Impact Analysis of a Commercial Airplane Over a Nuclear Spent Fuel Dry Storage Cask

Abstract

The evaluation of the structural integrity of a vertical cask that is used for spent nuclear fuel dry storage is reported. The cask diameter and height are 3.566 m (140 in.) and 5.28 m (207.75 in.), respectively. The analysis focuses on such a cask being impacted by a commercial airplane. The dry storage container standards, which are under evaluation and approval by the U.S. Nuclear Regulatory Commission, are considered. The storage container inner basket is made of a stainless steel plate cylinder. It is located within an outer shell. The last one is manufactured with concrete and has internal and external steel liners. The commercial airplane considered in this analysis has a length of 40.39 m (132 ft, 6 in.). Its wingspan and height are 35.23 m (115 ft, 7 in.) and 11.98 m (39 ft, 4 in.), respectively. Its take-off weight is 81 090 kg (178 773 lb). An explicit analysis with the finite element method is carried out. The impact angles were 0, 30, 45, and 60 deg with respect to the horizontal. The mesh of the domain has 1 104 229 hexahedral elements and 1 516 156 nodes. Initially, all the structures are considered without restrictions and free of stresses. The vertical container for dry storage is at rest on a rigid concrete base. The aircraft velocity is 234 m/s or 842 km/h (523 mph). The impact event is simulated in an interval of 0.03 s. The maximum principal stress fields show that there are points at the lid of the container that are above the elastic limit and the ultimate strength. Under these conditions, brittle failure is expected.