Each design has its own advantages and disadvantages. The analyses presented in this paper show that a relatively small longlife reactor core could be developed that maintains decay heat removal by. Gas cooled reactors have been in operation for many years. The advanced gas cooled reactor agr was developed in the united kingdom as the successor to reactors of the calder hall class, which combined plutonium production and power generation. Breeder reactors are often touted as the answer to uraniumscarcity, which may affect conventional reactors. International interest in developing high temperature gas cooled reactors is increasing because they can provide efficient and cost effective electricity and produce hightemperature process heat usable for various industrial applications. Other articles where graphitemoderated reactor is discussed. What are their advantages and disadvantages of nuclear and. There are four general types of fastneutron reactors. Pdf high temperature gas cooled reactor regulation. The high temperature gas could also be used in energyintensive processes that currently rely on fossil fuels, such as hydrogen production, desalination, district heating, petroleum. Although there are many other types of reactor cooled by gas, the terms gcr and to a lesser extent gas cooled reactor are particularly used to refer to this type of reactor.
Understanding the advantages and disadvantages of breeder. Cstrs continuous stirred tank reactor and pfrs have fundamentally different equations, so the kinetics of the reaction being undertaken will to some extent determine which system should be used. Gas cooled fast reactor research and development in the. Description of the advanced gas cooled type of reactor agr pdf report. These are the second generation of british gas cooled reactors, using graphite as the neutron moderator and carbon dioxide as coolant. As the name itself suggests, a gas cooled reactor is cooled using a gas, and the heat extracted by the gas during the process of cooling the reactor is used either indirectly to generate steam which in turn is used for turbine propulsion, or this heated coolant could be used directly as the working fluid of the gas turbine thus eliminating the need for a separate steam circuit. Gascooled fast reactor an overview sciencedirect topics. Scribd is the worlds largest social reading and publishing site. There are also some disadvantages, resulting from the very poor specific heat capacity of gases in. Xenergy is developing a pebble bed reactor that they say. Calder hall, the first nuclear station to feed an appreciable amount of power into a civilian network opened in 1956. Each design had clear advantages and disadvantages.
Comparing the competing ihx types clearly illustrated the advantages of using a compact design, thus favoring pches and platefin designs. Generation iv nuclear reactor comparisons common energy plants coal, natural gas, nuclear employ a rankine steam cycle for electric power production. During that period, the gcfr concept was expected to increase the breeding gain, the thermal efficiency of a nuclear power plant, and alleviate some of the problems associated with liquid metal coolants. Although there are many other types of reactor cooled by gas, the terms gcr. Therefore, be careful when you argue for or against thorium reactors.
The reaction time necessary to reach a conversions x in a batch reactor is. Other countries also have pursued development of hightemperature reactors htgrs with helium as coolant, and graphite as moderator. Certain 4 th generation reactor models are modular, allowing for standardized construction and better investment progressivity. To partially overcome the inherent disadvantages of gas coolants and at the same time to obtain. Since the excess reactivity is originally small, in the magnox nuclear reactor it is difficult to burn the fuel efficiently and, for it to work stably, it is. Design of compact intermediate heat exchangers for gas. Different types of gas reactors prismatic block general atomics fuel compacts in graphite blocks pebble bed german technology. It is feared that an explosion in the monju breeder reactor in japan can release 60 times the energy of the atom bomb dropped on nagasaki in 1945.
Open knowledge wiki general design and principles of the. Plug flow reactor model advantages and disadvantages. Some of the following points can be valid for one reactor design and another point can be invalid for another thoriumbased reactor. Xenergy is developing its xe100 reactor and specialized uraniumbased pebble fuel that could be available in the market as early as the late 2020s.
An advanced gascooled reactor agr is a british design of nuclear reactor. Buzzle lists out the advantages and disadvantages of breeder reactors. An advanced gascooled reactor agr is a type of nuclear reactor designed and operated in the united kingdom. However there are a few general comments that can be made with regards to pfrs compared to other reactor types. They are particularly attractive in situations where enriched uranium is not easily available since they can be designed to maintain a sustained nuclear reaction with natural uranium.
Sandias supercritical co2 direct cycle gas fast reactor. Xenergy, located just outside the nations capital in rockville, maryland, is working on a pebble bed, hightemperature gas cooled reactor that the company says cant meltdown. Then you have the crew operating and maintaining it. Specifically, nuclear plants using the rankine cycle are limited by the amount of heat they can produce, radioactive embrittlement, and radiated coolant. It combines the advantages of fastspectrum systems for longterm sustainability of uranium resources and waste minimisation through fuel multiple reprocessing and fission of longlived actinides, with those of hightemperature systems high thermal cycle efficiency. The fuel consists of natural uranium metal clad with an alloy of magnesium known as magnox thus the name for the reactor type. During this period, the gcfr concept was found to be. They have been the backbone of the uks nuclear generation fleet since the 1980s.
The main disadvantages are in the lower heattransfer and heattransport characteristics of gases, requiring large contact surfaces and flow passages within the reactor and heat exchangers, and their high pumping requirements between 8. These are the second generation of british gas cooled reactors. Ross and wilson anatomy and physiology pdf downloadgolkes. There are advantages and disadvantages to a nuclear family. Nuclear power nuclear power plant types of reactors advanced gascooled reactor. Gas cooled reactor natural uranium, graphitemoderated reactors were developed in the united states during world war ii for the conversion of 238u to 239pu for military purposes. Agrs are using graphite as the neutron moderator and carbon dioxide as coolant. As a result of this, the secondary side steam and water are not radioactive as they are in a boiling water reactor. This includes being a strong support system or feeling completed isolated. Commercial gas cooled reactors are currently in use only in the united kingdom. Gascooled reactors, high temperature gascooled reactors. Advantage and disadvantages of thorium reactors pros and.
Disadvantages of gas coolants include the following. The newer advanced gas cooled agr reactors use a slightly enriched uranium dioxide clad with stainless steel. What are advantages and disadvantages of nuclear family. Description of the advanced gas cooled type of reactor agr. It includes articles, reports, books, and patents, reactors cooled by air are included, as well as all types of reactors by functionpower reactors, research reactors, design studies, and prototypes. In the uk there are currently seven agr nuclear power stations 5 in england and 2 in scotland each with two operating reactors. The torness agr plant on the lothian coastline of scotland, 60 km east of edinburgh. The very high temperature reactor is cooled by flowing gas and is designed to operate at high temperatures that can produce electricity extremely efficiently. Although a significant amount of work is still required, this type of reactor concept maintains some potentially significant advantages over ideal gas cooled systems and liquid metal cooled systems. A gascooled reactor gcr is a nuclear reactor that uses graphite as a neutron moderator and carbon dioxide as coolant. Gas cooled reactors an overview sciencedirect topics.
Up to now, only liquid sodium cooled fast neutron reactors have been built on any large scale. It is very difficult to explain the possible advantages and disadvantages. Heavy wwater ater cooled reactors candukey ccandu andu features canada deuterium uranium. The following table gives reaction times for first r a kc a and second r a k in a batch reactor the following table gives the various times necessary to. Design of compact intermediate heat exchangers for gas cooled fast reactors. Fast neutron reactors, however, have a terrible track record in safety and economics, and are not capable of solving the waste problem.
Most first generation gas cooled power plants were designed and built in the uk the magnox series and in france the nugg. The key advantage of heliumcooled reactors is that the reactor can operate at much. Each station is supplied with twin reactors, the site of heysham has two. For instance, although there are fewer mechanical components in the steam cycle of a bwr design, additional components are required to support the reactor s. Liquid phase or gas phase in a steel container in terms of conversion. The present report comprises a technical description of the advanced gas cooled reactor agr, a reactor type which has only been built in great britain. Download cbse notes, neet notes, engineering notes, mba notes and a lot more from our. The research is directed towards developing the gfr as an economic electricity generator, with good safety and sustainability characteristics. In the united kingdom, nuclear electricity is mostly generated in co 2 cooled magnox and advanced gas cooled reactors agrs. Gas cooled, graphite moderated of the six main commercial reactor types, two magnox and agr owe much to the very earliest reactor designs in that they are graphite moderated and gas cooled. As is often the case in the battle to set a standard, the final outcome was based on a bit of luck, a lot of marketing effort, and substantial help from development partners.
Tsvetkov, in handbook of generation iv nuclear reactors, 2016. The gfr system is a hightemperature helium cooled fastspectrum reactor with a closed fuel cycle. Gas cooled fast reactor gfr research is directed towards fulfilling the ambitious goals of generation iv gen iv, that is, to develop a safe, sustainable, reliable, proliferationresistant and economic nuclear energy system. A compilation of 517 references to the unclassified literature to may 1959 on gas cooled reactors is presented. The gascooled fast reactor gfr offers the advantage of building on the hightemperature. An advanced gascooled reactor agr is a type of nuclear reactor designed and operated in. What is gas cooled reactor a gascooled reactor gcr is a nuclear reactor that uses graphite as a neutron moderator and carbon dioxide helium can also be used as coolant. The advanced gas reactor agr represents the generation ii of british gas cooled reactors, developed from the earlier generation i magnox reactor design see magnox design on page 7 of gas cooled reactors. High temperature gas cooled reactor htgr, which is a graphite moderated, helium cooled reactor, is particularly attractive due to capability of producing high temperature helium gas and its inherent safety characteristics, as well as an option to efficiently burn weaponsgrade plutonium for energy production.
1307 822 1008 1077 1450 293 1149 767 1512 1104 1225 873 102 1311 567 399 1136 432 56 394 514 962 685 536 176 710 71 354 1204 139