Most analyses show the cheapest way to fully decarbonize will include some baseline sources like nuclear.

Show me a single serious one pls...

The whole concept of baseline production is obsolete. I was the idea of having a steady, cheap base load producer (mostly coal) with a quickly reacting, more expensive peaker (oil or gas) to cover the actual demand.

But coal isn't cheap anymore, neither do we actually want to burn more of it even if it was. And nuclear can't fullfill either role. It's useless as traditional base load in the actual sense of the concept as it's not cheap. It's useless as a peaker.

And renewables plus batteries (both having seen exponentially drops in costs for years now) can actually already cover that base load concept. Get enough capacity to shift the production peak at noon to the demand peak in early evening and you are set (that is in fact what California is already doing).

The actual route to full decarbonisation is that renewables+short-term storage and some long-term storage. And a big part of that long-term storage is power-to-gas (from excess renewable production at peaks) and gas-peakers.

Nuclear can play a role in reducing some of the demand for short-term storage (flattening the curve by always producing at some level) and make electrolysis more economical (not only running with renewable excess power in the day but also at night when demand drops and nuclear still produces). But this is mostly from a perspective of already having nuclear, wanting nuclear for geopolitical reasons and then finding a niche were is can work in the renewable/storage system.

(For reference: RTE, the French grid provider –they have the higher share of nuclear after all–, did a big study about the future of nuclear up to 2050in 2021), modeling a lot of scenarios... Long story short: Renewables, batteries and power-to-gas with peakers is the way to go. Nuclear can work in this setup (at about 35%, 65% renewables) when that's politically demanded.)

Oh, I totally agree with the sentiment of using already build nuclear power plants in the meantime to speed up decarbonisation.

But long-term nuclear and renewables just don't go along well. Renewables need short-term storage (about the amount to shift production peak at noon to demand peak in the early evening) and seasonal long-term storage. Nuclear with it's constant production (because dialing production down temporarily doesn't save money making an already expensive producer even more so) can replace some of need for short-term storage. That's it. And it's much too expensive to compete batteries.

(If you want details: RTE, the French grind provider, did an extensive study about the future of nuclear and it's economical perspective compared with renewables in lat 2021. With lots of scenarios modelled for comparison. Long story short: You don't beat renewables plus storage. The niche nuclear can work in (and that really that's more from an "we have nuclear, we want nuclear, how do we make it work"-perspective) is in a renewable system with power-to-gas and peak burners as a long-term storage concept where it makes electrolysis much more economical because it does not only run when there is access renewable power produced but also through the night when nuclear still produces without much demand.)

A major part of it is that nuclear hasn't been allowed to be cheap.

There's been active sabotage from the oil industry since the beginning, starting with the Rockefeller Foundation sponsoring fraudulent science via their employee, Herman Mueller. To the CEO of Atlantic oil funding the creation of an explicitly anti-nuclear environmentalist group called Friends Of The Earth in 1970 or so.

Which coincidentally was about the time that the Rockefeller Foundation started funneling money to another explicitly anti-nuclear environmentalist group called Greenpeace.

The political pressure from these groups, plus direct pressure from the oil companies, got extremely restrictive regulations passed, with the goal, and result, of making nuclear more expensive to build and operate.

Look up the double guillotine break, which is a nonsense requirement that nuclear engineers have to design around. Nonsense because the equipment required to prevent this impossible scenario make it harder to deal with the actual likely scenario, which is leak before break.

Those are basically nuclear batteries, in the disposable reaction sense. It's not fission, fission requires huge amounts of water. Fundamentally, even if you used another coolant and another way of turning the power to electricity, you need massive heat dissipation (which is very difficult in space)

Nuclear batteries are basically decay powered, they give a small amount of power for a really long time. Totally different technology

That's another kind of storage, much more long-term. Even before battery prices dropped to rediculous levels, pumped hydro often had a battery system, too, because it was often more economical.

It is. It's ridiculously cheap. It's only the regulations and bureaucracy surrounding it that make it so expensive. It goes beyond safety and into unreasonable requirements spawned by decades of attempts to appease NIMBYS whos entire knowledge of "nuclear" is restricted bombs and Chernobyl. There are also the countless officials and agencies who created needless red tape to benefit themselves, or had a vested interest in seeing nuclear fail.

Let me be ABUNDANTLY clear: safety regulations and red tape ARE good. Holy shit, please do not think I am arguing against them wholesale. But regulations on nuclear plants go so far beyond what is actually needed that it balloons costs and time-frames to multitudes of what they should be.

It feels completely disingenuous to use those excess costs to argue that nuclear is expensive, because they are entirely our own fault that they're there. It's like saying running a mile is too painful, but then it turns out you shoot yourself in the leg every time before you try. The issue isn't running the mile, it's that you choose to shoot yourself in the leg. You shouldn't be able to use that to argue against running a mile.