THE 9 m DROP TEST ONTO AN UNYIELDING TARGET VERSUS DROPS FROM GREATER HEIGHTS ONTO REAL TARGETS

In order to calculate the mechanical cask stresses which occur in a real impact, a method of calculation was used based on the model of an inelastic impact. It was found that the stresses resulting from the hypothetical drops of two different cask types from a height of 27.2 m were greater than those resulting from a typical Type B test. It is worth noting that the 27.2 m drop was onto a 2 m thick reinforced concrete platform. The greater stress which was discerned demanded additional verification. Thus, drop tests were conducted using an existing model of one of the actual casks, corresponding to the calculated results. For the second cask, previously ascertained findings of instrumented high-impact drop tests, showing the degree of tolerable stresses, were used. These figures could be accepted for the cask to be evaluated because of the geometrical similarity, as well as the similar material properties and comparable sealing system. It was shown that both casks were able to withstand the more rigorous requirements.