Nobel Laureate Enrico Fermi led the group that first demonstrated a controlled nuclear reaction (on December 2, 1942).

On November 4, 1943, Fermi witnessed the initial operation of the Graphite Reactor in Oak Ridge.

Designed using the results of the Chicago experiment, the Graphite Reactor produced small amounts of plutonium, setting the stage for large-scale plutonium production by reactors in Hanford, Washington. It was the world's first isotope-production reactor.

Eugene Wigner, later an ORNL director who won a Nobel Prize for physics, predicted that radiation damage could be a problem for reactors. The behavior of irradiated materials was studied at ORNL, which became a leading materials research laboratory.

Irradiated materials are drawn from the Graphite Reactor.

The first neutron-scattering studies using a reactor were performed at the Graphite Reactor by Ernie Wollan and Clifford Shull, who won a Nobel Prize for physics in 1994 for advancing the understanding of the positions of atoms and molecules in materials.

Ion-exchange chromatography used at the Graphite Reactor enabled the discovery of promethium (element 61).

The pressurized water reactor was conceived by Eugene Wigner and Alvin Weinberg, who later became ORNL directors. This design was later used in Navy submarines and commercial nuclear power plants, which today supply one-fifth of the nation's electricity.

Radiation detectors and dosimeters were developed to monitor worker exposure to radiation from reactors and other nuclear sources.

The first shipment of radioisotopes from the Graphite Reactor was made to a hospital for treating cancer patients; by the end of the decade, the Graphite Reactor was the world's leading source of isotopes needed for, agriculture, industry, and medicine.

It was found that experiments with mice could help scientists estimate the human genetic effects of different types and intensities of radiation from atomic weapon tests and reactors.

A way to separate zirconium from hafnium to provide pure zirconium (which absorbs few neutrons) was devised for use in fuel cladding for reactors in Navy submarines.

Methods of reactor control and protection developed at the Graphite Reactor and refined at later ORNL reactors are used widely in today's commercial nuclear power plants.

Using a washing-machine mechanism to move materials into the Graphite Reactor for neutron irradiation, Herb Pomerance discovered that zirconium's ability to absorb neutrons was overestimated because it is usually contaminated with hafnium, a "poison" which absorbs many more neutrons.

ORNL experts in solvent extraction began developing the PUREX process, which became the worldwide method of recovering uranium and plutonium from spent reactor fuels. They also invented the THOREX process to separate thorium from uranium-233.

Reactor-produced radioactive materials were first used at ORNL to trace the natural movement of nutrients and pollutants in forests.

ORNL's Bulk Shielding Reactor provided data for calculations to determine how best to make shielding - different thicknesses and configurations of lead, steel, and concrete - adequately protect people and equipment from exposure to hazardous radiation levels.

ORNL researchers Liane and Bill Russell informed the medical community that the stage of prenatal development in mice strongly influences the amount and type of radiation damage to the embryo and fetus. Their specific recommendations for avoiding the risks of diagnostic X-rays to unsuspected human pregnancies were adopted worldwide.

ORNL's Oak Ridge Automated Computer and Logical Engine (ORACLE), then the world's most powerful computer, was slower and less powerful than today's desktop machines.

For the U.S. Army, ORNL designed a transportable reactor to generate heat and electricity at remote sites such as Antarctica, Greenland, and the Panama Canal Zone.

The Tower Shielding Facility (TSF) provided data for ORNL calculations to aid the design of compact, lightweight shielding to protect a nuclear airplane's flight crew from reactor radiation. The nuclear-powered plane was never built, but ORNL's participation in the national Aircraft Nuclear Propulsion Program produced a wealth of useful nuclear technologies.

The first successful experiment was carried out in which a chemical reaction was studied by colliding molecular beams of two different reactants.

ORNL's most famous reactor of the 1950s was the small "swimming pool" reactor shipped to Geneva, Switzerland, for the United Nations Conference on Peaceful Uses of the Atom.

Using ORNL mouse data, a National Academy of Sciences committee predicted genetic effects of radiation in humans. Later, national and international bodies relied on ORNL data for recommending human radiation exposure limits.

Neutron dosimetry techniques that have been used throughout the world were devised to protect workers from exposure to hazardous levels of radiation.

ORNL biologists used radiation to suppress the immune response in mice and then performed the world's first bone marrow transplants.

Using radioactive tags to study the chemistry of life, ORNL biologists discovered that messenger RNA "reads" DNA's genetic code and turns itself into a template for mass-producing proteins.

ORNL's first fusion research device, the Direct-Current Experiment (DCX), showed that hydrogen ions could be obtained and trapped in a magnetic field.

ORNL provided leadership in setting standards on permissible doses of radiation for medical diagnosis and treatment and for the workplace.

ORNL began "Project Salt Vault," the first national effort to locate a high-level nuclear waste repository. An ORNL test site for storing nuclear wastes is located near Lyons, Kansas.

Performing the first experiment on the Oak Ridge Research Reactor, researchers confirmed the electron-neutrino theory of beta decay. For 30 years, the ORR was used to produce radioisotopes for industrial and medical uses, study the effects of radiation on materials, and carry out neutron-scattering experiments that uncovered the rich variety of crystal and magnetic structures in rare-earth elements.

Spreading a certain dose of radiation over weeks was found to produce fewer mutations in mice than giving the same amount within minutes. This work provided the first evidence that damage that results in mutations can be repaired.

The Clinch River was studied to evaluate the potential long-term hazards of radioisotope releases from a major nuclear facility.

Maleness in the mouse was found to depend on the presence of a Y chromosome.

Personal radiation monitors were developed, including the pocket screamer that chirps and flashes when gamma radiation levels go too high.

A program was started to develop graphite structures and coated-particle fuels for high-temperature gas-cooled reactors.

ORNL researchers developed advanced mathematical and computer approaches to understanding the dynamics of terrestrial ecosystems.

Integrated circuits for electronic applications were first developed as a result of ORNL's calutrons (normally used to produce stable isotopes). They were used to show that silicon implanted with boron and phosphorus ions forms electrical junctions, and then to produce semiconductor samples for industry.

The Health Physics Research Reactor provided radiation-exposure data that helped scientists refine occupational dose limits, design dosimeters for nuclear workers, and devise shields for power plants and space craft.

ORNL became a center for research on civil defense to protect the U.S. population in case of a nuclear war. Drawing on its expertise in shielding and radiation protection, the center evaluated protective measures such as underground shelters.

Aided by computer modeling, ORNL physicists discovered ion channeling in crystalline solids. This insight that energetic ions aimed down open regions in crystal lattices lose less energy than those ions entering in random directions led to precisely controlled implantation of electrically active impurities within crystals. The result: improved semiconductor chips that created the electronic revolution.

A forest stand in Oak Ridge was tagged with cesium-137, providing data for computer models and validating the long-term behavior of this key radioactive waste material.

ORNL researchers applied analysis of signal fluctations (noise) to the identification of operational problems in some reactors, such as vibrations in key parts caused by coolant water flow. ORNL measurements later prompted the decision to let some commercial reactors operate at reduced power until the problem was solved.

The Oak Ridge Isochronous Cyclotron (ORIC) was first operated. It later played an important role in the Holifield nuclear physics accelerator complex.

The Radiation Shielding Information Center at ORNL implemented concepts for information analysis centers in specialized fields, as suggested by a Presidential panel led by ORNL Director Alvin Weinberg.

ORNL's "Water for Peace" desalination concept, in which heat from nuclear reactors in arid lands produces irrigation water for agriculture from seawater, was featured at a United Nations conference. Nuclear-powered desalination complexes were planned for India, Israel, Mexico, Puerto Rico, and the Soviet Union.

ORNL started a long-range program to measure the genetic effects of chemicals such as pesticides, gasoline fumes, drugs, and tobacco.

An important achievement of a program to develop radioisotope heat sources to power space satellites was the construction of an isotope-powered generator for the lunar probe Surveyor.

The discovery of delayed light was one of ORNL's internationally recognized fundamental discoveries in photosynthesis, including evidence for the electronic nature of the process's first step.

ORNL's High Flux Isotope Reactor, which has the world's highest steady-state thermal neutron flux, continued to be used for neutron-scattering experiments, materials irradiation, neutron activation analysis, and production of transuranium isotopes, such as californium-252, which is used to treat cancer.

Studies of the effects of pollutants and movements of nutrients in living systems in water and on land began at the new Walker Branch Watershed research facility. The National Science Foundation selected ORNL to lead a major study of ecosystems in the eastern United States.

A long-running program was started to evaluate the effects of laws, property variations, and residual stresses on the reliability of pressure vessels in light-water reactors.

ORNL's Heavy-Section Steel Technology Program overpressurized intermediate reactor vessels until they fractured. Typically, three times the design pressure was required to induce failure or leakage, confirming that standard reactor operating pressures are safe.

ORNL's Molten Salt Reactor Experiment, which was the first reactor to operate on uranium-233 fuel, was brought to power with the aid of Nobel Laureate Glenn Seaborg.

Developed by Norman Anderson and his associates, ORNL's centrifugal fast analyzer was made into a commercial product that revolutionized medical testing of body fluids in hospitals and clinics.

The Apollo 11 moon rock scoop was designed at ORNL.

ORNL researchers conducted tests on its new doughnut-shaped (tokamak) fusion research machine, the ORMAK. During the 1970s researchers also built and tested the ELMO Bumpy Torus and devices called Impurity Study Experiments to illuminate the behavior of impurities inside fusion reactor plasmas.

To help AEC prepare required envionmental impact statements for nuclear power plants, ORNL researchers gathered needed data on the impacts on fish of heated cooling water from these facilities. This research led to strict temperature limits on nuclear plant discharges, resulting in the installation of massive cooling towers.

Nuclear safety research studies determined at what reactor temperatures and pressures the cladding of nuclear fuel rods begins to collapse.

ORNL researchers began a program of energy research, which later resulted in national insulation standards, more efficient delivery of electrical power, and more energy-efficient designs for refrigerators, heat pumps, ovens, and water heaters.

Researchers at ORNL froze, thawed, and implanted mouse embryos in surrogate mothers, who gave birth to healthy mouse pups. The technique was adopted by the livestock industry for multiplying the reproductive potential of prize cattle.

A set of stiffer nuclear safety criteria emerged after ORNL scientists testified along with nuclear-power opponents at AEC's public hearings on emergency cooling of reactor cores.

ORNL scientists analyzed moon rocks for uranium and thorium.

A chromium-molybdenum steel was developed at ORNL for the U.S. government's breeder reactor project. It is now manufactured and marketed internationally for use in electric utility boilers and oil refinery furnaces.

The Energy Reorganization Act created the Energy Research and Development Administration (ERDA) and the U.S. Nuclear Regulatory Commission (NRC) from the Atomic Energy Commission. Four years later, ERDA became the Department of Energy (DOE), the major source of funding to ORNL and other national labs.

Because of disruptions in the supply of Mideastern oil to the U.S., the government started research on producing liquid and gaseous fuels from coal.

A tougher iridium alloy was created to contain plutonium fuel for radioisotope thermoelectric generators that power the Voyager I, Voyager II, Galileo, Ulysses, and Cassini spacecraft.

Some 40 to 70% of sulfur and nitric acids deposited on ORNL's Walker Branch Watershed forest was found to have arrived in dry particulates rather than rain.

Bioreactors were developed to produce chemicals and fuels (e.g., ethanol from corn) and treat waste streams.

ORNL researchers examine an abnormal cricket grown from an egg that had been exposed to coal-derived chemicals.

ORNL researchers studies the composition and mobility of trace contaminants found in the residues from various coal conversion processes.

Biological effects of chemicals produced by converting coal to liquid and gaseous fuels were studied. This work led to ORNL's developing the scientific field of ecological risk assessment, including a risk assessment method adopted by the U.S. Environmental Protection Agency.

Construction began on Large Coil Test Facility for superconducting fusion magnets.

ORNL researchers developed a method for refueling fusion reactors by injecting frozen hydrogen pellets into their plasmas. The pellet injector (used at the Princeton Plasma Physics Laboratory's Tokamak Fusion Test Reactor) was later adopted for tokamaks in Europe and the United States. A year later, ORNL's neutral-beam injectors achieved record fusion plasma temperatures at the PPPL.

The small angle X-ray scattering device became part of a National Center for Small-Angle Scattering Research established at ORNL.

ORNL researchers helped determine the cause of the loss-of-coolant accident at the Three Mile Island nuclear power plant. They also assessed the core damage, helped prevent the release of radioactively contaminated gases, and devised ways to decontaminate thousands of gallons of emergency coolant.

Bill Russell, a renowned ORNL geneticist, discovered that ethylnitrosourea is the most effective chemical in inducing mutations in mice. ENU is now used widely to discover genes linked to human diseases.

Bill Appleton, Jim Williams and others developed accelerator-based ion implantation techniques to improve the properties of semiconductors, metallic alloys, and ceramics. It was discovered that implanting the surface of an artificial titanium-alloy knee or hip with nitrogen ions greatly improves its resistance to wear and corrosion, delaying the need for a painful replacement operation.

The Holifield Heavy Ion Research Facility began operation on nuclear physics studies and became a scientific user facility. The 25- million-volt electrostatic accelerator, which was linked to the Oak Ridge Isochronous Cyclotron, had the highest direct-voltage current in the world.

ORNL researchers began developing whisker-toughened ceramics now used to make commercial cutting tools.

An assortment of parts, including tubing and ceramic heat-engine components as well as cutting tools, can be made from ORNL's fracture-resistant whisker-reinforced ceramics.

Work was begun to make brittle nickel aluminides ductile; ORNL's modified aluminide alloys have been used in industrial heat-treating equipment, rolls for making steel, and dies for making truck brake parts. Pictured at left are modified nickel aluminide furnace trays that hold automobile parts transferred to a furnace for heat treating at General Motors-Saginaw.

ORNL initiated an extensive ten-year study for the Nuclear Regulatory Commission of fission product release (species and rates) from heated nuclear reactor fuel. Results from this work continue to be referenced as the best available information concerning potential release under accident conditions.

At ORNL's Large Coil Test Facility, researchers from several nations successfully tested superconducting electromagnets half the size of those expected to be used at future fusion power plants.

The Carbon Dioxide Information Analysis Center, which was established at ORNL to serve DOE's Carbon Dioxide Research Program, later became an internationally known repository of data on global change. CDIAC is one of the best known of ORNL's information centers, which started with the nuclear data center in the 1940s. Information centers for collecting, analyzing, and synthesizing information proliferated at ORNL in the 1960s and 1970s. They embraced such areas as nuclear safety, toxic materials, and the human genome.

Bob DeVault designed the gas-fired triple effect absorption chiller for cooling commercial buildings.

ORNL developed insulation standards adopted later by federal agencies and standards to make electric appliances more efficient. ORNL designs led to more efficient commercial heat pump water heaters and refrigerators.

Hypercube concurrent computers were first operated at ORNL's Center for Engineering Science Advanced Research to control robots. Bill Hamel and Chuck Weisbin, then CESAR director, examine the HERMIES-II robot used by CESAR for concept demonstrations of artificial intelligence planning and learning algorithms.

Eli Greenbaum studied photosynthetic water splitting using spinach and later algae for releasing energy-rich gases, such as hydrogen.

ORNL's first distributed memory parallel computer was delivered. This Intel IPSC/1, which had 32 central processing units, was a predecessor of the Intel Paragon supercomputer, which was installed at ORNL in 1992.

At the HHIRF (Holifield Heavy Ion Research Facility) physicists discovered the giant quadrupole resonance in nuclei bombarded with highly energetic ions. In this phenomenon, the nucleus alternately compresses and expands, causing many of its protons and neutrons to move at the same time.

ORNL researchers developed gelcasting, an advanced process for forming ceramic material into complex shapes such as automotive turbines, accelerator magnets, and artificial bone.

ORNL developers published the three-dimensional TORT radiation transport simulation code.

The High Temperature Materials Laboratory was completed, enabling research on developing ceramics for the most energy-efficient engines and high-temperature superconducting materials for efficient electricity distribution.

The High Temperature Materials Laboratory opened as a user facility. Guest researchers from industry, academia, and other government laboratories used HTML's suite of sophisticated instruments to characterize their materials and determine how to improve them.

In research on the newly discovered phenomenon of high-temperature superconductivity, ORNL researchers were among the first to use laser ablation to make superconducting thin films.

The Advanced Toroidal Facility began operating, allowing ORNL researchers to learn more about the physics of fusion energy from experiments on this stellarator.

ORNL's Center for Global Environmental Studies was formed. ORNL is a leader in studies of the environmental effects of increased atmospheric concentrations of carbon dioxide.

ORNL began work with the Nuclear Regulatory Commission to develop the Generic Environmental Impact Statement for use in renewing the licenses of more than 100 U.S. commercial nuclear power plants.

Z-contrast imaging, developed at ORNL, allowed scientists using a scanning transmission electron microscope to see columns of atoms in materials ranging from superconductors to automobile catalysts.

Scientists used the Oak Ridge Electron Linear Accelerator to confirm the existence of separate positive and negative electrical charges (quarks) within the neutron. ORELA was later used to help shed light on the synthesis of elements in the universe.

The Airlift Deployment Analysis System (ADANS) computer code developed at ORNL was used to efficiently deploy military personnel and equipment to the Persian Gulf, Somalia, Rwanda, Haiti, and Bosnia.

Neutron activation analysis using reactors, which was pioneered at ORNL and used for forensic, studies, was applied to hair and nail samples from the grave of President Zachary Taylor. Results of the analysis at ORNL's High Flux Isotope Reactor indicated he had not been poisoned by arsenic while in office, as one historian suspected.

Researchers at ORNL and the University of Tennessee developed a parallel virtual machine (PVM) software package that allows desktop computers linked by a network to be used as a single large parallel computer. It is being used worldwide to solve important scientific, industrial, and medical problems.

ORNL researchers identified and cloned the mouse agouti gene, which causes altered fur color, obesity, diabetes, and skin cancer in mice and which has a human counterpart.

ORNL researchers developed a neural network system for recognizing genes in DNA sequences sent to it by electronic mail. The Gene Recognition and Analysis Internet Link (GRAIL) system is widely used today.

The rhenium-188 isotope generator was developed to treat cancer-induced bone pain and arthritis and prevent the buildup of smooth muscle cells in coronary arteries after balloon angioplasty. Since the mid-1970s, using radioisotopes from Laboratory sources, ORNL's nuclear medicine researchers developed new radioactive imaging agents for medical scanning diagnosis of heart disease.

ORNL's Tuan Vo-Dinh and two medical researchers at Thompson Cancer Survival Center of Knoxville developed a new laser technique for determining without surgery whether a tumor in the esophagus is cancerous.

ORNL researchers developed mass spectrometry techniques for detecting or analyzing explosives, engine exhaust, carriers of the cystic fibrosis gene, and proteins. A direct-sampling ion trap mass spectrometer devised to detect environmental pollutants will be used to detect biological and chemical warfare agents.

ORNL researchers led by Mike Ramsey developed the "lab on a chip," which shows promise as a fast and inexpensive method for DNA sequencing, and forensic fingerprinting, environmental monitoring, diagnosing disease and developing new drugs.

ORNL researchers developed the rolling-assisted biaxial textured substrates (RABiTSTM) technique for fabricating nickel-based, high-temperature superconducting wire. Above, Mariappan Paranthaman uses electron beam evaporation to make a superconducting wire 7 centimeters long.

ORNL researchers led by Vinod Sikka developed a technique for efficiently and safely melting and casting alloys of ORNL-designed nickel aluminides, which are used by the automobile and steel industries.

ORNL researchers developed a more energy-efficient refrigerator-freezer by altering a popular refrigerator model to cut its energy use in half.

Lynne Parker developed ALLIANCE, which directs teams of robots like these in carrying out tasks cooperatively

At the Holifield Radioactive Ion Beam Facility, nuclear structure and nuclear astrophysics studies began, using radioactive ions that do not exist naturally on the earth. A radioactive fluorine beam was developed to measure the rates of nuclear reactions that produce isotopes in stars. ORNL supercomputers are used to model forces within exploding stars (supernovae) that disseminate elements essential to life on the earth.

An upgrade of the High Flux Isotope Reactor will allow it to lead the world in both thermal and cold neutron intensities for use in neutron science. Neutron scattering experiments at HFIR and elsewhere have contributed information that has led to improved consumer products, such as credit cards, computer disks, compact discs, automatic windows, shatterproof windshields, and life-saving bulletproof vests.

ORNL ecological experiment to determine the effects on forest growth of increased concentrations of atmospheric carbon dioxide and reduced precipitation.

Some of ORNL's 60,000 mice are now being scanned with the MicroCAT, a high-resolution X-ray imaging device developed to noninvasively detect internal genetic disorders in mammals whose parents were exposed to radiation or chemicals.

The world's sharpest electron microscope image of a crystal was recorded in 1998 at ORNL. This image of a silicon crystal had double (0.78 vs 1.6 Angstrom) the resolution of a typical transmission electron microscope image.

Xudong Fan uses Z-contrast transmission scanning electron microscope to study iodine-doped carbon nanotubes, strong materials that conduct electricity.