to create MOX - at the Sellafield MOX plant. 7% PuO2 (of which the PU239 content is 60%) is mixed with 93% UO2 (of which U235 is about 4.5%) in powder form.
They are then turned into ceramic pellets measuring 2cm by 1cm.
Around 300 pellets are loaded into 3m hollow metal pins.
There are 289 pins per each MOX fuel assembly.
