[phscguy]

Yeah, any positive news on fusion progress and there always seems to be the same set of comments appear that are overwhelmingly critical of fusion development. Fusion is not well funded and imo has been let down by mismanagement of ITER, and despite this keeps making progress.

I feel that fusion is one of humanity's best shots at actively reversing climate change, and it is disheartening to see such widespread pessimism about it. Yeah it's hard. There are huge hurdles in making it economicly viable, but if we can go from first powered flight to the moon in 70 years, and put billions of transistors on a chip in 50, then maybe we can get fusion going. It's clearly possible.

[crazygringo]

> I feel that fusion is one of humanity's best shots at actively reversing climate change

Couldn't the same thing be said about current fission reactors?

I get that fusion doesn't have the downsides of fission... but I'm also worried that people will be "scared" of fusion in the same way they're against GMO vegetables and irradiated fruits, totally irrationally...

[phscguy]

Sadly no. While I think that it would work and probably be cheaper and easier than fusion, fission has an absolutely abysmal public image.

People are terrified of radiation, even if the danger is very low. This means it becomes prohibitively difficult and hence expensive to build and run a fission plant because safety has to be prioritized so heavily. That is even if permission is granted to build in the first place.

I think it is unlikely for irrational fear of fusion to become mainstream like it has with fission.

Because of this I think the barriers to fusion power are at this point lower than the barriers to scaling up fission power.

[nickik]

Fusion also produces radiation. So not sure why changing one word to the other should magically change public opinion.

We can just rename fission to #goodenergy or something, that would be cheaper then developing fusion.

People don't even know that nuclear reactors use fission, so the idea that this would change anything is crazy. People opposed will call fusion reactors 'nuclear' just like they do fission.

[zaarn]

Fusion Radiation is only immediate, ie, only in the area where the reactor is. And it can be contained with comparatively little effort, even put to use to breed Tritium for more Fusion fuel.

If a Fusion reactor blows up, the radiation risk is basically 0, aside from the lack of potential melt downs.

[phscguy]

The amount of long lived radioactive material produced by fusion reactors is many orders of magnitude less than fission. Iirc it's about the same amount of the radioactivity released as burning coal in a coal plant of the same power output.

[lambdatronics]

Yeah, I don't have much hope that the general public will understand the nuances here, especially if the greenies decide to mount a PR campaign against it. OTOH, we can call it "fusion" instead of "nuclear fusion" and that will undoubtedly help. (lol)

Fusion does indeed come with radiological hazards: a fire could release radioactive gas and dust. If designed right, the worst-case scenario would still be way less severe than for a fission plant -- and the worst-case scenario is really what stokes all the popular fears about 'nuclear'. OTOH, tritium leakage could mean that routine emissions are larger.

[krageon]

> even if the danger is very low

The day-to-day danger perhaps, but it's kind of hilarious in a sad way to read this right after fukushima spent god knows how long leaking radioactive shit into the ocean.

[phscguy]

Yeah. It's these low probability events that scare people away from fission. Fossil fuel pollution kills millions of people per year. Like more than 5 million. How many has nuclear power killed in 60 years? Probably less than 100,000 as a conservative estimate. Events like Chernobyl and Fukushima are sensational and radiation is a sexy topic. People dieing of lung cancer from air carcinogens produced by coal burning is not.

[ncmncm]

There is no need worry about that. Extreme high cost will suffice. It could never come within 10x fission cost. You might notice people are not breaking down doors to build fission plants.

[UnFleshedOne]

There is a species of environmentalism that would consider successful fusion or similar high tech mega scale energy source actually detrimental because you can't build one in your hippy community using old tractor parts and alternative ways of knowing.

Environmentally clean energy source is not enough, it needs to be ideologically pure as well.

[mcswell]

Like Mr Fusion? runs on beer, from what I've seen.

[pfdietz]

This is projection. The irrationality is thinking that fusion is something desirable. I suspect this follows from exposure to fusion reactors as a trope in SF stories. From a hard nosed engineering point of view fusion is just terrible.

[phscguy]

I can understand that from an enginneering perspective ITER is terrible, but fusion in general?

There are all sorts of approaches to fusion, and things such as type 2 superconductors were undiscovered 30 ago and uneconomic/unpractical 10 years ago. Timing control systems for magnetised target fusion were impossible but now are doable. Our understanding of plasma has been advancing a lot, simulations are good now, we can control plasmas much better. Chirped pulsed laser amplification is a thing now and really good at making high amplitude pulsed lasers for inertial approaches...

I could go on and on. This isn't the 90s anymore, and our technology is still rapidly advancing. What happens if we find more efficient/cheap/high power density thermocouples, or find a direct energy electrostatic power capture method?

Fusion's economic realities today may be overcome soon, we really do not know what we can do in even 20 years from now. The fundamental truth is that there is vast amounts of energy available in hydrogen, and all it takes is 100MK to ignite it.

[pfdietz]

DT fusion looks bad even if you totally ignore anything related to plasma physics or magnetic fields. Simply handling the heat flow and neutrons from the reactor looks to make the reactor too big to compete, compared to fission reactors.

And then you have the problem of having to stick sophisticated stuff in the hot zone where hands-on maintenance is impossible (compared to a fission reactor, where just the fuel and relatively simple hardware is in that zone.)

[gfodor]

Fusion doesn’t have the stigma of fission, or a lot of the risks, and so if we can get to a point where we are actually building new fusion reactors, we should assume the technology will improve rapidly.

[pfdietz]

It's a common error to think that fission power plants aren't being built because of "stigma". The actual problem is failed economics. Fusion promises to be even more expensive, for the reasons I explained.

It's not clear why one should expect fusion to have good experience effects. Fission didn't, and the non-nuclear parts of fusion power plants will be mature technologies.

[sprafa]

Please tell me how it’s terrible, Mr Hard Nosed Engineer ?

[pfdietz]

Low power density (at least an order of magnitude worse than fission), high complexity, need to maintain large complex objects for which hands-on maintenance is impossible and for which there are many parts for which no redundancy is possible. Fusion reactors are the opposite of "Keep It Simple, Stupid".

The engineering undesirability of DT fusion has been known for decades. All the recent excitement doesn't address any of the known showstoppers.