Breeder reactor
Encyclopedia
A breeder reactor is a nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...

 capable of generating more fissile material than it consumes because its neutron economy
Neutron economy
Neutron economy is defined as the ratio of an adjoint weighted average of the excess neutron production divided by an adjoint weighted average of the fission production....

 is high enough to breed fissile from fertile material
Fertile material
Fertile material is a term used to describe nuclides which generally themselves do not undergo induced fission but from which fissile material is generated by neutron absorption and subsequent nuclei conversions...

 like uranium-238
Uranium-238
Uranium-238 is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239...

 or thorium-232. Breeders were at first considered superior because of their superior fuel economy compared to light water reactor
Light water reactor
The light water reactor is a type of thermal reactor that uses normal water as its coolant and neutron moderator. Thermal reactors are the most common type of nuclear reactor, and light water reactors are the most common type of thermal reactor...

s. (Light water reactors consume less than 1% of natural uranium
Natural uranium
Natural uranium refers to refined uranium with the same isotopic ratio as found in nature. It contains 0.7 % uranium-235, 99.3 % uranium-238, and a trace of uranium-234 by weight. In terms of the amount of radioactivity, approximately 2.2 % comes from uranium-235, 48.6 % uranium-238, and 49.2 %...

.) Interest in breeders reduced after the 1960s as more uranium reserves were found, and new methods of uranium enrichment reduced fuel costs.

Nuclear waste became a greater concern by the 1990s. Breeding fuel cycles became interesting again because they can reduce actinide
Actinide
The actinide or actinoid series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.The actinide series derives its name from the group 3 element actinium...

 wastes, particularly plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...

 and minor actinides
Minor actinides
The minor actinides are the actinide elements in used nuclear fuel other than uranium and plutonium, which are termed the major actinides. The minor actinides include neptunium, americium, curium, berkelium, californium, einsteinium, and fermium...

. After the spent nuclear fuel
Spent nuclear fuel
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor...

 is removed from a light water reactor
Light water reactor
The light water reactor is a type of thermal reactor that uses normal water as its coolant and neutron moderator. Thermal reactors are the most common type of nuclear reactor, and light water reactors are the most common type of thermal reactor...

, after 1000 to 100,000 years, these transuranics would make most of the radioactivity. Eliminating them eliminates much of the long-term radiotoxicity of spent nuclear fuel.

In principle, breeder fuel cycles can recycle and consume all actinides, leaving only fission product
Fission product
Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The...

s. So, after several hundred years, the waste's radioactivity drops to the low level of the long-lived fission products). If the fuel reprocessing
Nuclear reprocessing
Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing...

 process used for the fuel cycle leaves actinides in its final waste stream, this advantage is reduced.

There are two well-known breeding cycles that reduce wastes' radiotoxicity from actinides:
  • The fast breeder reactor's fast neutrons can fission even actinides with even neutron number
    Neutron number
    The neutron number, symbol N, is the number of neutrons in a nuclide.Atomic number plus neutron number equals mass number: Z+N=A....

    s. Even numbered actinides usually lack the low-speed "thermal neutron" resonances of fissile
    Fissile
    In nuclear engineering, a fissile material is one that is capable of sustaining a chain reaction of nuclear fission. By definition, fissile materials can sustain a chain reaction with neutrons of any energy. The predominant neutron energy may be typified by either slow neutrons or fast neutrons...

     fuels used in LWRs.
  • The thorium fuel cycle
    Thorium fuel cycle
    The thorium fuel cycle is a nuclear fuel cycle that uses the naturally abundant isotope of thorium, , as the fertile material. In the reactor, is transmuted into the fissile artificial uranium isotope which is the nuclear fuel. Unlike natural uranium, natural thorium contains only trace amounts...

     simply produces lower levels of heavy actinides. The fuel starts with few isotopic impurities (i.e. there's nothing like U238 in the reactor), and the reactor gets two chances to fission the fuel: First as U233, and as it absorbs neutrons, again as U235.


A reactor whose main purpose is to destroy actinides, rather than increasing fissile fuel stocks, is sometimes known as a burner reactor. Both breeding and burning depend on good neutron economy, and many designs can do either. Breeding designs surrounded the core by a breeding blanket of fertile material. Waste burners surround the core with non-fertile wastes to be destroyed. Some designs add neutron reflectors or absorbers.

Today's LWRs do breed some plutonium. They do not make enough to replace the uranium-235
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...

 consumed. Only about 1/3 of fissions over a fuel element's life cycle are from bred plutonium. However, LWRs are not able to consume all the plutonium and minor actinides they produce. Nonfissile isotopes of plutonium
Isotopes of plutonium
Plutonium is an artificial element, except for trace quantities of primordial 244Pu, and thus a standard atomic mass cannot be given. Like all artificial elements, it has no stable isotopes. It was synthesized long before being found in nature, the first isotope synthesized being 238Pu in 1940....

 build up. Even with reprocessing, reactor-grade plutonium can be recycled only once in LWRs as mixed oxide fuel
MOX fuel
Mixed oxide fuel, commonly referred to as MOX fuel, is nuclear fuel that contains more than one oxide of fissile material. MOX fuel contains plutonium blended with natural uranium, reprocessed uranium, or depleted uranium. MOX fuel is an alternative to the low-enriched uranium fuel used in the...

. This reduces long term waste radioactivity somewhat, but not as much as purpose-designed breeding cycles.

Breeding ratio

One measure of a reactor's performance is the "breeding ratio" (the average number of fissile
Fissile
In nuclear engineering, a fissile material is one that is capable of sustaining a chain reaction of nuclear fission. By definition, fissile materials can sustain a chain reaction with neutrons of any energy. The predominant neutron energy may be typified by either slow neutrons or fast neutrons...

 atoms created per fission event
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...

). Historically, attention has focused on reactors with low breeding ratios, from 1.01 for the Shippingport Reactor
Shippingport Reactor
The Shippingport Atomic Power Station, "the world’s first full-scale atomic electric power plant devoted exclusively to peacetime uses," was located near the present-day Beaver Valley Nuclear Generating Station on the Ohio River in Beaver...

 running on thorium fuel and cooled by conventional light water to over 1.2 for the Russian BN-350
BN-350 reactor
The BN-350 was a sodium-cooled fast reactor nuclear power plant located at Aktau , Kazakhstan, situated on the shore of the Caspian Sea. Construction of the BN-350 Fast breeder reactor began in 1964, and the plant first produced electricity in 1973...

 liquid-metal-cooled reactor. Theoretical models of breeders with liquid sodium coolant flowing through tubes inside fuel elements ("tube-in-shell" construction) show breeding ratios of at least 1.8 are possible. The breeding ratios of ordinary commercial non-breeders are lower than 1; however, industry trends are pushing breeding ratios steadily higher, blurring the distinction.

Breeding versus burnup

All commercial reactors breed fuel, but they have low (though still significant) breeding ratios compared to machines traditionally considered "breeders." In recent years, the commercial power industry has been emphasizing high-burnup
Burnup
In nuclear power technology, burnup is a measure of how much energy is extracted from a primary nuclear fuel source...

 fuels, which last longer in the reactor core. As burnup increases, a higher percentage of the total power is due to the fuel bred in the reactor. At a burnup of 30 gigawatt-days per metric ton of uranium (GWd/MTU), about thirty percent of the total energy comes from bred plutonium. At 40 GWd/MTU, that increases to about forty percent. This corresponds to a breeding ratio of about 0.4 to 0.65. Correspondingly, this effect extends the cycle life for such fuels to sometimes nearly twice what it would be otherwise. MOX fuel
MOX fuel
Mixed oxide fuel, commonly referred to as MOX fuel, is nuclear fuel that contains more than one oxide of fissile material. MOX fuel contains plutonium blended with natural uranium, reprocessed uranium, or depleted uranium. MOX fuel is an alternative to the low-enriched uranium fuel used in the...

 has a smaller breeding effect than U-235 fuel and is thus more challenging and slightly less economic to use due to a quicker drop off in reactivity through cycle life.

This is of interest largely because next-generation reactors such as the European Pressurized Reactor
European Pressurized Reactor
The EPR is a third generation pressurized water reactor design. It has been designed and developed mainly by Framatome , Electricité de France in France, and Siemens AG in Germany...

, AP1000 and ESBWR are designed to achieve very high burnup. This directly translates to higher breeding ratios. Current commercial power reactors have achieved breeding ratios of roughly 0.55, and next-generation designs like the AP1000 and EPR should have breeding ratios of 0.7 to 0.8, meaning that they produce 70 to 80 percent as much fuel as they consume, improving their fuel economy by roughly 15 percent points compared to current high-burnup reactors.

Breeding of fissile fuel is a common feature in reactors, but in commercial reactors not optimized for this feature it is referred to as "enhanced burnup". Up to a third of all electricity produced in the current US reactor fleet comes from bred fuel, and the industry is working steadily to increase that percentage as time goes on.

Types of breeder reactors

Two types of traditional breeder reactor have been proposed:
  • fast breeder reactor or FBR — The superior neutron economy of a fast neutron reactor
    Fast neutron reactor
    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...

     makes it possible to build a reactor that, after its initial fuel charge of plutonium
    Plutonium
    Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...

    , requires only natural (or even depleted) uranium feedstock as input to its fuel cycle. This fuel cycle has been termed the plutonium economy.

  • thermal breeder reactor — The excellent neutron capture characteristics of fissile uranium-233
    Uranium-233
    Uranium-233 is a fissile isotope of uranium, bred from Thorium as part of the thorium fuel cycle. It has been used in a few nuclear reactors and has been proposed for much wider use as a nuclear fuel. It has a half-life of 160,000 years....

     make it possible to build a moderated reactor that, after its initial fuel charge of enriched uranium
    Enriched uranium
    Enriched uranium is a kind of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight...

    , plutonium or MOX
    Mox
    MOX might be a name or acronym for:*Malaysian Oxygen Berhad - A Malaysian company that is specializes in providing total gas solutions.*Mixed Oxide Fuel, from nuclear reprocessing*An alien race in the TimeSplitters 2 video game, the Mox...

    , requires only thorium
    Thorium
    Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....

     as input to its fuel cycle. Thorium-232 produces uranium-233 after neutron capture and beta decay
    Beta decay
    In nuclear physics, beta decay is a type of radioactive decay in which a beta particle is emitted from an atom. There are two types of beta decay: beta minus and beta plus. In the case of beta decay that produces an electron emission, it is referred to as beta minus , while in the case of a...

    .


In addition to this, there is some interest in so-called "reduced moderation reactors", which are derived from conventional reactors and use conventional fuels and coolants, but are designed to be reasonably efficient as breeders. Such designs typically achieve breeding ratios of 0.7 to 1.01 or even higher.

Reprocessing

Fission of the nuclear fuel in any reactor produces neutron-absorbing fission products, and because of this it is necessary to reprocess
Nuclear reprocessing
Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing...

 the fuel and breeder blanket from a breeder reactor if one is to fully utilise its ability to breed more fuel than it consumes. The most common reprocessing technique, PUREX
PUREX
PUREX is an acronym standing for Plutonium - URanium EXtraction — de facto standard aqueous nuclear reprocessing method for the recovery of uranium and plutonium from used nuclear fuel. It is based on liquid-liquid extraction ion-exchange.The PUREX process was invented by Herbert H. Anderson and...

, is generally considered a large proliferation
Nuclear proliferation
Nuclear proliferation is a term now used to describe the spread of nuclear weapons, fissile material, and weapons-applicable nuclear technology and information, to nations which are not recognized as "Nuclear Weapon States" by the Treaty on the Nonproliferation of Nuclear Weapons, also known as the...

 concern because such reprocessing technologies can be used to extract weapons grade plutonium from a reactor operated on a short refuelling cycle. For this reason, the FBR closed fuel cycle
Nuclear fuel cycle
The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the front end, which are the preparation of the fuel, steps in the service period in which the fuel is used during reactor operation, and steps in...

 is often seen as a greater proliferation concern than a once-through thermal fuel cycle
Nuclear fuel cycle
The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the front end, which are the preparation of the fuel, steps in the service period in which the fuel is used during reactor operation, and steps in...

.

However, to date all known weapons programs have used far more easily built thermal reactor
Thermal reactor
A thermal reactor is a nuclear reactor that uses slow or thermal neutrons. Most power reactors are of this type. These type of reactors use a neutron moderator to slow neutrons until they approach the average kinetic energy of the surrounding particles, that is, to reduce the speed of the neutrons...

s to produce plutonium, and there are some designs such as the SSTAR
SSTAR
SSTAR is an acronym for the "small, sealed, transportable, autonomous reactor" - being primarily researched and developed in the USA by Lawrence Livermore National Laboratory. It is designed as a fast breeder nuclear reactor that is passively safe...

 which avoid proliferation risks by both producing low amounts of plutonium at any given time from the U-238, and by producing three different isotopes of plutonium (Pu-239, Pu-240, and Pu-242) making the plutonium used infeasible for atomic bomb use.

Furthermore, several countries are developing more proliferation resistant reprocessing methods that don't separate the plutonium from the other actinides. For instance, the pyrometallurgical process when used to reprocess fuel from the Integral Fast Reactor
Integral Fast Reactor
The Integral Fast Reactor is a design for a nuclear reactor using fast neutrons and no neutron moderator . IFR is distinguished by a nuclear fuel cycle that uses reprocessing via electrorefining at the reactor site.The U.S...

 leaves large amounts of radioactive actinides in the reactor fuel. Removing these transuranics in a conventional reprocessing plant would be extremely difficult as many of the actinides emit strong neutron radiation
Neutron radiation
Neutron radiation is a kind of ionizing radiation which consists of free neutrons. A result of nuclear fission or nuclear fusion, it consists of the release of free neutrons from atoms, and these free neutrons react with nuclei of other atoms to form new isotopes, which, in turn, may produce...

, requiring all handling of the material to be done remotely, thus preventing the plutonium from being used for bombs while still being usable as reactor fuel.

Thorium
Thorium
Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....

 fueled reactors may pose a slightly higher proliferation risk than uranium based reactors because, while Pu-239 will fairly often fail to undergo fission after neutron capture
Neutron capture
Neutron capture is a kind of nuclear reaction in which an atomic nucleus collides with one or more neutrons and they merge to form a heavier nucleus. Since neutrons have no electric charge they can enter a nucleus more easily than positively charged protons, which are repelled...

 and produce Pu-240, the corresponding process in the thorium cycle is relatively rare. Thorium-232 converts to U-233, which will almost always undergo fission successfully, meaning that there will be very little U-234 produced in the reactor's thorium/U-233 breeder blanket, and the resulting pure U-233 will be comparatively easy to extract and use for weapons. However, the opposite process (neutron knock-off) happens as a matter of course, producing U-232, which has the strong gamma emitter Tl-208
Isotopes of thallium
Thallium has 37 isotopes which have atomic masses that range from 176 to 212. 203Tl and 205Tl are the only stable isotopes and 204Tl is the most stable radioisotope with a half-life of 3.78 years...

 in its decay chain. These gamma rays complicate the safe handling of a weapon and the design of its electronics; this explains why U-233 has never been pursued for weapons beyond proof-of-concept demonstrations.

Associated reactor types

One design of fast neutron reactor, specifically designed to address the waste disposal and plutonium issues, was the Integral Fast Reactor
Integral Fast Reactor
The Integral Fast Reactor is a design for a nuclear reactor using fast neutrons and no neutron moderator . IFR is distinguished by a nuclear fuel cycle that uses reprocessing via electrorefining at the reactor site.The U.S...

(also known as an Integral Fast Breeder Reactor, although the original reactor was designed to not breed a net surplus of fissile material).

To solve the waste disposal problem, the IFR had an on-site electrowinning
Electrowinning
Electrowinning, also called electroextraction, is the electrodeposition of metals from their ores that have been put in solution or liquefied. Electrorefining uses a similar process to remove impurities from a metal. Both processes use electroplating on a large scale and are important techniques...

 fuel reprocessing unit that recycled the uranium and all the transuranics (not just plutonium) via electroplating
Electroplating
Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...

, leaving just short half-life
Half-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...

 fission product
Fission product
Nuclear fission products are the atomic fragments left after a large atomic nucleus fissions. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat , gamma rays and neutrinos. The...

s in the waste. Some of these fission products could later be separated for industrial or medical uses and the rest sent to a waste repository (where they would not have to be stored for anywhere near as long as wastes containing long half-life transuranics). It is thought that it would not be possible to divert fuel from this reactor to make bombs, as several of the transuranics spontaneously undergo fission so rapidly that any assembly would melt before it could be completed. The project was canceled in 1994, at the behest of then-United States Secretary of Energy
United States Secretary of Energy
The United States Secretary of Energy is the head of the United States Department of Energy, a member of the President's Cabinet, and fifteenth in the presidential line of succession. The position was formed on October 1, 1977 with the creation of the Department of Energy when President Jimmy...

 Hazel O'Leary.
Use of a breeder reactor assumes nuclear reprocessing
Nuclear reprocessing
Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing...

 of the breeder blanket at least, without which the concept is meaningless. In practice, all proposed breeder reactor programs involve reprocessing of the fuel elements as well. This is important due to nuclear weapons proliferation concerns, as any nation conducting reprocessing using the traditional aqueous-based PUREX
PUREX
PUREX is an acronym standing for Plutonium - URanium EXtraction — de facto standard aqueous nuclear reprocessing method for the recovery of uranium and plutonium from used nuclear fuel. It is based on liquid-liquid extraction ion-exchange.The PUREX process was invented by Herbert H. Anderson and...

 family of reprocessing techniques could potentially divert plutonium towards weapons building. In practice, commercial plutonium from reactors with significant burnup would require sophisticated weapon designs, but the possibility must be considered. To address this concern, modified aqueous reprocessing systems, which add extra reagents, forcing minor actinide
Actinide
The actinide or actinoid series encompasses the 15 metallic chemical elements with atomic numbers from 89 to 103, actinium through lawrencium.The actinide series derives its name from the group 3 element actinium...

 "impurities" such as curium
Curium
Curium is a synthetic chemical element with the symbol Cm and atomic number 96. This radioactive transuranic element of the actinide series was named after Marie Skłodowska-Curie and her husband Pierre Curie. Curium was first intentionally produced and identified in summer 1944 by the group of...

 and neptunium
Neptunium
Neptunium is a chemical element with the symbol Np and atomic number 93. A radioactive metal, neptunium is the first transuranic element and belongs to the actinide series. Its most stable isotope, 237Np, is a by-product of nuclear reactors and plutonium production and it can be used as a...

 to commingle with the plutonium, have been proposed. Such impurities matter little in a fast spectrum reactor, but make weaponizing the plutonium extraordinarily difficult, such that even very sophisticated weapon designs are likely to fail to fire properly. Such systems as the TRUEX and SANEX are meant to address this.

Even more comprehensive are systems such as the Integral Fast Reactor
Integral Fast Reactor
The Integral Fast Reactor is a design for a nuclear reactor using fast neutrons and no neutron moderator . IFR is distinguished by a nuclear fuel cycle that uses reprocessing via electrorefining at the reactor site.The U.S...

 (IFR) pyroprocessing system, which uses pools of molten cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...

 and electrorefiners to reprocess metallic fuel directly on-site at the reactor. Such systems not only commingle all the minor actinides with both uranium and plutonium, they are compact and self-contained, so that no plutonium-containing material ever needs to be transported away from the site of the breeder reactor. Breeder reactors incorporating such technology would most likely be designed with breeding ratios very close to 1.00, so that after an initial loading of enriched uranium and/or plutonium fuel, the reactor would then be refueled only with small deliveries of natural uranium metal. A quantity of natural uranium metal equivalent to a block about the size of a milk crate delivered once per month would be all the fuel such a 1 gigawatt reactor would need. Such self-contained breeders are currently envisioned as the final self-contained and self-supporting ultimate goal of nuclear reactor designers.

The fast breeder reactor

As of 2006, all large-scale FBR power stations have been liquid metal fast breeder reactors (LMFBR) cooled by liquid sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

. These have been of one of two designs:
  • Loop type, in which the primary coolant is circulated through primary heat exchangers outside the reactor tank (but inside the biological shield due to radioactive sodium-24 in the primary coolant)
  • Pool type, in which the primary heat exchangers and pumps are immersed in the reactor tank


All current fast reactor designs use liquid metal as the primary coolant, to transfer heat from the core to steam used to power the electricity generating turbines. FBRs have been built cooled by liquid metals other than sodium—some early FBRs used mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...

, other experimental reactors have used a sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

-potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...

 alloy
NaK
NaK, or sodium-potassium alloy, an alloy, of potassium , and sodium , is usually liquid at room temperature. Various commercial grades are available. NaK is highly reactive with water and may catch fire when exposed to air, so must be handled with special precautions...

. Both have the advantage that they are liquids at room temperature, which is convenient for experimental rigs but less important for pilot or full scale power stations. Lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

 and lead-bismuth alloy
Lead-bismuth eutectic
Lead-Bismuth Eutectic or LBE is a eutectic alloy of lead and bismuth used as a coolant in some nuclear reactors, and is a proposed coolant for the lead-cooled fast reactor, part of the Generation IV reactor initiative....

 have also been used. The relative merits of lead vs sodium are discussed here. Looking further ahead, three of the proposed generation IV reactor
Generation IV reactor
Generation IV reactors are a set of theoretical nuclear reactor designs currently being researched. Most of these designs are generally not expected to be available for commercial construction before 2030...

 types are FBRs:
  • Gas-Cooled Fast Reactor
    Gas-cooled fast reactor
    The Gas-Cooled Fast Reactor system is a nuclear reactor design which is currently in development. Classed as a Generation IV reactor, it features a fast-neutron spectrum and closed fuel cycle for efficient conversion of fertile uranium and management of actinides...

    (GFR) cooled by helium
    Helium
    Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...

    .
  • Sodium-Cooled Fast Reactor
    Sodium-cooled fast reactor
    The sodium-cooled fast reactor or SFR is a Generation IV reactor project to design an advanced fast neutron reactor.It builds on two closely related existing projects, the LMFBR and the Integral Fast Reactor, with the objective of producing a fast-spectrum, sodium-cooled reactor.The reactors are...

    (SFR) based on the existing Liquid Metal FBR (LMFBR) and Integral Fast Reactor
    Integral Fast Reactor
    The Integral Fast Reactor is a design for a nuclear reactor using fast neutrons and no neutron moderator . IFR is distinguished by a nuclear fuel cycle that uses reprocessing via electrorefining at the reactor site.The U.S...

     designs.
  • Lead-Cooled Fast Reactor (LFR) based on Soviet naval propulsion units.


FBRs usually use a mixed oxide fuel core of up to 20% plutonium dioxide
Plutonium dioxide
Plutonium oxide is the chemical compound with the formula PuO2. This high melting point solid is a principal compound of plutonium. It can vary in color from yellow to olive green, depending on the particle size, temperature and method of production....

 (PuO2) and at least 80% uranium dioxide
Uranium dioxide
Uranium dioxide or uranium oxide , also known as urania or uranous oxide, is an oxide of uranium, and is a black, radioactive, crystalline powder that naturally occurs in the mineral uraninite. It is used in nuclear fuel rods in nuclear reactors. A mixture of uranium and plutonium dioxides is used...

 (UO2). Another fuel option is metal alloys, typically a blend of uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

, plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...

, and zirconium
Zirconium
Zirconium is a chemical element with the symbol Zr and atomic number 40. The name of zirconium is taken from the mineral zircon. Its atomic mass is 91.224. It is a lustrous, grey-white, strong transition metal that resembles titanium...

 (used because it is "transparent" to neutrons). Enriched uranium
Enriched uranium
Enriched uranium is a kind of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight...

 can also be used on its own.

In many designs, the core is surrounded in a blanket of tubes containing non-fissile
Fissile
In nuclear engineering, a fissile material is one that is capable of sustaining a chain reaction of nuclear fission. By definition, fissile materials can sustain a chain reaction with neutrons of any energy. The predominant neutron energy may be typified by either slow neutrons or fast neutrons...

 uranium-238
Uranium-238
Uranium-238 is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239...

 which, by capturing fast neutrons from the reaction in the core, is converted to fissile plutonium-239
Plutonium-239
Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has also been used and is currently the secondary isotope. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in...

 (as is some of the uranium in the core), which is then reprocessed and used as nuclear fuel. Other FBR designs rely on the geometry of the fuel itself (which also contains uranium-238), arranged to attain sufficient fast neutron capture. The plutonium-239
Plutonium-239
Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has also been used and is currently the secondary isotope. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in...

 (or the fissile uranium-235
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...

) fission cross-section is much smaller in a fast spectrum than in a thermal spectrum, as is the ratio between the 239Pu
Plutonium-239
Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has also been used and is currently the secondary isotope. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in...

/235U
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...

 fission cross-section and the 238U
Uranium-238
Uranium-238 is the most common isotope of uranium found in nature. It is not fissile, but is a fertile material: it can capture a slow neutron and after two beta decays become fissile plutonium-239...

 absorption cross-section. This increases the concentration of 239Pu
Plutonium-239
Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has also been used and is currently the secondary isotope. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in...

/235U
Uranium-235
- References :* .* DOE Fundamentals handbook: Nuclear Physics and Reactor theory , .* A piece of U-235 the size of a grain of rice can produce energy equal to that contained in three tons of coal or fourteen barrels of oil. -External links:* * * one of the earliest articles on U-235 for the...

 needed to sustain a chain reaction
Nuclear chain reaction
A nuclear chain reaction occurs when one nuclear reaction causes an average of one or more nuclear reactions, thus leading to a self-propagating number of these reactions. The specific nuclear reaction may be the fission of heavy isotopes or the fusion of light isotopes...

, as well as the ratio of breeding to fission.

On the other hand, a fast reactor needs no moderator
Neutron moderator
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235....

 to slow down the neutrons
Thermalisation
In physics, thermalisation is the process of particles reaching thermal equilibrium through mutual interaction....

 at all, taking advantage of the fast neutrons producing a greater number of neutrons per fission than slow neutrons. For this reason ordinary liquid water, being a moderator as well as a neutron absorber, is an undesirable primary coolant for fast reactors. Because large amounts of water in the core are required to cool the reactor, the yield of neutrons and therefore breeding of 239Pu
Plutonium-239
Plutonium-239 is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 has also been used and is currently the secondary isotope. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in...

 are strongly affected. Theoretical work has been done on reduced moderation water reactor
Reduced moderation water reactor
The Reduced-Moderation Water Reactor , also referred to as the Resource-renewable BWR, is a proposed type of light water moderated nuclear power reactor, featuring some characteristics of a fast neutron reactor, thereby combining the established and proven technology of light water reactors with...

s, which may have a sufficiently fast spectrum to provide a breeding ratio slightly over 1. This would likely result in an unacceptable power derating and high costs in an liquid-water-cooled reactor, but the supercritical water coolant of the SCWR has sufficient heat capacity to allow adequate cooling with less water, making a fast-spectrum water-cooled reactor a practical possibility. In addition, a heavy water
Heavy water
Heavy water is water highly enriched in the hydrogen isotope deuterium; e.g., heavy water used in CANDU reactors is 99.75% enriched by hydrogen atom-fraction...

 moderated thermal breeder reactor, using thorium to produce uranium-233, is also possible (see Advanced Heavy Water Reactor
Advanced Heavy Water Reactor
The Advanced Heavy Water Reactor is the latest Indian design for a next generation nuclear reactor that will burn thorium in its fuel core. It is slated to form the third stage in India's 3 stage fuel cycle plan. Thorium is an element that is 3 times more abundant globally than uranium...

).

Several prototype FBRs have been built, ranging in electrical output from a few light bulbs' equivalent (EBR-I
Experimental Breeder Reactor I
Experimental Breeder Reactor I is a decommissioned research reactor and U.S. National Historic Landmark located in the desert about southeast of Arco, Idaho. At 1:50 pm on December 20, 1951 it became the world's first electricity-generating nuclear power plant when it produced sufficient...

, 1951) to over 1000 MWe. As of 2006, the technology is not economically competitive to thermal reactor technology—but India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

, Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...

and Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

 are all committing substantial research funds to further development of Fast Breeder reactors, anticipating that rising uranium prices will change this in the long term. Germany, in contrast, abandoned the technology due to political and safety concerns. The SNR-300
SNR-300
The Fast Breeder nuclear reactor SNR-300 was built near the town of Kalkar, Germany The Fast Breeder nuclear reactor SNR-300 was built near the town of Kalkar, Germany The Fast Breeder nuclear reactor SNR-300 was built near the town of Kalkar, Germany (located in the federal state of North...

 fast breeder reactor was finished after 19 years despite cost overruns summing up to a total of 3.6 billion Euros, only to then be abandoned.

As well as their thermal breeder program, India
Nuclear power in India
Nuclear power is the fourth-largest source of electricity in India after thermal, hydroelectric and renewable sources of electricity. As of 2010, India has 20 nuclear reactors in operation in six nuclear power plants, generating 4,780 MW while seven other reactors are under construction and...

 is also developing FBR technology, using both uranium and thorium feedstocks.

Traveling wave reactor

The traveling wave reactor
Traveling wave reactor
A traveling-wave reactor, or TWR, is a type of conceptual nuclear reactor that theorists speculate can convert fertile material into fissile fuel as it runs using the process of nuclear transmutation...

 proposed in a patent by Intellectual Ventures
Intellectual Ventures
Intellectual Ventures is a private company notable for being one of the top-five owners of U.S. patents, as of 2011. Its business model has a focus on developing a large patent portfolio and licensing these patents to companies. Publicly, it states that a major goal is to assist small inventors...

 is a fast breeder reactor designed to not need fuel reprocessing during the decades-long lifetime of the reactor, leaving the spent fuel in place. Over the years, a wave of fission starting at one end of the fuel cylinder would drive a wave of breeding ahead of it.

The thermal breeder reactor

"The Advanced Heavy Water Reactor
Advanced Heavy Water Reactor
The Advanced Heavy Water Reactor is the latest Indian design for a next generation nuclear reactor that will burn thorium in its fuel core. It is slated to form the third stage in India's 3 stage fuel cycle plan. Thorium is an element that is 3 times more abundant globally than uranium...

 is one of the few proposed large-scale uses of thorium
Thorium
Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....

. As of 2006 only India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 is developing this technology. Indian interest is motivated by their substantial thorium reserves; almost a third of the world's thorium reserves are in India, which in contrast has less than 1% of the world's uranium. Their stated intention is to use both fast and thermal breeder reactors to supply both their own fuel and a surplus for non-breeding thermal power reactors. Total worldwide resources of thorium are roughly three times those of uranium, so in the extreme long term this technology may become of more general interest.

"The Liquid fluoride thorium reactor
Liquid fluoride thorium reactor
The liquid fluoride thorium reactor is a thermal breeder reactor which uses the thorium fuel cycle in a fluoride-based molten salt fuel to achieve high operating temperatures at atmospheric pressure....

 (LFTR) was also developed as a thermal breeder. Liquid-fluoride reactors have many attractive features, such as deep inherent safety (due to their strong negative temperature coefficient of reactivity and their ability to drain their liquid fuel into a passively cooled and non-critical configuration) and ease of operation. They are particularly attractive as thermal breeders because they can isolate protactinium-233 (the intermediate breeding product of thorium) from neutron flux and allow it to decay to uranium-233, which can then be returned to the reactor. Typical solid-fueled reactors are not capable of accomplishing this step and thus U-234 is formed upon further neutron irradiation."

Breeder reactor development and notable breeder reactors

FBRs have been built and operated in the USA
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, the former USSR
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. An experimental FBR in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 was built but never operated. There are very few breeder reactors actually used for power generation, there are a few planned, and quite a few are being used for research related to the Generation IV reactor initiative. In many countries, nuclear power has been opposed politically and thus many breeder reactors have been shut down, or are planned to be shut down, with various justifications.

France

France's first fast reactor, Rapsodie
Rapsodie
Rapsodie is an experimental nuclear reactor built in Cadarache in France.It was France's first fast reactor, and first achieved criticality in 1967. Rapsodie was a loop-type reactor with a thermal output of 40MW and no electrical generation facilities, and closed in 1983....

 first achieved criticality in 1967. Built at Cadarache
Cadarache
The CEA Cadarache facility is a French scientific research centre which specialises in nuclear energy research. It is located in the commune of Saint-Paul-lès-Durance, Bouches-du-Rhône, in the southern region of Provence-Alpes-Côte-d'Azur...

 near Aix-en-Provence, Rapsodie was a loop-type reactor with a thermal output of 40MW and no electrical generation facilities, and closed in 1983. The plant was also a focus point of anti-nuclear political activity by the Green party and other groups. Right wing groups claim the plant was shut down for political reasons and not lack of power generation.

This was followed by the 233 MWe Phénix
Phénix
Phénix was a small-scale prototype fast breeder reactor, located at the Marcoule nuclear site, near Orange, France. It was a pool-type liquid-metal fast breeder reactor cooled with liquid sodium...

, grid connected since 1973, both as a power reactor and more importantly as the center of work on reprocessing of nuclear waste by transmutation
Nuclear transmutation
Nuclear transmutation is the conversion of one chemical element or isotope into another. In other words, atoms of one element can be changed into atoms of other element by 'transmutation'...

. It was definitely shut down in 2009. The life-time load factor was just below 40 per cent, according to the IAEA data base PRIS.

Superphénix
Superphénix
Superphénix or SPX was a nuclear power station on the Rhône River at Creys-Malville in France, close to the border with Switzerland. A fast breeder reactor, it halted electricity production in 1996 and was closed as a commercial plant in 1997....

, 1200 MWe, entered service in 1984 and as of 2006 remains the largest FBR yet built. It was shut down in 1998 due to political commitment of the left-wing government to competitive market forces. The power plant had not produced electricity for most of the preceding ten years. The life time load factor was 7.79 percent according to IAEA.

Germany

Germany has built two FBRs.

KNK-II as a Research reactor
Research reactor
Research reactors are nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for electricity production, heat generation, or maritime propulsion.-Purpose:...

 was converted from a thermal reactor, KNK-I, which had been used to study sodium cooling. KNK-II first achieved criticality as a fast reactor in 1977, and produced 20MWe. It was shut down in 1991 and is being dismantled

Construction of the 300MWe SNR-300
SNR-300
The Fast Breeder nuclear reactor SNR-300 was built near the town of Kalkar, Germany The Fast Breeder nuclear reactor SNR-300 was built near the town of Kalkar, Germany The Fast Breeder nuclear reactor SNR-300 was built near the town of Kalkar, Germany (located in the federal state of North...

at Kalkar
Kalkar
Kalkar is a municipality in the district of Kleve, in North Rhine-Westphalia, Germany. It is located near the Rhine, approx. 10 km south-east of Cleves. The most famous building of Kalkar is its church St...

 in North Rhine-Westphalia
North Rhine-Westphalia
North Rhine-Westphalia is the most populous state of Germany, with four of the country's ten largest cities. The state was formed in 1946 as a merger of the northern Rhineland and Westphalia, both formerly part of Prussia. Its capital is Düsseldorf. The state is currently run by a coalition of the...

 was completed in 1985 but never operated. The price had exploded from 0.5 billion DM to 7.1 billion DM, the Three Mile Island accident
Three Mile Island accident
The Three Mile Island accident was a core meltdown in Unit 2 of the Three Mile Island Nuclear Generating Station in Dauphin County, Pennsylvania near Harrisburg, United States in 1979....

 had heightened public opposition to nuclear power, and the expected increase in electricity consumption had not occurred. The plant was maintained and staffed until a decision to close it was finally made in 1991, and has since been decommissioned. Today it houses an amusement park (Wunderland Kalkar).

India

India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 has an active development programme featuring both fast and thermal breeder reactors.

India’s first 40 MWt Fast Breeder Test Reactor (FBTR
FBTR
The Fast Breeder Test Reactor is a breeder reactor located at Kalpakkam, India. The Indira Gandhi Center for Atomic Research and Bhabha Atomic Research Center jointly designed, constructed, and operate the reactor.-History:...

) attained criticality on 18 October 1985. Thus, India became the sixth nation to have the technology to build and operate an FBTR after US, UK, France, Japan and the former USSR. India has developed the technology to produce the plutonium rich U-Pu mixed carbide fuel. This can be used in the Fast Breeder Reactor.

At present the scientists of the Indira Gandhi Centre for Atomic Research (IGCAR
IGCAR
The Reactor Research Centre set up at Kalpakkam, India, 80 km south of Chennai in 1971 under the Department of Atomic Energy was renamed Indira Gandhi Center for Atomic Research in 1985. The center is primarily a research facility besides being a nuclear power plant aiding in meeting a...

), one of the nuclear R & D institutions of India, are engaged in the construction (already in its final stages) of another FBR — the 500 MWe prototype fast breeder reactor
Prototype fast breeder reactor
The Prototype Fast Breeder Reactor is a 500MWe fast breeder nuclear reactor presently being constructed in Kalpakkam, India. The Indira Gandhi Centre for Atomic Research is responsible for the design of this reactor....

 - at Kalpakkam
Kalpakkam
Kalpakkam is a small town in Tamil Nadu, India, situated on the Coromandel Coast 70 kilometres south of Chennai. A conglomerate of two villages and a DAE township, it is about 55 km from Thiruvanmiyur....

, near Chennai
Chennai
Chennai , formerly known as Madras or Madarasapatinam , is the capital city of the Indian state of Tamil Nadu, located on the Coromandel Coast off the Bay of Bengal. Chennai is the fourth most populous metropolitan area and the sixth most populous city in India...

, with plans to build more as part of its three stage nuclear power program
India's three stage nuclear power programme
India's three stage nuclear power programme was formulated to use the available uranium and thorium reserves found in the monazite sands of coastal regions of South India. Importance of nuclear energy was recognised as soon as India became independent...

.

India has the capability to use thorium
Thorium
Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....

 cycle based processes to extract nuclear fuel. This is of special significance to the Indian nuclear power generation strategy as India has among the world largest reserves of thorium, which could fuel nuclear projects for an estimated 2,500 years. The higher construction expense of the Fast Breeder Reactor in comparison with the Pressurised Heavy Water Reactors (PHWR) in use is one of the main reasons why India is looking at the cheaper option — uranium fuel.

Japan

Japan has built one demonstration FBR, Monju, in Tsuruga, Fukui Prefecture
Fukui Prefecture
is a prefecture of Japan located in the Chūbu region on Honshū island. The capital is the city of Fukui.- Prehistory :The Kitadani Dinosaur Quarry, on the Sugiyama River within the city limits of Katsuyama, has yielded the Fukuiraptor kitadaniensis and Fukuisaurus tetoriensis as well as an unnamed...

, adding on to the research base developed by its older research FBR, the Joyo reactor. Monju is a sodium-cooled, MOX-fueled loop type reactor with 3 primary coolant loops, producing 714 MWt / 280 MWe.

Monju began construction in 1985 and was completed in 1991. It first achieved criticality on 5 April 1994. It was closed in December 1995 following a sodium leak and fire in a secondary cooling circuit, and was expected to restart in 2008. The reactor was restarted for tests in May 2010, for the goal to production usage in 2013. However, on August 26, 2010, a 3.3-tonne "In‐Vessel Transfer Machine" fell into the reactor vessel when being removed after a scheduled fuel replacement operation. The fallen device was not retrieved from the reactor vessel until June 23, 2011.

In April 2007, the Japanese Government selected Mitsubishi Heavy Industries
Mitsubishi Heavy Industries
, or MHI, is a Japanese company. It is one of the core companies of Mitsubishi Group.-History:In 1870 Yataro Iwasaki, the founder of Mitsubishi took a lease of Government-owned Nagasaki Shipyard. He named it Nagasaki Shipyard & Machinery Works, and started the shipbuilding business on a full scale...

 as the "core company in FBR development in Japan". Shortly thereafter, MHI started a new company, Mitsubishi FBR Systems
Mitsubishi FBR Systems
Mitsubishi FBR Systems, Inc. is a company formed on July 1, 2007 by Mitsubishi Heavy Industries to develop Fast breeder reactor technology. The establishment of the company was based on the April 2007 decision by the Japanese government to select Mitsubishi as the core company for FBR development...

 (MFBR), with the explicit purpose of developing and eventually selling FBR technology.

UK

The UK fast reactor programme was conducted at Dounreay
Dounreay
Dounreay is the site of several nuclear research establishments located on the north coast of Caithness, in the Highland area of Scotland...

, Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

, from 1957 until the programme was cancelled in 1994. Three reactors were constructed, two of them fast neutron power reactors, and the third, DMTR, being a heavy water moderated research reactor used to test materials for the program. Fabrication and reprocessing facilities for fuel for the two fast reactors and for the test rigs for DMTR were also constructed onsite. Dounreay Fast Reactor (DFR) achieved its first criticality in 1959. It used NaK
NaK
NaK, or sodium-potassium alloy, an alloy, of potassium , and sodium , is usually liquid at room temperature. Various commercial grades are available. NaK is highly reactive with water and may catch fire when exposed to air, so must be handled with special precautions...

 coolant and produced 14MW of electricity. This was followed by the sodium-cooled 250 MWe Prototype Fast Reactor (PFR) in the 1970s. PFR was closed down in 1994 as the British government withdrew major financial support for nuclear energy development, DFR and DMTR both having previously been closed.

USA

On December 20, 1951, the fast reactor EBR-I
Experimental Breeder Reactor I
Experimental Breeder Reactor I is a decommissioned research reactor and U.S. National Historic Landmark located in the desert about southeast of Arco, Idaho. At 1:50 pm on December 20, 1951 it became the world's first electricity-generating nuclear power plant when it produced sufficient...

 (Experimental Breeder Reactor-1) at the Idaho National Laboratory
Idaho National Laboratory
Idaho National Laboratory is an complex located in the high desert of eastern Idaho, between the town of Arco to the west and the cities of Idaho Falls and Blackfoot to the east. It lies within Butte, Bingham, Bonneville and Jefferson counties...

 in Idaho Falls, Idaho produced enough electricity to power four light bulbs, and the next day produced enough power to run the entire EBR-I building. This was a milestone in the development of nuclear power reactors. The reactor was decommissioned in 1964.

The next generation experimental breeder was EBR-II
Experimental Breeder Reactor II
Experimental Breeder Reactor-II is a reactor at the Materials and Fuels Complex of the Idaho National Laboratory, formerly the West Campus of Argonne National Laboratory in Idaho....

 (Experimental Breeder Reactor-2), which went into service at the INEEL in 1964 and operated until 1994. It was designed to be an "integral" nuclear plant, equipped to handle fuel recycling onsite. It typically operated at 20 megawatts out of its 62.5 megawatt maximum design power, and provided the bulk of heat and electricity to the surrounding facilities.

The world's first commercial LMFBR, and the only one yet built in the USA, was the 94 MWe
MWE
MWE may refer to:*Manufacturer's Weight Empty*McDermott Will & Emery*Midwest Express, an airline*Merowe Airport - IATA code*Multiword expressionMWe may refer to:*Megawatt electrical...

 Unit 1 at Enrico Fermi Nuclear Generating Station
Enrico Fermi Nuclear Generating Station
The Enrico Fermi Nuclear Generating Station is a nuclear power plant on the shore of Lake Erie near Monroe, in Frenchtown Charter Township, Michigan. It is approximately halfway between Detroit, Michigan, and Toledo, Ohio. It is also visible from parts of Amherstburg, Ontario. Two units have been...

. Designed in a joint effort between Dow Chemical and Detroit Edison
Detroit Edison
The Detroit Edison Company, founded in 1903, is an investor-owned electric utility which serves most of Southeast Michigan. Its parent company, DTE Energy , provides energy services to a variety of clients beyond Detroit Edison's service area.- History :...

 as part of the Atomic Power Development Associates consortium, groundbreaking in Lagoona Beach, Michigan (near Monroe, Michigan
Monroe, Michigan
Monroe is a city in the U.S. state of Michigan. The population was 20,733 at the 2010 census. It is the largest city and county seat of Monroe County. The city is bordered on the south by Monroe Charter Township, but both are politically independent. The city is located approximately 14 miles ...

) took place in 1956. The plant went into operation in 1963. It shut down on October 5, 1966 due to high temperatures caused by a loose piece of zirconium which was blocking the molten sodium
Sodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

 coolant nozzles. Partial melting damage to six subassemblies within the core was eventually found. (This incident was the basis for a controversial book by investigative reporter John G. Fuller
John G. Fuller
John Grant Fuller, Jr. was a New England-based American author of several non-fiction books and newspaper articles, mainly focusing on the theme of extra-terrestrials and the supernatural. For many years he wrote a regular column for the Saturday Review magazine, called "Trade Winds"...

 titled We Almost Lost Detroit
We Almost Lost Detroit
We Almost Lost Detroit, a 1975 Reader's Digest book by John G. Fuller, presents a history of Fermi 1, America's first commercial breeder reactor, with emphasis on the 1966 partial nuclear meltdown. It was republished in 1984 by Berkley....

.
) The zirconium blockage was removed in April 1968, and the plant was ready to resume operation by May 1970, but a sodium coolant fire delayed its restart until July. It subsequently ran until August 1972 when its operating license renewal was denied.

The Clinch River Breeder Reactor Project
Clinch River Breeder Reactor Project
The Clinch River Breeder Reactor Project was a joint effort of the U.S. Atomic Energy Commission and the U.S. electric power industry to design and construct a sodium-cooled fast-neutron nuclear reactor...

 was announced in January, 1972. A government/business cooperative effort, construction proceeded fitfully and abandoned in 1982 because the US has since halted its spent-fuel reprocessing
Nuclear reprocessing
Nuclear reprocessing technology was developed to chemically separate and recover fissionable plutonium from irradiated nuclear fuel. Reprocessing serves multiple purposes, whose relative importance has changed over time. Originally reprocessing was used solely to extract plutonium for producing...

 program and thus made breeders pointless. Funding for this project was halted by Congress on October 26, 1983.

The Fast Flux Test Facility
Fast Flux Test Facility
The Fast Flux Test Facility is a 400 MW nuclear test reactor owned by the U.S. Department of Energy.It is situated in the 400 Area of the Hanford Site, which is located in the state of Washington.-History:...

, first critical in 1980, is not a breeder but is a sodium-cooled fast reactor. It is in cold standby.

USSR

The Soviet Union constructed a series of fast reactors, the first being mercury cooled and fueled with plutonium metal, and the later plants sodium cooled and fueled with plutonium oxide.

BR-1 (1955) was 100W (thermal) was followed by BR-2 at 100 kW and then the 5MW BR-5.

BOR-60 (first criticality 1969) was 60 MW, with construction started in 1965.

BN-350
BN-350 reactor
The BN-350 was a sodium-cooled fast reactor nuclear power plant located at Aktau , Kazakhstan, situated on the shore of the Caspian Sea. Construction of the BN-350 Fast breeder reactor began in 1964, and the plant first produced electricity in 1973...

(1973) was the first full-scale Soviet FBR. Constructed on the Mangyshlak Peninsula
Mangyshlak Peninsula
Mangyshlak or Mangghyshlaq Peninsula is located in westernKazakhstan. It borders on the Caspian Sea in the north and west.Administratively, the peninsula is in Kazakhstan's Mangystau Province. The largest city,and the capital of the province,...

 in Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...

 and on the shore of the Caspian Sea, it supplied 130MW of electricity plus 80,000 tonnes per day of desalinated fresh water to the city of Aktau
Aktau
Aktau , formerly known as Shevchenko , is a city in Kazakhstan's Mangyshlak Peninsula and country's only seaport on the Caspian Sea. It is the capital of Mangystau Province in western Kazakhstan...

. Its total output was regarded as the equivalent of 350MWe, hence the designation.

BN-600
BN-600 reactor
The BN-600 reactor is a sodium-cooled fast breeder reactor, built at the Beloyarsk Nuclear Power Station, in Zarechny, Sverdlovsk Oblast, Russia. Designed to generate electrical power of 600 MW in total, the plant dispatches 560 MW to the Middle Urals power grid...

(1986, end of life 2020) is 1470MWth / 600MWe.

There are plans for the construction of two larger plants, BN-800 (800 MWe) at Beloyarsk
Beloyarsk Nuclear Power Station
The Beloyarsk Nuclear Power Station , was the second of the then Soviet Union's nuclear plants. It is situated by Zarechny in Sverdlovsk Oblast, Russia. Zarechny township was created to service the station, which is named after the Beloyarsky District...

, expected to be completed in Q1/2013, and BN-1200 (1200 MWe), expected to be completed in 2018.

Future plants

As of 2003 one indigenous FBR was planned for India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, which is due to be completed by 2010. The FBR program of India includes the concept of using fertile thorium
Thorium
Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....

-232 to breed fissile uranium-233. India is also pursuing the thermal breeder reactor, again using thorium. A thermal breeder is not possible with purely uranium/plutonium based technology. Thorium fuel is the strategic direction of the power program of India, owing to their large reserves of thorium, but worldwide known reserves of thorium are also some four times those of uranium. India's Department of Atomic Energy (DAE) says that it will simultaneously construct four more breeder reactors of 500 MWe each including two at Kalpakkam.

The China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 Experimental Fast Reactor (CEFR), scheduled for completion in 2008, is a 25 MW(e) prototype for the planned China Prototype Fast Reactor (CFRP). It started generating power on July 21, 2011.

The People’s Republic of China has also initiated a research and development project in thorium molten-salt thermal breeder reactor technology (Liquid fluoride thorium reactor
Liquid fluoride thorium reactor
The liquid fluoride thorium reactor is a thermal breeder reactor which uses the thorium fuel cycle in a fluoride-based molten salt fuel to achieve high operating temperatures at atmospheric pressure....

). It was formally announced at the Chinese Academy of Sciences
Chinese Academy of Sciences
The Chinese Academy of Sciences , formerly known as Academia Sinica, is the national academy for the natural sciences of the People's Republic of China. It is an institution of the State Council of China. It is headquartered in Beijing, with institutes all over the People's Republic of China...

 (CAS) annual conference in January 2011. Its ultimate target is to investigate and develop a thorium based molten salt nuclear system in about 20 years.
Kirk Sorensen, former NASA scientist and Chief Nuclear Technologist at Teledyne Brown Engineering, has been a long time promoter of thorium fuel cycle
Thorium fuel cycle
The thorium fuel cycle is a nuclear fuel cycle that uses the naturally abundant isotope of thorium, , as the fertile material. In the reactor, is transmuted into the fissile artificial uranium isotope which is the nuclear fuel. Unlike natural uranium, natural thorium contains only trace amounts...

 and particularly liquid fluoride thorium reactor
Liquid fluoride thorium reactor
The liquid fluoride thorium reactor is a thermal breeder reactor which uses the thorium fuel cycle in a fluoride-based molten salt fuel to achieve high operating temperatures at atmospheric pressure....

s. In 2011, Sorensen founded Flibe Energy
Flibe Energy
Flibe Energy is a company that intends to design, construct and operate small modular reactors based on liquid fluoride thorium reactor technology.-Corporation:...

, a company aimed to develop 20-50 MW LFTR reactor designs to power military bases.
South Korea
South Korea
The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...

 is developing a design for a standardized modular FBR for export, to complement the standardized PWR
Pressurized water reactor
Pressurized water reactors constitute a large majority of all western nuclear power plants and are one of three types of light water reactor , the other types being boiling water reactors and supercritical water reactors...

 (Pressurized Water Reactor) and CANDU
CANDU reactor
The CANDU reactor is a Canadian-invented, pressurized heavy water reactor. The acronym refers to its deuterium-oxide moderator and its use of uranium fuel...

 designs they have already developed and built, but has not yet committed to building a prototype.

The BN-600 (Beloyarsk NNP in the town of Zarechny
Zarechny, Sverdlovsk Oblast
Zarechny is a town in Sverdlovsk Oblast, Russia, located on the Pyshma River east of Yekaterinburg. Population: It was granted urban-type settlement status in 1957; town status was granted in 1992....

, Sverdlovsk Oblast
Sverdlovsk Oblast
Sverdlovsk Oblast is a federal subject of Russia located in the Urals Federal District. Its administrative center is the city of Yekaterinburg formerly known as Sverdlovsk. Population: -Geography:...

) is still operational. A second reactor (BN-800) is scheduled to be constructed before 2015.

On 16 February 2006 the U.S., France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 signed an "arrangement" to research and develop sodium-cooled fast reactors in support of the Global Nuclear Energy Partnership
Global Nuclear Energy Partnership
The International Framework for Nuclear Energy Cooperation formerly the Global Nuclear Energy Partnership began as a U.S. proposal, announced by United States Secretary of Energy Samuel Bodman on February 6, 2006, to form an international partnership to promote the use of nuclear power and close...

.

See also

  • Liquid fluoride thorium reactor
    Liquid fluoride thorium reactor
    The liquid fluoride thorium reactor is a thermal breeder reactor which uses the thorium fuel cycle in a fluoride-based molten salt fuel to achieve high operating temperatures at atmospheric pressure....

  • Fast neutron reactor
    Fast neutron reactor
    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...

  • Sodium-cooled fast reactor
    Sodium-cooled fast reactor
    The sodium-cooled fast reactor or SFR is a Generation IV reactor project to design an advanced fast neutron reactor.It builds on two closely related existing projects, the LMFBR and the Integral Fast Reactor, with the objective of producing a fast-spectrum, sodium-cooled reactor.The reactors are...

  • Integral Fast Reactor
    Integral Fast Reactor
    The Integral Fast Reactor is a design for a nuclear reactor using fast neutrons and no neutron moderator . IFR is distinguished by a nuclear fuel cycle that uses reprocessing via electrorefining at the reactor site.The U.S...

  • Lead-cooled fast reactor
    Lead cooled fast reactor
    The lead-cooled fast reactor is a nuclear power Generation IV reactor that features a fast neutron spectrum, molten lead or lead-bismuth eutectic coolant. Options include a range of plant ratings, including a number of 50 to 150 MWe units featuring long-life, pre-manufactured cores...

  • Gas-cooled fast reactor
    Gas-cooled fast reactor
    The Gas-Cooled Fast Reactor system is a nuclear reactor design which is currently in development. Classed as a Generation IV reactor, it features a fast-neutron spectrum and closed fuel cycle for efficient conversion of fertile uranium and management of actinides...

  • Generation IV reactor
    Generation IV reactor
    Generation IV reactors are a set of theoretical nuclear reactor designs currently being researched. Most of these designs are generally not expected to be available for commercial construction before 2030...

  • Radioactive boy scout

External links

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