BORAX experiments

The BORAX Experiments were a series of safety experiments on boiling water nuclear reactors conducted by Argonne National Laboratory in the 1950s and 1960s at the National Reactor Testing Station in eastern Idaho. They were performed using the five BORAX reactors that were designed and built by Argonne. BORAX-III was the first nuclear reactor to supply electrical power to the grid in the United States in 1955.

Evolution of BORAX

This series of tests began in 1952 with the construction of the BORAX-I nuclear reactor. The BORAX-I experiment proved that a reactor using direct boiling of water in the core could be stable, because the bubble formation creates a negative void coefficient. Subsequently, the reactor was used for power excursion tests which showed that rapid conversion of water to steam would safely control the reaction. The final, deliberately destructive test in 1954 produced an unexpectedly large power excursion that "instead of the melting of a few fuel plates, the test melted a major fraction of the entire core." Data from this core meltdown and release of nuclear fuel and nuclear fission products helped improve mathematical models. The tests proved key safety principles of the design of modern nuclear power reactors. Design power of BORAX-I was 1.4 megawatts thermal. The BORAX-I design was a precursor to the SL-1 plant, which began operations nearby in 1958.