Canceling the nuclear waste repository at Yucca is an incredibly huge legal liability for all involved. There is a huge after-life on nuclear waste and it needs to be contained and maintained at a safe level - It is the responsibility of the people that put it there to make sure that it happens.
Yucca Mountain nuclear waste repository was always unnecessary and dangerous, and canceling it was a good idea. We already have storage for nuclear waste, and there is no reason to use federal land 100 mile from Las Vegas as a new storage site for nuclear waste. We should instead concentrate on not generating that waste in the first place, and funding would be better used in the transfer to safe and renewable energy sources.