It’s a poor solution for what people like to call “baseline power”.
The argument goes: solar and wind don’t provide consistent power, so there has to be some power generation that doesn’t fluctuate so we always have X amount of power to make up for when solar/wind don’t suffice. Nuclear is consistent and high-output, so it’s perfect for this.
Unfortunately, reality is a little different. First problem is that solar/wind at scale don’t fluctuate as much. The sun always shines somewhere, and the wind always blows somewhere. You have to aggregate a large area together, but that already exists with the European energy market.
Second issue is that solar/wind at scale regularly (or will regularly) produce more than 100% of the demand. This gives you two options: either spend the excess energy, or stop generating so much of it. Spending the excess requires negative energy prices so people will use it, causing profitability issues for large power plants. As nuclear is one of the most expensive sources of energy, this requires hefty subsidies which need to be paid for by taxpayers. The alternative is shutting the power plant down, but nuclear plants in particular aren’t able to quickly shut off and on on demand. And as long as they’re not turned on they’re losing money, again requiring hefty subsidies. You could try turning off renewable power generation, but that just causes energy prices to rise due to a forced market intervention. Basically, unless your baseline power generator is able to switch off and on easily and can economically survive a bit of downtime, it’s not very viable.
Nuclear is safe. It produces a lot of power, the waste problem is perfectly manageable and the tech has that cool-factor. But with the rapid rise of solar and wind, which are becoming cheaper every day, it’s economic viability is under strong pressure. It just costs too much, and all that money could have been spent investing into clean and above all cheap energy instead. I used to be pro-nuclear, but after seeing the actual cost calculations for these things I think it’s not worth doing at the moment.
As for what I think a good baseline power source would be: I think we have to settle for (bio-)gas. It’s super quick to turn off and on and still fairly cheap. And certainly not as polluting as coal. We keep the gas generators open until we have enough solar/wind/battery/hydrogen going, as backup. If nuclear gets some kind of breakthrough that allows them to be cheaper then great! Until then we should use the better solutions we have available right now (and no, SMRs are not the breakthrough you might think it is. They’re still massively more expensive than the alternatives and so far have not really managed to reduce either costs or buils times by any significant margin).
Maybe fusion in the future manages to be economically viable. Fingers crossed!