> if only because the upper bound potential for damage is so much higher.
Chernobyl was a nuclear excursion that blew the roof wide open and shot fuel out into the air. Air rushed in and ignited a nearly inextinguishable graphite fire that propelled the nuclear fuel high into the atmosphere. There was no containment structure around the core. And yet this killed 60+ people, caused up to 4000 early cancer deaths, and (yes) did cause a bunch of thyroid cancers. (Fortunately, thyroid cancers are usually treatable. Not saying they're ok, but not fatal like fossil + biofuel air pollution).
I would claim that Chernobyl is a reasonable example of a nearly-worst-case nuclear reactor accident. With modern reactors having containments, it's hard to postulate radiation releases of that magnitude. Case in point, Fukushima was 3 meltdowns and had much less radiation release and therefore health impact. I don't think saying nuclear reactor accidents are nearly unbounded wildly beyond Chernobyl is reasonable.
And again, fossil + biofuel kill a Chernobyl's worth of people every 7.5 hours...! The WHO numbers linked are due to the fossil fuel + biofuel. I'll link more detailed meta-analyses below.
Also, the area around Chernobyl is not really uninhabitable at all [1]
[1] https://thoughtscapism.com/2019/05/08/what-about-radioactive...
As for thinking the UNSCEAR values on deaths are a sham, yeah I mean Greenpeace has been saying against all scientific consensus that the impacts are way higher for years. But the science does not support that. UNSCEAR is basically like the IPCC for nuclear.
I highly recommend listening e.g. to Gerry Thomas on this topic for details. [2]
[2] https://www.titansofnuclear.com/experts/gerrythomas
As for air pollution, see this [3] for more specific attribution to fossil fuel and biofuel.