((a)) The Commission shall establish a system to ensure that materials described in subsection (b), when transferred or received in the United States by any party pursuant to an import or export license issued pursuant to this chapter, are accompanied by a manifest describing the type and amount of materials being transferred or received. Each individual receiving or accompanying the transfer of such materials shall be subject to a security background check conducted by appropriate Federal entities.

((b)) Except as otherwise provided by the Commission by regulation, the materials referred to in subsection (a) are byproduct materials, source materials, special nuclear materials, high-level radioactive waste, spent nuclear fuel, transuranic waste, and low-level radioactive waste (as defined in ).