96 Sentences With "fission reactor" | Random Sentence Generator

Kilopower is a prototype miniature nuclear fission reactor that uses a six-inch chunk of uranium-235 as fuel.

In fact, it is the first new operable fission reactor concept designed in the US in over 21980 years.

Kilopower test unitPhoto: NASANASA announced today that it has completed tests of its Kilopower portable nuclear fission reactor, a device designed to one day power bases on Mars or the moon.

A miniature fission reactor could work on other extreme environments, including the moon, said Lee Mason, NASA principal technologist for power and energy storage for power and energy storage, in a release.

Those are the problems NASA's Kilopower project hopes to solve with a compact nuclear fission reactor that uses a uranium-235 reactor core "roughly the size of a paper towel roll," reports Reuters.

Since most nuclear power plants on Earth are designed to produce hundreds of kilowatts electricity, this meant that Gibson and his colleagues would have to come up with a new fission reactor design.

Instead of a fission reactor, Phoenix employs a small-scale version of a process that some hope will one day lead to fusion reactors (and which already lies at the heart of hydrogen bombs).

The downside of such an approach is that the rest of the reactor will absorb neutrons as well, making the whole thing radioactive (though nothing like as radioactive as a conventional fission reactor) and ultimately damaging its structure.

There is no risk of a runaway reaction and meltdown as with nuclear fission and, while radioactive waste is produced, it is not nearly as long-lived as the spent fuel rods and irradiated components of a fission reactor.

Both of these processes contribute to the copious quantities of beta rays and electron antineutrinos produced by fission-reactor fuel rods.

The Oklo natural nuclear fission reactor contains evidence that significant amounts of technetium-99 were produced and have since decayed into ruthenium-99.

The transuranic elements from americium to fermium, including berkelium, occurred naturally in the natural nuclear fission reactor at Oklo, but no longer do so.

All gas- core reactor rocket designs share several properties in their nuclear reactor cores, and most designs share the same materials. The closest terrestrial design concept is the gaseous fission reactor.

In Gabon, mining used to occur in Oklo, but the deposits are reported to be exhausted. In 1972, remains of a natural nuclear fission reactor were found at the Oklo deposits.

Numerous nuclear research activities are conducted at Cadarache, including mixed-oxide fuel (MOX) production, nuclear propulsion and fission reactor prototyping, nuclear fusion research and research into new forms of fission fuel. Nuclear waste is also treated and recycled at the site.

Gas core reactor rockets are a conceptual type of rocket that is propelled by the exhausted coolant of a gaseous fission reactor. The nuclear fission reactor core may be either a gas or plasma. They may be capable of creating specific impulses of 3,000–5,000 s (30 to 50 kN·s/kg, effective exhaust velocities 30 to 50 km/s) and thrust which is enough for relatively fast interplanetary travel. Heat transfer to the working fluid (propellant) is by thermal radiation, mostly in the ultraviolet, given off by the fission gas at a working temperature of around 25,000 °C.

Kosmos 1818 was a nuclear powered Soviet surveillance satellite in the RORSAT program, which monitored NATO vessels using radar. Kosmos 1818 was the first satellite to use the TOPAZ-1 fission reactor. In July 2008, the satellite was damaged, and leaked a trail of sodium coolant.

In general terms, fusion reactors would create far less radioactive material than a fission reactor, the material it would create is less damaging biologically, and the radioactivity "burns off" within a time period that is well within existing engineering capabilities for safe long- term waste storage. In specific terms, except in the case of aneutronic fusion, the large flux of high-energy neutrons in a reactor make the structural materials radioactive. The radioactive inventory at shut-down may be comparable to that of a fission reactor, but there are important differences. The half-life of the radioisotopes produced by fusion tends to be less than those from fission, so that the inventory decreases more rapidly.

In the near future, the clash between oil and green energy conglomerates results in skyrocketing energy prices and global riots. Amidst this chaos, the corporation Auxilisun develops the tri-fission reactor, a device that not only produces abundant nuclear energy through atomic fission, but also converts nuclear waste into additional clean energy. The tri-fission reactor renders all other forms of energy production obsolete, and Auxilisun power plants are built around the world, providing an inexhaustible supply of cheap energy for all. Decades later, on Christmas Day, Auxilisun technician Abby travels to Gibson Desert North, the flagship Auxilisun plant built over a nuclear waste storage facility deep within a radioactive "red zone", to restore a broken communications relay.

A subcritical reactor is a nuclear fission reactor concept that produces fission without achieving criticality. Instead of sustaining a chain reaction, a subcritical reactor uses additional neutrons from an outside source. There are two general classes of such devices. One uses neutrons provided by a nuclear fusion machine, a concept known as a fusion–fission hybrid.

A possible explanation, therefore, was that the uranium ore had operated as a natural fission reactor. Other observations led to the same conclusion, and on September 25, 1972, the CEA announced their finding that self-sustaining nuclear chain reactions had occurred on Earth about 2 billion years ago. Later, other natural nuclear fission reactors were discovered in the region.

Some of the instruments proposed for the design included a 1.5-meter telescope for observations and a 1-meter telescope for laser communication with Earth. After launch it would accelerate to about 106 km/s (about 22.4 AU/year, or ~0.0004% the speed of light) over 10 years, using xenon as propellant and a nuclear fission reactor for power.

They concluded that the deposit had been in a reactor: a natural nuclear fission reactor, around 1.8 to 1.7 billion years BP – in the Paleoproterozoic Era during Precambrian times. At that time the natural uranium had a concentration of about 3% 235U, and could have reached criticality with natural water as neutron moderator allowed by the special geometry of the deposit.

Feasible current, or near-term fission reactor designs can generate up to 2.2 kW per kilogram of reactor mass. Without any payload, such a reactor could drive a photon rocket at nearly 10−5 m/s² (10−6g; see g-force). This could perhaps provide interplanetary spaceflight capability from Earth orbit. Nuclear fusion reactors could also be used, perhaps providing somewhat higher power.

Kosmos 1402 () was a Soviet spy satellite that malfunctioned, resulting in the uncontrolled re-entry of its nuclear reactor and its radioactive uranium fuel. Kosmos 1402 was launched on August 30, 1982 and re-entered the atmosphere on 23 January 1983. The fission reactor entered a few days later; on 7 February 1983. Kosmos 1402 was a RORSAT surveillance satellite that used radar for monitoring NATO vessels.

The inherent danger of a conventional fission reactor is any situation leading to a positive feedback, runaway, chain reaction such as occurred during the Chernobyl disaster. In a hybrid configuration the fission and fusion reactions are decoupled, i.e. while the fusion neutron output drives the fission, the fission output has no effect whatsoever on the fusion reaction, completely eliminating any chance of a positive feedback loop.

Proponents believe that much of the ITER criticism is misleading and inaccurate, in particular the allegations of the experiment's "inherent danger". The stated goals for a commercial fusion power station design are that the amount of radioactive waste produced should be hundreds of times less than that of a fission reactor, and that it should produce no long-lived radioactive waste, and that it is impossible for any such reactor to undergo a large-scale runaway chain reaction. A direct contact of the plasma with ITER inner walls would contaminate it, causing it to cool immediately and stop the fusion process. In addition, the amount of fuel contained in a fusion reactor chamber (one half gram of deuterium/tritium fuel) is only sufficient to sustain the fusion burn pulse from minutes up to an hour at most, whereas a fission reactor usually contains several years' worth of fuel.

Gabon is notable for the Oklo reactor zones, the only known natural nuclear fission reactor on Earth which was active two billion years ago. The site was discovered during uranium mining in the 1970s to supply the French nuclear power industry. Gabon's largest river is the Ogooué which is long. Gabon has three karst areas where there are hundreds of caves located in the dolomite and limestone rocks.

Once initiated, the energy from fusion maintains the necessary temperature for subsequent fusion events. The eventual device may reach in width. The company claims that each design iteration is shorter and far lower cost than large-scale projects such as the Joint European Torus, ITER or NIF. A Pth reactor, long by in diameter, produces about a reactor, similar in size to an A5W nuclear submarine fission reactor.

Marvin Herndon: Whole-Earth Decompression Dynamics Cornell University Astrophysics, 2005J. Marvin Herndon: A New Basis of Geoscience: Whole-Earth Decompression Dynamics Cornell University Physics 2013 Recent measurements of "geoneutrino" fluxes in the KamLAND and Borexino experiments have placed stringent upper limits on Herndon's "georeactor" hypothesis on the presence of an active nuclear fission reactor in the Earth's inner core, so that such reactor would produce less than 3 TW.

The BM-40A reactor is the nuclear fission reactor used to power four of the seven boats of the Soviet Navy's Project 705 Лира (Lira or Alfa in NATO designation) fourth generation submarines. It is a liquid metal cooled reactor (LMR), using highly enriched uranium-235 fuel to produce 155 MWt of power. It was developed by OKB Gidropress in cooperation with IPPE. BM-40A has two steam circulation loops.

Nuclear weapons also produce very large quantities of neutrinos. Fred Reines and Clyde Cowan considered the detection of neutrinos from a bomb prior to their search for reactor neutrinos; a fission reactor was recommended as a better alternative by Los Alamos physics division leader J.M.B. Kellogg. Fission weapons produce antineutrinos (from the fission process), and fusion weapons produce both neutrinos (from the fusion process) and antineutrinos (from the initiating fission explosion).

Small modular reactors (SMRs) are a type of nuclear fission reactor which are smaller than conventional reactors. This allows them to be manufactured at a plant and brought to a site to be assembled. Modular reactors allow for less on-site construction, increased containment efficiency, and enhanced safety due to passive nuclear safety features. SMRs have been proposed as a way to bypass financial and safety barriers that have plagued conventional nuclear reactors.

Atmospheric curium compounds are poorly soluble in common solvents and mostly adhere to soil particles. Soil analysis revealed about 4,000 times higher concentration of curium at the sandy soil particles than in water present in the soil pores. An even higher ratio of about 18,000 was measured in loam soils. The transuranic elements from americium to fermium, including curium, occurred naturally in the natural nuclear fission reactor at Oklo, but no longer do so.

In 1959, WBFO was launched as an AM radio station by UB's School of Engineering and Applied Sciences, and run by UB's students. The station has since become the launching pad of two modern National Public Radio personalities: Terri Gross and Ira Flatow. In 1961, the Western New York nuclear research program was created at the university. This program installed a miniature, active nuclear fission reactor on the University's South (Main Street) Campus.

Alternatively, extrapolating from recent NASA research into fission reactors for deep space missions, it is estimated that sufficient fission- reactor based electric power infrastructure might mass between , requiring at least two Starships for transport. A Mars power system using solar and vertical axis wind turbine design to produce sufficient power might mass just over ."Engineering Mars commercial rocket propellant production for the Big Falcon Rocket (part 3)" . Steve Hoeser, The Space Review.

Nuclear weapons employ high quality, highly enriched fuel exceeding the critical size and geometry (critical mass) necessary in order to obtain an explosive chain reaction. The fuel for energy purposes, such as in a nuclear fission reactor, is very different, usually consisting of a low-enriched oxide material (e.g. UO2). There are two primary isotopes used for fission reactions inside of nuclear reactors. The first and most common is U-235 or uranium-235.

Oklo Mine (sometimes Oklo Reactor or Oklo Mines), located in Oklo, Gabon on the west coast of Central Africa, is believed to be the only natural nuclear fission reactor. Oklo consists of 16 sites at which self-sustaining nuclear fission reactions are thought to have taken place approximately 1.7 billion years ago, and ran for hundreds of thousands of years. It is estimated to have averaged under 100 kW of thermal power during that time.

Any nuclide that strongly absorbs neutrons is called a reactor poison, because it tends to shut down (poison) an ongoing fission chain reaction. Some reactor poisons are deliberately inserted into fission reactor cores to control the reaction; boron or cadmium control rods are the best example. Many reactor poisons are produced by the fission process itself, and buildup of neutron-absorbing fission products affects both the fuel economics and the controllability of nuclear reactors.

Orthodox chemical rockets use heat energy produced by chemical reactions in a reaction chamber to heat the gas products. The products are then expelled through a propulsion nozzle at a very high speed, creating thrust. In a nuclear thermal rocket (NTR), thrust is created by heating a fluid by using a nuclear fission reactor. The lower the molecular weight of the exhaust, hydrogen having the lowest possible, the more efficient the motor can be.

The project also aimed to produce a safe and long-lasting space fission reactor system for a spacecraft's power and propulsion, replacing the long-used RTGs. Budget constraints resulted in the effective halting of the project, but Project Prometheus has had success in testing new systems. After its creation, scientists successfully tested a High Power Electric Propulsion (HiPEP) ion engine, which offered substantial advantages in fuel efficiency, thruster lifetime, and thruster efficiency over other power sources.

A nuclear fission reactor might fulfill most of a Moon base's power requirements.Stephanie Schierholz, Grey Hautaluoma, Katherine K. Martin: NASA Developing Fission Surface Power Technology. National Aeronautics and Space Administration, September 10, 2008, retrieved June 27, 2011 With the help of fission reactors, one could overcome the difficulty of the 354 hour lunar night. According to NASA, a nuclear fission power station could generate a steady 40 kilowatts, equivalent to the demand of about eight houses on Earth.

Geological situation in Gabon leading to natural nuclear fission reactors A fossil natural nuclear fission reactor is a uranium deposit where self- sustaining nuclear chain reactions have occurred. This can be examined by analysis of isotope ratios. The conditions under which a natural nuclear reactor could exist had been predicted in 1956 by Paul Kazuo Kuroda. The phenomenon was discovered in 1972 in Oklo, Gabon by French physicist Francis Perrin under conditions very similar to what was predicted.

Brooks also discusses the Oklo natural nuclear fission reactor, in which the natural conditions in caves in Gabon 2 billion years ago caused the uranium there to react. It may be that the amount of energy released was different from today. Both sets of data are subject to ongoing investigation and debate but, Brooks suggests, may indicate that the behaviour of matter and energy can vary radically and essentially as the conditions of the universe changes through time.

The OK-550 reactor is the nuclear fission reactor used to power three of the seven boats of the Soviet Navy's Project 705 Лира (Lira or Alfa in NATO designation) fourth generation submarines. It is a liquid metal cooled reactor (LMR), using highly enriched uranium-235 fuel to produce 155 MWt of power. OK-550 has three separate steam circulation loops, and was used in the boats built at Severodvinsk. The reactor was developed by OKBM.

In the electric power industry, megawatt electrical (MWe or MWe ) refers by convention to the electric power produced by a generator, while megawatt thermal or thermal megawatt (MWt, MWt, or MWth, MWth) refers to thermal power produced by the plant. For example, the Embalse nuclear power plant in Argentina uses a fission reactor to generate 2109 MWt (i.e. heat), which creates steam to drive a turbine, which generates 648 MWe (i.e. electricity). Other SI prefixes are sometimes used, for example gigawatt electrical (GWe).

In order to conduct a proposed crewed trip to Mars in 39 days,Video: "Mars in 39 Days?: the VASIMR Plasma Engine. Franklin Chang-Diaz, Ph.D." the VASIMR would require an electrical power level projected to be developed only by nuclear propulsion in an application of nuclear power in space.David Buden, Space Nuclear Fission Electric Power System: Book 3: Space Nuclear Propulsion and Power This kind of nuclear fission reactor might use a traditional Rankine/Brayton/Stirling engine to convert heat to electricity.

Kilopower is an experimental project aimed at producing new nuclear reactors for space travel. The project started in October 2015, led by NASA and the DoE’s National Nuclear Security Administration (NNSA). As of 2017, the Kilopower reactors were intended to come in four sizes, able to produce from one to ten kilowatts of electrical power (1-10 kWe) continuously for twelve to fifteen years. The fission reactor uses uranium-235 to generate heat that is carried to the Stirling converters with passive sodium heat pipes.

Alexander Isaakovich Shlyakhter (; died June 2000) was a Russian nuclear physicist and risk analyst. Shlyakhter is best known for discovering empirical evidence for the constancy of fundamental constants. While still a student in Leningrad, he observed that the products of past nuclear reactions at a natural nuclear fission reactor at Oklo, Gabon demonstrate that the fine- structure constant α has changed less than 10−17 per year over the last two billion years. He published the finding in a letter to Nature in 1976.

Like most radioisotopes found in the radium series, 206Pb was initially named as a variation of radium, specifically radium G. It is the decay product of both 210Po (historically called radium F) by alpha decay, and the much rarer 206Tl (radium EII) by beta decay. Lead-206 has been proposed for use in fast breeder nuclear fission reactor coolant over the use of natural lead mixture (which also includes other stable lead isotopes) as a mechanism to greatly suppress unwanted production of highly radioactive byproducts.

Within a nuclear fission reactor, the neutron flux is the primary quantity measured to control the reaction inside. The flux shape is the term applied to the density or relative strength of the flux as it moves around the reactor. Typically the strongest neutron flux occurs in the middle of the reactor core, becoming lower toward the edges. The higher the neutron flux the greater the chance of a nuclear reaction occurring as there are more neutrons going through an area per unit time.

Given the very constrained supply of plutonium, the Stirling converter is notable for producing about four times as much electric power from the plutonium fuel as compared to a radioisotope thermoelectric generator (RTG). The Stirling generators were extensively tested on Earth by NASA, but their development was cancelled in 2013 before they could be deployed on actual spacecraft missions. A similar NASA project still under development as of , called Kilopower, also utilizes Stirling engines, but uses a small uranium fission reactor as the heat source.

The VT-1 reactor was the nuclear fission reactor used in a pair to power Soviet submarine K-27 as part of the Soviet Navy's Project 645 Кит-ЖМТ. It is a liquid metal cooled reactor (LMR), using highly enriched uranium-235 fuel to produce 73 MW of power. K-27 was a November class first generation nuclear submarine, and the only one of its class fitted with liquid metal cooled reactors. However the seven-member Alfa class were subsequently fitted with liquid metal cooled reactors.

This leads to an alternate design where the primary purpose of the fusion–fission reactor is to reprocess waste into new fuel. Although far less economical than chemical reprocessing, this process also burns off some of the nastier elements instead of simply physically separating them out. This also has advantages for non- proliferation, as enrichment and reprocessing technologies are also associated with nuclear weapons production. However, the cost of the nuclear fuel produced is very high, and is unlikely to be able to compete with conventional sources.

Theoretical research since the design of HiPER in the early 2000s has cast doubt on fast ignition but a new approach known as shock ignition has been proposed to address some of these problems. Japan developed the KOYO-F fusion reactor design and laser inertial fusion test (LIFT) experimental reactor. In April 2017, Bloomberg News reported that Mike Cassidy, former Google vice-president and director of Project Loon with Google[x], started a clean energy startup, Apollo Fusion, to develop a hybrid fusion-fission reactor technology.

In Lisa's room, Homer sees her entry for the science fair, which is a history of nuclear physics and a scale model of the first nuclear reactor. However, Martin shows them his project, a childlike robot named CHUM. With Lisa sure to lose, Homer decides to help her by stealing some plutonium from the power plant and building a small working Class II plutonium fission reactor. After showing it to Lisa, she is horrified and alerts Marge to the danger, who tells Homer to get rid of the "irradiating whatsit".

Californium is not a major radionuclide at United States Department of Energy legacy sites since it was not produced in large quantities. Californium was once believed to be produced in supernovas, as their decay matches the 60-day half-life of 254Cf. However, subsequent studies failed to demonstrate any californium spectra, and supernova light curves are now thought to follow the decay of nickel-56. The transuranic elements from americium to fermium, including californium, occurred naturally in the natural nuclear fission reactor at Oklo, but no longer do so.

As an example, 1.7×109 years ago the NA of 235U was 3.1% compared with today's 0.7%, and for that reason a natural nuclear fission reactor was able to form, something that cannot happen today. However, the natural abundance of a given isotope is also affected by the probability of its creation in nucleosynthesis (as in the case of samarium; radioactive 147Sm and 148Sm are much more abundant than stable 144Sm) and by production of a given isotope as a daughter of natural radioactive isotopes (as in the case of radiogenic isotopes of lead).

Sevmorput is powered by a single KLT-40 nuclear fission reactor with a thermal output of 135 megawatts. The reactor core contains of 30–40- or 90-percent90 % according to information provided to Norwegian government in 1990, 30–40 % according to Bellona Foundation citing communication with Murmansk Shipping Company. (Diakov, Anatoli C. et al.) enriched uranium in uranium-zirconium alloy and has reportedly required refueling only twice. The nuclear power plant on board the vessel produces 215 tons of steam per hour at a pressure level of and temperature of .

The use of an aqueous homogeneous nuclear fission reactor for the simultaneous hydrogen production by water radiolysis and process heat production was examined at the University of Michigan, in Ann Arbor in 1975. Several small research projects continue this line of inquiry in Europe. Atomics International designed and built a range of low power (5 to 50,000 watts thermal) nuclear reactors for research, training, and isotope production purposes. One reactor model, the L-54, was purchased and installed by a number of United States universities and foreign research institutions, including Japan.

One group, studying distant quasars, has claimed to detect a variation of the fine structure constant at the level in one part in 105. Other authors dispute these results. Other groups studying quasars claim no detectable variation at much higher sensitivities. For over three decades since the discovery of the Oklo natural nuclear fission reactor in 1972, even more stringent constraints, placed by the study of certain isotopic abundances determined to be the products of a (estimated) 2 billion year-old fission reaction, seemed to indicate no variation was present.

This procedure is well known as nuclear transmutation, but it is still being developed for americium.Baetslé, L. Application of Partitioning/Transmutation of Radioactive Materials in Radioactive Waste Management , Nuclear Research Centre of Belgium Sck/Cen, Mol, Belgium, September 2001, Retrieved 28 November 2010Fioni, Gabriele; Cribier, Michel and Marie, Frédéric Can the minor actinide, americium-241, be transmuted by thermal neutrons? , Department of Astrophysics, CEA/Saclay, Retrieved 28 November 2010 The transuranic elements from americium to fermium occurred naturally in the natural nuclear fission reactor at Oklo, but no longer do so.

Although the plasma in a fusion power station is expected to have a volume of or more, the plasma density is low and typically contains only a few grams of fuel in use. If the fuel supply is closed, the reaction stops within seconds. In comparison, a fission reactor is typically loaded with enough fuel for several months or years, and no additional fuel is necessary to continue the reaction. It is this large amount of fuel that gives rise to the possibility of a meltdown; nothing like this exists in a fusion reactor.

In order to maintain criticality, the fuel has to retain that extra concentration of U-235. A typical fission reactor burns off enough of the U-235 to cause the reaction to stop over a period on the order of a few months. A combination of burnup of the U-235 along with the creation of neutron absorbers, or poisons, as part of the fission process eventually results in the fuel mass not being able to maintain criticality. This burned up fuel has to be removed and replaced with fresh fuel.

The spacecraft variant of the gaseous fission reactor is called the gas core reactor rocket. There are two approaches: the open and closed cycle. In the open cycle, the propellant, most likely hydrogen, is fed to the reactor, heated up by the nuclear reaction in the reactor, and exits out the other end. Unfortunately, the propellant will be contaminated by fuel and fission products, and although the problem can be mitigated by engineering the hydrodynamics within the reactor, it renders the rocket design completely unsuitable for use in atmosphere.

Development of nuclear models (such as the liquid-drop model and nuclear shell model) made prediction of properties of nuclides possible. No existing model of nucleon–nucleon interaction can analytically compute something more complex than based on principles of quantum mechanics, though (note that complete computation of electron shells in atoms is also impossible yet). The most developed branch of nuclear physics in 1940s was studies related to nuclear fission due to its military significance. The main focus of fission-related problems is interaction of atomic nuclei with neutrons: a process that occurs in a fission bomb and a nuclear fission reactor.

Artists's Conception of Jupiter Icy Moons Orbiter which was mission for Prometheus. It was to be powered by a small fission reactor providing electrical power to ion engines and electronics. A long boom is used to create distance between the reactor and the rest of the spacecraft, and fins radiate waste heat into space In 2002, NASA announced an initiative towards developing nuclear systems, which later came to be known as Project Prometheus. A major part of the Prometheus Project was to develop the Stirling Radioisotope Generator and the Multi-Mission Thermoelectric Generator, both types of RTGs.

Using Li-6, neutrons from the fission would make up for the losses, but only at the cost of removing them from causing other fission reactions, lowering the reactor power output. The designer has to choose which is more important; burning up the fuel through fusion neutrons, or providing power through self- induced fission events. The economics of fission–fusion designs have always been questionable. The same basic effect can be created by replacing the central fusion reactor with a specially designed fission reactor, and using the surplus neutrons from the fission to breed fuel in the blanket.

This was a self-contained design with the entire fusion section packaged into a cylindrical concrete building not unlike a fission reactor confinement building, although larger at diameter. The central building was flanked by smaller rectangular buildings on either side, one containing the turbines and power handling systems, the other the tritium plant. A third building, either attached to the plant or behind it depending on the diagram, was used for maintenance. Inside the central fusion building, the beam-in-a-box lasers were arranged in two rings, one above and one below the target chamber.

Unlike Daedalus, which used an open-cycle fusion engine, Longshot would use a long-lived nuclear fission reactor for power. Initially generating 300 kilowatts, the reactor would power a number of lasers in the engine that would be used to ignite inertial confinement fusion similar to that in Daedalus. The main design difference is that Daedalus also relied on the fusion reaction to power the ship, whereas in the Longshot design the internal reactor would provide this power. The reactor would also be used to power a laser for communications back to Earth, with a maximum power of 250 kW.

The power source for the satellite was a BES-5 nuclear fission reactor, which used about of enriched uranium as a fuel source. The satellite operated in low earth orbit, and the reactor was designed to eject to a higher parking orbit at the end of the satellite's mission, or in the event of a mishap. This ejection mechanism was implemented in the RORSAT satellites after a nuclear accident caused by a previous malfunction of Kosmos 954, five years earlier over Canada's Northwest Territories. In response to the Kosmos 954 mishap, RORSAT satellites were modified with an ejection system for their nuclear reactors.

Forward view of JIMO JIMO was to have a large number of revolutionary features. Throughout its main voyage to the Jupiter moons, it was to be propelled by an ion propulsion system via either the High Power Electric Propulsion or NEXIS engine, and powered by a small fission reactor. A Brayton power conversion system would convert reactor heat into electricity. Providing a thousand times the electrical output of conventional solar- or radioisotope thermoelectric generator (RTG)-based power systems, the reactor was expected to open up opportunities like flying a full scale ice-penetrating radar system and providing a strong, high-bandwidth data transmitter.

Because of the short half- > life of all isotopes of fermium, any primordial fermium, that is fermium > that could be present on the Earth during its formation, has decayed by now. > Synthesis of fermium from naturally occurring actinides uranium and thorium > in the Earth crust requires multiple neutron capture, which is an extremely > unlikely event. Therefore, most fermium is produced on Earth in scientific > laboratories, high-power nuclear reactors, or in nuclear weapons tests, and > is present only within a few months from the time of the synthesis. The > transuranic elements from americium to fermium did occur naturally in the > natural nuclear fission reactor at Oklo, but no longer do so.

Nuclear fission reactors are a natural energy phenomenon, having naturally formed on earth in times past, for example a natural nuclear fission reactor which ran for thousands of years in present-day Oklo Gabon was discovered in the 1970s. It ran for a few hundred thousand years, averaging 100 kW of thermal power during that time. Conventional, human manufactured, nuclear fission power stations largely use uranium, a common metal found in seawater, and in rocks all over the world, as its primary source of fuel. Uranium-235 "burnt" in conventional reactors, without fuel recycling, is a non-renewable resource, and if used at present rates would eventually be exhausted.

Columbia's Plasma Physics Laboratory is part of the School of Engineering and Applied Science (SEAS), in which the HBT and Columbia Non-Neutral Torus are housed. The school also has two wind tunnels, a machine shop, a nanotechnology laboratory, a General Dynamics TRIGA Mk. II nuclear fission reactor, a large scale centrifuge for geotechnical testing, and an axial tester commonly used for testing New York City bridge cables. Each department has numerous laboratories on the Morningside Heights campus; however, other departments have holdings throughout the world. For example, the Applied Physics department has reactors at Nevis Labs in Irvington, NY and conducts work with CERN in Geneva.

Retrieved 3 April 2019.Snapshot, Gunther's Space Page. Retrieved 3 April 2019. The test marked both the world's first operation of a nuclear reactor in orbit,"History of US Astronuclear Reactors part 1: SNAP-2 and 10A", Beyond NERVA, April 3, 2019. Retrieved 3 April 2019.Andrew LePage, "The First Nuclear Reactor in Orbit", Drew Ex Machina, April 3, 2015. Retrieved 3 April 2019. and the first operation of an ion thruster system in orbit. It is the only fission reactor power system launched into space by the United States. The reactor stopped working after just 43 days due to a non-nuclear electrical component failure.

Nuclear fuel pellets are used to release nuclear energy The most common type of nuclear fuel used by humans is heavy fissile elements that can be made to undergo nuclear fission chain reactions in a nuclear fission reactor; nuclear fuel can refer to the material or to physical objects (for example fuel bundles composed of fuel rods) composed of the fuel material, perhaps mixed with structural, neutron moderating, or neutron reflecting materials. The most common fissile nuclear fuels are 235U and 239Pu, and the actions of mining, refining, purifying, using, and ultimately disposing of these elements together make up the nuclear fuel cycle, which is important for its relevance to nuclear power generation and nuclear weapons.

Nuclear gas core closed cycle rocket engine diagram, nuclear "light bulb" A nuclear lightbulb is a hypothetical type of spacecraft engine using a gaseous fission reactor to achieve nuclear propulsion. Specifically it would be a type of gas core reactor rocket that uses a quartz wall to separate nuclear fuel from coolant/propellant. It would be operated at temperatures of up to 22,000°C where the vast majority of the electromagnetic emissions would be in the hard ultraviolet range. Fused silica is almost completely transparent to this light, so it would be used to contain the uranium hexafluoride and allow the light to heat reaction mass in a rocket or to generate electricity using a heat engine or photovoltaics.

The Central Research Institute of Electric Power Industry (CRIEPI; 電力中央研究所) is a Japanese non-profit foundation that conducts research and development of technologies in a variety of scientific and technical fields related to the electric power industry. Also, CRIEPI researches many aspects of social matters through subordinate laboratories. CRIEPI not only engages in research and education in Japan, but also provides education, training and technology transfer worldwide. It is similar to the U.S. EPRI, though its energy research extends into areas that could be considered to be in the domain of the USDOE's national laboratories in the United States, such as research and design of fission reactor concepts.

Because of the short half-life of all isotopes of einsteinium, any primordial einsteinium—that is, einsteinium that could possibly have been present on the Earth during its formation—has long since decayed. Synthesis of einsteinium from naturally-occurring actinides uranium and thorium in the Earth's crust requires multiple neutron capture, which is an extremely unlikely event. Therefore, all terrestrial einsteinium is produced in scientific laboratories, high-power nuclear reactors, or in nuclear weapons tests, and is present only within a few years from the time of the synthesis. The transuranic elements from americium to fermium, including einsteinium, occurred naturally in the natural nuclear fission reactor at Oklo, but no longer do so.

Vaygach is powered by a single KLT-40M nuclear fission reactor located amidships with a thermal output of 171 MW. The nuclear power plant on board the icebreaker produces superheated steam, which is used to generate electricity for the propulsion motors and other shipboard consumers as well as heat to maintain operational capability at . Vaygach has two main turbogenerators aft of the reactor compartment consisting of Soviet-made steam turbines coupled to Siemens generators, each producing 18,400 kW of electricity at 3,000 rpm for the propulsion motors. In addition the ship has two auxiliary turbogenerators, manufactured in the Soviet Union, which produce 2,000 kW of electrical power for shipboard consumers.Atomivoimalla päin ahtojäitä. Navigator 4/88.

It was a proposed nuclear electric rocket spacecraft that used a 1 MW fission reactor and an ion drive (with a burn time of about 10 years) to reach a distance of 1000 AU in 50 years. The primary goal of the mission was to improve parallax measurements of the distances to stars inside and outside the Milky Way, with secondary goals being the study of the heliopause, measurements of conditions in the interstellar medium, and (via communications with Earth) tests of general relativity. One of the tasks envisioned for TAU would be a flyby of Pluto. A Pluto flyby was achieved in 2015 by the New Frontiers program mission New Horizons.

This is enough energy to cause fission in U-238, and many other transuranic elements as well. This reaction is used in H-bombs to increase the yield of the fusion section by wrapping it in a layer of depleted uranium, which undergoes rapid fission when hit by the neutrons from the fusion bomb inside. The same basic concept can also be used with a fusion reactor like LIFE, using its neutrons to cause fission in a blanket of fission fuel. Unlike a fission reactor, which burns out its fuel once the U-235 drops below a certain threshold value, these fission–fusion hybrid reactors can continue producing power from the fission fuel as long as the fusion reactor continues to provide neutrons.

The development of Kilopower began with an experiment called DUFF or Demonstration Using Flattop Fissions, which was tested in September 2012 using the existing Flattop assembly as a nuclear heat source. When DUFF was tested at the Device Assembly Facility at the Nevada Test Site, it became the first Stirling engine powered by fission energy and the first use of a heat pipe to transport heat from a reactor to a power conversion system. According to David Poston, the leader of the Compact Fission Reactor Design Team, and Patrick McClure, the manager for small nuclear reactor projects at Los Alamos National Laboratory, the DUFF experiment showed that "for low-power reactor systems, nuclear testing can be accomplished with reasonable cost and schedule within the existing infrastructure and regulatory environment".

The neutrons in nuclear reactors are generally categorized as slow (thermal) neutrons or fast neutrons depending on their energy. Thermal neutrons are similar in energy distribution (the Maxwell–Boltzmann distribution) to a gas in thermodynamic equilibrium; but are easily captured by atomic nuclei and are the primary means by which elements undergo nuclear transmutation. To achieve an effective fission chain reaction, neutrons produced during fission must be captured by fissionable nuclei, which then split, releasing more neutrons. In most fission reactor designs, the nuclear fuel is not sufficiently refined to absorb enough fast neutrons to carry on the chain reaction, due to the lower cross section for higher-energy neutrons, so a neutron moderator must be introduced to slow the fast neutrons down to thermal velocities to permit sufficient absorption.

FFA accelerators have potential medical applications in proton therapy for cancer, as proton sources for high intensity neutron production, for non-invasive security inspections of closed cargo containers, for the rapid acceleration of muons to high energies before they have time to decay, and as "energy amplifiers", for Accelerator-Driven Sub-critical Reactors (ADSRs) / Sub-critical Reactors in which a neutron beam derived from a FFA drives a slightly sub-critical fission reactor. Such ADSRs would be inherently safe, having no danger of accidental exponential runaway, and relatively little production of transuranium waste, with its long life and potential for nuclear weapons proliferation. Because of their quasi-continuous beam and the resulting minimal acceleration intervals for high energies, FFAs have also gained interest as possible parts of future muon collider facilities.

For most of the journey, this would be used at a much lower power for sending data about the interstellar medium; but during the flyby, the main engine section would be discarded and the entire power capacity dedicated to communications at about 1 kilobit per second. Longshot would have a mass of at the start of the mission including 264 tonnes of helium-3/deuterium pellet fuel/propellant. The active mission payload, which includes the fission reactor but not the discarded main propulsion section, would have a mass of around 30 tonnes. A difference in the mission architecture between Longshot and the Daedalus study is that Longshot would go into orbit about the target star while the higher speed Daedalus would do a one shot fly-by lasting a comparatively short time.

In 1983, as assistant director for the MIT Plasma Fusion Center, Lidsky wrote an influential article about the difficulties of making a working nuclear fusion power plant.. The ensuing reduction in federal funding for fusion research led him to resign from the center, and caused him to be "drummed out" of the nuclear fusion research community.. Because of his concerns with the viability of fusion power, he instead became by 1989 an advocate for safer nuclear fission reactor designs.. In 1999 he was named a fellow of the American Association for the Advancement of Science "for outstanding contributions to both nuclear fission and fusion in education, research, system design and analysis, technical publications and federal policy".. He died March 1, 2002 in Newton, Massachusetts, after struggling with cancer for many years...

Leo Szilard (; ; born Leó Spitz; February 11, 1898 – May 30, 1964) was a Hungarian-American physicist and inventor. He conceived the nuclear chain reaction in 1933, patented the idea of a nuclear fission reactor in 1934, and in late 1939 wrote the letter for Albert Einstein's signature that resulted in the Manhattan Project that built the atomic bomb. According to György Marx he was one of the Hungarian scientists known as The Martians. Szilard initially attended Palatine Joseph Technical University in Budapest, but his engineering studies were interrupted by service in the Austro-Hungarian Army during World War I. He left Hungary for Germany in 1919, enrolling at Technische Hochschule (Institute of Technology) in Berlin-Charlottenburg, but became bored with engineering and transferred to Friedrich Wilhelm University, where he studied physics.

Sierra Class Project 945 Submarine The OK-650 reactor is the nuclear fission reactor used for the powering the Soviet Navy's Project 685 Плавник/Plavnik (Mike), Project 971 Щука-Б/Shchuka-B (Akula), and Project 945 Барракуда/Barrakuda, Кондор/Kondor, and Марс/Mars (Sierra) submarines, and in pairs to power the Project 941 Акула/Akula (Typhoon) and Project 949 Гранит/Granit and Антей/Antei (Oscar) third generation submarines. Borei Class Project 955 Submarine This pressurized water reactor (PWR) uses 20-45% enriched uranium-235 fuel to produce 190 MW of thermal power. Developed during the 1970s, these reactors were designed with the aim of minimizing accidents and malfunctions. Monitoring subsystems, designed for rapid detection of leaks, were included, along with newer-generation emergency cooling systems for the main reactor core.

Small amounts of fission products are naturally formed as the result of either spontaneous fission of natural uranium, which occurs at a low rate, or as a result of neutrons from radioactive decay or reactions with cosmic ray particles. The microscopic tracks left by these fission products in some natural minerals (mainly apatite and zircon) are used in fission track dating to provide the cooling (crystallization) ages of natural rocks. The technique has an effective dating range of 0.1 Ma to >1.0 Ga depending on the mineral used and the concentration of uranium in that mineral. About 1.5 billion years ago in a uranium ore body in Africa, a natural nuclear fission reactor operated for a few hundred thousand years and produced approximately 5 tonnes of fission products.

Sample of plutonium metal displayed at the Questacon museum Trace amounts of plutonium-238, plutonium-239, plutonium-240, and plutonium-244 can be found in nature. Small traces of plutonium-239, a few parts per trillion, and its decay products are naturally found in some concentrated ores of uranium, such as the natural nuclear fission reactor in Oklo, Gabon. The ratio of plutonium-239 to uranium at the Cigar Lake Mine uranium deposit ranges from to . These trace amounts of 239Pu originate in the following fashion: on rare occasions, 238U undergoes spontaneous fission, and in the process, the nucleus emits one or two free neutrons with some kinetic energy. When one of these neutrons strikes the nucleus of another 238U atom, it is absorbed by the atom, which becomes 239U. With a relatively short half- life, 239U decays to 239Np, which decays into 239Pu.

Taymyr is powered by a single KLT-40M nuclear fission reactor located amidships with a thermal output of 171 MW. The nuclear power plant on board the icebreaker produces superheated steam, which is used to generate electricity for the propulsion motors and other shipboard consumers as well as heat to maintain operational capability at . Taymyr has two main turbogenerators aft of the reactor compartment consisting of Soviet-made steam turbines coupled to Siemens generators, each producing 18,400 kW of electricity at 3,000 rpm for the propulsion motors. In addition the ship has two auxiliary turbogenerators, manufactured in the Soviet Union, which produce 2,000 kW of electrical power for shipboard consumers.. Taymyr has a nuclear- turbo-electric powertrain, in which steam produced by the nuclear reactor is converted first into electricity, which in turn rotates the propulsion motors coupled to the propellers. The ship has three shafts with Strömberg AC motors controlled by cycloconverters.

The mushroom cloud of the atomic bomb dropped on Nagasaki, Japan on August 9, 1945, rose over above the bomb's hypocenter. An estimated 39,000 people were killed by the atomic bomb,The Atomic Bombings of Hiroshima and Nagasaki. atomicarchive.com of whom 23,145–28,113 were Japanese factory workers, 2,000 were Korean slave laborers, and 150 were Japanese combatants. One class of nuclear weapon, a fission bomb (not to be confused with the fusion bomb), otherwise known as an atomic bomb or atom bomb, is a fission reactor designed to liberate as much energy as possible as rapidly as possible, before the released energy causes the reactor to explode (and the chain reaction to stop). Development of nuclear weapons was the motivation behind early research into nuclear fission which the Manhattan Project during World War II (September 1, 1939 – September 2, 1945) carried out most of the early scientific work on fission chain reactions, culminating in the three events involving fission bombs that occurred during the war.

The energy produced by Mr. Fusion replaces plutonium as the primary power source of the DeLorean's time travel, allowing the characters to bypass the arduous power-generation requirements upon which the plot of the first film hinges. The plutonium fission reactor was most likely left installed underneath Mr. Fusion as a backup power source. The Mr. Fusion can provide enough power to the flux capacitor and the time circuits, but is not used to power up the DeLorean itself, which makes use of an ordinary gasoline combustion engine to reach the 88 mph speed necessary for it to time travel, a limitation that proved itself crucial in the third movie when Doc and Marty find themselves stuck in 1885 and unable to return with the DeLorean out of gas (due to a fuel leak). The vehicle's hover system is powered by Mr. Fusion and is capable of bringing the DeLorean up to the required 88 mph; the combustion engine was also probably left on board as a backup.

While doing their research, the events of World War II forced them to eventually move to England, bringing with them the world's entire stock of heavy water, given on loan by Norway to France so that it would not fall into German hands. They continued their research at the Cavendish Laboratory in Cambridge for the MAUD Committee, part of the wartime Tube Alloys project. Just before the invasions, the records and papers of Frédéric Joliot, Hans Halban and Lew Kowarski were smuggled out of France, and eventually to England. Included in this operation were 26 drums of heavy water, the world’s entire stock at the time. Some of the papers written by Halban and Kowarski were deposited at the Royal Society in the UK, where they were sealed with a note from James Chadwick, dated December 18, 1941, that said, “The paper is such that it would be inadvisable to publish it at the present time.” The papers described the outline of a design for a nuclear fission reactor.