All systems go for UK’s £55M fusion energy experiment

Achieving fusion would be a god-send, but aneutronic fusion - which is generally considered 'the next step' - would be utterly spectacular.

First, it would save you having to build very expense and complex steam turbines. Like Chernobyl had 4 nuclear reactors powering 1 steam turbine, because the engineering required to build a high quality high capacity one is super expensive. With aneutronic fusion you could just use the energy from the generated charged particles and directly turn that into juice.

The huge, huge, huge thing though would be no more neutron radiation. It would vastly simplify reactor construction, reactor cleanup, biological shielding, etc. etc.

Aneutronic fusion would also us to just spam power plants, safely and cheaply, in a way that's difficult for modern society to even understand. Assuming the aneutronic reactor itself isn't mega expense of course.

Why do you need to put those neutrons in a fission reactor?

Neutrons would still be absorbed and produce heat.

Is it because those neutrons damage the reactor structure?

Why would it not be economic?

After the first reactor, do we expect building a replica, without all the R&D costs would be significantly more expensive than a standard nuclear reactor?

To me, 10x the energy sounds really good.

It's not 10-11MW heat out for 1MW electricity in. It's "500 MW plasma from 50 MW of injected thermal power" which would need 300 MW electrical input. After conversion back to electricity, it might give as much electricity out as is put in!

See these links for more: Question asked in the EU parliament: https://www.europarl.europa.eu/doceo/document/E-8-2018-00081...

https://news.newenergytimes.net/2020/11/03/open-letter-to-it...

I thought the UK has left, giving notice for Euratom explicitly at the same time as for the EU because the UK government wasn’t sure leaving Euratom would be automatic? And that Switzerland was a participating associated state?

The UK left Euratom on 31st January 2020.

But ITER is not EU only, having the US and other countries, so they might still participate

(Regardless of the merits of ITER of course)

If the UK wanted to I'm sure that they could stay in ITER considering that "third countries" (ie. non EU) like China are major participants.

Only half way through the article, but the issue does not appear to be that ITER project in praticular has a glaring flaw.

Rather, the scientist appears to be sceptical of fusion as a near term practical energy source on the whole.

I feel that humanity will never amount to anything without fusion.

Energy requirements of space travel assure of that.

You might be right on this one. I'm a bit curious if any other HN-reader is aware of the private fusion project (aka the SAFIRE project) which is now run by the company Aureon Energy (https://aureon.ca/). I do highly recommend watching the video (also available on the legacy page https://safireproject.com/) for the video recording of the experiments. It's not yet quite mainstream physics but we have to remember that once upon the time the mainstream physics people didn't think that heavier-than-air flying machines are possible while nowadays they have wasted countless billions on their fusion experiments and achieved close to nothing.

I am used to hearing this from software engineers who are secure in the knowledge that when they want to try out a concept, hardware time to do so will be cheap and readily available. At some point, you are going to have to take all of your shiny materials science and turbulence simulations, and actually build a piece of apparatus to test it out on the scale that your chosen application (in this case, power generation) will require. The universe is under no obligation to make sure that it will cost less than billions to do so; hence ITER.

Having said that, there's been a lot of extremely promising recent progress in high field superconductors and fusion designs based on them (MIT ARC, Tokamak Energy, etc) that could shrink the necessary scale for a working reactor, so perhaps it will turn out we're lucky with the physics on this one after all.

Kind of ironic to post this on the web, given it's history.

Note that ITER's output is heat, rather than electricity. Maybe the heat will be useful, but it's an important distinction.

ITER's volumetric thermal power density (volume of reactor + plasma) will be 50 kW/m^3, some 400x worse than the volumetric power density of a commercial PWR (reactor vessel + core).

ITER also use a CuZr alloy backing up its first wall materials. This material is unsuitable for long neutron exposure. DEMO would have to use RAFM steel instead there, with an order of magnitude lower thermal conductivity. As a result, the power/area at the surface of the first wall in DEMO may be even lower than in ITER.

your link has 404 status

The power density of the ARC proposal (volume of the magnets and everything inboard of that) is some 40x worse than the volumetric power density of a commercial PWR (volume of the primary reactor vessel + core). This is much better than ITER, but still much worse than existing fission reactors.

I'd characterize as "low effort" the shallow dismissal of very real issues facing fusion.

Better superconductors allow reactors to be made smaller, up to a point. But they still would have lousy power density. ARC's power density (total reactor volume, not just plasma volume) is 40x worse than a commercial PWR.

Fusion reactor power is ultimately limited by the need to radiate energy through the wall of the reactor, and the limit from that would apply even if plasma confinement were a nonissue.

Imagine you have installed one of these things in your garage, or maybe better 10 or 20 ft below, to keep from sterilizing your offspring. You got it for a fire-sale bargain at only $50M, even including the turbine and cooling tower. It produces, what, 100kW? (Plus 100kW of waste heat you might be able find a use for.) Or is that too optimistic?

How many MW of solar panels can you buy for that $50M? Let's even figure in plenty of battery backup. (Hint: lots.) How many MW of wind turbines? (Hint: lots.)

Where would such a garage-sized fusion reactor be useful? And how long before it is a radioactive slag heap? (It was good planning to bury it up-front.) How many GW-years does the fleet need to produce before it pays off the tens of $billions already sunk, to date?

The only guaranteed product of all nuclear power schemes is monstrous exaggeration of cost effectiveness.

"Outputs net energy" is very, very far short of useful.