Photo by DS stories from Pexels: https://www.pexels.com/photo/a-notepad-with-a-question-mark-drawing-6991443/
These are questions that the Communications Office have received via email from the website audience; hence the rather conversational tone. We attempt to answer each question with the available facts. The top FAQs are the ones that receive most views on our website. If you have a question, write to us!
While it might seem confusing that energy can be generated by both fusion and fission, as they appear to be quite opposite processes, the explanation lies in the size of the nuclei.
The fusion reaction releases neutrons, which would be quite dangerous to humans, however the production of neutrons ceases within milliseconds when the plant is turned off.
The answer is one of the key advantages of fusion as a potential energy source over nuclear fission power stations – its inherent safety.
In order for fusion to occur in the very hot gas – or plasma –created inside JET, the plasma must be heated to temperatures in excess of 150 million degrees Celsius.
Strangely enough, the sun is a very inefficient fusion reactor, producing only 1 watt per cubic metre – luckily it is very big so the total is a lot of power. Here on earth we are aiming for efficiencies a million times better than that!
The First Law of Thermodynamics explains how the amount of energy gained from something cannot exceed the amount put in. So it seems to violate the laws of thermodynamics – but…
In fission, energy is gained by splitting apart heavy atoms into smaller atoms whereas fusion is combining light atoms, which form a heavier one. Both reactions release energy.
Using nuclear fission and fusion for generating electricity requires very different technologies and engineering.