What if we had commercial fusion power?

[phyzguy]

Guess the square cube law is not a friend of small fusion designs.
Would a stellarator such as the German Wendelstein 7 be less impacted?

I don't see why. It still loses energy out the surface and generates energy in the volume. There is no way around this.

 

[consuli]

Someone told me, that

1. nuclear fusion is overvalued anyway, as it were neutron rich, thus also producing radioactive contamination of the fusion reactor.
2. the really missing thing for a clean nuclear power technology would be some kind of "nuclear radiation to electrical energy converter" (similar to a solar cell).

Is that true?

 

[etudiant]

Fusion reactions that largely produce charged particles do exist, but require much more aggressive temperatures, so they have not been pursued as a priority.
Afaik, there are some ventures that hope to achieve this. They propose inducing fusion via ion beams rather than magnetically confined plasmas.
Whether this can be made to work is unknown. The leading entity pursuing this path is Tri Alpha Energy, web site:
https://tae.com/company/ .

 

[Astronuc]

These guys are most probably working under militarily classified conditions.

No. Companies/corporation like LMCO have proprietary interests that they protect. Westinghouse, GE/GNF and Framatome each have their own proprietary interests, or intellectual property, that they do not share except with the regulators and their customers, usually with some protection such as a non-disclosure agreement.

• nuclear fusion is overvalued anyway, as it were neutron rich, thus also producing radioactive contamination of the fusion reactor.

• the really missing thing for a clean nuclear power technology would be some kind of "nuclear radiation to electrical energy converter" (similar to a solar cell).

At the moment, even the easiest fusion reaction, d+t, is challenging to develop into a viable fusion power system. Some have contemplated d+d, which produces lower energy neutrons part of the time, and p+t part of the time, but one still has to address neutrons. Aneutronic reactions like d+³He, would be ideal; however, the fact that He has Z=2 means higher temperatures for fusion and slightly higher losses (bremsstrahlung and cyclotron) due to more electrons per nuclei. Energy losses increase with Z, since more free electrons are present to maintain charge neutrality. More electrons at a given temperature mean greater pressure. Even so, in a d+³He plasma, one has to deal with d+d reactions, which are more like than d+³He at the same temperature, while ³He+³He would be much less.

There have been and are concepts for so-called direct conversion, in which electrons are captured/collected separately, passed to the load then recombined with positively charged nuclei. That is also a challenge.

 

[gmax137]

Someone told me, that

1. nuclear fusion is overvalued anyway, as it were neutron rich, thus also producing radioactive contamination of the fusion reactor

Activation of the materials in the fusion machine is probably a much smaller problem than the radiation release from a coal burning station (in the stack discharge and in the fly ash). And nobody cares about that.

 

[artis]

because literally nobody knows about that...

 

[russ_watters]

Activation of the materials in the fusion machine is probably a much smaller problem than the radiation release from a coal burning station (in the stack discharge and in the fly ash). And nobody cares about that.

because literally nobody knows about that...

I'm not sure it is that simple. I see a couple of other possible angles:

It is my understanding that at one time people really did believe that "the solution to pollution is dilution". Under that model, pollution of any kind injected into the atmosphere is easier to deal with than a pile of it that you have to find a home for. Obviously, that's the opposite of the current paradigm.

Arguments against coal have gotten stronger lately, so they may not need extra help from public recognition of this issue to shut it down. The problem though is that coal is the hidden other principal in the proxy fight between nuclear and intermittent renewables. E.G., environmentalists think they are arguing against nuclear (fission today, maybe fusion later) and in favor of intermittent renewables when in fact they are often arguing against nuclear and by default in favor of coal.

This was discussed some in @phyzguy's thread on attitudes toward fusion...

 

[gmax137]

because literally nobody knows about that...

just who are you calling "nobody"? Me? OK . How about these guys

https://www.scientificamerican.com/article/coal-ash-is-more-radioactive-than-nuclear-waste/

 

[artis]

My reply was meant as a figure of speech, the majority of the population simply thinks coal is bad because of CO2 and nothing else as well as they think nuclear is dangerous because of "radioactivity". People tend to memorize things by remembering simple phrases attached to complicated issues.

Ask any ordinary person who is not a scientist about coal and radioactivity and I am sure they will not know what you are talking about.Although I must say i find the link to the article from Scientific American that you posted "fake news" because it's title says "
Coal Ash Is More Radioactive Than Nuclear Waste" although anyone with a basic understanding of nuclear physics knows this is not true as nuclear waste aka the waste from a nuclear reactor core aka burnt up fuel has orders of magnitude higher radioactivity and much more different decaying isotopes than a pile of coal ash, which by the way should have no decaying isotopes because coal never undergoes fission unlike uranium in a fuel pellet. Only later in the article it says "In fact, the fly ash emitted by a power plant—a by-product from burning coal for electricity—carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy."

So now we are not talking about radioactive waste aka used nuclear fuel but instead we are talking about the amount of radioactive substance release from a plant during operation which is a totally different category. Also a well maintained nuclear plant is not supposed to have any waste release into the environment and coal plant smoke and ash release doesn't release radioactive waste instead it releases the leftover powder or particles which contain small amounts of natural uranium which has the same emission levels as many rocks also containing natural uranium etc.

And basically the article itself denies its seriousness further down as experts from ORNL and other places say that even though coal has traces of natural uranium and thorium the levels are not normally dangerous etc etc, so we are now back to the primary danger of burning coal which is CO2 emission and secondary which is large piles of ash and trash. I kind of feel the article is not up to the standards of being a serious scientific article.

 

[Klystron]

Oddly enough in an environment associated with past nuclear weapon tests, with major sunlight and few coal resources; air pollution from coal-fired power plants on federal lands remains a health hazard. Several reports mention ozone and fine particulate damage to the lungs of tribal members living nearby. While the situation is improving with solar power stations online, this example from summer 2018 indicates wide spread pollution.

https://www.lasvegasnow.com/news/epa-hears-from-paiute-tribe-over-air-quality/75430322

 

[russ_watters]

Mod Note: Several posts were re-located from the "State of Nuclear Fusion Power" thread.