As many nuclear skeptics are keen to point out, the main counterargument to nuclear is construction costs. In the tens of billions. As Elon Musk has demonstrated though, there is nothing set in stone when it comes to manufacturing costs, the lower bound is only the cost of raw materials. If manufacturing costs go to zero, a new nuclear power plant could cost of the order of $10 MM rather than $20 BN. Elon has shown us that you can reduce manufacturing costs of rockets by a factor of 10 to 100 in a mater of one to two decades, if you put your mind to it.

Small nuclear reactors are the only chance of the nuclear industry to reduce manufacturing costs, but once they get rolling, there is no reason to believe they can't reduce their costs by a factor of 10 at least. For example, this article mentions a cost of $2.4BN per small reactor. A comparable US Navy small reactor (used for submarines) costs around $100 MM [1]. For some reason the US Navy doesn't appear inclined to share its know-how with the civilians, but that should give us an idea of what's possible.

[1] https://www.quora.com/How-much-does-it-cost-to-build-the-rea...