Abstract
To demonstrate the sealing performance of a metal cask subjected to impact load due to a commercial aircraft crash against a spent fuel storage facility, a horizontal impact test was carried out. In the test, an aircraft engine missile with a speed of 57.3 m/s attacked the reduced scale metal cask standing vertically containing helium gas. In the test, the leak rate of the helium gas and sliding displacement of the cask lid were measured. At the impact, the leak rate increased rapidly and reached to 4.0×10-6 Pa·m3/s. After that, the leak rate decreased slowly and converged to 1.0×10-6 Pa·m3/s after 20 hours from the impact test. The leak rate of a full scale cask was evaluated using that of the reduced scale cask obtained by the test taking account of the reduction factor. As the result, the leak rate of the full scale cask was less than 1×10-4 Pa·m3/s. This result showed that the sealing performance of the full scale metal cask would not be affected immediately by the horizontal impact of the aircraft engine with a speed of 57.3 m/s. In addition, to simulate the cask behavior in the impact test, an impact analysis using dynamic analysis code LS-DYNA has been executed. The numerical results agree well with test results. The following were necessary to obtain good results by the analysis. 1)Experimental material data for input to the analysis contition 2)Exact analytical model of the cask lid 3)Initial conditions around the cask lid simulating the test for the analysis.
