Consideration of Accident Events During On-Site Waste Handling

Abstract

The safe on-site transport of spent nuclear fuel must rely on the structural integrity of the transport container and the system of transport. Regard for safe and efficient on-site transport routes are important and manageable using well thought-out planning. Difficulties arise when non-manageable incidences occur such as flying debris from tornado-force winds that may result in high velocity impact on the transport system. Part of the site Nuclear Safety Design Guide considers design basis tornado (Level F0) incidents. A Dry Storage Container (DSC) is used to transport and store spent fuel. A DSC is loaded with spent fuel and typically travels on-site to a processing building for permanent lid attachment. During on-site transport a lid clamp is utilized to ensure the container lid remains in place. This paper consists of simulations that consider several wind borne projectiles impacting the DSC. These types of postulated accident scenarios are analysed using detailed nonlinear finite element techniques. A state-of-the-art, large deformation, non-linear, finite element code is used in the simulations.


Projectile impact poses two concerns. Large object impact (large poles, piping) in the vicinity of the lid/container interface may result in damage to the lid clamp and dislodging of the lid. Small object impact (slender solid rods) may result in through-wall penetration and loss of shielding. Impact simulation results for these two types of objects show that for large projectiles the lid clamp retains the lid/body interface and for small projectiles there is no penetration of the container wall, ensuring safe containment of spent fuel under tornado conditions.