Nuclear base load and renewables is actually one of the two viable concepts (the other is storage).
But electricity demand will massively increase: Most countries nowadays only cover about 20% of their primary energy by electricity. But all the oil and gas used in transport and industry needs to be converted to electricity (directly or indirectly). (On the other hand electricity is more efficient in a lot of cases, so it's not the full factor 5 in increase that will be needed. But still a lot.)
And not single country seems to be able to even start investing on the scale necessary to build the needed base load. ~30-35% is the minimum, but that's 30-35% of the future demand. Which is probably at least 2,5 times the demand of today. So basically any country that is not planning or already building enough nuclear capacities to cover at least 80% of todays electricity production purely on nuclear (which will be ~30% of the demand in 2-3 decades) is already failing. And pretending that that one (or a few) reactor(s) planned is more than symbolic is a lie.
As I said France comes close but only if they start being honest and build all the 14 planned new reactors. And if they can keep their aging fleet of existing reactors running long enough until those are build. (PS: The few lucky countries with a lot of hydro potential can of course cover some of that base load with hydro. But that's irrelevant for most other countries without the same geography.)
Why nobody is actually planning proper amounts while pretending to trust in nuclear power as a solution? That's easy: the cost. Even when we assume that the massive nuclear upbuild needed is not more expensive than the alternatively needed infrastructure and storage, the latter is an continues investment over decades. Nuclear comes with a massive upfront cost now to be ready in decades (maybe one if Europe suddenly rediscovers how to build them quickly, but I wouldn't bet on it).
And it even becomes worse. Most countries planning with nuclear are also lacking proper renewables although their own model requires them and massively so (65%-70% to complement the nuclear base load... multiplied with at least 2,5 for the future demand...).
That's the legacy of decades of nuclear lobbyism going for the perceived competition and trying to discredit renewables or nowadays telling us how storage is impossible on the required scale. At this point reacting to plans to build renewables with "oh, so you want to burn more fossil fuels and kill the planet?" is completely normal although also completely insane of course.
And now comes the best part: nuclear power doesn't work without the same storage they tell everyone isn't possible: Just look at France. They are massively overproducing in summer right now and still don't have enough electricity in the coldest weeks of winter and need imports. But now imagine a future where everyone is either running nuclear and renewables or even more renewables and storage. There will be no export market most of the year (because everyone has a surplus at the same time) making nuclear much more expensive. There also will be no one with a sizeable surplus in the coldest weeks of the year, which means you need even more reactors producing even more surplus over most of the year.
RTE (France' grid provider) did a extensive study in 2020 about electricity demand in 2050. That's where the minimal needed base load of about 35% comes from, also the announced 14 new reactors first announced less than a year later coincidently have the capacity to cover 35% of their projected demand in 2050. (Side note: They also compared their models to purely renewable ones... always funny to see how the guys working in that field and with nuclear are not the ones doubting the viability of a renewable model)
The gist of it... nuclear and renewables are economical viable compared to fully renewable models, even more than the minimum base load can even be better economically. But only because all their models were based on hydrogen production basically all year from excess electricity... used in industry, as long term storage or as the new way of exporting energy.