A remarkable series of experiments in National Laboratories of the United States in the 50s and 60s did not deliver the nuclear airplane that the US Airforce wanted, but it did deliver a technology that has the potential to produce clean, carbon free energy for tens of thousands of years. This ‘molten salt reactor’ demonstrated the perspective of a nuclear energy system, unparalleled in safety, controllability, resource efficiency, without generating long term waste. Political agendas sidetracked the molten salt reactor, but in recent years it’s making a remarkable comeback.