Five Boiling Reactor Experiments (BORAX I through V) were conducted by Argonne National Laboratory from 1953 through 1964. These experiments provided new insights into how reactors would behave if the cooling water were allowed to boil into steam inside of the reactor vessel:

• BORAX I showed that the boiling water design concept was feasible.
• BORAX II, which operated at a higher power level, continued testing of the boiling water concept.
• BORAX III operated at yet higher power levels. In addition, the reactor was hooked up to a generator and tied into the power grid, which enabled INL to make more history in the summer of 1955:

  On the night of July 17, 1955, the reactor produced sufficient power to light the city of Arco (500 kilowatts), the BORAX test facility (500 kilowatts), and part of the Central Facilities Area at the NRTS (1000 kilowatts).

Proving the Principle, Susan M. Stacy

• BORAX IV was used to test new fuel designs, such as ceramic fuels.
• BORAX V was used to test new concepts for generating steam at higher temperatures.