Molten salt reactors inherently don't. But you can burn up higher actinides resulting in waste that only needs to be stored a few 100 years and pose very little danger even in the most absurd scenarios.

You don't need to separate all the different parts. You reprocess our old waste into fuel for modern reactors. In those reactors higher actinides will be burned up. And the resulting output does not have higher actinides and only needs to be stored as long.

Moltex Energy is currently engaged with the Canadian regulator for such a facility, the process is called WATSS. Doing this is actually cheaper then the deep storage storage facilities proposed in many countries. Sadly because of political bullshit reprocessing has been made illegal in the US.

Such things would have been doable decades ago, and the money for it is already on bank accounts in most countries. But politician force the 'dig a hole for everything' solutions instead.

> Plus a fusion plant can be very quick to start and shutdown or throttle down which is very useful for base load.

Next generation fusion would also be very reactive to changes. Far more then traditional.

But the reality is you actually want to run full power as much as you can, no matter if fission or fusion.