The experimental reactor was started (reached criticality) in 1964 and was decommissioned in 1966 and was used for research about direct energy conversion.

Experimental reactor, operated as an irradiation test facility.

Experimental reactors of that era were not required to have the same type of containment structures that shield modern nuclear reactors.

Those experimental reactors were constructed more than 40 years ago.

There have also been several experimental reactors that use graphite for moderation, such as the pebble bed reactor concepts and the molten-salt reactor experiment (graphite core shown at right).