It should not be overlooked that fusion power, while expected to be using only light elements (usually hydrogen/deuterium) as an input fuel, requires sufficiently high particle fluxes at high energy that it renders everything used to build the device eventually radioactive.

Whether the problem is safely storing "depleted fuel" that was once highly radioactive and now is less so, or safely storing initially inert nuts and bolts made radioactive by being used in or near a fusion reactor the problems remain very similar.

The point is not that fusion power is too dangerous to ever use, but that it's not inherently that much safer or cleaner than fission, does not inherently produce "no radiation waste byproducts" - so it makes no real sense to wait for "something better." It won't be that much better.

If the disposal problems can be dealt with satisfactorily, and my personal opinion is that mostly they can, then the real question is whether fusion or fission reactors are at least "no more destructive than fossil fuel plants."

In terms of real environmental and human health costs, it cannot be said that fossil fuels are low impact, or even that they have less impact than a nuke meltdown now and then. [slightly sarcastic I guess. Sorry.]

John