Companies are in the process of building test units for small modular reactors, which could be used to power rural areas. Credit: Kairos PowerNuclear power plants have not exactly sprouted like daisies across the United States. The country’s first commercial nuclear reactor of the twenty-first century didn’t come online until 2016. That was Unit 2 of the Watts Bar Nuclear Plant in Tennessee, which arrived two decades after Unit 1.But that drought, and a similar one in Europe, might be ending. Tw...