zlacker

Operating costs for a coal-fired power plant, a nuclear reactor power plant, and a solar-battery power plant (requirement: steady power output 24-7) are all pretty comparable these days. Upfront constuction costs on nuclear are higher than others, so nuclear comes out near the top of the cost envelope. A lot also depends on variable costs of uranium ore and the fuel rod production process.

While a 1 GW coal plant might burn as much as 4 million tons of coal a year, a comparable nuclear power plant only consumes some 30 tons of fuels rods per year - but depending on ore quality and U-235 enrichment level, that might translate to 300,000 tons of uranium ore that needs to be mined and converted into fuel rods through an expensive multi-step process. Coal is much dirtier in terms of average daily emissions (though there's always the catastrophic failure risk with nuclear).

Solar / wind / storage operating costs are limited to maintenance and battery replacement, which can still be considerable.