This is part of why I'm moderately excited about aneutronic fusion: the radiation damage you mention will be greatly lessened by reactions that release dramatically fewer neutrons.<p>As for the commercial cost of fusion, the reason you've never seen such a study is because nobody even knows yet how to get fusion to produce commercially usable amounts of power, and there are so many possible methods being looked at, with such different costs involved, that we can't really do a meaningful study of fusion economics yet.