From what I’ve researched, there’s not that much waste from reactors anymore. The glowing sludge of doom usually comes from enriched isotopes for weapons.
Needless to say it is rather radioactive...
But it is easily contained by the water in the pools, and then the dry storage casks it is moved to once it is no longer "thermally hot" and needs constant cooling.
This guy is just your typical anti-nuke posting the classic talking points about all the billions of tonnes of used fuel?