Prof. Whyte thinks that they have that by making really interesting stainless steel coiled tape stuff. I really lost the plot at this point in the presentation and did not understand how it would work, but then he passed round some samples (which could have been anything at all to be fair) so I became convinced that the stainless steal coiled tape approach to fabrication is real and practical.

I think his idea is to make the magnets now, quickly, and use them for things like magnetic resonance scanners. I think that will prove the technology which he then intends to scale to a reactor; and several Ph.D folks are busily designing said reactors.

And even if the strong steel beams hold them initially, the bombardment with the neutrons will weaken them. And then... boom.