Any effort spent building nuclear for the 2040s is effort that could build 5x as much solar and wind for 2025.
Plus transitioning to nuclear just builds another set of kochs and saudis.
Plus it makes your entire economy beholden to one of China, Russia, France, or the US.
Plus it just kicks the can down the road. If you consider direct thermal forcing. We are exactly where we were in the late 19th century with greenhouse gases. There is no option but to transition to a steady state economy, and starting a bunch of projects that only pay off if you use as much energy as possible from them (and even then, solar + storage will be a fraction of the cost by the time they open) isn't the way to get there.
Plus those same five countries won't even let half the world have nuclear power plants.
Plus the world's uranium reserves won't actually last very long if you carry on with exponential growth (doubly so without reprocessing and breeding).
Then there's all the usual risks people mention.
The solution is the same as it has ever been. Degrowth, stopping waste, and renewables.
If Europe can continue to buy cheap Russian gas and oil and use it as they have done in the past then 5x as much solar and wind for 2025 sounds great. That was the Great Plan of the green movement in Germany. In 2010, 2020, 2030, 2040, 2050 or a time after that green hydrogen will become cheaper than Russian gas and oil and then this plan will be completed.
If however Europe can't continue to burn gas and oil when demand exceeds supply because of the weather, then there is a major problem that is going to need fixing in a very expensive and time consuming way. If green hydrogen don't drop in price and no other storage solution can arrive to become cheap than gas and oil, then the climate change goals won't be achieved.
To add to the problem in northern Europe, the locations for hydropower is practically already at maxed utilization. They are also quite old and with large maintenance debts. They are also is causing extinction of several species, and fixing that would cost prohibitively much money, and the solutions will reduce outputs.
The thing is, 5x solar and wind sounds great but if I can specific the time and space for it, I would make a great profit of trading 5 units of energy for 1x at a different space and time. The price difference in northern Europe can be a factor of 10 or even higher between low and high. 5 kwh worth 3 cent each is worth much less than 1 kwh worth 40 cent.
Solar and wind are nice, but they don't solve the base load problem. They aren't consistent enough to operate as base load on a power grid. They are certainly convenient for maintaining peak load, but without solving the energy storage issue in parallel to the added capacity, we need alternatives.
Then comes storage, curtailment, and backup (always necessary: fossil-fuel plants always produce around 9% of electricity in fully-nuclearized France).
Moreover backup is now provided thanks to gas turbines, and we know to run them thanks to hydrogen (clean), which can be green hydrogen (cleanly produced thanks to renewable sources overproduction).
There is no need for each location to deploy each and every type of production unit: each region has its own geography and preferences.
Those benefiting from huge potential for hydro, offshore wind or solar (deserts...) are at an advantage.
Those benefiting from a low production time-profile correlation with most other ones also are blessed.
Those totally unable to deploy anything probably don't need huge amounts of energy or are rich to the point of already importing it (is there a counter-example?).
Plus transitioning to nuclear just builds another set of kochs and saudis.
Plus it makes your entire economy beholden to one of China, Russia, France, or the US.
Plus it just kicks the can down the road. If you consider direct thermal forcing. We are exactly where we were in the late 19th century with greenhouse gases. There is no option but to transition to a steady state economy, and starting a bunch of projects that only pay off if you use as much energy as possible from them (and even then, solar + storage will be a fraction of the cost by the time they open) isn't the way to get there.
Plus those same five countries won't even let half the world have nuclear power plants.
Plus the world's uranium reserves won't actually last very long if you carry on with exponential growth (doubly so without reprocessing and breeding).
Then there's all the usual risks people mention.
The solution is the same as it has ever been. Degrowth, stopping waste, and renewables.