It sure looks like they've just banned all weapons that use fission or fusion without defining every particular method though.
(c)The term “atomic energy” means all forms of energy released in the course of nuclear fission or nuclear transformation.
(d)The term “atomic weapon” means any device utilizing atomic energy, exclusive of the means for transporting or propelling the device (where such means is a separable and divisible part of the device), the principal purpose of which is for use as, or for development of, a weapon, a weapon prototype, or a weapon test device.