I guess that's because you are missing part of the picture.
> For starters the economical costs are accidental bureaucratic contingencies.
Yes, everything says that it's possible to create safer nuclear reactors. But our current ones aren't. Safe reactors are on the same level of "nobody does this because of market and bureaucratic constraints" as cheap open-storage fuel cells. Except that the constraints are harder to change for the reactors.
We should be trying very hard to change both. But until we do, the reality will be that both nuclear reactors and batteries are expensive. And our current reactors are only safe because of the safeguards put on them, remove the safeguards, and they won't be safe anymore.
> renewable is increasing the cost of nuclear operation (underusage of maximal throughput) for nor reason
That's a pretty bad way to frame it. The problem here is that all non-dipatchable (on the economical sense, not the technical one) sources compete to get full utilization. That's not a problem when most of the power is dispatchable, but none of the options you are considering (renewables - except for buifuels - or nuclear) are. Adding nuclear capacity will increase the nuclear operational cost even more than renewables (because they have the same generation profile).
The only solution here is storage.
> solar panel have a short lifespan (20-30 years) with diminishing returns of efficiency ... the cost that people usually refer for solar panel must be doubled.
You noticed that you took the manufacturer guarantee and cited it as expected lifetime, right? AFAIK, we don't have a good number for how long our current tech of solar panels will last, because after just a few decades on the field, nobody catalogued enough failures to measure it. But we know it's way longer than that.
Anyway, doubling the cost of solar panels is both the wrong way to go (interest rates exist), and changes about nothing when comparing with the current costs of nuclear. (It would make them lose to coal, but then, both solar and coal are normally built by private business with proper accounting in practice to compare their costs.)
> Solar and wind economics are absurd
Well, you clearly didn't dig into those. Storage seems to be viable even with current tech (not using batteries). But it will of course always lose to natural gas generation.
Anyway, natural gas generation at night is a pretty good stop-gap.
> not even talking about the immense stress that would have on lithium resources which are seriously needed for the future of mankind
I don't expect grid storage to use lithium at all, but the fact that you have gone over lithium¹ reserves and are ignoring uranium reserves shows a very biased research. TLDR, none will be a problem soon (or probably ever for lithium).
> In the end, once renewable reach a major percentage of energy and heat production, the use of gaz and fuel as pilotable energies will skyrocket making the point moot.
Well, eventually we will need storage. That's true for nuclear too.
But anyway, renewables don't increase the consumption of fossil fuel based sources in any way, so the only way they can push the prices higher is by reducing economies of scale, what is actually the goal.
1 - Of any element you could choose, you decided to go with lithium, one of the most available ones on the Earth's surface? But well, once in a while somebody pops up talking about iron or silicon shortages, so you could have done worse.