Meredith asked: "In metals at high temp, you can expect the dpa-induced structural problems to anneal out, at least to some extent. Will they anneal out in the non-oxide ceramics?"
Ceramics aren't my field of expertise, but I believe the answer is "yes." SiC, graphite, and related materials are being examined for high-DPA applications.
Anonymous asked: "Isn't one of the advantages of the MSR designs the fact that they are not 'fast' reactors but thermal ones, which hence implies that the neutrons are themselves slower when they hit the containment material than their fast reactor cousins?"
Different reactor designs will suffer more or less neutron damage due to their neutron energy, but even a "thermal" reactor has a fair number of fast neutrons flying about.