51 1986 Integral Fast Reactor Safety Demonstration On April 3, 1986, operators deliberately took the EBR-II shutdown systems out of service. Then, with the reactor operating at full power, they shut down the cooling pumps, simulating the failures that caused core meltdowns at Chernobyl and Three Mile Island. Within minutes following a brief spike, EBR-II’s power and temperature dropped to a safe, maintainable level without any further operator interaction.The tests demonstrated the inherent safety of the Integral Fast Reactor concept, which employs self-regulating metallic alloy fuel, a large reservoir of highly efficient metallic sodium coolant and mechanical design that assures natural coolant circulation without the aid of pumps.This remarkable demonstration inspired designers of other reactor concepts to incorporate passive safety into their advanced reactor systems. “ It worked on the blackboard, it worked in computer simulations, and the engineers were willing to bet their lives that it would work in practice.” — A reporter present at the EBR-II station blackout simulation