Is there a collective repository on breakthroughs in energy generation by fusion? Sure, this team solves one "big" problem. But hints there are a plethora of other problems (or technology limitations) in this field.
Part of the excitement these days is that the general march of technology has removed a lot of those technology limitations, due to advances in superconductors, lasers, supercomputers, fast high-power electronics, etc. (Superconductors and computers would be the ones relevant to stellarators, of course.)
Even with all of these advancements I don't see how you get around fusion reactors still being more complicated and expensive to build as fission reactors, and just as radioactive due to the huge amounts of neutron radiation the "easiest" kinds of fusion produce.
The difference is that waste from neutron activation is "just" an engineering problem which might have an engineering solution (we hope).
Waste in the form of long-lived nuclear fission products is fundamentally an unsolvable issue. Transmutation has been proposed but isn't really practicable, shooting it into the sun isn't really an option either, so the only choice is to confine it for geological timescales somehow.
Both options are really much better, in my opinion, than pumping more carbon dioxide into our biosphere.
Storing fission waste products is a solved problem. You can either reprocess them as is done in France. Or you can store them forever. Neither approach is difficult or poorly understood. We can store an infinite amount of fission waste products in the ocean, underground or in the mantle.
In theory, sure. In practice, complex technological and political issues remain - apparent by the fact that no country has solved the issue yet.
You apparently stable salt mines start leaking. Locals don't like having toxic stuff buried below them. Other countries dislike that you dump nuclear waste in the middle of the Atlantic. Digging deep becomes too expensive.
Nuclear waste isn't an engineering problem at all, it's a social problem. Objectively, dropping it all into a deep ocean crevice is utterly safe and effective but you'll never get the ignorant public who go off feelings to buy into it.
Fusion is only better insofar as the public don't yet understand how radioactive the reactor will become, but counting on that ignorance is a bad long term strategy.
This is a major fallacy that makes people think DT fusion is more promising than it actually is.
Engineering problems are perfectly capable of killing a technology. After all, fission after 1942 was "just an engineering problem". And DT fusion faces very serious engineering problems.
I include cost issues as engineering problems, as engineering cannot be divorced from economic considerations. Engineering involves cost optimization.
True. Launch loops are "just" an engineering problem which could be built with known materials but in reality the engineering problems are so huge it's hardly any better than space elevators which call for undiscovered materials.
You also have the associated economic problems; the up-front cost of a launch loop would be so huge that you could never convince anybody to build it instead of using rockets. Fusion has the same problem; even if you can design a fusion power plant that produces net power, it needs to produce net power by a massive margin to have any chance of being economically competitive with fission let alone solar.
And fusion reactors cannot end up like a Chernobyl disaster.
That's a huge safety plus and one of the major concerns many countries are phasing out fission reactors.
How expensive a fusion reactor is depends on which designs end up working. Some of them are actually projected to be pretty cheap, and mass-producible. Helion for example is expecting a cost of two cents/kWh, and uses more advanced fuel with much less neutron radiation. Stellarators on the other hand are quite complicated to build, though some recent work has simplified them significantly.
Activated D-T reactor parts only have to be buried for a few decades and then they're fine.
Long-term fission waste is almost entirely transuranics, formed by heavy atoms absorbing neutrons without fissioning. If we were to use fast reactors or thorium molten salt reactors, then that problem would go away, and we'd be left with just fission products, which are only troublesome for a couple centuries.
