Neoliberal capitalism is bad at long-term projects. That's why we're struggling so much with climate change mitigation. A lot of the gigantic power projects that required such long-term planning were built in the New Deal era and the postwar industrial boom. During this time, corporate tax rates and workers' salaries were high because the government was genuinely afraid of worker power.

Building a modern nuclear power plant requires subcontracting it out into what is essentially a builders' market in which companies compete with each other for pieces of state-level building grants. None of these companies want to undertake risky long-term ventures like a new nuclear reactor because they want to maximize their short-term revenue (profit). So they jack up the prices until the project budget is overrunning already in the planning stage, and it's doomed from the start.

you don't even really need to subsidize it, you just need to front the cost for the plant, build it, and the produce power. Might be time for a nationalized US power company.