Nuclear waste is just that - waste. It's generally no longer capable of supercriticality. Nuclear explosions as a method of space propulsion is a viable idea [

Nuclear waste is just that - waste. It's generally no longer capable of supercriticality. Nuclear explosions as a method of space propulsion is a viable idea [1], however. (Using the Moon would be rather inefficient though.) [1] https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...