Well, it's not, and there doesn't seem to be much focus by the DoE to do so. Therefore storage of waste is still a major problem if you want to generate electricity with nuclear power plants in the US.
The politics around nuclear waste are preventing the construction of reactor designs which exist today which could take waste that exists today and use it with an output with a much more manageable half-life than the waste we have just sitting around right now.
Right... The only technical problem, how to store waste indefinitely, is only a problem because there's a larger political problem that prevents the waste from being recycled/reused. Since the political problem is highly unlikely to be resolved within a few decades, that leaves us with the technical problem of how to deal with the waste as we are currently generating/storing it.
The amounts of hi-level waste generated are manageable and no one is claiming we are in danger of imminently running out of space. Long before this becomes a problem we will either recycle the waste or use most of this "waste" to generate electricity. While there are issues with nuclear power, the worry some people have about nuclear waste is greatly overblown to say the least.
Well, it's not, and there doesn't seem to be much focus by the DoE to do so. Therefore storage of waste is still a major problem if you want to generate electricity with nuclear power plants in the US.