Thanksgiving is a time for us to reflect on our many blessings, and being a part of the Department of Energy's Pacific Northwest National Laboratory is one for which I am especially grateful.
In fast-neutron reactors, fuel is sealed in ~7 millimeter diameter steel tubes called cladding. When a high-energy "fast" neutron strikes an atom in the steel, it can knock the atom out of place, like a cue ball striking another billiard ball. This leaves two types of damage in the metal: an empty spot where the atom was, and the displaced atom wedged between other atoms. Over time, these defects typically drive undesirable rearrangement of the microstructure, potentially reducing the life of the cladding.