Extended Brittle Fracture Safety Demonstrations of Cubic Ductile Cast Iron Containers

In Germany cubic monolithic ductile cast iron CDCn casks are provided for transport. interim storage, and final disposal of non-heat-generating radioactive waste. The approval of such multipurpose casks has to consider the requirements from three different fields of operation. These are the IAEA IP-2, -3, Type A orB package requirements for transportation, as well as the requirements from the specific conditions of the interim storage facility and from the repository. The mechanical design requirements for Type B transport packages are defmed in the IAEA Safety Series No. 6 for normal conditions (such as mass dependent drop test, stacking test with five times the mass of the actual package, penetration test) and for accident conditions (9 m drop test onto an unyielding target, 1 m drop onto a solid mild steel bar). In consequence of these tests, different limitations of activity release and dose rates must not be exceeded. The requirements for German storage facilities are very similar, with few different requirements for normal conditions (impact test with a velocity of 4 m/s, stacking test with a min. height of 6 m), accident conditions (5 m drop onto the real ground of the facility), and in consequence of these tests, limitations of tightness, integrity, and activity release. The covering requirements, especially the most critical accident scenarios, are the basis for the design performance tests by BAM.