| Abstract: | Recently, the dry-storage technique for storing spent fuels or radioactive wastes in shipping containers has been improved as one of the new technologies in the nuclear-fuel cycle. Mitsui Engineering and Shipbuilding has engaged for 5 years in the development of a radioactive waste container made of modular cast iron. This paper describes the physical properties of nodular cast iron and a fracture mechanical study of the container made of this material.The material is equivalent to FCD 37 in the JIS Standard. Many tests were carried out to obtain the mechanical properties, the fracture toughness and other characteristics using specimens machined from a thick-walled casting block.Then, the structural integrity of the cubic-type container made of this material was estimated on the basis of fracture mechanics. The critical flaw sizes regarding stresses occurred during a 9-meter drop test and a 1-meter punch-drop test were calculated. The results indicate that these sizes can be determined by a nondestructive inspection.Consequently, it has been analytically confirmed that nodular cast iron containers are strong enough to withstand an impact load during drop tests if the applied stresses are less than the yield stress. |
