Development of very low deceleration shock-absorbers

We developed a 131 tons weights cask that can transport and storage 69 BWR nuclear spent fuels. A deceleration of the cask at 9m horizontal drop test have to keep below 50G(G= gravity acceleration) in order to assure both structure integrity and seal integrity. Then, 2types of shock-absorbers were developed. Those shock-absorbers are made of woods that have low compression strength and large lock-up strain. Through a quarter(1/4) model 9m horizontal drop test, we proved that a real scale cask with balsa and redwood shock-absorbers have below 40G deceleration.