>Which to we ignore for coal? Cost to build a new plant? Cost to run? The decommissioning costs? (Yes we ignore the externalities, and no I don't think we should burn coal. My point is Nuclear has yet to pay its way anywhere in the world, without heavy heavy govt support - far exceeding that given to renewables)

Yes, all three. Building a nuke plant without the additional concern for outcome that we put on nuke would be relatively inexpensive. It's just concrete, pumps, and a turbine. It's a ismilar level of complexity to a coal plant. Same with running cost, same with decommissioning costs.

https://en.wikipedia.org/wiki/Kingston_Fossil_Plant_coal_fly...

Suppose we designed, operated, and budgeted every coal plant to make accidents like this a statistical impossibility. Not very unlikely, that's not the standard we hold nuke to. An impossiblity. Imagine what that would cost.