I've always thought that this argument really shows a lack of education more than anything. People do not understand the simple principle that you cannot have a highly radioactive substance and it be long living at the same time (this is because radiation is the process of matter being expelled from the atoms. Higher radiation levels, more matter/energy being expelled). But it also shows that people don't understand that things that things can also be dangerous and have no half life. Like lead and heavy metals don't decay and there are no safe levels of heavy metals.

> So after a few decades or so, the most deadly waste has decayed.

Yes. "Long half-life" = "less radioactive". By definition.

But a lot of people don't get that. They hear, "nuclear waste from nuclear plant is highly deadly because it is radioactive. It could kill you in minutes."

Then they hear, "Nuclear waste from nuclear plants will be radioactive for thousands of years."

They then assume, "Nuclear waste from nuclear plants is highly deadly and could kill you within minutes for thousands of years."

Yeah, in reality, nuclear waste needs years to kill you. It's predicted that 65 000 people will die by 2005 due to radioactive poisoning by Chornobyl disaster. Radiation is SLOOOOOOOW.