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107-717: The Prototype Fast Breeder Reactor ( PFBR ) is a 500 MWe sodium-cooled, fast breeder reactor that is being constructed at Kokkilamedu, near Kalpakkam , in Tamil Nadu state, India . The Indira Gandhi Centre for Atomic Research (IGCAR) is responsible for the design of this reactor, the Advanced Fuel Fabrication Facility at the Bhabha Atomic Research Centre in Tarapur is responsible for MOX fuel fabrication and BHEL

214-433: 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

321-460: 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

428-455: 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

535-535: 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

642-497: A controlled flow of energy while also functionally isolating the independent AC frequencies of each side. The benefits of synchronous zones include pooling of generation, resulting in lower generation costs; pooling of load, resulting in significant equalizing effects; common provisioning of reserves, resulting in cheaper primary and secondary reserve power costs; opening of the market, resulting in possibility of long-term contracts and short term power exchanges; and mutual assistance in

749-465: A different region to ensure continuing, reliable power and diversify their loads. Interconnection also allows regions to have access to cheap bulk energy by receiving power from different sources. For example, one region may be producing cheap hydro power during high water seasons, but in low water seasons, another area may be producing cheaper power through wind, allowing both regions to access cheaper energy sources from one another during different times of

856-538: 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

963-416: 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

1070-1190: 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 :

1177-437: A large scale within an electrical power grid . Electrical energy is stored during times when electricity is plentiful and inexpensive (especially from intermittent power sources such as renewable electricity from wind power , tidal power and solar power ) or when demand is low, and later returned to the grid when demand is high, and electricity prices tend to be higher. As of 2020 , the largest form of grid energy storage

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1284-457: 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

1391-428: A local power grid, it will cause safety issue like burning out. Grids are designed to supply electricity to their customers at largely constant voltages. This has to be achieved with varying demand, variable reactive loads, and even nonlinear loads, with electricity provided by generators and distribution and transmission equipment that are not perfectly reliable. Often grids use tap changers on transformers near to

1498-521: A loss of generation capacity for customers, or excess demand. This will often cause the frequency to reduce, and the remaining generators will react and together attempt to stabilize above the minimum. If that is not possible then a number of scenarios can occur. A large failure in one part of the grid — unless quickly compensated for — can cause current to re-route itself to flow from the remaining generators to consumers over transmission lines of insufficient capacity, causing further failures. One downside to

1605-478: A lower voltage distribution network and distributed generators. Microgrids may not only be more resilient, but may be cheaper to implement in isolated areas. A design goal is that a local area produces all of the energy it uses. Example implementations include: A wide area synchronous grid , also known as an "interconnection" in North America, directly connects many generators delivering AC power with

1712-584: A number of hours by the four independent circuits. The fact that the PFBR is cooled by liquid sodium creates additional safety requirements to isolate the coolant from the environment, especially in a loss of coolant accident scenario, since sodium explodes if it comes into contact with water and burns when in contact with air. This latter event occurred in the Monju reactor in Japan in 1995. Another consideration with

1819-571: A prototype. Electrical grid Grids are nearly always synchronous, meaning all distribution areas operate with three phase alternating current (AC) frequencies synchronized (so that voltage swings occur at almost the same time). This allows transmission of AC power throughout the area, connecting the electricity generators with consumers. Grids can enable more efficient electricity markets . Although electrical grids are widespread, as of 2016 , 1.4 billion people worldwide were not connected to an electricity grid. As electrification increases,

1926-419: 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

2033-568: A regional scale or greater that operates at a synchronized frequency and is electrically tied together during normal system conditions. These are also known as synchronous zones, the largest of which is the synchronous grid of Continental Europe (ENTSO-E) with 667  gigawatts (GW) of generation, and the widest region served being that of the IPS/UPS system serving countries of the former Soviet Union. Synchronous grids with ample capacity facilitate electricity market trading across wide areas. In

2140-456: A security risk. Particular concerns relate to the more complex computer systems needed to manage grids. A microgrid is a local grid that is usually part of the regional wide-area synchronous grid but which can disconnect and operate autonomously. It might do this in times when the main grid is affected by outages. This is known as islanding , and it might run indefinitely on its own resources. Compared to larger grids, microgrids typically use

2247-592: 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

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2354-566: 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

2461-745: A widely connected grid is thus the possibility of cascading failure and widespread power outage . A central authority is usually designated to facilitate communication and develop protocols to maintain a stable grid. For example, the North American Electric Reliability Corporation gained binding powers in the United States in 2006, and has advisory powers in the applicable parts of Canada and Mexico. The U.S. government has also designated National Interest Electric Transmission Corridors , where it believes transmission bottlenecks have developed. A brownout

2568-693: A year of successful operation of the PFBR. Other four FBR are planned to follow beyond 2030, at sites to be defined. In 2007, the reactor was planned to begin its operation in 2010, but as of 2019, it was expected to reach first criticality in 2020. In July 2017, it was reported that the reactor is in final preparation to go critical. However in August 2020, it was reported that the reactor might go critical only in December 2021. As of February 2021, around ₹ 6,840 crore (equivalent to ₹ 77 billion or US$ 919.65 million in 2023) have been spent in

2675-524: Is three-phase . Three phase, compared to single phase, can deliver much more power for a given amount of wire, since the neutral and ground wires are shared. Further, three-phase generators and motors are more efficient than their single-phase counterparts. However, for conventional conductors one of the main losses are resistive losses which are a square law on current, and depend on distance. High voltage AC transmission lines can lose 1-4% per hundred miles. However, high-voltage direct current can have half

2782-403: Is a pool type LMFBR with 1,750 tonnes of sodium as coolant. Designed to generate 500  MWe of electrical power, with an operational life of 40 years, it will burn a mixed uranium-plutonium MOX fuel , a mixture of PuO 2 and UO 2 . A fuel burnup of 100 GWd/t is expected. The Fuel Fabrication Facility (FFF), under the direction of Bhabha Atomic Research Centre (BARC), Tarapur

2889-885: Is a wide-area transmission network that is intended to make possible the trade of high volumes of electricity across great distances. It is sometimes also referred to as a mega grid . Super grids can support a global energy transition by smoothing local fluctuations of wind energy and solar energy . In this context they are considered as a key technology to mitigate global warming . Super grids typically use High-voltage direct current (HVDC) to transmit electricity long distances. The latest generation of HVDC power lines can transmit energy with losses of only 1.6% per 1000 km. Electric utilities between regions are many times interconnected for improved economy and reliability. Electrical interconnectors allow for economies of scale, allowing energy to be purchased from large, efficient sources. Utilities can draw power from generator reserves from

2996-498: Is an intentional or unintentional drop in voltage in an electrical power supply system. Intentional brownouts are used for load reduction in an emergency. The reduction lasts for minutes or hours, as opposed to short-term voltage sag (or dip). The term brownout comes from the dimming experienced by incandescent lighting when the voltage sags. A voltage reduction may be an effect of disruption of an electrical grid, or may occasionally be imposed in an effort to reduce load and prevent

3103-422: Is dammed hydroelectricity , with both conventional hydroelectric generation as well as pumped storage hydroelectricity . Developments in battery storage have enabled commercially viable projects to store energy during peak production and release during peak demand, and for use when production unexpectedly falls giving time for slower responding resources to be brought online. Two alternatives to grid storage are

3210-601: Is designed to use uranium-238 to breed plutonium in a sodium-cooled fast reactor design. The use of thorium-232 , which in itself is not a fissile material, as a blanket is also envisaged in this stage. By transmutation, thorium will create fissile uranium-233 which will be used as fuel in the third stage. FBR is thus a stepping stone for the third stage of the program paving the way for the eventual full utilization of India's abundant thorium reserves. The surplus plutonium (or uranium-233 for thorium reactors) from each fast reactor can be used to set up more such reactors and grow

3317-564: 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,

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3424-403: 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

3531-457: 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

3638-430: Is more than 20 years after construction began and 14 years after the original commissioning date, as of December 2023. The project's cost has doubled from ₹3,500 crore to ₹7,700 crore due to the multiple delays. The construction was completed on 4th March 2024 with commencement of core loading of the reactor hence paving the way for the eventual full utilization of India’s abundant thorium reserves. The Kalpakkam PFBR

3745-462: Is providing technology and equipment for construction of the reactor. The facility builds on the decades of experience gained from operating the lower power Fast Breeder Test Reactor (FBTR). At first, the reactor's construction was supposed to be completed in September 2010, but there were several delays. The Prototype Fast Breeder Reactor is scheduled to be put into service in December 2024, which

3852-449: Is responsible for the fuel rods manufacturing. FFF comes under "Nuclear Recycle Board" of Bhabha Atomic Research Center and has been responsible for fuel rod manufacturing of various types in the past. FFF Tarapur in early 2023 had successfully completed fabrication of 100,000 PFBR fuel elements. The prototype fast breeder reactor has a negative void coefficient , thus ensuring a high level of passive nuclear safety . This means that when

3959-417: Is simply rerouted while repairs are done. Because the power is often generated far from where it is consumed, the transmission system can cover great distances. For a given amount of power, transmission efficiency is greater at higher voltages and lower currents. Therefore, voltages are stepped up at the generating station, and stepped down at local substations for distribution to customers. Most transmission

4066-411: Is stored in the immediate short term by the rotational kinetic energy of the generators. Although the speed is kept largely constant, small deviations from the nominal system frequency are very important in regulating individual generators and are used as a way of assessing the equilibrium of the grid as a whole. When the grid is lightly loaded the grid frequency runs above the nominal frequency, and this

4173-408: Is taken as an indication by Automatic Generation Control systems across the network that generators should reduce their output. Conversely, when the grid is heavily loaded, the frequency naturally slows, and governors adjust their generators so that more power is output ( droop speed control ). When generators have identical droop speed control settings it ensures that multiple parallel generators with

4280-440: 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

4387-570: Is the final stage in the delivery of power; it carries electricity from the transmission system to individual consumers. Substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2  kV and 35 kV . But the voltage levels varies very much between different countries, in Sweden medium voltage are normally 10  kV between 20 kV . Primary distribution lines carry this medium voltage power to distribution transformers located near

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4494-584: Is the maximum power output on a grid that is immediately available over a given time period, and is a far more useful figure. Most grid codes specify that the load is shared between the generators in merit order according to their marginal cost (i.e. cheapest first) and sometimes their environmental impact. Thus cheap electricity providers tend to be run flat out almost all the time, and the more expensive producers are only run when necessary. Failures are usually associated with generators or power transmission lines tripping circuit breakers due to faults leading to

4601-406: Is the process of generating electric power from sources of primary energy typically at power stations . Usually this is done with electromechanical generators driven by heat engines or the kinetic energy of water or wind. Other energy sources include solar photovoltaics , nuclear power , and geothermal power . The sum of the power outputs of generators on the grid is the production of

4708-445: 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

4815-400: 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

4922-531: 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

5029-476: 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

5136-453: 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

5243-630: 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

5350-479: 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

5457-407: 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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5564-689: The ENTSO-E in 2008, over 350,000 megawatt hours were sold per day on the European Energy Exchange (EEX). Each of the interconnects in North America are run at a nominal 60 Hz, while those of Europe run at 50 Hz. Neighbouring interconnections with the same frequency and standards can be synchronized and directly connected to form a larger interconnection, or they may share power without synchronization via high-voltage direct current power transmission lines ( DC ties ), or with variable-frequency transformers (VFTs), which permit

5671-548: 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

5778-458: 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

5885-406: 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

5992-428: 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

6099-414: 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

6206-497: 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

6313-491: The capability to use thorium cycle based processes to extract nuclear fuel. This is of special significance to the Indian nuclear power generation strategy as India has one of the world's largest reserves of thorium , which could provide power for perhaps as long as 60,000 years. The design of this reactor was started in the 1980s, as a prototype for a 600 MW FBR. Construction of the first two FBR are planned at Kalpakkam, after

6420-495: The chain reaction. A few lower power physics experiments will be carried out once sustained nuclear chain reaction is achieved. The next step will link the reactor to electrical grid and start producing power on a commercial basis, pending approval from AERB. Kalpakkam will see the construction of two more fast breeder reactors after the Department of Atomic Energy (DAE) is satisfied with the reactor's performance. The reactor

6527-590: The construction and commissioning of the reactor. The reactor is now expected to be operational by October 2022. Prime Minister Narendra Modi was in Kalpakkam on 4 March 2024 to witness the initiation of its first core loading. A press release described the PFBR as marking the second stage of India's three-stage nuclear power program. On 31 July 2024, the Atomic Energy Regulatory Board (AERB) approved adding nuclear fuel and starting

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6634-467: The consumers to adjust the voltage and keep it within specification. In a synchronous grid all the generators must run at the same frequency, and must stay very nearly in phase with each other and the grid. Generation and consumption must be balanced across the entire grid, because energy is consumed as it is produced. For rotating generators, a local governor regulates the driving torque, maintaining almost constant rotation speed as loading changes. Energy

6741-424: 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

6848-429: The course of a whole 24 hour period. An entire synchronous grid runs at the same frequency, neighbouring grids would not be synchronised even if they run at the same nominal frequency. High-voltage direct current lines or variable-frequency transformers can be used to connect two alternating current interconnection networks which are not synchronized with each other. This provides the benefit of interconnection without

6955-456: The customer's premises. Distribution transformers again lower the voltage to the utilization voltage . Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level. Distribution networks are divided into two types, radial or network. In cities and towns of North America, the grid tends to follow the classic radially fed design. A substation receives its power from

7062-493: 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

7169-508: The event of disturbances. One disadvantage of a wide-area synchronous grid is that problems in one part can have repercussions across the whole grid. For example, in 2018 Kosovo used more power than it generated due to a dispute with Serbia , leading to the phase across the whole synchronous grid of Continental Europe lagging behind what it should have been. The frequency dropped to 49.996 Hz. This caused certain kinds of clocks to become six minutes slow. A super grid or supergrid

7276-426: 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

7383-428: 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

7490-474: 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

7597-573: 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

7704-447: 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

7811-494: The grid, typically measured in gigawatts (GW). Electric power transmission is the bulk movement of electrical energy from a generating site, via a web of interconnected lines, to an electrical substation , from which is connected to the distribution system. This networked system of connections is distinct from the local wiring between high-voltage substations and customers. Transmission networks are complex with redundant pathways. Redundancy allows line failures to occur and power

7918-426: 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

8025-542: The losses of AC. Over very long distances, these efficiencies can offset the additional cost of the required AC/DC converter stations at each end. Substations may perform many different functions but usually transform voltage from low to high (step up) and from high to low (step down). Between the generator and the final consumer, the voltage may be transformed several times. The three main types of substations, by function, are: Aside from transformers, other major components or functions of substations include: Distribution

8132-490: 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

8239-416: 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,

8346-403: 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)

8453-694: The need to synchronize an even wider area. For example, compare the wide area synchronous grid map of Europe with the map of HVDC lines. The sum of the maximum power outputs ( nameplate capacity ) of the generators attached to an electrical grid might be considered to be the capacity of the grid. However, in practice, they are never run flat out simultaneously. Typically, some generators are kept running at lower output powers ( spinning reserve ) to deal with failures as well as variation in demand. In addition generators can be off-line for maintenance or other reasons, such as availability of energy inputs (fuel, water, wind, sun etc.) or pollution constraints. Firm capacity

8560-448: 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

8667-478: The nuclear capacity in tune with India's needs for power. The PFBR is a part of the three-stage nuclear power program . PFBR, with closed fuel cycle as the energy resource, is capable of generating a large amount of U-233 (a fissile isotope) from the abundant available thorium-232 within the country, to launch the third stage nuclear energy programme based on U-233 fuel cycle. The fuel for the PFBR will initially be Uranium-Plutonium mixed oxide ( MOX ). India has

8774-549: The number of people with access to grid electricity is growing. About 840 million people (mostly in Africa), which is ca. 11% of the World's population, had no access to grid electricity in 2017, down from 1.2 billion in 2010. Electrical grids can be prone to malicious intrusion or attack; thus, there is a need for electric grid security . Also as electric grids modernize and introduce computer technology, cyber threats start to become

8881-447: The possible accident scenario of a single blockage halting coolant flow. The active-safety reactor decay heat removal system consists of four independent coolant circuits of 8MWt capacity each. Further active defenses against the positive feedback possibility include two independent SCRAM shutdown systems, designed to shut the fission reactions down effectively within a second, with the remaining decay heat then needing to be cooled for

8988-507: 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

9095-529: 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

9202-453: 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

9309-672: 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 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

9416-418: 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

9523-406: The reactor overheats (below the boiling point of sodium) the speed of the fission chain reaction decreases, lowering the power level and the temperature. Similarly, before such a potential positive void condition may form from a complete loss of coolant accident , sufficient coolant flow rates are made possible by the use of conventional pump inertia, alongside multiple inlet-perforations, to prevent

9630-501: 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

9737-508: 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

9844-408: 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,

9951-519: 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

10058-771: The same relative frequency to many consumers. For example, there are four major interconnections in North America (the Western Interconnection , the Eastern Interconnection , the Quebec Interconnection and the Texas Interconnection ). In Europe one large grid connects most of Western Europe . A wide area synchronous grid (also called an "interconnection" in North America) is an electrical grid at

10165-515: The same settings share load in proportion to their rating. In addition, there's often central control, which can change the parameters of the AGC systems over timescales of a minute or longer to further adjust the regional network flows and the operating frequency of the grid. For timekeeping purposes, the nominal frequency will be allowed to vary in the short term, but is adjusted to prevent line-operated clocks from gaining or losing significant time over

10272-431: 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

10379-404: The substation, but for reliability reasons, usually contains at least one unused backup connection to a nearby substation. This connection can be enabled in case of an emergency, so that a portion of a substation's service territory can be alternatively fed by another substation. Grid energy storage (also called large-scale energy storage ) is a collection of methods used for energy storage on

10486-433: The transmission network, the power is stepped down with a transformer and sent to a bus from which feeders fan out in all directions across the countryside. These feeders carry three-phase power, and tend to follow the major streets near the substation. As the distance from the substation grows, the fanout continues as smaller laterals spread out to cover areas missed by the feeders. This tree-like structure grows outward from

10593-498: 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

10700-414: The use of peaking power plants to fill in supply gaps and demand response to shift load to other times. The demand, or load on an electrical grid is the total electrical power being removed by the users of the grid. The graph of the demand over time is called the demand curve . Baseload is the minimum load on the grid over any given period, peak demand is the maximum load. Historically, baseload

10807-446: The use of sodium as a coolant is the absorption of neutrons to generate the radioactive isotope Na , which has a 15-hour half life . Breeder reactor#Fast breeder reactor A breeder reactor 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

10914-479: 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

11021-485: The year. Neighboring utilities also help others to maintain the overall system frequency and also help manage tie transfers between utility regions. Electricity Interconnection Level (EIL) of a grid is the ratio of the total interconnector power to the grid divided by the installed production capacity of the grid. Within the EU, it has set a target of national grids reaching 10% by 2020, and 15% by 2030. Electricity generation

11128-506: 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

11235-404: Was commonly met by equipment that was relatively cheap to run, that ran continuously for weeks or months at a time, but globally this is becoming less common. The extra peak demand requirements are sometimes produced by expensive peaking plants that are generators optimised to come on-line quickly but these too are becoming less common. However, if the demand of electricity exceed the capacity of

11342-424: 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

11449-477: 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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