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Robot begins removing Fukushima nuclear plant’s melted fuel.
(www.voanews.com)
This is a most excellent place for technology news and articles.
Depends heavily on the kind (and intensity) of radiation. Beta (electron/positron) and gamma (photon) generally won't, but neutron and alpha can. Many of the atoms that become radioactive will rapidly decay, and that's one of the mechanisms behind the impact to structural integrity.