Neutron economy is defined as the ratio of excess neutron production divided by the rate of fission . The numbers are a weighted average based primarily on the energies of the neutrons.
67-473: FBR may refer to: Science, medicine, and technology [ edit ] Fast breeder reactor Fluidized bed reactor Foreign body response Full Bridge Rectifier Other uses [ edit ] Beveren railway station 's station code FBR Capital Markets , an American investment banking firm Federal Board of Revenue , central revenue collection agency of Pakistan Fortnite Battle Royale ,
134-433: A chain reaction , as well as the ratio of breeding to fission. On the other hand, a fast reactor needs no moderator to slow down the neutrons 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 and neutron absorber , is an undesirable primary coolant for fast reactors. Because large amounts of water in
201-460: A blend of uranium, plutonium, and zirconium (used because it is "transparent" to neutrons). Enriched uranium can be used on its own. Many designs surround the reactor core in a blanket of tubes that contain non-fissile uranium-238, which, by capturing fast neutrons from the reaction in the core, converts to fissile plutonium-239 (as is some of the uranium in the core), which is then reprocessed and used as nuclear fuel. Other FBR designs rely on
268-455: A breeder reactor then needs to be reprocessed to remove those neutron poisons . This step is required to fully utilize the ability to breed as much or more fuel than is consumed. All reprocessing can present a proliferation concern, since it can extract weapons-usable material from spent fuel. The most common reprocessing technique, PUREX , presents a particular concern since it was expressly designed to separate plutonium. Early proposals for
335-535: A chain reaction), fission products are viewed as nuclear 'ashes' left over from consuming fissile materials. Furthermore, only seven long-lived fission product isotopes have half-lives longer than a hundred years, which makes their geological storage or disposal less problematic than for transuranic materials. With increased concerns about nuclear waste, breeding fuel cycles came under renewed interest as they can reduce actinide wastes, particularly plutonium and minor actinides. Breeder reactors are designed to fission
402-435: A chance to cause fission, for instance. Others will be absorbed through various processes in the mass, and still others will be deliberately absorbed by control rods or similar devices to maintain the correct overall balance. The process of moderating the neutrons almost always leads to some of them being absorbed as well. Neutron economy is a measure of the number of neutrons being released that can cause fission compared to
469-538: A fission reactor. Breeder reactors by design have high burnup compared to a conventional reactor, as breeder reactors produce more of their waste in the form of fission products, while most or all of the actinides are meant to be fissioned and destroyed. In the past, breeder-reactor development focused on reactors with low breeding ratios, from 1.01 for the Shippingport Reactor running on thorium fuel and cooled by conventional light water to over 1.2 for
536-416: A half-life between 91 and 200,000 years. As a result of this physical oddity, after several hundred years in storage, the activity of the radioactive waste from an FBR would quickly drop to the low level of the long-lived fission products . However, to obtain this benefit requires the highly efficient separation of transuranics from spent fuel. If the fuel reprocessing methods used leave a large fraction of
603-1190: A heavily moderated thermal design, evolved into the fast reactor concept, using light water in a low-density supercritical form to increase the neutron economy enough to allow breeding. Aside from water-cooled, there are many other types of breeder reactor currently envisioned as possible. These include molten-salt cooled , gas cooled , and liquid-metal cooled designs in many variations. Almost any of these basic design types may be fueled by uranium , plutonium , many minor actinides , or thorium , and they may be designed for many different goals, such as creating more fissile fuel, long-term steady-state operation, or active burning of nuclear wastes . Extant reactor designs are sometimes divided into two broad categories based upon their neutron spectrum, which generally separates those designed to use primarily uranium and transuranics from those designed to use thorium and avoid transuranics. These designs are: All current large-scale FBR power stations were liquid metal fast breeder reactors (LMFBR) cooled by liquid sodium . These have been of one of two designs: There are only two commercially operating breeder reactors as of 2017 :
670-457: A light-water reactor for longer than 100,000 years, the transuranics would be the main source of radioactivity. Eliminating them would eliminate much of the long-term radioactivity from the spent fuel. In principle, breeder fuel cycles can recycle and consume all actinides, leaving only fission products. As the graphic in this section indicates, fission products have a peculiar "gap" in their aggregate half-lives, such that no fission products have
737-483: A neutron will be captured increases greatly when its energy is about that of the target nucleus, which is known as a "thermal neutron". In order to maintain a chain reaction in a nuclear reactor , a neutron moderator is used to slow the neutrons down. This moderator is often used as the coolant that is used for energy extraction as well, and the most common moderator is water. The neutrons also slow due to elastic and inelastic collisions with fuel and other materials in
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#1732783116086804-584: A prototype. Neutron economy Nuclear fission is a process in which the nuclei of atoms are split apart. Among the various particles released in this process are high-energy neutrons with energies spread over the neutron spectrum . Those neutrons may cause other nuclei to undergo fission, leading to the possibility of a chain reaction . However, the neutrons can only cause another fission under certain conditions based on their energy; high-energy, or "relativistic", neutrons will often fly right through another nucleus without causing fission. The chance that
871-470: A reactor is exactly critical —that is, the neutron production is exactly equal to neutron destruction—the reactivity is zero. If the reactivity is positive, the reactor is supercritical . If the reactivity is negative, the reactor is subcritical . The term "neutron economy" is used not just for the instantaneous reactivity of a reactor, but also to describe the overall efficiency of a nuclear reactor design. Common reactor designs using conventional water as
938-419: A reactor's performance is the "conversion ratio", defined as the ratio of new fissile atoms produced to fissile atoms consumed. All proposed nuclear reactors except specially designed and operated actinide burners experience some degree of conversion. As long as there is any amount of a fertile material within the neutron flux of the reactor, some new fissile material is always created. When the conversion ratio
1005-592: A third of the world's thorium reserves are in India, which lacks significant uranium reserves. The third and final core of the Shippingport Atomic Power Station 60 MWe reactor was a light water thorium breeder, which began operating in 1977. It used pellets made of thorium dioxide and uranium-233 oxide; initially, the U-233 content of the pellets was 5–6% in the seed region, 1.5–3% in
1072-566: A thorium thermal breeder. Liquid-fluoride reactors may have attractive features, such as inherent safety, no need to manufacture fuel rods, and possibly simpler reprocessing of the liquid fuel. This concept was first investigated at the Oak Ridge National Laboratory Molten-Salt Reactor Experiment in the 1960s. From 2012 it became the subject of renewed interest worldwide. Breeder reactors could, in principle, extract almost all of
1139-483: A video game Foundation for Biomedical Research , an American animal welfare organization Free Burma Rangers , a Burmese humanitarian organization Friedman Billings Ramsey , an American real estate investment trust Fueled by Ramen , an American record label FBR Ltd, formerly Fastbrick Robotics , an Australian construction robot development company Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
1206-465: Is a nuclear reactor that generates more fissile material than it consumes. These reactors can be fueled with more-commonly available isotopes of uranium and thorium , such as uranium-238 and thorium-232 , as opposed to the rare uranium-235 which is used in conventional reactors. These materials are called fertile materials since they can be bred into fuel by these breeder reactors. Breeder reactors achieve this because their neutron economy
1273-564: Is due to the nation's large reserves, though known worldwide reserves of thorium are four times those of uranium. India's Department of Atomic Energy said in 2007 that it would simultaneously construct four more breeder reactors of 500 MWe each including two at Kalpakkam . BHAVINI , an Indian nuclear power company, was established in 2003 to construct, commission, and operate all stage II fast breeder reactors outlined in India's three-stage nuclear power programme . To advance these plans,
1340-403: Is enough fuel for breeder reactors to satisfy the world's energy needs for 5 billion years at 1983's total energy consumption rate, thus making nuclear energy effectively a renewable energy . In addition to seawater, the average crustal granite rocks contain significant quantities of uranium and thorium that with breeder reactors can supply abundant energy for the remaining lifespan of the sun on
1407-457: Is greater than 1, it is often called the "breeding ratio". For example, commonly used light water reactors have a conversion ratio of approximately 0.6. Pressurized heavy-water reactors running on natural uranium have a conversion ratio of 0.8. In a breeder reactor, the conversion ratio is higher than 1. "Break-even" is achieved when the conversion ratio reaches 1.0 and the reactor produces as much fissile material as it uses. The doubling time
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#17327831160861474-438: Is high enough to create more fissile fuel than they use. These extra neutrons are absorbed by the fertile material that is loaded into the reactor along with fissile fuel. This irradiated fertile material in turn transmutes into fissile material which can undergo fission reactions . Breeders were at first found attractive because they made more complete use of uranium fuel than light-water reactors , but interest declined after
1541-440: Is the amount of time it would take for a breeder reactor to produce enough new fissile material to replace the original fuel and additionally produce an equivalent amount of fuel for another nuclear reactor. This was considered an important measure of breeder performance in early years, when uranium was thought to be scarce. However, since uranium is more abundant than thought in the early days of nuclear reactor development, and given
1608-445: Is transuranics (atoms heavier than uranium), which are generated from uranium or heavier atoms in the fuel when they absorb neutrons but do not undergo fission. All transuranic isotopes fall within the actinide series on the periodic table , and so they are frequently referred to as the actinides. The largest component is the remaining uranium which is around 98.25% uranium-238, 1.1% uranium-235, and 0.65% uranium-236. The U-236 comes from
1675-400: The activity of the waste is about the same as that produced by a light-water reactor. Waste from a breeder reactor has a different decay behavior because it is made up of different materials. Breeder reactor waste is mostly fission products, while light-water reactor waste is mostly unused uranium isotopes and a large quantity of transuranics. After spent nuclear fuel has been removed from
1742-531: The BN-600 reactor , at 560 MWe, and the BN-800 reactor , at 880 MWe. Both are Russian sodium-cooled reactors. The 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 ; other experimental reactors have used a sodium-potassium alloy . Both have
1809-476: The Chinese Academy of Sciences annual conference in 2011. Its ultimate target was to investigate and develop a thorium-based molten salt nuclear system over about 20 years. South Korea is developing a design for a standardized modular FBR for export, to complement the standardized pressurized water reactor and CANDU designs they have already developed and built, but has not yet committed to building
1876-453: The FBR-600 is a pool-type sodium-cooled reactor with a rating of 600 MWe. The China Experimental Fast Reactor is a 25 MW(e) prototype for the planned China Prototype Fast Reactor. It started generating power in 2011. China initiated a research and development project in thorium molten-salt thermal breeder-reactor technology (liquid fluoride thorium reactor), formally announced at
1943-693: The International Panel on Fissile Materials said "After six decades and the expenditure of the equivalent of tens of billions of dollars, the promise of breeder reactors remains largely unfulfilled and efforts to commercialize them have been steadily cut back in most countries". In Germany, the United Kingdom, and the United States, breeder reactor development programs have been abandoned. The rationale for pursuing breeder reactors—sometimes explicit and sometimes implicit—was based on
2010-479: The supercritical water reactor (SCWR) has sufficient heat capacity to allow adequate cooling with less water, making a fast-spectrum water-cooled reactor a practical possibility. The type of coolants, temperatures, and fast neutron spectrum puts the fuel cladding material (normally austenitic stainless or ferritic-martensitic steels) under extreme conditions. The understanding of the radiation damage, coolant interactions, stresses, and temperatures are necessary for
2077-407: The 1960s as more uranium reserves were found and new methods of uranium enrichment reduced fuel costs. Many types of breeder reactor are possible: A "breeder" is simply a nuclear reactor designed for very high neutron economy with an associated conversion rate higher than 1.0. In principle, almost any reactor design could be tweaked to become a breeder. For example, the light-water reactor ,
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2144-548: The Soviet BN-350 liquid-metal-cooled reactor. Theoretical models of breeders with liquid sodium coolant flowing through tubes inside fuel elements ("tube-in-shell" construction) suggest breeding ratios of at least 1.8 are possible on an industrial scale. The Soviet BR-1 test reactor achieved a breeding ratio of 2.5 under non-commercial conditions. Fission of the nuclear fuel in any reactor unavoidably produces neutron-absorbing fission products . The fertile material from
2211-458: The actinide wastes as fuel and thus convert them to more fission products. After spent nuclear fuel is removed from a light water reactor, it undergoes a complex decay profile as each nuclide decays at a different rate. There is a large gap in the decay half-lives of fission products compared to transuranic isotopes. If the transuranics are left in the spent fuel, after 1,000 to 100,000 years the slow decay of these transuranics would generate most of
2278-406: 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. Three of the proposed generation IV reactor types are FBRs: FBRs usually use a mixed oxide fuel core of up to 20% plutonium dioxide (PuO 2 ) and at least 80% uranium dioxide (UO 2 ). Another fuel option is metal alloys , typically
2345-428: The amount of plutonium available in spent reactor fuel, doubling time has become a less important metric in modern breeder-reactor design. " Burnup " is a measure of how much energy has been extracted from a given mass of heavy metal in fuel, often expressed (for power reactors) in terms of gigawatt-days per ton of heavy metal. Burnup is an important factor in determining the types and abundances of isotopes produced by
2412-414: The blanket region, and none in the reflector region. It operated at 236 MWt, generating 60 MWe, and ultimately produced over 2.1 billion kilowatt hours of electricity. After five years, the core was removed and found to contain nearly 1.4% more fissile material than when it was installed, demonstrating that breeding from thorium had occurred. A liquid fluoride thorium reactor is also planned as
2479-497: The breeder-reactor fuel cycle posed an even greater proliferation concern because they would use PUREX to separate plutonium in a highly attractive isotopic form for use in nuclear weapons. Several countries are developing reprocessing methods that do not separate the plutonium from the other actinides. For instance, the non-water-based pyrometallurgical electrowinning process, when used to reprocess fuel from an integral fast reactor , leaves large amounts of radioactive actinides in
2546-633: The coolant and moderator generally have poor relative neutron economies because the water will absorb some of the thermal neutrons, reducing the number available to keep the reaction going. In contrast, heavy water already has an extra neutron, and the same reaction generally causes it to be released, meaning that a reactor moderated with heavy water does not absorb neutrons and thus has a better neutron economy. Reactors with high neutron economies have more "leftover neutrons" which can be used for other purposes, like breeding additional fuel or causing sub-critical fission in nuclear waste to "burn off" some of
2613-424: The core are required to cool the reactor, the yield of neutrons and therefore breeding of Pu are strongly affected. Theoretical work has been done on reduced moderation water reactors , 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 a liquid-water-cooled reactor, but the supercritical water coolant of
2680-493: The energy contained in uranium or thorium, decreasing fuel requirements by a factor of 100 compared to widely used once-through light water reactors, which extract less than 1% of the energy in the actinide metal (uranium or thorium) mined from the earth. The high fuel-efficiency of breeder reactors could greatly reduce concerns about fuel supply, energy used in mining, and storage of radioactive waste. With seawater uranium extraction (currently too expensive to be economical), there
2747-426: The fertile material in the uranium fuel cycle has an atomic weight of 238. That mass difference means that thorium-232 requires six more neutron capture events per nucleus before the transuranic elements can be produced. In addition to this simple mass difference, the reactor gets two chances to fission the nuclei as the mass increases: First as the effective fuel nuclei U233, and as it absorbs two more neutrons, again as
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2814-428: The following key assumptions: Some past anti-nuclear advocates have become pro-nuclear power as a clean source of electricity since breeder reactors effectively recycle most of their waste. This solves one of the most-important negative issues of nuclear power. In the documentary Pandora's Promise , a case is made for breeder reactors because they provide a real high-kW alternative to fossil fuel energy. According to
2881-474: The fuel nuclei 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 surround 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. One measure of
2948-573: 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 project was canceled in 1994 by United States Secretary of Energy Hazel O'Leary . The first fast reactor built and operated was the Los Alamos Plutonium Fast Reactor (" Clementine ") in Los Alamos, NM. Clementine
3015-447: The geometry of the fuel (which also contains uranium-238), arranged to attain sufficient fast neutron capture. The plutonium-239 (or the fissile uranium-235) fissile cross-section is much smaller in a fast spectrum than in a thermal spectrum, as is the ratio between the Pu/ U fission cross-section and the U absorption cross-section. This increases the concentration of Pu/ U needed to sustain
3082-426: The long term. Germany, in contrast, abandoned the technology due to safety concerns. The SNR-300 fast breeder reactor was finished after 19 years despite cost overruns summing up to a total of € 3.6 billion, only to then be abandoned. The advanced heavy-water reactor is one of the few proposed large-scale uses of thorium. India is developing this technology, motivated by substantial thorium reserves; almost
3149-490: The main sequence of stellar evolution. No fission products have a half-life in the range of 100 a–210 ka ... ... nor beyond 15.7 Ma In broad terms, spent nuclear fuel has three main components. The first consists of fission products , the leftover fragments of fuel atoms after they have been split to release energy. Fission products come in dozens of elements and hundreds of isotopes, all of them lighter than uranium. The second main component of spent fuel
3216-416: The minor actinides (neptunium, americium, curium, etc.). Since breeder reactors on a closed fuel cycle would use nearly all of the isotopes of these actinides fed into them as fuel, their fuel requirements would be reduced by a factor of about 100. The volume of waste they generate would be reduced by a factor of about 100 as well. While there is a huge reduction in the volume of waste from a breeder reactor,
3283-403: The movie, one pound of uranium provides as much energy as 5,000 barrels of oil . 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 5 MW BR-5. BOR-60 (first criticality 1969)
3350-448: The non-fission capture reaction where U-235 absorbs a neutron but releases only a high energy gamma ray instead of undergoing fission. The physical behavior of the fission products is markedly different from that of the actinides. In particular, fission products do not undergo fission and therefore cannot be used as nuclear fuel. Indeed, because fission products are often neutron poisons (absorbing neutrons that could be used to sustain
3417-405: The number needed to maintain the chain reaction. This is not simply an accounting of the total number of neutrons, as it also includes a weighting based on the energy. Thus, remaining high-energy neutrons are not a major part of the "overall economy" as they do not maintain the chain reaction. The quantity that indicates how much the neutron economy is out of balance is given the term reactivity . If
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#17327831160863484-507: The power produced by commercial nuclear reactors comes from fission of plutonium generated within the fuel. Even with this level of plutonium consumption, light water reactors consume only part of the plutonium and minor actinides they produce, and nonfissile isotopes of plutonium build up, along with significant quantities of other minor actinides. Breeding fuel cycles attracted renewed interest because of their potential to reduce actinide wastes, particularly various isotopes of plutonium and
3551-529: The protactinium remains in the reactor, small amounts of uranium-232 are also produced, which has the strong gamma emitter thallium-208 in its decay chain. Similar to uranium-fueled designs, the longer the fuel and fertile material remain in the reactor, the more of these undesirable elements build up. In the envisioned commercial thorium reactors , high levels of uranium-232 would be allowed to accumulate, leading to extremely high gamma-radiation doses from any uranium derived from thorium. These gamma rays complicate
3618-453: The radioactivity in that spent fuel. Thus, removing the transuranics from the waste eliminates much of the long-term radioactivity of spent nuclear fuel. Today's commercial light-water reactors do breed some new fissile material, mostly in the form of plutonium. Because commercial reactors were never designed as breeders, they do not convert enough uranium-238 into plutonium to replace the uranium-235 consumed. Nonetheless, at least one-third of
3685-418: The reactor fuel. More conventional water-based reprocessing systems include SANEX, UNEX, DIAMEX, COEX, and TRUEX, and proposals to combine PUREX with those and other co-processes. All these systems have moderately better proliferation resistance than PUREX, though their adoption rate is low. In the thorium cycle, thorium-232 breeds by converting first to protactinium-233, which then decays to uranium-233. If
3752-423: The reactor. A fission reactor is based on the idea of maintaining criticality , where every fission event leads to another fission event, no more and no less. As fission of uranium releases two or three neutrons, this means some of the neutrons must be removed as part of the overall process. Some will be lost purely due to geometry, those released travelling outward from the outer edge of the fuel mass will not have
3819-501: The reactor. This process is an obvious chemical operation which is not required for normal operation of these reactor designs, but it could feasibly happen beyond the oversight of organizations such as the International Atomic Energy Agency (IAEA), and thus must be safeguarded against. Like many aspects of nuclear power, fast breeder reactors have been subject to much controversy over the years. In 2010
3886-508: The safe handling of a weapon and the design of its electronics; this explains why uranium-233 has never been pursued for weapons beyond proof-of-concept demonstrations. While the thorium cycle may be proliferation-resistant with regard to uranium-233 extraction from fuel (because of the presence of uranium-232), it poses a proliferation risk from an alternate route of uranium-233 extraction, which involves chemically extracting protactinium-233 and allowing it to decay to pure uranium-233 outside of
3953-408: The safe operation of any reactor core. All materials used to date in sodium-cooled fast reactors have known limits. Oxide dispersion-strengthened alloy steel is viewed as the long-term radiation resistant fuel-cladding material that can overcome the shortcomings of today's material choices. One design of fast neutron reactor, specifically conceived to address the waste disposal and plutonium issues,
4020-519: The salt carrier with heavier metal chlorides (e.g., KCl, RbCl, ZrCl 4 ). Several prototype FBRs have been built, ranging in electrical output from a few light bulbs' equivalent ( EBR-I , 1951) to over 1,000 MWe . As of 2006, the technology is not economically competitive to thermal reactor technology, but India , Japan, China, South Korea, and Russia are all committing substantial research funds to further development of fast breeder reactors, anticipating that rising uranium prices will change this in
4087-431: 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 . A quantity of natural uranium equivalent to a block about the size of a milk crate delivered once per month would be all
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#17327831160864154-464: The title FBR . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=FBR&oldid=1252808690 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Fast breeder reactor A breeder reactor
4221-498: The transuranics in the final waste stream, this advantage would be greatly reduced. The FBR's fast neutrons can fission actinide nuclei with even numbers of both protons and neutrons. Such nuclei usually lack the low-speed "thermal neutron" resonances of fissile fuels used in LWRs. The thorium fuel cycle inherently produces lower levels of heavy actinides. The fertile material in the thorium fuel cycle has an atomic weight of 232, while
4288-479: The waste. Some of these fission products could later be separated for industrial or medical uses and the rest sent to a waste repository. The IFR pyroprocessing system uses molten cadmium cathodes and electrorefiners to reprocess metallic fuel directly on-site at the reactor. Such systems co-mingle all the minor actinides with both uranium and plutonium. The systems are compact and self-contained, so that no plutonium-containing material needs to be transported away from
4355-506: Was 60 MW, with construction started in 1965. India has been trying to develop fast breeder reactors for decades but suffered repeated delays. By December 2024 the Prototype Fast Breeder Reactor is due to be completed and commissioned. The program is intended to use fertile thorium-232 to breed fissile uranium-233. India is also pursuing thorium thermal breeder reactor technology. India's focus on thorium
4422-424: Was fueled by Ga-stabilized delta-phase Pu and cooled with mercury. It contained a 'window' of Th-232 in anticipation of breeding experiments, but no reports were made available regarding this feature. Another proposed fast reactor is a fast molten salt reactor , in which the molten salt's moderating properties are insignificant. This is typically achieved by replacing the light metal fluorides (e.g. LiF, BeF 2 ) in
4489-477: Was the integral fast reactor (IFR, 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 fuel-reprocessing unit that recycled the uranium and all the transuranics (not just plutonium) via electroplating , leaving just short- half-life fission products in
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