Sfr sodiumcooled fast reactor lfr leadcooled fast reactor gfr gascooled fast reactor minor actinide destruction and plutonium management sustainability and proliferation benefits. Generation iv fast reactors university of cambridge. The nuclear regulatory commission, protecting people and the environment. This potential advantage may have helped to convince planners to provide ongoing support for gas reactor cooled research and development, but it did nothing to encourage actual sales. Using an organic fluid had a major advantage over conventional designs using water as the. A gascooled reactor gcr is a nuclear reactor that uses graphite as a neutron moderator and. They have been the backbone of the uks nuclear generation fleet since the 1980s. An organic nuclear reactor, or organic cooled reactor ocr, is a type of nuclear reactor that uses some form of organic fluid, typically a hydrocarbon substance like polychlorinated biphenyl pcb, for cooling and sometimes as a neutron moderator as well. Open knowledge wiki general design and principles of the. The steam dump system discharges the residual heat, thus cooling the reactor core if it can no longer be cooled by the normal systems, and avoids having to open. This occurs because of the absorption of neutrons by fissile material. Water cooled reactors have played a significant role in the commercial nuclear industry since its beginnings and currently account for more than 95 per cent of all operating civilian power reactors in the world. Hightemperature gascooled reactor physics britannica. Other articles where hightemperature gascooled reactor is discussed.
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. The use of gases leads to a harder neutron spectrum compared with the fast reactor cores of sodium and leadcooled fast reactors waltar et al. An advanced gascooled reactor agr is a type of nuclear reactor designed and operated in the united kingdom. Larger mass flow rate of precooling water injection will accelerate the precooling process, but the temperature descending rate of the structures should also be limited to avoid the potential damage on the. Designs for a gascooled fast reactor, originally referred to as the gcfr, were developed in the united states and europe as an alternative to liquid metal reactors during the 1960s through 1980s. The advantage of the design is that the coolant can be heated to higher temperatures than water. Gascooled reactor definition of gascooled reactor by the. Successful decay heat removal under wide range of pressurized and depressurized conditions. Gascooled reactors, high temperature gascooled reactors. The uranium dioxide fuel is enriched to about 3% u235 natural uranium is only 0.
Jan 21, 20 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. Designs for a gas cooled fast reactor, originally referred to as the gcfr, were developed in the united states and europe as an alternative to liquid metal reactors during the 1960s through 1980s. There are two competitive designs of this reactor type. The end result is the same the production of heat to generate steam. All structured data from the file and property namespaces is available under the creative commons cc0 license. The nuclear reactor is only one of the components of the system to be implemented in order to achieve these objectives. Years after startup of the first gas cooled nuclear reactor. The concept was revisited in 2002 through the generation iv international forum gif assessment, and the acronym was changed to gfr. Chapter 2 design and operation of a pressurised water reactor. Research on the gas cooled fast reactor system is directed towards fulfilling the ambitious long term goals of generation iv gen iv, i. Other articles where sodiumcooled fast reactor is discussed. A precooling injection is needed to cool down the steam generator, which remains with high pressure and high temperature level after emergency shutdown of high temperature gas cooled reactor. Pdf gascooled thorium reactor with fuel block of the.
Research on the gascooled fast reactor system is directed towards fulfilling the ambitious long term goals of generation iv gen iv, i. This approach is similar to the 30 mwhttrgas cooled reactor. The gfr system is a hightemperature heliumcooled fastspectrum reactor with a closed fuel cycle. Description of the advanced gas cooled type of reactor agr. Modular hightemperature gascooled reactor power plant kurt. In such reactors, the reaction rate expression must be known determined. Overview and motivation for leadcooled fast reactor systems. Each station is supplied with twinreactors, the site of heysham has two.
Pebble bed reactor 1 10 mwe helium cooled indirect cycle 8 % enriched fuel built in 2 years factory built site assembled online refueling modules added to meet demand. A gas cooled reactor gcr is a nuclear reactor that uses graphite as a neutron moderator and carbon dioxide as coolant. 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. The agr was developed from the magnox reactor, the uks first. During this period, the gcfr concept was found to be more.
In an attempt to allow nuclear power to reach its full economic potential, general atomics is developing the energy multiplier module em 2, which is a compact gas cooled fast reactor gfr. There are high temperature gas cooled reactors but i do not think that a simple air cooled reactor, like an air cooled engine, will be able to operate. An advanced gas cooled reactor agr is a type of nuclear reactor designed and operated in the united kingdom. Part 6 high temperature gas cooled reactors daryanenergyblog. Part 6 high temperature gas cooled reactors there are various iterations on this concept, most notably the vhtr very high temperature reactor, an iaea proposed generation iv design, the pebble bed reactor or the httr in all cases they share a number of common characteristics, so i shall group them under the umbrella of high temperature. In the gas cooled reactor gcr, the moderator is graphite. 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 the gcr was able to use natural uranium as fuel, enabling the countries that developed them to. The gfr system is a hightemperature helium cooled fastspectrum reactor with a closed fuel cycle. No only do you have to have a sufficient mass flow rate to carry away a useable amount of heat. As the name suggests, it is an advance on the earlier uk magnox design.
The pin assembly consists of the fuel pin placed in a core matrix hastellay x to form an annular flow passage including a re riinwrap spacer. Nuclear small modular reactor description a small modular reactors smr is a nuclear power plant that is smaller in size 300 mw or less than current generation base load plants 1,000 mw or higher. The reactor core can be either a prismatic block reminiscent of a. These smaller, compact designs are factory fabricated reactors that can be transported by truck or rail to a nuclear power site. As a result, higher plant efficiency 40% or more could be obtained compared to the water cooled design 3334%. Nov 21, 2016 there are high temperature gas cooled reactors but i do not think that a simple air cooled reactor, like an air cooled engine, will be able to operate. Neutronic design for a lithium cooled reactor for space applications washington, d. Most first generation gascooled power plants were designed and built in the uk the magnox series and in france the nugg. Reactors are usually designed based on rate considerations. These are the second generation of british gascooled reactors, using graphite as the neutron moderator and carbon dioxide as coolant. 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. Smith naval postgraduate school observer giflfrpssc minoru takahashi tokyo institute of technology member giflfrpssc alessandro alemberti ansaldo nucleare.
The use of gases leads to a harder neutron spectrum compared with the fast reactor cores of sodium and lead cooled fast reactors waltar et al. Harder spectra in gfrs allow for a broad range of fast spectrum system applications ranging from historical breeder cores to advanced burner reactors. Some have operated well, while others have done poorly. Here, nuclear energy means the energy released in nuclear fission. In a sodiumcooled fast reactor, commonly called a liquidmetal reactor lmr, the fuel consists of uranium dioxide or uraniumplutonium dioxide pellets french design or of uraniumplutoniumzirconium metal alloy pins u. Two commonly used reactors are the cstr continuous stirred tank reactor and the pfr plug flow reactor. For sale by the clearinghouse for federal scientific and technical information, 1971, by charles l. An htgr is a graphitemoderated, heliumcooled reactor with thermal neutron spectrum. Sodiumcooled fast reactor sfr characteristics sodium coolant 500c outlet temp 150 to 0 mwe metal or oxide fuel possible benefitsbenefits efficient fissile material generation breeding sodium is excellent heat transfer fluid and has high boiling point 880 c relatively high temperature good. High temperature gascooled 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.
In addition, the majority of nuclear reactors under development and construction are water cooled. Survive loss of active reactivity shutdown capability without core damage a full recycling of actinides. Sodiumcooled fast reactors have a checkered history. A compact gascooled fast reactor with an ultralong fuel. In a sodium cooled fast reactor, commonly called a liquidmetal reactor lmr, the fuel consists of uranium dioxide or uraniumplutonium dioxide pellets french design or of uraniumplutoniumzirconium metal alloy pins u. The components of an agr reactor core are discussed in further detail below. The space reactor contains suflicient rhenium a neutron poison to make the reactor subcritical under water immersion accidents without the use of internal shutdown rods. Advanced gascooled reactor agr this is the type of reactor operated by british energy and is unique to the uk. Farrington daniels, director of the metalurgical laboratory in chicago, had prewar high temperature industrial experience in developing processes to fix nitrogen from the.
The vhtr is a type of hightemperature reactor htr that can conceptually have an outlet temperature of c. All these reactors are primarily fuelled by triso tri isostructural coated particles. Whitmarsh, lewis research center, and united states national aeronautics and space. The torness agr plant on the lothian coastline of scotland, 60 km east of edinburgh. Sodium cooled fast reactor technology is suitable for reviving an industrial capability for their construction at home and internationally we have a legacy of sfr design and construction experience no large high pressure components are require except for steam generator watersteam headers. Cstr continuous stirred tank reactor and the pfr plug flow reactor. In a typical agr system the reactor core, boilers and gas circulators are housed in a single prestressed concrete cavity known as the pressure. Gas cooled reactor article about gas cooled reactor by. Commercial gas cooled reactors are currently in use only in the united kingdom. Gascooled thorium reactor with fuel block of the unified design article pdf available in advances in materials science and engineering 20151 august 2015 with 173 reads how we measure reads. Gas cooled fast reactors gfrs share the positive attributes of fast reactors.
Experimental facilities for gascooled reactor safety studies. 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. A compact gascooled fast reactor with an ultralong fuel cycle. Sodium cooled fast reactors have a checkered history. An organic nuclear reactor, or organic cooled reactor ocr, is a type of nuclear reactor that uses some form of organic fluid, typically a hydrocarbon substance like polychlorinated biphenyl pcb, for cooling and sometimes as a neutron moderator as well using an organic fluid had a major advantage over conventional designs using water as the coolant. This approach is similar to the 30 mwhttrgas cooled reactor that is operating in japan and that has gas exit temperatures of 11231223 k saito, 2002. Gas cooled fast reactor research in europe request pdf. Heavy wwater ater cooled reactors candukey ccandu andu features. Files are available under licenses specified on their description page. Gascooled reactors have had a long and varied his tory dating back to the very early days of nuclear energy development. No reprocessing high burnup 90,000 mwdmt direct disposal of hlw.
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. Other articles where sodium cooled fast reactor is discussed. A cross sectional view of the gascooled reactor concept is shown in figure 3 and a more detailed view is in figwe 4. Temperature gascooled reactor mhtgr that was initially designed in the middle to late. It introduces the power plants driven by modular high temperature gascooled. Part 1 elements of nuclear reactor theory is composed of only elements but the main resource for the lecture of nuclear reactor theory, and. Status report for 2012 gif symposium generation iv international forum gif symposium november 14, 2012 san diego, ca, usa craig f.
The gen iv gas cooled fast reactor nuclear energy agency. A gascooled reactor gcr is a nuclear reactor that uses graphite as a neutron moderator and carbon dioxide as coolant. 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. 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 and industrial use of the. Larger mass flow rate of precooling water injection will accelerate the precooling process, but the temperature descending rate of the structures should. Neutronic design for a lithiumcooled reactor for space applications washington, d. To design a gas cooled fast reactor system with a high level of safety. Water cooled reactors, in contrast, were already operating fairly close to their maximum temperature based on the triple point of water.
Survive loss of active reactivity shutdown capability without core damage a full recycling of actinides highly proliferation resistant no external blankets, conversion. High temperature gas cooled reactor fuels and materials. Significant efforts are underway in several member states to develop high temperature gas cooled reactors htgr based on either pebble bed or prismatic designs. The veryhightemperature reactor vhtr, or hightemperature gascooled reactor htgr, is a generation iv reactor concept that uses a graphitemoderated nuclear reactor with a oncethrough uranium fuel cycle. With this in mind, this course nuclear reactor theory is designed for students who are studying nuclear engineering for the first time. The gascooled fast reactor gfr was chosen as one of the generation iv nuclear reactor systems to be developed based on its excellent potential for sustainability through reduction of the volume and radio toxicity of both its own fuel and other spent nuclear fuel, and for extendingutilizing uranium resources orders of magnitude beyond what the current open fuel cycle can realize. These reactors provide enough residence time for the reaction to take place with satisfactory conversion. Gascooled reactor definition of gascooled reactor by. The most recent commercial demonstration reactors belong in the latter category. The fundamental idea of matching a high temperature gas cooled reactor with a simple brayton cycle heat engine originated during the final years of the manhattan project.
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