Upon a finding that an export of uranium depleted in the isotope 235 is incorporated in defense articles or commodities solely to take advantage of high density or pyrophoric characteristics unrelated to its radioactivity, such exports shall be exempt from the provisions of the Atomic Energy Act of 1954 [42 U.S.C. 2011 et seq.] and of the Nuclear Non-Proliferation Act of 1978 [22 U.S.C. 3201 et seq.] when such exports are subject to the controls established under the Arms Export Control Act [22 U.S.C. 2751 et seq.] or the Export Administration Act of 1979.