Development of ‘MST-30’ Packaging for Enriched Uranium Hexafluoride

Abstract

Revised IAEA Regulations for the Safe Transport of Radioactive Materials (ST-1) sets forth incremental requirements for the transport of uranium hexaflouride (UF₆). Of extreme importance is the new requirement (para. 677 (b)) that mandates the leak-tightness of the cylinder valve under accident conditions of transport. This new requirement is added from the point of view of the criticality safety of UF₆. A new package, known as ‘MST-30’, of Type A Fissile Material for enriched UF₆, has been developed by Mitsubishi Materials Corporation (MMTL) to satisfy both new regulatory requirements and the present transport system. MST-30 reinforces the valve protection function and utilises high-density polyurethane foam as a shock absorbing media, instead of natural wood components. This paper: (i) reviews the historical background that motivated the development, (ii) presents the design concept and features of the MST-30 package, and (iii) reports on the compliance test results that demonstrated the MST-30's superior ability to withstand accident conditions of transport.