Your point is not wrong, but I'd clarify a couple things;
The primary cost of a traditional plant is fuel. However a nuclear plant needs a tad more (qualified) oversight than a coal plant.
In the same way that the navy has specialists for running nuclear propulsion systems versus crew needed for diesel engines. Not surprisingly nuclear engines cost "more than fuel".
That cost may end up being insignificant in the long run, but cost is not zero. And shortages of staff would matter (like it does with ATC at the moment.)
Construction cost should be much lower than it is, but I don't think it'll be as cheap as say coal or diesel. The nature of the fuel would always require some extras, if only because the penalty-for-failure is so high. There's a difference between a coal-plant catastrophe and Chernobyl.
So there are costs gor running nuclear, I don't think it necessarily gets "too cheap to measure".
There are some costs that a coal plant wouldn't have, but those aren't really variable costs. If the plant's capacity is 1000MW and the grid is only demanding 500 MW right now, you don't get to send home any nuclear engineers, so what's the point in pricing kWh to discourage anyone from using more? If you build a 5GW plant instead of a 500MW plant, you don't need 10 times as many engineers just because this one's pipes have a larger diameter, so it's more economical to build larger plants, but the only times it makes sense to charge per kWh are when demand exceeds capacity and then those times become rare.
Solar is on its way to do something incredibly disruptive because it's the same "too cheap to meter" but only when the sun is shining, and then you still need the independent capacity to supply power from something else when it isn't. So now instead of "you pay ~$0.12/kWh all the time" you have a situation where power during sunshine hours is basically free but power at other times costs dramatically more than it used to because the infrastructure to supply that power has to recover its costs over significantly less usage.
The primary cost of a traditional plant is fuel. However a nuclear plant needs a tad more (qualified) oversight than a coal plant.
In the same way that the navy has specialists for running nuclear propulsion systems versus crew needed for diesel engines. Not surprisingly nuclear engines cost "more than fuel".
That cost may end up being insignificant in the long run, but cost is not zero. And shortages of staff would matter (like it does with ATC at the moment.)
Construction cost should be much lower than it is, but I don't think it'll be as cheap as say coal or diesel. The nature of the fuel would always require some extras, if only because the penalty-for-failure is so high. There's a difference between a coal-plant catastrophe and Chernobyl.
So there are costs gor running nuclear, I don't think it necessarily gets "too cheap to measure".