ORNL's Thirteen Nuclear Reactors

The Graphite Reactor, the world’s first continuously operated nuclear reactor, goes critical at the Manhattan Project’s X-10 site – now known as Oak Ridge National Laboratory. 

The Low-Intensity Test Reactor establishes the feasibility of water-cooled reactors. 

The Bulk Shielding Reactor begins operations and is used for studying radiation shielding and materials irradiation. 

1952: The Homogeneous Reactor Experiment goes critical and provides the first nuclear-generated electricity to the commercial power grid. 

The Aircraft Reactor Experiment is the first molten salt reactor design to go critical and leads to the development of several new reactor designs. 

Tower Shielding Reactor I begins operations and holds a reactor and its shielding 200 feet above ground, which offers unique research capabilities. 

The Geneva Reactor debuts at the first United Nations International Conference on the Peaceful Uses of Atomic Energy—becoming the prototype of future “swimming pool” reactors.

The Homogeneous Reactor Test starts up and offers valuable insights for the development of future nuclear facilities. 

Tower Shielding Reactor II goes critical and provides valuable data in shielding materials and air scattering in more than 30 years of operation 

The Oak Ridge Research Reactor starts up and becomes the world’s major supplier of radioisotopes, while supporting numerous research efforts. 

The Health Physics Research Reactor goes critical and is home to research focused on dosimetry development and radiobiology studies. 

The Molten Salt Reactor Experiment begins operations using uranium-235. Three years later, the reactor breaks new ground by using uranium-233 for fuel. 

The High Flux Isotope Reactor achieves criticality, producing super heavy elements and also being used for groundbreaking materials science.