" (Neutron embrittlement of the reactor vessel is one obvious problem.)"
That's the first thing I thought of too. :)
There's probably also contamination by neutron excitation of things just lying around, paperweights, beltbuckles, door locks, radiators, etc.
Nevertheless, it looks promising in about 50 years (same statement last year, next year....)
"Neutron embrittlement of the reactor vessel is one obvious problem."
Well *sigh* "...If the Roswell Aliens, can fly in a "vessel" across the galaxy...can't we" PING!