UK scientists celebrate ‘major breakthrough’ in nuclear fusion

Researchers make landmark advance in the quest to unlock virtually limitless clean energy from the same reaction that powers the stars

On a former military airfield a few miles south of Oxford, a group of scientists are trying to bottle the sun. Not literally, of course — but their ambitions come close.

Inside a four metre-tall, apple-shaped machine known as the Mega Amp Spherical Tokamak Upgrade (MAST-U), they are attempting to recreate, control and ultimately commercialise the fusion reactions that power the stars. In the past few weeks, they have made landmark progress.

Fusion is physics’ grand prize, promising a virtually limitless, carbon-free source of energy. The idea is beguilingly simple: hydrogen atoms are squeezed together so that they merge, or fuse, to become helium. A tiny portion of mass is lost along the way and converted into a great deal of energy.

The process is fundamentally different to the fission reactions that split atoms apart to power conventional nuclear plants. Instead of leaving behind long-lived radioactive waste, fusion’s byproducts are short-lived and far easier to manage.

The challenge lies in persuading fusion to happen. The fuel — atoms of hydrogen — must be heated to tens of millions of degrees, until it becomes plasma, a churning, charged state of matter so hot that no solid wall can contain it. The only way to confine such a temperamental substance is with magnetism.

The MAST-U team is now announcing what the UK Atomic Energy Authority (UKAEA), which runs the experiment, has called a “major breakthrough”. For the first time in a spherical tokamak — a more compact type of fusion machine than the larger, doughnut-shaped devices other researchers have focused on — they have used small magnetic coils to stabilise the plasma’s outer edge. Until now, that edge has been where...

The very nature of science is to generally fail, a lot. Then keep probing, where many advancements come from surprise outcomes that can’t initially be explained.

The “scientific community” has political pressures just like everything else. The term “peer reviewed” isn’t the “proof of being true” that people think it is.

Half of all “peer reviewed” work ends up being false.

I used to read Scientific American, the last page would have “predictions from the past”, where you’d get a good laugh about what people thought would be the future.

I love science but it tends to make people very gullible when they hear “proven science”.

> I love science but it tends to make people very gullible when they hear “proven science”. <

Yep. Old saying:

“If it’s settled, it’s not science. And if it’s science, it’s not settled.”

That’s one thing that infuriates me about the Climate Change discussion. We’re told that it’s “settled science”. And so it’s a moral crime to challenge Al Gore, etc. It would be a moral crime to NOT challenge them!

A good theory should welcome (and survive) such challenges.

We saw the exact same thing during Covid.

“We don’t have enough CO2 in the atmosphere. Plants need it to grow, even to stay alive - and that’s where our food comes from. Burn fossil fuels in massive quantities and stop trying to reduce carbon output.”

Put the pipe down. At least have a valid scientific point. All of the grasses evolved for 150-180 ppm CO2 levels it’s why they evolved in the first place the C4 vs C3 plants and the much more efficient CAM plants too. Nearly all of the staple foods are grasses, corn,rice,wheat,rye,barley,sorghum all evolved in 150ppm and all thrive in 200+ we are at 440. The CAM plants agave specifically was a staple for thousands of years in meso America it also is optimized for 100-200 ppm CO2 levels both the CAM and C4 plants can still do photosynthesis down to single digit CO2 ppm levels.

So at least be factual. Is more carbon bad the jury is out on that is less bad nope plants are fine down to the 100s ppm it would take over a thousand years from today if humans suddenly died off for the ppm levels to go back to post glacier maximum levels. Do some plants produce more yield of biomass at higher CO2 levels sure some do not all. Cannabis does, already super efficient C4 corn does not, C3 wheat does increase but only under water stress, same for soybeans. The CAM plants don’t care what the CO2 level is they respirate separately from solar photosynthesis input.

“From where will they source a steady stream of hydrogen?”

Bro....

[The world’s oceans contain approximately (4.6 times 10^13) (46 trillion) metric tons of deuterium. This vast amount of deuterium, also known as “heavy hydrogen,” makes up about 0.0156% of all hydrogen atoms in the ocean, meaning roughly one out of every 6,420 hydrogen atoms is deuterium. ]

You don’t need to make fusion a net energy gain you want the high energy neutrons to cause U238 to fission and to breed Pu239. The U238 fission multiplies the fusion energy input by 50-200x so you have not only net output but huge amounts of nuclear heat to run turbines with and desal water new district heating/cooling. The slower captured neutrons in U238 breed thousands of Kg per year of Pu239 the perfect fission fuel much better than U235 or U233. Fast breeder reactors can for every Kg of Pu239 put in also breed 1.3-1.4 Kg out a gain of 30-40% or you could burn Pu239 in CANDU the most efficient thermal spectrum reactors. For one gigawatt year electric you need 3 gigawatt years thermal as CANDU is 33% thermal to electrons. This means you need 87.6kg of Pu239 to be burnt. CANDU have a conversion ratio themselves of 0.80 compared to a fast breeder of 1.3+ this means for every Kg of Pu out on 8/10s of a Kg is in the spent fuel on the way out. Overall 50% of the energy coming out of a CANDU is from insitu breed Pu. If you fuel a CANDU with pure MOX using breed Pu239 + depleted U which is 99.98% U238 you need half of the 87.6Kg so 43.8Kg Pu per gigawatt year. A decent sized fusion fission hybrid would make 1500kg of Pu per year...it’s a fuel factory that happens to make some net electricity too. One hybrid makes fuel for 38 CANDU of 900 megawatts electric for an entire 24/7/365 100% capacity run. Like I said it’s a fuel factory that even if it didn’t make a single kWh of power to sell the Pu breed is worth $168,000 per GRAM in power sales at a retail power price of 12 cents per kWh. At the wholesale rates typical of say ERCOT it’s 5 cents per kWh is still $70,000 per gram of Pu that’s how power dense Pu is it’s the best fission fuel.

There is 40 trillion tonnes of uranium in the top 5-20km
of the earth’s crust. Billions of years worth. The ocean’s contain 4.5billion tonnes alone and more washes in every year from crustal erosion. Every tonne of U238 can be turned into 30-40% Pu in a fast reactor and nearly 100% U238 to Pu conversion in a fusion neutron driven breeder. Billions and billions of years at 5000+ exajoule usage rates why that huge number that’s what ten billion humans would us if they all lived at EU levels of energy consumption double that number to get to USA levels.

There are only four sources of energy that can meet that size. Solar, engineered geothermal in the first 5km gradient, and fast spectrum or fusion driven nuclear. Or D-D, D-T, D-He3 pure fusion. T & He3 has to breed on earth by neutrons for Li6 to T or via D-D fusion which exhausts 50% T and 50% He as fusion “ash” either way you must breed T or He3. Or go to Saturn,Uranus or Neptune and mine the helium from the upper atmosphere...you need fusion rockets to even dream of that sorry Elon starship doesn’t have the delta V for a deep space run like those.

https://www.sciencedirect.com/science/article/abs/pii/S0920379619307884

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