I'd say no, although the amount of helium that's produced is small enough that it's not quite as absurd as I would have thought. Worldwide helium production is something around 25,000 tons/year. A nuclear power plant produces about 25 tons of waste per year. There are about 440 nuclear power plants in the world. If their waste consisted entirely of helium, that would be roughly 44% of total world helium production. More than I guessed! But, of course, only a tiny, tiny, tiny fraction of that waste ever turns into helium, so even if you somehow made it decay all at once, it would be be pretty insignificant on a world scale.