Thank you. Every time I see a fusion article - and it’s always a breathless “just around the corner” puff piece - I scan it to see if they’ve solved neutron embrittlement, or even come close. So far, no one has.
But of course no one has solved the neutron damage issue. How could they? To develop a material, if that's even possible, that could withstand 14 MeV neutrons well enough, one would need a fusion reactor to make those neutrons to test the materials (and tritium breeding to keep it running). This circular dependency would be very difficult to traverse.