shall not include merchant vessels or, as defined by the Atomic Energy Act of 1954, as amended (
42 U.S.C.
2011), source material (except uranium depleted in the isotope 235 which is incorporated in defense articles solely to take advantage of high density or pyrophoric characteristics unrelated to radioactivity), by-product material, special nuclear material, production facilities, utilization facilities, or atomic weapons or articles involving Restricted Data.