THE INTEGRAL FAST REACTOR*

On April 3rd, 1986, two dramatic demonstrations of the inherent capability of sodium-cooled fast reactors to survive unprotected loss of cooling accidents were carried out on the experimental sodium-cooled power reactor, EBR-II, on the Idaho site of Argonne National Laboratory. Transients potentially of the most serious kind, one an unprotected loss of flow, the other an unprotected loss of heat sink, both initiated from full power. In both cases the reactor quietly shut itself down, without damage of any kind. The contrast between the consequences of these events in EBR-II and the Chernobyl events just twentythree days later thrust EBR-II, and the underlying Integral Fast Reactor development program at Argonne, into the national news. The paper describes the IFR concept, the inherent safety tests, and status of IFR development today.