If you read some of the Dune supplementary materials, the sandworms are biological nuclear reactors. It's kinda handwavey but it's a cool concept - how do you k

If you read some of the Dune supplementary materials, the sandworms are biological nuclear reactors. It's kinda handwavey but it's a cool concept - how do you keep a creature the size of a freight train moving constantly in a very thick medium... how about harvesting fissionables?