Any fusion reactor that produces masses of free neutrons is uneconomic, because the neutrons are ridiculously corrosive to everything they collide with. Neutron activation produces a mess of radioactive isotopes, some of which fission quickly. It doesn't take long - certainly much less than a year - before you're left with components that no longer do their jobs and are also radioactive.
This is a much less sexy problem than containment, but it's a showstopper for commercialisation. You can just about imagine an epically huge reactor with unfeasibly powerful containment fields that trap fusion in the centre of a large cloud of hydrogen, which captures neutrons to make tritium to power the reaction. But that's completely unbuildable with current tech.
Aneutronic fusion is possible, but it happens at even more extreme temperatures, which are barely theoretical at the moment.
At this point we've been chasing fusion for more than 70 years, and commercialisation is as far away as ever.
You might as well just build yourself a small star.
Or perhaps even spend all that research money on making better use of the star we already have.
General Fusion claim to get around these issues by having the fusion take place inside a centrifuge of liquid lithium. I'm not knowledgable enough to determine how plausible their claims are, though.
This is a much less sexy problem than containment, but it's a showstopper for commercialisation. You can just about imagine an epically huge reactor with unfeasibly powerful containment fields that trap fusion in the centre of a large cloud of hydrogen, which captures neutrons to make tritium to power the reaction. But that's completely unbuildable with current tech.
Aneutronic fusion is possible, but it happens at even more extreme temperatures, which are barely theoretical at the moment.
At this point we've been chasing fusion for more than 70 years, and commercialisation is as far away as ever.
You might as well just build yourself a small star.
Or perhaps even spend all that research money on making better use of the star we already have.