Coal isn't the cheapest though. For new build power renewables + storage are. That is to say, the incremental cost of running a coal plant isn't that massive, but cost to build + fuel one amortised over the lifetime is more than renewables + storage.

So yes, you can enforce "adequate regulation" and nuclear will still be the most expensive.

People are not stupid. They will never choose the financially unwise option

I see you've never been to the U.S.

People do often act stupid, but you are seeing it from what I consider to be an incomplete perspective. Nuclear could be financially unwise overall, but someone would still get a payday. That 17B over budget wasn't burned and unmade, it went into the pockets of the people organizing and building the power plant.

All this to say, the huge majority of the people involved in making the power plant a reality weren't motivated by the efficiency of the power production on a cost basis. Most of them were probably making more money while it was still being subsidized, planned, and built. And while I think subsidies are generally useful and good, they can be a vector of financial abuse when it comes to unprofitable industries.

Lastly "lifetime cost" is a bit of a useless metric when the majority of that lifetime comes too late. No point to a power source that will cleanly produce power after it has meaningfully contributed to pushing us over the edge and past the breaking point for a climate that can support agriculture as we know it. There isn't enough time or margin for error in emissions left available to build all the nuclear plants needed to meet energy demands.

Can you find any recent analysis that supports your claim that nuclear costs are at the same level as solar?

The only one I’ve seen suggest this was from a nuclear industry lobby group, and it inflated the costs or solar by insane amounts.

In Australia this is a bit of a hot topic and all impartial estimates suggest that nuclear will not get close to renewables in any way, even taking into account storage and grid costs.

In the 10 years since this single reactor was built, one of our states has transitioned to almost 100% renewables. Wholesale costs have plummeted, but renewable projects are still profitable in the market. I was involved in a reactor project in a western nation some time ago (it’s still being completed unsurprisingly), and the lock-in wholesale price to support that project was simply extortionate. Solar generation prices are a whole magnitude smaller.