so why do nuclear (high capital-long life technologically intense large scale little greenhouse emission) plants
get the most scrutiny and harshness?

Doesn't it seem backwards? Government investment is useful when the quantity needed and timescale needed is deeper and longer than typical, and where the benefits are diffuse.

so why do nuclear (high capital-long life technologically intense large scale little greenhouse emission) plants
get the most scrutiny and harshness?

Says who?

Isn't it truw that the more public money you need, the worse your economics are, perhaps?

maybe chernobyl et three mile island ?

It's about Liability. If an accident occurs, who pays the claims? Gov't as self-insurers or the industry? If the industry, it exposes itself to bankrupty. Imagine the claim amount. Thus govt's usually cover the tab.