National Institute for Computational Sciences

Oak Ridge National Laboratory (ORNL) is a federally funded research and development center in Oak Ridge, Tennessee, United States. Founded in 1943, the laboratory is now sponsored by the United States Department of Energy and administered by UT–Battelle, LLC.Established in 1943, ORNL is the largest science and energy national laboratory in the Department of Energy system (by size) and third largest by annual budget. It is located in the Roane County section of Oak Ridge, Tennessee. Its scientific programs focus on materials, nuclear science, neutron science, energy, high-performance computing, environmental science, systems biology and national security, sometimes in partnership with the state of Tennessee, universities and other industries. ORNL has several of the world's top supercomputers, including Frontier, ranked by the TOP500 as the world's most powerful. The lab is a leading neutron and nuclear power research facility that includes the Spallation Neutron Source, the High Flux Isotope Reactor, and the Center for Nanophase Materials Sciences. Commissioned in 1944, the USS Oak Ridge is named after Oak Ridge National Laboratory.

The Multiprogram Research Facility (MRF, also known as Building 5300) is a facility at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. It is used by the U.S. National Security Agency (NSA) to design and build supercomputers for cryptanalysis and other classified projects. It houses the classified component program of the High Productivity Computing Systems (HPCS) project sponsored by the Defense Advanced Research Projects Agency (DARPA).

New Bethel Baptist Church is a historic church on Bethel Valley Road in Oak Ridge, Tennessee. The church was built in about 1900. One of the concrete steps that leads to the church entrance is inscribed with the date "1924," but this is not thought to be an original part of the church. The property was added to the National Register of Historic Places in 1992. The church was founded in 1851. The church ceased operation in 1942 when the land was taken over by the U.S. federal government for Manhattan Project facilities. A large stone marker was erected behind the church in 1949 to commemorate the church and its congregation. It is inscribed "The church having been left in extended session in 1942, this monument was dedicated and the final church session closed at Memorial Day services May 29, 1949." The New Bethel Baptist Church is the only remaining structure from the pre-World War II community of Scarboro, Tennessee.The church building is a frame, gable-front, three-bay structure with weatherboard siding, resting on a poured concrete foundation.

The X-10 Graphite Reactor is a decommissioned nuclear reactor at Oak Ridge National Laboratory in Oak Ridge, Tennessee. Formerly known as the Clinton Pile and X-10 Pile, it was the world's second artificial nuclear reactor (after Enrico Fermi's Chicago Pile-1), and the first designed and built for continuous operation. It was built during World War II as part of the Manhattan Project. While Chicago Pile-1 demonstrated the feasibility of nuclear reactors, the Manhattan Project's goal of producing enough plutonium for atomic bombs required reactors a thousand times as powerful, along with facilities to chemically separate the plutonium bred in the reactors from uranium and fission products. An intermediate step was considered prudent. The next step for the plutonium project, codenamed X-10, was the construction of a semiworks where techniques and procedures could be developed and training conducted. The centerpiece of this was the X-10 Graphite Reactor. It was air-cooled, used nuclear graphite as a neutron moderator, and pure natural uranium in metal form for fuel. DuPont commenced construction of the plutonium semiworks at the Clinton Engineer Works in Oak Ridge on February 2, 1943. The reactor went critical on November 4, 1943, and produced its first plutonium in early 1944. It supplied the Los Alamos Laboratory with its first significant amounts of plutonium, and its first reactor-bred product. Studies of these samples heavily influenced bomb design. The reactor and chemical separation plant provided invaluable experience for engineers, technicians, reactor operators, and safety officials who then moved on to the Hanford site. X-10 operated as a plutonium production plant until January 1945, when it was turned over to research activities, and the production of radioactive isotopes for scientific, medical, industrial and agricultural uses. It was shut down in 1963 and was designated a National Historic Landmark in 1965.

The Fission Product Pilot Plant, building 3515 at Oak Ridge National Laboratory (ORNL), was built in 1948 to extract radioactive isotopes from liquid radioactive waste. It was formerly known as the 'ruthenium-106 tank arrangement'. It is a relatively small facility; the task of extracting radioactive isotopes later took place at a number of specialised buildings nearby. References differ as to when the plant was built; 'radioactive waste management at ORNL' says that it was completed in 1957, the 1955 Annual Report has engineering drawings indicating that the building was fully designed in 1955, but other references suggest that there was a building on the site in 1948.

The Molten-Salt Reactor Experiment (MSRE) was an experimental molten salt reactor research reactor at the Oak Ridge National Laboratory (ORNL). This technology was researched through the 1960s, the reactor was constructed by 1964, it went critical in 1965, and was operated until 1969. The costs of a cleanup project were estimated at about $130 million. The MSRE was a 7.4 MWth test reactor simulating the neutronic "kernel" of a type of inherently safer epithermal thorium breeder reactor called the liquid fluoride thorium reactor. It primarily used two fuels: first uranium-235 and later uranium-233. The latter 233UF4 was the result of breeding from thorium in other reactors. Since this was an engineering test, the large, expensive breeding blanket of thorium salt was omitted in favor of neutron measurements. In the MSRE, the heat from the reactor core was shed via a cooling system using air blown over radiators. It is thought similar reactors could power high-efficiency heat engines such as closed-cycle gas turbines. The MSRE's piping, core vat and structural components were made from Hastelloy-N and its moderator was a pyrolytic graphite core. The fuel for the MSRE was LiF-BeF2-ZrF4-UF4 (65-29.1-5-0.9 mole %), the graphite core moderated it, and its secondary coolant was FLiBe (2LiF-BeF2), it operated as hot as 650 °C and operated for the equivalent of about 1.5 years of full power operation. The result promised to be a simple, reliable reactor. The purpose of the Molten-Salt Reactor Experiment was to demonstrate that some key features of the proposed molten-salt power reactors could be embodied in a practical reactor that could be operated safely and reliably and be maintained without excessive difficulty. For simplicity, it was to be a fairly small, one-fluid (i.e. non-breeding) reactor operating at 10 MWth or less, with heat rejection to the air via a secondary (fuel-free) salt.

The High Flux Isotope Reactor (HFIR) is a nuclear research reactor at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, United States. Operating at 85 MW, HFIR is one of the highest flux reactor-based sources of neutrons for condensed matter physics research in the United States, and it has one of the highest steady-state neutron fluxes of any research reactor in the world. The thermal and cold neutrons produced by HFIR are used to study physics, chemistry, materials science, engineering, and biology. The intense neutron flux, constant power density, and constant-length fuel cycles are used by more than 500 researchers each year for neutron scattering research into the fundamental properties of condensed matter. HFIR has about 600 users each year for both scattering and in-core research. The neutron scattering research facilities at HFIR contain a world-class collection of instruments used for fundamental and applied research on the structure and dynamics of matter. The reactor is also used for medical, industrial, and research isotope production; research on severe neutron damage to materials; and neutron activation to examine trace elements in the environment. Additionally, the building houses a gamma irradiation facility that uses spent fuel assemblies and is capable of accommodating high gamma dose experiments. With projected regular operations, the next major shutdown for a beryllium reflector replacement will not be necessary until about 2023. This outage provides an opportunity to install a cold source in radial beam tube HB-2, which would give an unparalleled flux of cold neutrons feeding instruments in a new guide hall. With or without this additional capability, HFIR is projected to continue operating through 2040 and beyond. In November 2007 ORNL officials announced that time-of-flight tests on a newly installed cold source (which uses liquid helium and hydrogen to slow the movement of neutrons) showed better performance than design predictions, equaling or surpassing the previous world record set by the research reactor at the Institut Laue–Langevin in Grenoble, France.

The Spallation Neutron Source (SNS) is an accelerator-based neutron source facility in the U.S. that provides the most intense pulsed neutron beams in the world for scientific research and industrial development. Each year, this facility hosts hundreds of researchers from universities, national laboratories, and industry, who conduct basic and applied research and technology development using neutrons. SNS is part of Oak Ridge National Laboratory, which is managed by UT-Battelle for the United States Department of Energy (DOE). SNS is a DOE Office of Science user facility, and it is open to scientists and researchers from all over the world.

The Coherent Collaboration (stylized as COHERENT Collaboration) is a multi-institutional effort to measure Coherent Elastic Neutrino-Nucleus Scattering (CEvNS) using the Spallation Neutron Source (SNS) at Oak Ridge National Lab in Oak Ridge, Tennessee. The Coherent collaboration has deployed a suite of detectors with different detector technologies and target nuclei with the goal of directly measuring CEvNS, and this was accomplished in 2017 with a CsI[Na] scintillator crystal detector, making them the first in the world to do so. By taking measurements of the CEvNS cross section for various target nuclei, the Coherent collaboration is able to provide a strong test of the predictions of the standard model. There are also opportunities to study various Beyond the Standard Model (BSM) effects, such as dark matter and sterile neutrinos.

Melton Hill Dam is a hydroelectric dam on the Clinch River just south of Oak Ridge, Tennessee, United States. The dam is operated by the Tennessee Valley Authority, which built the dam in the early 1960s to extend the Tennessee Valley's continuous navigation channel up the Clinch as far as Clinton and to increase TVA's overall power-generating capacity. The dam impounds the 5,470-acre (2,210 ha) Melton Hill Lake, and is the only TVA tributary dam serviced by a navigation lock. The dam and associated infrastructure were listed on the National Register of Historic Places in 2017. Melton Hill Dam was named for a knob atop nearby Copper Ridge where the United States Coast and Geodetic Survey installed a triangulation station in 1884.