I totally agree that current nuclear power generation should be left running until we have enough green energy to pick up the slack, because it does provide clean and safe energy. However, I totally disagree on the scalability, for two main reasons:

1. Current nuclear power generation is non-renewable. It is somewhat unclear how much Uranium is available worldwide (for strategic reasons), but even at current production, supply issues have been known to happen. And it goes without saying that waiting to scale up some novel unproven or inexistent sustainable way of nuclear power production is out of the question, for time and safety reasons. Which brings me to point 2.

2. We need clean, sustainable energy right now if we want to have any chance of fighting climate change. From start of planning of a new nuclear power plant to first power generation can take 15 or 20 years easily. Currently, about 10% of all electricity worldwide is produced by about 400 nuclear reactors, while around 15 new ones are under construction. So, to make any sort of reasonable impact, we would have to build to the tune of 2000 new reactors, pronto. To do that within 30 years, we’d have to increase our construction capacity 5 to 10 fold. Even if that were possible, which I strongly doubt, I would wager the safety and cost impacts would be totally unjustifiable. And we don’t even have 30 years anymore. That is to say nothing of regulatory checks and maintenance that would also have to be increased 5 fold.

So imho nuclear power as a solution to climate change is a non-starter, simply due to logistical and scaling reasons. And that is before we even talk about the very real dangers of nuclear power generation, which are of course not operational, but due to things like proliferation, terrorist attacks, war, and other unforseen disruptions through e.g. climate change, societal or governmental shifts, etc.