Enrico Fermi was right on two counts.
He believed that nuclear power could replace coal power as an electrical source. He also believe that the emissions for coal plants was lead poisoning the general population. As a Roman himself he would know a great deal about lead poisoning.
The Atomic Energy Commission run by Lewis Strauss (Robert Downey Jr in the film) gave him a site in Idaho to build a Experimental Breeder Reactor. Fermi led a team of scientists to create a self-sustaining nuclear chain reaction. It worked spectacularly. Unfortunately Fermi was already too sick from exposure to radiation to build the first Nuclear Power Plant, the USSR did it first.
Dr. Herb Needleman, a pediatrician, would prove Fermi right.