This seems to be a very broad definition of 'nuclear waste'. When I search for "waste" on that page, I find one incident, involving a waste furnace explosion (not the waste itself) and a second one in Russia in 1957 where a large amount of waste was released with no immediate fatalities, but possibly 200 later excess deaths. And, as the page points out, coal burning power plants emit (with little or no long-term "containment") 100-times as much radioactive waste.
The argument against nuclear power is safe disposal of the "waste", but, as the OP pointed out, it is hard to find any examples of deaths because of nuclear waste (there certainly have been more deaths because of accidents, but even here, coal mining/burning/waste disposal clearly is much higher risk, even ignoring CO2 output).
Which accident are you referring to? https://en.m.wikipedia.org/wiki/Kyshtym_disaster refers a source that claims 8015 deaths and no comparison to coal-fired power plants. Of course, one could argue that the accident was related to processing spent fuel into nuclear weapons material and would not have happened if it had just been buried. Or that it is should not be called waste if it's treated as raw material to something else.
The argument against nuclear power is safe disposal of the "waste", but, as the OP pointed out, it is hard to find any examples of deaths because of nuclear waste (there certainly have been more deaths because of accidents, but even here, coal mining/burning/waste disposal clearly is much higher risk, even ignoring CO2 output).