The power grid is a complex beast. In Europe, as an example, the power grid is the subject to the regulations, political ambitions, restrictions and technological legacy of around 30 countries, the European Union, Commonwealth of Independent States, NATO, CSTO and probably a bunch of others as well. Getting everyone to play along amidst power-play, public opinion, financial concerns and so forth is a nightmare, and yet that is BEFORE the expected major impact from any major changes introduced in order to fight climate change.
So, in order to be able to do a large roll-out of nuclear power, you need to:
1) Find a location where building a plant is viable and from where you will be able to transmit the produced energy to it's indended destination.
2) Convince the public that the plant won't render their home uninhabitable.
3) Convince the public that the plant won't result in more environtal damage in their back yard compared to someone else's back yard.
4) Convince the authorities to give you a permits for new plants.
5) Convince the authorities that you're the right one to build it, because they WILL have an issue if you involve people seen as political opponents, say a business from another power block.
5) Convince someone that it's OK if you dig down depleted fuel in their back yard for 100,000 years.
6) Convince the authorities that that it's OK to dig down that depleted fuel in someones back yard for 100,000 years.
Now, if you fail any of those things, then your new shiny plant will most likely never be constructed. Even if you do make it, you still need to compete with solar/wind/storage to make ends meet, while a semi-monopoly sold by the state to private investors in the 90's is still sitting on the huge dam built in the 20's, and can churn out base power from it considerably cheaper.
After all, it's not their problem if your local power grid is to weak to handle all that energy being sent through the entire country through one single line built in the 50's. You should have thought of that beforce you decided to replace your coal plant with a nuclear one!
End result: the owner of the local grid gets the blame and everyone switches to solar because the government is trying to stimulate the market and no matter how inefficient and insufficient it may or may not be compared to your nuclear plant, a solar panel on the roof is preferable to a nuclear power plant for many, many people.
I'm sure there will be new nuclear plants built in the future too. Not many though -- the situation's too messed up for that.