Nuclear fission happens here. There are thousands of uranium fuel pellets in metal zirconium tubes called fuel rods. Around 250 fuel rods are bunched into fuel assemblies and approx. 250 of these make up the reactor core.
The reactor is closed down for refueling every 18-24 months; fuel assemblies are replaced or moved around (to ensure even ‘burn up’). Each one lasts 5-6 years.
Uranium is a radioactive metal found in rocks and seawater. It is mined and then artificially enriched to increase its proportion of uranium-235.
Fuel efficiency
To run this power station for an hour, just 3.5kg of uranium fuel pellets is needed – about the weight of a watermelon or an Xbox. Making the same amount of power using fossil fuel, on the other hand, would use up around 640,000kg of coal – 6 or 7 train wagons full!
