but does not include merchant vessels or (as defined by the Atomic Energy Act of 1954 [
42 U.S.C.
2011 et seq.]) 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), byproduct material, special nuclear material, production facilities, utilization facilities, or atomic weapons or articles involving Restricted Data;