Candu canada deutrium uranium it is a canadianinvented,heavy water reactor. Aecl is currently offering a new version of the candu design concept. The primary loop is in yellow and orange, the secondary in blue and red. Aecl, which maintained proven elements of existing candu design, while making some. This extracts a further 3040% energy from the uranium. Id say fogler, for problems and easy comprehension of the fundamentals of ideal reactor design chapters 1 9, levenspiel is an excellent book once youve adquired basic knowledge, and it. The latest, singleunit design of this type is the candu 9, a 935 mwe reactor based on the multiunit darlington and bruce b designs with additional enhancements from ongoing aecl engineering and research programs reference 3. Risks of operating candu 6 nuclear power plants banktrack. Reactor grade plutonium can be used as a booster fissile fuel material in the form of mixed tho 2 puo 2 fuel in a candu fuel bundle in order to assure reactor criticality. Aecl has evolved the advanced candu reactor acr design from its highly successful candu6 design. Investigation of candu reactors as a thorium burner. Capacity factor is the reactors actual electricity production divided by perfect output what the reactor would produce if it always operated at its design rating. The acronym refers to its deuterium oxide heavy water moderator and its use of originally, natural uranium fuel.
Since there is a smaller fraction of fissile material in natural uranium, a somewhat larger reactor core was needed. Given that nobody is advocating the building of more rmbks, indeed its difficult to believe the. Yu, evolutionary candu 9 plant improvements, international. The candu canada deuterium uranium is a canadian pressurized heavy water reactor. What is the best book to study the reactor design, foglar. An important operational feature of the candu reactor design is that it can be refuelled while. The material for this text is based principally on the candu 9 480nu technical description, aecl document 69071ted001 rev. These were invented and developed in canada in the 1960s, when canada decided that they did not want to build enrichment plants. The cool heavy water in the calandria can be seen in pink, along with partially inserted. All canadian nuclear reactors are of the candu type but the. A candu reactor design 1 fuel bundle, 2 calandria, 3 adjuster rods, 4 heavy water pressure reservoir, 5 steam generator, 6 light water pump, 7 heavy water pump, 8 fueling machines, 9 heavy water moderator, 10 pressure tube, 11 steam going to steam turbine, 12 cold water returning from turbine, containment building source. In short, it would be quite possible for a potential proliferator to make a nuclear explosive from reactorgrade plutonium using a simple design that would be assured of having a yield in the range of one to a.
Part 5 heavy water and candu reactors daryanenergyblog. Atomic energy of canada limited aecl developed the candu reactor technology starting in the 1950s. Business business, international chemicals, plastics and rubber fuel reprocessing nuclear reactors analysis nuclear fuels nuclear industry production management nuclear power plants plutonium usage pressurized water reactors thermodynamics reactor fuel reprocessing. The candu reactor design is extremely flexible and with much space to improve, since the core had been originally designed to optimize the performance of natural uranium fuel and to achieve high neutron economy. Reduced project implementation risk for candu 9 has been assured by a thorough program of upfront. Duncan said candu employees have stopped the ongoing safety analysis thats performed on reactors, and are not available to make any repairs to the reactors. A short history of the candu nuclear power system 5 revision 2, december 2002. The candu 6 reactor design has been chosen as a reference and a brief description of its main components with typical design parameters follows with a comparison with the candu 9 reactor. Canada deuterium uranium candu reactors use heavy water as a coolant instead of regular old light water. With a more sophisticated design, weapons can be built with reactorgrade plutonium that would be assured of having higher yields. Candu power reactor designers and operators are fully aware of the need for caution in starting up power reactors. All canadian nuclear reactors are of the candu type but the reactor has also been marketed abroad until october 2011 aecl marketed and. Phw power reactor fuel bundle design, and describes the various designs. Approaching dynamic psa within candu 6 npps paperback may 9.
It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as. The candu reactor consists of the horizontal cylinder called the calandria. The growing trend towards more competitive electricity markets worldwide will also discourage candu sales, because nuclear power. Diagrams and text have also been based on various aecl and ontario hydro training. This record is a remarkable achievement for large construction projects. 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.
A short history of the candu nuclear power system 3 revision 2, december 2002 canada made two early entries into the international power reactor supply field. I will highlight some of the achievements in the development of candu, taken from the new book canada enters the nuclear age. The advanced candu reactor acr 1,2,3,4 represented the continuing evolution of candu design to match changing market conditions. It enables those new to candu to learn about candu as an overall system and to pursue specialized topics in depth. Being able to always maintain control of the nuclear chain reaction at all times is very important.
It is based on advances made in nuclear power utilization and computational methods over the past 40 years, covering core design of boiling water reactors and pressurized water reactors, as well as fast reactors and hightemperature gascooled reactors. From candu, it takes the heavy water moderator, which gives the design an improved neutron economy that. However, the open literature describing these established methods is quite sparse, especially with regard to the unique advantages in operability and safety that arise from the computerdriven reactor regulating system rrs. Candus have a number of serious technical, and safety problems, as well as the unique environmental problem of tritium emissions. Candu advantages candu stands for canada deuterium uranium, because it was invented in canada, uses deuterium oxide also known as heavy water as a moderator, and uranium as a fuel. Like the candu 6, the candu 9 is essentially a repackaging of the bruce design, so that it can be built as a singlereactor unit. Exporting disaster the cost of selling candu reactors 1. The reactor, refueling machine, and fuel designs are illustrated and. The candu canada deuterium uranium is a canadian pressurized heavywater reactor design used to generate electric power. In the candu design, the heavy water moderator circulates through a large tank called the calandria and through the. Cge had developed this design on the basis of its earlier work in the.
Candu fuel cycle advantages operational reactors nue candu reactor inherent safety features new build reactors afcr future with water coolant dr. Analysis of control rod drop accidents for the canadian scwr using coupled 3dimensional neutron kinetics and thermal hydraulics. This was initiated by unene, administered by candu owners group cog and funded by all candu utilities in canada and offshore with prof. It combines features of the existing candu pressurised heavy water reactors phwr with features of lightwater cooled pressurized water reactors pwr. Acr was slightly larger but less expensive to build and run. The reactor, refueling machine, and fuel designs are illustrated and discussed under candu reactor and fuel design. Assume that the reactor has been designed to operate under design center conditions. As was the case for the development of the pickering design into the candu 6, the bruce design was also developed into the similar candu 9. Candu was designed for natural uranium with only 0.
The name refers to its design power in the 1,000 mwe class, with the baseline around 1,200 mwe. The neutronic calculations are based on a gentillyii design modified to a canduthorium reactor, as described in refs. The basic operation of the candu design is similar to other nuclear reactors. 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. These combined stresses limit the fuel channel working life to about 20 years and the reactor working life to about 60 years. Candu reactors are unique in that they use natural, unenriched uranium as a fuel. Like the candu 6, the candu 9 is essentially a repackaging of the bruce design so it can be built as a singlereactor unit.
A heavywater design can sustain a chain reaction with a lower concentration of fissile atoms than lightwater reactors, allowing it to use some alternative fuels. The essential candu is brought to you by unene with administrative and sponsorship support from cog. All nuclear power plants in canada are powered by candu reactors. The candu reactor 9 is a design in which heat is generated from a critical reaction in uranium in a cylindrical vessel on its side.
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. The enhanced candu 6tm reactor generation iii candu. The phenomena of the accidents is coupled to the logicprobabilistics of the plant, including plant systems and operator actions. It demonstrates the maturity of the candu technology. Canadian utilities are no longer building candu reactors because of their high cost and poor performance. Candu is the most efficient of all reactors in using uranium. The chapter includes a note on the advantages of the candu. Nuclear reactor design an advanced course in nuclear. Apr 01, 2011 fortunately, the candus basic design means the rods in ontarios reactors are already surrounded by a huge pool of cool water, says jerry hopwood, vicepresident of product development at.
The phenomena of the accidents is coupled to the logicprobabilistics of. Candu energy enacts contingency plans as workers hit the. Nov 07, 2014 candu6 heattransport system design reactor coolant parameters outlet header pressure 10 mpa outlet header temperature 310. The candu development program is aimed at enhancing these two reactor designs. The candu canada deuterium uranium reactor is a pressurized heavy water reactor phwr designed and built by canadian nuclear laboratories since the 1950s. The acr was introduced as a lowerpriced option compared to a larger version of the candu design then being considered, the candu 9. With the successful candu6 design well established, aecl is developing two further candu designs, a smaller 450 mw candu3 and a larger candu 9 in the 900.
Candu reactors were first developed in the late 1950s and 1960s by a partnership between atomic energy of canada limited aecl. Candu reactor explained everything explained today. The candu 9 uses the same 37element fuel bundle design as the other operating. This candu textbook is suitable for students, educators, trainers and working professionals at a target level of senior undergraduate year university engineering and science. The canadian supercritical watercooled reactor scwr design is the result of the fusion of a candu reactor and a boiling water reactor bwr 1. The present book is an attempt to approach dynamic psa in generic candu 6 reactor design. The paper investigates the prospects of exploiting the rich world thorium reserves in candu reactors. The enhanced candu 6 ec6 is a 740 mwe class heavy water moderated pressure tube reactor, designed to provide safe, reliable, nuclear power. Nuclear power plant systems and operation candu owners group. Contrary to the myth of candu superiority, in 1995, the load factor for candu reactors worldwide was 61. Controlled fission in the several hundred fuel channels of a candu reactor generates heat. Candu heavy water reactors use natural uranium, of which 0.
One of the contributing factors leading up to the accident at the chernobyl nuclear power plant was the design of. The essential candu a textbook on the candu nuclear power plant technology. Fortunately, the candus basic design means the rods in ontarios reactors are already surrounded by a huge pool of cool water, says jerry hopwood, vicepresident of product development at. The basic parts of a nuclear reactor are the core, a moderator, control rods, a coolant, and shielding. December 31, 1969 every nuclear reactor is a disaster waiting to happen and candu reactors are no exception. There have been two major types of candu reactors, the original design of around. As a result, a candu reactor has a positive void coefficient of reactivity.
The first step is the design of the reactor itself. This book focuses on core design and methods for design and analysis. The enhanced candu 6tm reactor generation iii candu medium size global reactor s. Kuran vp, advanced fuel candu reactor workshop on advanced reactors, neaoecd paris, france, april 2017. Through the 1980s and 1990s the nuclear power market suffered a major crash, with few new plants being. The fuel assemblies lie horizontally in tubes through which heavywater coolant flows under pressure. The calandria tubes, made of zircalloy2, are arranged in square arrays in the d 2 o moderator at low temperature 9 the candu reactor design imposes a combination of neutron stress, pressure stress, erosion and fretting on the fuel channels and related coolant flow path components. 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. During operation some state variables change and others are manipulated, causing the reactors state vector operating trajectory to wander like a worm in the ndimensional space as time progresses. Risks of the candu reactor design introduction the candu canada deuterium uranium reactor is a pressurized heavy water reactor of canadian design. The current candu products are the 700 mw class candu 6 reactor and the 900 mw class candu 9 reactor. Canducanada deutrium uranium it is a canadianinvented,heavy water reactor. Heavy water reactors an overview sciencedirect topics.
Moderator inlet and outlet tubes direct the moderator through the calandria, then to the external heat exchanger for cooling. By 1994, the average lifetime capacity factor at ontario hydros 20 reactors was 73. 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. Candu reactor article about candu reactor by the free. The candu reactor, however, has pressure tubes rather than a pressure vessel enclosing the reactor core, which makes refuelling under load possible by disconnecting individual pressure tubes onpower refuelling. The candu canada deuterium uranium reactor is a pressurized heavy water reactor of canadian design. The candu reactors cooling water tubes are pressurized to 1525 pounds per square inch, lower than pressurized water designs. Since the early 1990s, six new candu 6 plants were delivered on or ahead of schedule and on budget. Fission reactions in the reactor core heat pressurized water in a primary cooling loop. The heavy water in the moderator system is normally not highly pressurized.
1229 1666 936 591 452 358 854 136 1418 260 167 1543 1424 1654 354 980 689 775 181 1400 276 295 685 816 441 737 954 1302 638 569 471 628