"Pretty much every human activity carries a 'legacy cost'." MG

Perfectly true.
But very few are radioactive, and remain so for millennia, obliging its hundreds of steward generations (human generations) to protect that deadly waste, with virtually no benefit to them as a result.
As far as I know there is no precedent for such obligation in all human history. It is responsibility with virtually no benefit.

MG,
You seem perfectly OK with the one generation that gets the benefit.
But imagine if you were among the hundreds of generations that had to guard those hundreds and hundreds of tons of heavy toxins.

I would welcome you explaining to me why you think that would be OK.

And IF you think that's OK, how do you feel about federal deficit spending? Should one generation be legally allowed to spend the money of subsequent generations, before those generations are even born?

The U.S. was Founded to avoid such injustice. They even made a slogan out of it: "no taxation without representation".

Well, these unborn citizens are already nearly $9 $Trillion in debt.
$8.9 ...

http://www.brillig.com/debt_clock/

By what right do we spend their money?