Example for the application of IAES-TECDOC criteria for the brittle fracture safe design of a ductile iron shipping package

Abstract A proposed new IAEA regulation describes a procedure for proving a container to be safe against brittle fracture. A very important aspect is the definition of a reference flaw. In non-destructive testing (in this case 100% volumetric US testing) the probability of non-detection of any flaw must be on the order of 1 in 100. In combination with statistics the reference flaw depth will be about 5 times the minimum detectable flaw size. Additional requirements concern the sizes of rejection flaws and critical flaws. Once the reference flaw has been established, it must be shown that even for its most critical location and orientation, the applied stress intensity is smaller than the fracture toughness divided by a safety factor. The most critical location was found to be a subsurface flaw close to the surface. The relevant loading for the MOSAIK 80T (an 80 ton heavy-section ductile iron shipping vessel) investigated in this paper is the deceleration of 120g resulting from a 9 m side drop into an unyielding target. It was found that this container is indeed safe against brittle fracture.