Nuclear reactors are cheap. What is expensive is regulatory compliance, and regulatory boards changing the rules while the reactor is being constructed in place. A way around this is to buy a pre-fab reactor that has already made it through regulatory and was fabricated in a factory.
Building the reactor is a small fraction of the total cost. People love to talk about small modular reactors as if that’s the only cost but they still need actual turbines to generate power, electrical equipment, cooling, pumps, complex high pressure plumbing, giant buildings, spent fuel ponds, etc so the reactor’s themselves are not even the full construction cost to get power let alone the actual lifetime cost.
Equipment breaks down so you need to maintain, repair, and eventually replace it. Which is a large reason why you need roughly 500 people per GWh to run the things even without any regulations. You need not raw ore but concentrated u235 in complex and expensive to build fuel rods etc. You need lot’s of land near an abundant water source to cool them which is exactly the kind of places people want to live. Even when it breaks you still need to decommission them.
And that’s ignoring the need for someone to take on the risk of failure. Even when the public isn’t harmed nuclear accidents destroy expensive equipment and are expected to clean up. Accidents on average cost several Billion per GW, you might find cheaper insurance but don’t bet on it without subsidies.
