Jan 22, 2016 candu reactor the candu short for canada deuterium uranium reactor is a canadiandeveloped, pressurized heavy water reactor used for generating electric power. I recall visiting the candu complex at darlington just north of toronto in 1993. The history and current state of canadas candu nuclear reactor. Download the free pdf converter and create pdf files from any application with pdf creator. The calandria is closed and supported by end shields at each end. Jul 15, 2016 i recall visiting the candu complex at darlington just north of toronto in 1993.
Heavy water cooled and moderated the only design of heavy water moderated reactor in commercial use is the candu, designed in canada and subsequently exported to several countries. Candu stands for canada deuterium uranium, which reflects the key role of deuterium, or heavy water, which acts as the reactors neutron moderator, a unique trait of the candu. Candu lifetime performance operating candu reactors to september 30, 2009 lifetime capacity is the total energy produced by the reactor, divided by the energy that could have been produced if the reactor had run at full power, from first being declared in service to the present. To these features may be added a fourth, onpower refuelling. In the heavy water systems of the candu reactor, the proper equations describing the dissociation of heavy water. Table 53 mass comparison of candu unf including waste and nuclear material. Dyke was personally involved in the early assessments and design decisions that lead to current candu steam generator technology.
Candu stands for canadian deuterium uranium reactor playing on the north american boast of capability, can do. The candu, for canada deuterium uranium, is a canadiandeveloped, pressurized heavy water reactor used to generate electric power. From candu, it takes the heavy water moderator, which. Candu reactors were first developed in the late 1950s and 1960s by a partnership between atomic energy of canada limited aecl. The 5 mwe obninsk lwgr in russia, which commenced power generation in 1954, was the first to supply the grid and was shut down on 30 april 2002. The candu fuel contains pellets of uranium dioxide with natural uranium 0. Six types of reactor magnox, agr, pwr, bwr, candu and rbmk have emerged as the designs used to produce commercial electricity around the world. Candu is the most efficient of all reactors in using uranium. But i havent heard of it being a particular problem with the candu. The higher neutron fluxes of the fast breeder make it a special problem there, and it will be even worse for a fusion plant.
Candu reactor article about candu reactor by the free. All nuclear power plants in canada use the candu design a safe, reliable, reactor technology. It enables those new to candu to learn about candu as an overall system and to pursue specialized topics in depth. Chemistry in candu process systems september 2014 neutral point of water is lowered as temperature is increased, as illustrated by simple calculation the ph of neutral water at 250oc is 5. A candu reactor is a relatively sparse generator of plutonium as a weight percentage of its used fuel. The candu reactor has a modular core, made up of fuel channels. The candu is a pressurized heavy water reactor phwr using heavy water deuterium as both a moderator and coolant. It is a type of nuclear reactor that uses natural uranium as fuel,pressurised heavy water as coolant,unpressurised heavy water as moderator and uses pressurized tubes to contain the fuel and circulating coolant. The candu canada deuterium uranium is a canadian pressurized heavy water reactor.
Reactor facts and performance electricity was first generated by a nuclear reactor on 20 december 1951 when the ebri test reactor in the usa lit up four light bulbs. A candu reactor requires, in total, between 460 and 592 metric tonnes 1 tonne kg of heavy water, a little more than half of this in the moderator and the rest in the pressurized coolant for example, a candu 6 reactor uses 265 metric tonnes in its moderator and 192 metric tonnes in its coolant. December 31, 1969 every nuclear reactor is a disaster waiting to happen and candu reactors are no exception. Candu6 fuel optimization for advanced cycles sciencedirect. Nuclear power plant safety systems canadian nuclear safety. Point lepreau was the first candu 6 reactor to be licensed for operation, the first to achieve criticality and first to begin commercial operation. The candu reactor core is a horizontal cylinder known as a calandria. Introduction to reactor physics candu owners group. He has written the following summary of those important days. Douglas point was originally planned to be a twounit station, but the second unit was cancelled because of the success of the larger 515 mwe units at pickering.
The candu canada deuterium uranium reactor is a pressurized heavy water reactor phwr designed and built by canadian nuclear laboratories since the 1950s. Each fuel channel contains 12 or small fuel bundles, each of which is 50 cm long and 10 cm in diameter, and weighs about 24 kg. In the manual selection mode, the user specifies in input to the program the channels to. The heat transport system hts circulates the coolant through the reactor to remove the heat of fission from the fuel. Candu energy says its new nuclear technology, which is able to use spent fuel from other reactors, has cleared a hurdle in china. The candu runs on natural unenriched uranium, is heavy water moderated, and features 380 individually pressurized, horizontally arranged fuel channels. These were invented and developed in canada in the 1960s, when canada decided that they did not want to build enrichment plants or large pressure vessel manufacturing capabilities. Therefore, candu reactors represent a privileged environment to initiate the use of. Fission reactions in the reactor core heat pressurized water in a primary cooling loop.
Candu canada deutrium uranium it is a canadianinvented,heavy water reactor. Nov 06, 2014 candu energy says its new nuclear technology, which is able to use spent fuel from other reactors, has cleared a hurdle in china. Ontario hydro was one of the founding members of cogs predecessor, candev candu development and formation of cog in 1984. A feasibility study on the recycling of used candu fuel. Fission is the process of splitting atoms of natural uranium inside the reactor, releasing radiation and heat. The gentilly2 candu 6 reactor is owned and operated by hydro. Nuclear reactor types many different reactor systems have been proposed and some of these have been developed to prototype and commercial scale. Candu 6 is our 700 mwe class nuclear power reactor. Candu fuel is much cheaper than light water reactor ffuel uel candu fuelmanufacturing capability can readily be developed by even small ccountries ountries which purchase candu reactors.
Introduction this is a descriptive course on the physics of candu reactors. The first candu 6 plants went into service in the early 1980s as leadingedge technology, and the design has continuously evolved since to. While candu energy is trying to entice jordan and china to purchase candu reactors, within canada it is unsure whether the newest nuclear plant to be built in ontario will be a candu reactor. This manual also lists the corrective actions to be taken in case chemistry. Part 5 heavy water and candu reactors daryanenergyblog. In europe romania is the only country operating candu reactors at the cernavoda site. From candu, it takes the heavy water moderator, which gives the design an. The company said thursday that a chinese expert panel has given a. Canada 22, argentina 1, romania 2, south korea 4, china 2, pakistan 1 and india 2. The candu reactor consists of the horizontal cylinder called the calandria. Candu reactor the candu short for canada deuterium uranium reactor is a canadiandeveloped, pressurized heavy water reactor used for generating electric power.
Nuclear power energy in pakistan the main part of the plant is designed on the model. A candu reactor requires, in total, between 460 and 592 metric tonnes 1 tonne kg of heavy water, a little more than half of this in the moderator and the rest in the pressurized coolant for example, a candu 6 reactor uses 265 metric tonnes in. Canadas first nuclear power reactor, called nuclear power demonstration, with a net capacity of 22 electrical megawatts, was started up in 1962. Atomic energy of canada limited aecl developed the candu reactor technology starting in the 1950s. Candu fundamentals i table of contents 1 objectives 1 1. Heavy water reactors use heavy water d 2 0 deuterium as opposed to hydrogen as both a moderator, and in many cases a coolant also. Canada deuterium uranium candu reactors use heavy water as a coolant instead of regular old light water.
Candu stands for canada deuterium uranium, which reflects the key role of deuterium, or heavy water, which acts as the reactor s neutron moderator, a unique. Candu heavy water reactors use natural uranium, of which 0. Canducanada deutrium uranium it is a canadianinvented,heavy water reactor. The basic parts of a nuclear reactor are the core, a moderator, control rods, a coolant, and shielding. The main advantage of the candu reactor is that it can be operated with natural uranium so no uranium enrichment is. Figure 11 illustrates how candu reactors produce electricity. It combines features of the existing candu pressurised heavy water reactors phwr with features of lightwater cooled pressurized water reactors pwr. Wendy lyons sunshine is a former writer for the balance, the balance smb, and the balance everyday. Moderator inlet and outlet tubes direct the moderator through the calandria, then to the external heat exchanger for cooling. Opg is one of the largest and most diverse clean power producers in north america and currently operates darlington and pickering nuclear generating stations in addition to other assets, including a fleet of hydro. As a result, adding plutonium to the initial fuel would represent a smaller change in the physics of the reactor core than in the case of lwrs. The development of the first candu reactor began in 1954 through a partnership between atomic energy of canada ltd. Uniquely among candu stations, douglas point had an oilfilled window with a view of the east reactor face, even when the reactor was operating.
The candu nuclear reactor got its name because this heavy water reactor design was developed in. Candu reactors produce electricity through a process known as fission. The term heavy water reactor is a catch all term as it includes a broad range of reactor designs running from the rmbk right the way over to the candu design. Candu is a pressurized heavy water reactor phwr that uses heavy water deuterium oxide d2o as a moderator and coolant, and natural uranium as its fuel. Candu fuel cycle advantages operational reactors nue candu reactor inherent safety features new build reactors afcr future with water coolant dr. It can be operated with natural uranium, which contains 0. It is owned and operated by new brunswick power nb power and supplies approximately 30% of the provinces electricity. This study is based on the 675 mwe candu reactor operated at the gentilly2 power station in canada from 1983 to 20. No need for special borated casks it has few 7 different components. Candu fundamentals ii 3 radioactivity spontaneous nuclear processes 19.
The acronym refers to its deuterium oxide heavy water moderator and its use of originally, natural uranium fuel. It is a type of nuclear reactor that uses natural uranium. Risks of the candu reactor design introduction the candu canada deuterium uranium reactor is a pressurized heavy water reactor of canadian design. The basic operation of the candu design is similar to other nuclear reactors. Im skeptical about the claim that heavy water is toxic.
Candu reactor is a type of nuclear reactor which was developed in canada, and is currently used in nuclear power plants for electrical generation in various countries around the world. Molten salt reactors the next generation of nuclear power duration. Kuran vp, advanced fuel candu reactor workshop on advanced reactors, neaoecd paris, france, april 2017. All nuclear power plants in canada are powered by candu reactors.
Why arent all nuclear reactors candu instead of lwr. Given that nobody is advocating the building of more rmbks, indeed its. The optimum power output of a candu reactor for a given number of channels is obtained when the reactivity of approximately half of the fuel channels, located in the center of the reactor, is deliberately lowered so that the flux and therefore the power is constant across the socalled inner zone of the core. Best of all, pdf creator is absolutely free for anyone to use. Known as karachi nuclear power plant kanupp, the commercial power plant is a small 7mw candu reactor, a canadian pressurized heavy water reactor. The objective is to familiarize you with the basic concepts and ideas, definitions and quantities which are important in the understanding of reactor physics. Canadian utilities are no longer building candu reactors because of their high cost and poor performance. This work was completed in 3 units at the time of writing. As a result, adding plutonium to the initial fuel would represent a smaller change in the physics of. Apr 01, 20 molten salt reactors the next generation of nuclear power duration. Nuclear reactor, any of a class of devices that can initiate and control a selfsustaining series of nuclear fission s.
Write equations describing each of the following neutron. A heat exchanger, also known as a steam generator, transfers the heat to a secondary cooling loop, which powers a steam turbine with an electric generator attached to it for a typical rankine thermodynamic cycle. With no heavy reactor pressure vessel and the possibility of modular construction the erection time of a candu reactor can be shorter than that of some other reactor systems. This is eventually a problem with all classes of nuclear reactor. Candu, short for canada deuterium uranium, is a nuclear reactor that uses heavy water as a moderator and coolant and natural uranium as a fuel source. I liked the candu design and can see a number of advantages over comparable light water reactors. Nuclear power energy in pakistan the main part of the plant is designed on the model of chasma nuclear power plant and candu reactor. Pdfcreator download for free, download pdf printer, pdf. April 2001 an accident which would lead to flow stagnation in one core passthe sheath temperature at which failure was assumed to occur was 1700 degrees f. The candu reactor was designed by atomic energy canada limited as an alternative to other reactor designs which use slightly enriched uranium 25% u235. A tsunamitripped power outage and backup generator failures cut off pumps that basted cooling water over the japanese reactor cores, causing at least three of them to commence a meltdown. Candu nuclear power plants world wide nuclear power.
Having been developed to use natural uranium in conve niently small fuel bundles, the candu reactor. Intro to materials scienceguided inquiry uva 21,999 views. The history and current state of canadas candu nuclear. In normal candu operations with natural uranium fuel, more than half of the energy is provided by fissioning plutonium produced in the fuel as the reactor operates. The candu plutonium isotopic ratio in table 1 was calculated using the lattice code wimsaecl for the candu 6 design, but the numbers are indicative of the ratio in acr spent fuel as well. Reactor assembly the candu 6 reactor assembly, shown in the figure opposite, includes the fuel channels contained in and supported by a horizontal cylindrical tank known as the calandria. Heavy water versus light water in ontario nuclear war. Candu canada deuteriumuranium key candu characteristics pressure tubes containing fuel bundles located in cylindrical, low pressure moderator tank or calandria heavy water moderated natural uranium candus are heavy water cooled advanced candu reactor acr is light water cooled 43 units based on the candu. She is also an awardwinning energy industry journalist. The candu allows more local input in nations that do not have the capability to cast a pressure vessel. All canadian nuclear reactors are of the candu type but the.
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