The Chernobyl absolute exclusion zone is quite literally 1000 square miles. Nuclear advocates try to treat Chernobyl (and Fukushima and [insert nuclear disaster here]) as an irrelevant outlier rather than what it is: tangible evidence of the impact of inevitable human failure.
A plant has to be well-maintained and competently run. Waste products have to be safely stored and transported. As soon as you add corporations to the mix, you've now created a profit motive to neglect safety and maintenance because the risk of disaster is low but the failure modes are incredibly large. Humans have shown themselves to consistently be incredibly bad at managing low-probability high-impact failures.
> The US navy has fielded nuclear reactors in warzones since 1954 and no Chernobyl.
Military use of nuclear reactors is quite limited, being largely limited to a handful of submarines and aircraft carriers using highly enriched fuel. It's not done out of economic merit either. Having a nuclear missile submarine that can stay deployed for months can literally be done no other way.
All that has very little to do with commercial power generation.