> Are you going to overbuild nuclear to cover the peaks? Or are you going to build for baseload and then need storage to cover the gaps?
That obviously depends on the cost of storage relative to the cost of building more plants, but you don't even need to ask the question until after you've already built enough plants to replace all of the existing fossil fuel baseload, so let's start there.
> How are you going to get people to build nuclear power plants when they could make more money on solar?
Regulatory reform to address the maliciously, intentionally high cost of construction and operation, resulting in competitive prices.
> Who is going to pay to decommission nuclear power plants when they go bankrupt?
They don't get decommissioned because they don't result in that kind of bankruptcy. They cost a lot to build, but once they're built, they're going to exist for decades.
If something else turns out to be much cheaper the people who invested in it may get a below market rate of return, but still it doesn't get shut down, because the initial capital expenditure is a sunk cost that has already been paid. The incremental cost of continuing to generate power is much lower.
> Solar drives baseload plants bankrupt, which is why coal plants are going out of business.
Coal plants have a substantial fuel cost, which puts them at a disadvantage. They operate at a loss if the price of electricity drops below the price of coal, and then shut down, and then have to recover their capital costs by operating for fewer hours. Nuclear plants continue to operate at 100% output pretty much regardless of the price of electricity because their fuel cost is negligible. Notice that it's the existing coal plants going out of business and not the existing nuclear plants.
Nuclear also has untapped potential for things like cogeneration, thermal storage and on-site desalination, all of which would make it more cost competitive but are not currently being exploited.