Abstract: A tiedown system for releasably securing a cask of the type used to transport radioactive waste to a cradle assembly that is mounted onto the deck of a trailer is disclosed herein. The tiedown system includes a trunnion securing assembly for each of the opposing trunnions of the cask, as well as a compliant linkage connected between the trunnion securing assemblies and the cradle assembly for biasing the cask trunnions toward the cradle assembly with a tiedown force that remains substantially constant despite angular displacements of the trunnions which may occur when the trailer traverses rough or uneven roads. The compliant linkage includes a pair of inverted L-shaped levers for each of the opposing trunnion securing assemblies, as well as a tie-bar which is both axially and rotatably movable within a lower portion of the cradle assembly.

Abstract: An improved, lightweight cask assembly is disclosed herein. The cask assembly generally comprises at least two, cylindrically shaped and concentrically disposed structural walls formed from a titanium alloy and a shielding wall disposed within and supported by the titanium structural walls. Both the inner and outer walls are formed from a high-strength titanium alloy. The use of such an alloy advantageously allows the thickness of the inner wall to be minimized, thereby optimizing the shielding geometry of the shielding wall and minimizing the weight of the amount of shielding material used in the cask. The use of such an alloy in the outer structural wall also minimizes the weight of the outer wall thereby contributing to the weight reduction of the cask assembly as a whole. The upper and lower edges of the inner and outer structural walls are bound together by a reinforcing ring and an end plate assembly likewise formed from a titanium alloy.