The Integral Fast Reactor or Advanced Liquid-Metal Reactor is a design for a nuclear fast reactor with a specialized nuclear fuel cycle. A prototype of the reactor was built in the United States, but the project was canceled by the U.S. government in 1994, three years before completion. A Liquid metal cooled nuclear reactor is nuclear reactor where the primary coolant is a liquid molten metal. ... A fast neutron reactor or simply a fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons. ... The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. ...

Overview

This reactor is cooled by liquid sodium and fueled by a metallic alloy of uranium and plutonium. The fuel is contained in steel cladding with liquid sodium filling in the space between the fuel and the cladding. For sodium in the diet, see Salt. ... This article is about the chemical element. ... This article is about the radioactive element. ...

Safety

In traditional water-cooled reactors the core must be maintained at a high pressure to keep the water liquid at high temperatures. In contrast, since the IFR used a liquid metal as a coolant, the core could operate at close to ambient pressure, dramatically reducing the danger of a loss of coolant accident. The entire reactor core, heat exchangers and primary cooling pumps were immersed in a pool of liquid sodium, making a loss of primary coolant extremely unlikely. The coolant loops were also designed to allow for cooling through natural convection, meaning that in the case of a power loss or unexpected reactor shutdown, the heat from the reactor core would be sufficient to keep the coolant circulating even if the primary cooling pumps were to fail. A Loss of Coolant Accident (LOCA) is a mode of failure for a nuclear reactor; in a nuclear reactor, the results of a LOCA could be catastrophic to the reactor, the facility that houses it, and the immediate vicinity around the reactor. ... A heat exchanger is a device built for efficient heat transfer from one fluid to another, whether the fluids are separated by a solid wall so that they never mix, or the fluids are directly contacted. ... Convection in the most general terms refers to the movement of currents within fluids (i. ...

The IFR also utilized a passively safe fuel configuration. The fuel and cladding was designed such that when they expanded due to increased temperatures, more neutrons would be able to escape the core thus reducing the rate of the fission chain reaction. At sufficiently high temperatures this effect would completely stop the reactor even without external action from operators or safety systems. This was demonstrated in a series of safety tests on the prototype. Passive nuclear safety describes a safety feature of a nuclear reactor that does not require operator action or electronic feedback in order to shut down safely in the event of a particular type of emergency (usually overheating resulting from a loss of coolant or loss of coolant flow). ...

A safety disadvantage of using liquid sodium as coolant arises due to sodium's chemical reactivity. Liquid sodium is extremely flammable and ignites spontaneously on contact with air or water. Thus leaking sodium pipes could give rise to sodium fires, or explosions if the leaked sodium comes into contact with water. To reduce the risk of explosions following a leak of water from the steam turbines the IFR had an extra intermediate coolant loop between the reactor and the turbines. The purpose of this loop was to ensure that any explosion following accidental mixing of sodium and turbine water would be limited to the secondary heat exchanger and not pose a risk to the reactor. The requirement of such an extra loop significantly added to the cost of the reactor.

Efficiency and Fuel cycle

The goals of the IFR project were to increase the efficiency of uranium usage by breeding plutonium and eliminating the need for transuranic isotopes ever to leave the site. The reactor was an unmoderated design running on fast neutrons, designed to allow any transuranic isotope to be consumed (and in some cases used as fuel). Fission products are the residues of fission processes. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Annum is a Latin noun meaning year. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... The decay energy is the energy released by a nuclear decay. ... An electronvolt (symbol: eV) is the amount of kinetic energy gained by a single unbound electron when it passes through an electrostatic potential difference of one volt, in vacuum. ... In physics, the decay mode describes a particular way a particle decays. ... Krypton 85 is a radioactive synthetic isotope of krypton. ... General Name, Symbol, Number Strontium, Sr, 38 Series Alkaline earth metal Group, Period, Block 2 (IIA), 5, s Density, Hardness 2630 kg/m3, 1. ... Caesium-137 is a radioactive isotope which is formed mainly by nuclear fission. ... Fission products are the residues of fission processes. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Annum is a Latin noun meaning year. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... The decay energy is the energy released by a nuclear decay. ... An electronvolt (symbol: eV) is the amount of kinetic energy gained by a single unbound electron when it passes through an electrostatic potential difference of one volt, in vacuum. ... In physics, the decay mode describes a particular way a particle decays. ... Iodine-129 (129I) is a radioisotope of iodine, which decays with a half-life of 16. ... The fast breeder or fast breeder reactor (FBR) is a type of fast neutron reactor that produces more fissile material than it consumes. ... In chemistry, transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, the atomic number of Uranium. ... A fast neutron is a free neutron with a kinetic energy level close to 1 MeV (10 TJ/kg, hence a speed of 14,000 km/s. ...

Compared to current light-water reactors with a once-through fuel cycle that uses less than 1% of the energy in the uranium, the IFR has a very efficient (99.5% usage) fuel cycle. The basic scheme used electrolytic separation to remove transuranics and actinides from the wastes and concentrate them. These concentrated fuels were then reformed, on site, into new fuel elements.

The available fuel metals were never separated from the plutonium, and therefore there was no direct way to use the fuel metals in nuclear weapons. Also, plutonium never had to leave the site, and thus was far less open to unauthorized diversion.

Another important benefit of removing the long half-life transuranics from the waste cycle is that the remaining waste becomes a much shorter-term hazard. After the actinides (reprocessed uranium, plutonium, and minor actinides) are removed and recycled, the remaining radioactive waste isotopes are fission products, which have half lives of either 90 years (Sm-151) and less, or 211,100 years (Tc-99) and more; plus any neutron activation products from the non-fuel reactor components. (Tc-99 and I-129 are also candidates for nuclear transmutation to stable isotopes by neutron capture.) Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... Reprocessed uranium (RepU) is the uranium recovered from nuclear fuel reprocessing. ... This article is about the radioactive element. ... The minor actinides are the actinide elements in spent fuel other than uranium and plutonium, these are termed major actinides. ... Radioactive wastes are waste types containing radioactive chemical elements that do not have a practical purpose. ... Fission products are the residues of fission processes. ... Half-Life For a quantity subject to exponential decay, the half-life is the time required for the quantity to fall to half of its initial value. ... 151Sm is an radioisotope of samarium with a halflife of 90 years, decaying with low-energy beta emission, and a fission product yield of 0. ... General Name, Symbol, Number technetium, Tc, 43 Chemical series transition metals Group, Period, Block 7, 5, d Appearance silvery gray metal Atomic mass (98) g/mol Electron configuration [Kr] 4d5 5s2 Electrons per shell 2, 8, 18, 13, 2 Physical properties Phase solid Density (near r. ... Neutron activation is the process by which neutron radiation induces radioactivity in materials. ... General Name, Symbol, Number technetium, Tc, 43 Chemical series transition metals Group, Period, Block 7, 5, d Appearance silvery gray metal Atomic mass (98) g/mol Electron configuration [Kr] 4d5 5s2 Electrons per shell 2, 8, 18, 13, 2 Physical properties Phase solid Density (near r. ... Iodine-129 (129I) is a radioisotope of iodine, which decays with a half-life of 16. ... Nuclear transmutation is the conversion of one chemical element or isotope into another, which occurs through nuclear reactions. ... The process of neutron capture can proceed in two ways - as a rapid process (an r-process) or a slow process (an s-process). ...

The result is that within 200 years, such wastes are no more radioactive than the ores of natural radioactive elements.^[1]

Key benefits

• Enhanced passive safety because of the high thermal conductivity of the fuel. Able to withstand both a loss of flow without SCRAM and loss of heat sink without SCRAM.^[2][3]
• Ease of fuel fabrication. Because the sodium fills the space between the fuel and cladding, the fuel need not be precisely fabricated. The fuel is simply cast. Because casting is simple, the fuel can be fabricated remotely, reducing the hazards of its radioactivity.
• On-site reprocessing by pyroprocessing and electrorefining is simplified because there is no need to stringently reduce the radioactivity of the fuel. Actinides including transuranics can be incorporated into the fuel.
• Proliferation hazards are reduced by the high radioactivity of the fuel. Because the fuel contains significant levels of transuranics with high spontaneous fission rates, it is not possible to produce nuclear weapons using IFR fuel without centrifugal separation. This is more difficult than enrichment of natural uranium due to the smaller atomic mass difference between Pu-239 and Pu-240 as compared to U-235 vs U-238, and is rendered even more difficult by the high radioactivity of the fuel.
• The two forms of waste produced, a noble metal form and a ceramic form, contain no plutonium or other actinides. The radioactivity of the waste decays to levels similar to the original ore in about 200 years.^[1]
• The on-site reprocessing of fuel means that the quantity of nuclear waste leaving the plant is tiny relative to other nuclear facilities.^[4] This makes storage simpler and reduces the security risk associated with nuclear waste transportation.

A SCRAM is an emergency shutdown of a nuclear reactor - though the term has been extended to cover shutdowns of other complex operations, such as server farms and even large model railroads (see Tech Model Railroad Club). ... The actinide (or actinoid) series encompasses the 15 chemical elements that lie between actinium and lawrencium on the periodic table, with atomic numbers 89 - 103[1]. The actinide series derives its name from the first element in the series, actinium. ... In chemistry, transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than 92, the atomic number of Uranium. ...

Key disadvantages

• Because the current cost of reactor-grade enriched uranium is relatively low compared to the expected cost of large-scale pyroprocessing and electrorefining equipment and the cost of building a secondary coolant loop, the higher fuel costs of a thermal reactor over the expected operating lifetime of the plant are offset by the increased capital cost of an IFR. (Currently in the United States, utilities pay a flat rate of 1/10 of a cent per kilowatt hour for disposal of high level radioactive waste. If this charge were based on the longevity of the waste, then the IFR might become more financially competitive.)
• Reprocessing nuclear fuel using pyroprocessing and electrorefining has not yet been demonstrated on a commercial scale. As such, investing in a large IFR plant is considered a higher financial risk than a conventional light water reactor.
• The flammability of sodium. Sodium burns easily in air, and will ignite spontaneously on contact with water. The use of an intermediate coolant loop between the reactor and the turbines minimizes the risk of a sodium fire in the reactor core.
• Under neutron bombardment, sodium-24 is produced. This is highly radioactive, emitting an energetic gamma ray of 2.7 MeV followed by a beta decay to form magnesium-24. Half life is only 15 hours, so this isotope is not a long-term hazard - indeed it has medical applications. Nevertheless, the presence of sodium-24 further necessitates the use of the intermediate coolant loop between the reactor and the turbines.

These pie-graphs showing the relative proportions of uranium-238 (blue) and uranium-235 (red) at different levels of enrichment. ... A thermal reactor is the most common category of nuclear reactor. ... This is the amount on which you first claim CCA. The capital cost of a depreciable property is usually the total of the purchase price, not including the cost of land (which is not depreciable);the part of your legal, accounting, engineering, installation, and other fees that relates to the... In essence financial risk is any risk associated with money. ... A light water reactor or LWR is a thermal nuclear reactor that uses ordinary water, also called light water, as its neutron moderator. ... This article is about electromagnetic radiation. ... The electronvolt (symbol eV) is a unit of energy. ...

History

Research on the reactor began in 1984 at Argonne National Laboratory in Argonne, Illinois. Argonne is a part of the U.S. Department of Energy's national laboratory system, and is operated on a contract by the University of Chicago. Aerial photo of the Advanced Photon Source at Argonne National Laboratory. ... The United States Department of Energy (DOE) is a Cabinet-level department of the United States government responsible for energy policy and nuclear safety. ... For other uses, see University of Chicago (disambiguation). ...

Argonne previously had a branch campus named "Argonne West" in Idaho Falls, Idaho that is now part of the Idaho National Laboratory. In the past, at the branch campus, physicists from Argonne had built what was known as the Experimental Breeder Reactor II (EBR II). In the mean time, physicists at Argonne had designed the IFR concept, and it was decided that the EBR II would be converted to an IFR. Charles Till, a Canadian physicist from Argonne, was the head of the IFR project, and Yoon Chang, was the deputy head. Till was positioned in Idaho, while Chang was in Illinois. Idaho Falls is a city located in Bonneville County, Idaho. ... For other uses, see Idaho (disambiguation). ... The Idaho National Laboratory (INL) is an 890 square mile (2,300 km²) complex located in the Idaho desert between the towns of Arco and Idaho Falls. ... Experimental Breeder Reactor-II (EBR-II)is a sodium cooled reactor with a thermal power rating of 62. ...

With the election of President Bill Clinton in 1992, and the appointment of Hazel O'Leary as the Secretary of Energy, there was pressure from the top to cancel the IFR. Sen. John Kerry (D, MA) and O'Leary led the opposition to the reactor, arguing that it would be a threat to non-proliferation efforts, and that it was a continuation of the Clinch River Breeder Reactor Project that had been canceled by Congress. Despite support for the reactor by then-Rep. Richard Durbin (D, IL) and U.S. Senators Carol Mosley Braun (D, IL) and Paul Simon (D, IL), funding for the reactor was slashed, and it was ultimately canceled in 1994. William Jefferson Bill Clinton (born William Jefferson Blythe III[1] on August 19, 1946) was the 42nd President of the United States, serving from 1993 to 2001. ... Hazel OLeary Hazel Rollins OLeary (born May 17, 1937) was the seventh United States Secretary of Energy from 1993 to 1997. ... The United States Secretary of Energy is the head of the United States Department of Energy, concerned as the name suggests, with The Secretary is a member of the Presidents Cabinet. ... John Forbes Kerry (born December 11, 1943) is the junior United States Senator from Massachusetts, in his fourth term of office. ... The Clinch River Breeder Reactor Plant (CRBRP) Project was a joint effort of the U.S. Energy Research and Development Administration (ERDA) and the U.S. electric power industry to design and construct a sodium-cooled fast-neutron nuclear reactor. ... Richard Joseph Dick Durbin, (born November 21, 1944) is currently the senior United States Senator from Illinois and Democratic Whip, the second highest position in the party leadership in the Senate. ... Carol Moseley Braun (born August 16, American politician and lawyer, was the first (and to date only) black woman elected to the United States Senate (representing Illinois). ...

See also

• Experimental Breeder Reactor II
• Fast breeder reactor
• Fast neutron reactor
• Sodium-cooled fast reactor
• Lead-cooled fast reactor
• Gas-cooled fast reactor
• Generation IV reactor

References

MWe and MWt are units for measuring the output of a power plant. ...

External links

• The Unofficial IFR home page and page index
• Integral Fast Reactors: Source of Safe, Abundant, Non-Polluting Power by George S. Stanford, Ph.D.
• The IFR at Argonne National Laboratory
• Frontline interview with Dr. Till.