Nuclear fusion is coming — and we should be jumping with glee
Let’s get sustainable
Small step or big leap?
The recent results mark a real stepping stone in the quest for fusion power. The 59 million Joules of energy in total, produced over a five-second period, gave an average fusion power of around 11 million Watts. While this is only enough to heat about 60 kettles, it is nevertheless impressive – creating an energy output 2.5 times theprevious record, set back in 1997 (also at the JET facility, achieving 22 million Joules).
The success at JET is the culmination in years of planning and a highly experienced team of dedicated scientists and engineers. JET is currently the largest tokamak in the world, and the only device that is able to make use of both deuterium and tritium fuel (both isotopes of hydrogen).
The design of the machine, using copper magnets which heat up rapidly, means that it can only operate with plasma bursts of up to a few seconds. To make the step to longer sustained high-power operations, superconducting magnets will be needed.
Luckily, this is the case at theITER facility, currently being built in the south of France as part of an international effort involving 35 nations, which is now 80% complete. The recent results have therefore given great confidence in the engineering design and physics performance for the ITER machine design, also a magnetic confinement device, which is designed to produce 500 million Watts of fusion power.
Other important challenges remain, however. These include developing appropriately durable materials that are able to withstand the intense pressure within the machine, handling the huge power exhaust and, most importantly, generating energy that is economically competitive with other forms of energy production.
Achieving notable power outputs and sustaining them for more than very short periods of time has proved to be the major challenge in fusion for decades. Without this ultimately being solved, an eventual fusion powerplant simply cannot be made to function. This is why the JET results represent a significant landmark, albeit just marking a step along the way.
The giant leap will come with scaling up of the current fusion achievements in subsequent fusion systems, such as ITER, and then in demonstration power plants beyond this. And this should be within reach in the not too distant future, aiming for operation by the 2050s or possibly slightly earlier.
Crucial benefits
There’s a lot at stake. Fusion produces more energy per gram of fuel than any other process that could be achieved on Earth. Some of the main benefits of fusion are that the products of the process are helium and neutrons (particles which make up the atomic nucleus, alongside protons) – no carbon dioxide or other greenhouse gases are released. The raw fuels aredeuterium, which can be found in seawater, and lithium – which is also abundant and found in vast salt flats. The potential fusion energy released from thelithiumcontained in one laptop battery and a bathtub of water is estimated to be equivalent to around 40 tonnes of coal.
Fusion does produce some radioactivity in the materials comprising the reactor. But this isn’t expected to be anywhere near as long-lived or intense as theradioactive waste produced by nuclear fission – making it potentially a safer and more palatable choice than conventional nuclear power.
Ultimately, Rome wasn’t built in a day. Various other aspects of human ingenuity, such as aviation, have historically taken significant amounts of time to progress to fruition. That means steps along the way which make progress are hugely important and should rightly be celebrated.
Fusion is creeping inexorably forward and we are getting closer and closer to achieving that once distant dream of commercial fusion power. One day, it will provide a near limitless supply of low-carbon power for many future generations to come. So while it is not quite there yet, it is coming.
Article byPaul Norman, Senior Lecturer in Nuclear Physics,University of BirminghamandLee Packer, Applied Radiation Physics Section Leader,Culham Centre for Fusion Energy
This article is republished fromThe Conversationunder a Creative Commons license. Read theoriginal article.
Story byThe Conversation
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