We already know how to build nuke plants to replace coal. Fear-mongering over exceptional incidents at first and second generation sites like Chernobyl, Three-mile Island and Fukushima, and the extreme regulatory restrictions and NIMBYism are the problem there, not anything technical or economic.

Hell, you've got Germany closing perfectly good clean nuclear plants, that have to be replaced with new coal-burning plants, due to misguided environmental activism.

Innovative nuclear may be well priced out of the market at this rate but research (Gen IV, fusion) is going very fast nowadays and will only go faster with eDesign and cloud computing.