You can make Thorium reactors much smaller and cheaper, basically a 50MW unit is not much larger than a shipping container, while being much more safe than standard nuclear plants. The largest issue is over-regulation of the nuclear power in general.

A 50MW of solar installation is HUGE, and thats 50MW at the sunniest part of the planet: https://newsaf.cgtn.com/news/2019-12-15/Kenya-launches-Chinese-built-50MW-solar-power-plant-MqC575l6Te/index.html, We are basically talking about close to a square kilometer installation...

there is simply no way to call a 50MW solar plant cleaner than nuclear and its probably not even that much cheaper in the end. Compare that to a shipping container sized reactor... Only thing in the way, is the nuclear scare and government regulations.