Nuclear power is more expensive per KWh than renewables. Even more if you factor in nuclear waste storage. Why would you ever consider nuclear instead of renewables with this in mind?
Renewables provide cheap energy at the margin (e.g. negative energy prices in Germany at peak hours) but cannot be counted on all the time.
This kind of thinking is exactly what's wrong with armchair modeling of renewables.
Even if you're somewhere where the wind could give you 90% of your energy, you'll still need a reliable, baseline power source if you don't want everything to randomly shut down the other 10% of the time.
Wind + solar aren't as cheap as the LCOE makes it seem because you always have to pay for another source of power as baseline. If you added similar subsidies to natural gas it would be by far the cheapest energy source
For example using Norwegian hydro together with German, British and Danish wind.
Germany <-> Norway (2021): https://en.wikipedia.org/wiki/NordLink
UK <-> Norway (2021) https://en.wikipedia.org/wiki/North_Sea_Link
Denmark <-> Norway (1977) https://en.wikipedia.org/wiki/Skagerrak_(power_transmission_...
* The best option is storing it as potential energy for water, i.e. using a pump and a dam. That's 90% efficient, except, we can't exactly build dams everywhere.
* Power to gas to power has a dreadful 10% efficiency ratio, and it also requires energy to make. So, you use a ton of energy to store very little energy.
* Conversion to hydrogen has the same problems. Best we can do 25%. What do you do when you only have a tiny bit of excess energy? The process takes a constant amount of energy in, so you need a constant power source. Nuclear reactors, ideally.
Storing nuclear waste isn't hard. France is building a storage place that will handle all our nuclear waste produced until 2080, safely for hundreds of years. The project cost 25 billion euros, and that includes looking for potential places, running tests, and everything else involved in new things. Future projets would be much cheaper. Considering the country is subsidizing renewables to the tune of 70 billion, it costs us one third of the price for a solution of literally a lifetime. That's also taking into account that, ultimately, very little of the nuclear waste is truly oh-shit-oh-shit dangerous. With a simple phone call, you can most likely go visit a low activity waste storage location, which is 90% of the waste we produce, and you can just go dance on storage tanks. Radioactivity is basically nil.
Additionally, waste is only waste because we can't use it. Look at projects like Superphénix and breeder reactors, and suddenly you've got all this stored "waste" able to produce much more energy.
I doubt that it comes out cheaper than building pumped storage or hydrogen facilities. Even if that means building more renewables to account for inefficiencies involved
The challenge for countries like the UK is saving solar generation from summer to use for heating in the winter: The capital costs are much higher, because instead of storing one day's solar output, you need to store a few hundred days' output.
Of course, nuclear is super-expensive (or at least, it is the way my country tries to build it). I don't know what the answer is.
If you have seen what industrial-scale photovoltaic production can do to a rural area, you would at least consider this point. You need to build at least 1000a to cover the power output of even a small-scale nuclear power plant with PV. If you account for the load factor, you probably need something like 8 times as much.
Of course, nuclear power plants could be build close to cities and people living in cities are not affected by the space usage, so the political equation is clear.
edit: To put the space requirements into perspective. Germany has a (rough) requirement of 70GW of electrical power. To cover this with the (roughly) 1k hours of solar production and dense packaging of 1MW/a the country would have to install about 500000a of PV panels (plus some kind of storage over the year). That is about 3% of the currently used agricultural land. And covering here means putting up to 4m high steel structures on it, very close to each other. Generating the whole primary energy with PV would at least require five times the amount of space. Naturally, there are a lot of caveats (roofs, unused space, wind energy, storage, conversion efficiency...) but it should make clear why people are hesitant to accept such a buildup. Nuclear energy would, on the other hand, only require around 20-30 medium-sized powerplants for electricity or less than 100 of them for full primary energy generation (heating homes would be basically free due to waste heat). Of course, it would be much more expensive and you would have to deal with eithe proliferation and yet unknown error modes or an insane amount of radioactive waste, but you wouldn't need nearly the same amount of space.
You state this as fact but it seems to actually be pretty contentious. Wikipedia lists [0] many studies and the estimated costs of nuclear vs. renewables vary pretty wildly.
Of the global studies that considered nuclear, OECD NEA and IPCC both list nuclear as cheaper than solar and similar to onshore wind, while Lazard is quite favourable towards renewables.
Of the regional studies, on the positive side, France found nuclear cheaper than anything but hydro and Japan (pre-Fukushima) found it about half the price of solar or wind.
Of the regional studies, on the negative side, the UK found it marginally more expensive than solar, much more expensive than onshore wind and much marginally less expensive than offshore wind and the US EIA found it to be one of the most expensive options there were.
So the estimates vary pretty wildly, it's not an accepted fact that nuclear is more expensive than renewables.
Personally, I trust France, as they actually have large-scale nuclear power.
[0]: https://en.wikipedia.org/wiki/Cost_of_electricity_by_source