Effect of graphite nodule size on fracture toughness of ductile cast iron for spent-fuel shipping container

The spent-fuel shipping containers (CASK) have heretofore been primarily made of austenitic stainless steel. Recently, ductile cast iron has drawn an attention as an alternative candidate for CASK material because of its simple fabrication process and low cost. However, since ductile cast iron has less toughness than austenitic stainless steel, the ability of ductile cast iron to resist crack growth has to be properly examined.