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VHTR
A high-temperature gas-cooled reactor (HTGR), is a nuclear reactor that uses a graphite moderator with a once-through uranium fuel cycle. The HTGR is a type of high-temperature reactor (HTR) that can conceptually have an outlet temperature of . The reactor core can be either a "prismatic block" (reminiscent of a conventional reactor core) or a " pebble-bed" core. The high temperatures enable applications such as process heat or hydrogen production via the thermochemical sulfur–iodine cycle. The HTR is the predecessor of the Very-high-temperature reactor (VHTR), one of the future Generation IV reactor-models, which initially would work with temperatures of 750 to 950 °C. Overview The HTGR is a type of high-temperature reactor that conceptually can reach high outlet temperatures (up to 750 °C). There are two main types of HTGRs: pebble bed reactors (PBR) and prismatic block reactors (PMR).The prismatic block reactor refers to a prismatic block core configuration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very High Temperature Reactor
A high-temperature gas-cooled reactor (HTGR), is a nuclear reactor that uses a graphite-moderated reactor, graphite moderator with a once-through uranium fuel cycle. The HTGR is a type of high-temperature reactor (HTR) that can conceptually have an outlet temperature of . The nuclear reactor core, reactor core can be either a "prismatic block" (reminiscent of a conventional reactor core) or a "Pebble-bed reactor, pebble-bed" core. The high temperatures enable applications such as process heat or hydrogen production via the thermochemical sulfur–iodine cycle. The HTR is the predecessor of the Very-high-temperature reactor (VHTR), one of the future Generation IV reactor-models, which initially would work with temperatures of 750 to 950 °C. Overview The HTGR is a type of high-temperature reactor that conceptually can reach high outlet temperatures (up to 750 °C). There are two main types of HTGRs: pebble bed reactors (PBR) and prismatic block reactors (PMR).The pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very-high-temperature Reactor
A high-temperature gas-cooled reactor (HTGR), is a nuclear reactor that uses a graphite moderator with a once-through uranium fuel cycle. The HTGR is a type of high-temperature reactor (HTR) that can conceptually have an outlet temperature of . The reactor core can be either a "prismatic block" (reminiscent of a conventional reactor core) or a " pebble-bed" core. The high temperatures enable applications such as process heat or hydrogen production via the thermochemical sulfur–iodine cycle. The HTR is the predecessor of the Very-high-temperature reactor (VHTR), one of the future Generation IV reactor-models, which initially would work with temperatures of 750 to 950 °C. Overview The HTGR is a type of high-temperature reactor that conceptually can reach high outlet temperatures (up to 750 °C). There are two main types of HTGRs: pebble bed reactors (PBR) and prismatic block reactors (PMR).The prismatic block reactor refers to a prismatic block core configuration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generation IV Reactor
Generation IV reactors (Gen IV) are six nuclear reactor designs recognized by the Generation IV International Forum. The designs target improved safety, sustainability, efficiency, and cost. The most developed Gen IV reactor design is the sodium fast reactor. It has received the greatest share of funding that supports demonstration facilities, as well as two commercial reactors in Russia. One of these has been in commercial operation since 1981. Its principal Gen IV features relates its sustainable closed fuel cycle. Moir and Teller consider the molten-salt reactor, a less developed technology, as potentially having the greatest inherent safety of the six models. The very-high-temperature reactor designs operate at much higher temperatures than prior generations. This allows for high temperature electrolysis or for sulfur–iodine cycle for the efficient production of hydrogen and the synthesis of carbon-neutral fuels. The first commercial plants are not expected before 2040–2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur–iodine Cycle
The sulfur–iodine cycle (S–I cycle) is a three-step thermochemical cycle used to produce hydrogen. The S–I cycle consists of three chemical reactions whose net reactant is water and whose net products are hydrogen and oxygen. All other chemicals are recycled. The S–I process requires an efficient source of heat. Process description The three reactions that produce hydrogen are as follows: # I2 + SO2 + 2 H2O 2 HI + H2SO4 (); Bunsen reaction #*The HI is then separated by distillation or liquid/liquid gravitic separation. #2 H2SO4 2 SO2 + 2 H2O + O2 () #*The water, SO2 and residual H2SO4 must be separated from the oxygen byproduct by condensation. #2 HI I2 + H2 () #*Iodine and any accompanying water or SO2 are separated by condensation, and the hydrogen product remains as a gas. : : Net reaction: 2 H2O → 2 H2 + O2 The sulfur and iodine compounds are recovered and reused, hence the consideration of the process as a cycle. This S–I process is a chemical heat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pebble-bed Reactor
The pebble-bed reactor (PBR) is a design for a graphite- moderated, gas-cooled nuclear reactor. It is a type of very-high-temperature reactor (VHTR), one of the six classes of nuclear reactors in the Generation IV initiative. The basic design of pebble-bed reactors features spherical fuel elements called pebbles. These tennis ball-sized pebbles (approx. in diameter) are made of pyrolytic graphite (which acts as the moderator), and they contain thousands of micro-fuel particles called TRISO particles. These TRISO fuel particles consist of a fissile material (such as 235U) surrounded by a ceramic layer coating of silicon carbide for structural integrity and fission product containment. In the PBR, thousands of pebbles are amassed to create a reactor core, and are cooled by a gas, such as helium, nitrogen or carbon dioxide, that does not react chemically with the fuel elements. Other coolants such as FLiBe (molten fluoride, lithium, beryllium salt)) have also been suggeste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pebble Bed Reactor
The pebble-bed reactor (PBR) is a design for a graphite-moderated, gas-cooled nuclear reactor. It is a type of very-high-temperature reactor (VHTR), one of the six classes of nuclear reactors in the Generation IV initiative. The basic design of pebble-bed reactors features spherical fuel elements called pebbles. These tennis ball-sized pebbles (approx. in diameter) are made of pyrolytic graphite (which acts as the moderator), and they contain thousands of micro-fuel particles called TRISO particles. These TRISO fuel particles consist of a fissile material (such as 235U) surrounded by a ceramic layer coating of silicon carbide for structural integrity and fission product containment. In the PBR, thousands of pebbles are amassed to create a reactor core, and are cooled by a gas, such as helium, nitrogen or carbon dioxide, that does not react chemically with the fuel elements. Other coolants such as FLiBe (molten fluoride, lithium, beryllium salt)) have also been suggested for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-temperature Engineering Test Reactor
The high-temperature test reactor (HTTR) is a graphite-moderated gas-cooled research reactor in Ōarai, Ibaraki, Japan operated by the Japan Atomic Energy Agency. It uses long hexagonal fuel assemblies, unlike the competing pebble bed reactor designs. HTTR first reached its full design power of 30 MW (thermal) in 1999. Other tests have shown that the core can reach temperatures sufficient for hydrogen production via the sulfur-iodine cycle. Technical details The primary coolant is helium gas at a pressure of about 4 MPa, the inlet temperature of , and the outlet temperature of . The fuel is uranium oxide (enriched to an average of about 6%). See also *Very-high-temperature reactor *Hydrogen economy External links HTTRat the JAEA The is an Independent Administrative Institution formed on October 1, 2005 by a merger of two previous semi-governmental organizations. While it inherited the activities of both JNC and JAERI, it also inherited the nickname of JAERI, "Genken" .. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
THTR-300
The THTR-300 was a thorium cycle high-temperature nuclear reactor rated at 300 MW electric (THTR-300) in Hamm-Uentrop, Germany. It started operating in 1983, synchronized with the grid in 1985, operated at full power in February 1987 and was shut down September 1, 1989. The THTR-300 served as a prototype high-temperature reactor (HTR) to use the TRISO pebble fuel produced by the AVR, an experimental pebble bed operated by VEW (Vereinigte Elektrizitätswerke Westfalen). The THTR-300 cost €2.05 billion and was predicted to cost an additional €425 million through December 2009 in decommissioning and other associated costs. The German state of North Rhine Westphalia, Federal Republic of Germany, and Hochtemperatur-Kernkraftwerk GmbH (HKG) financed the THTR-300’s construction. History On 4 June 1974, the Council of the European Communities established the Joint Undertaking "Hochtemperatur-Kernkraftwerk GmbH" (HKG). The electrical generation part of the THTR-300 was finishe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AVR Reactor
The AVR reactor (german: Arbeitsgemeinschaft Versuchsreaktor) was a prototype pebble-bed reactor, located immediately adjacent to Jülich Research Centre in West Germany, constructed in 1960, grid connected in 1967 and shut down in 1988. It was a 15MWe, 46 MWt test reactor used to develop and test a variety of fuels and machinery. The AVR was based on the concept of a "Daniels pile" by Farrington Daniels, the inventor of pebble bed reactors. Rudolf Schulten is commonly recognized as the intellectual father of the reactor. A consortium of 15 community electric companies owned and operated the plant. Over its lifetime the reactor had many accidents, earning it the name "shipwreck." From 2011 to 2014, outside experts examined the historical operations and operational hazards and described serious concealed problems and wrongdoings in their final 2014 report. For example, in 1978 operators bypassed reactor shutdown controls to delay an emergency shutdown during an accident for six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MWTh
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Watt (1736–1819), an 18th-century Scottish inventor, mechanical engineer, and chemist who improved the Newcomen engine with his own steam engine in 1776. Watt's invention was fundamental for the Industrial Revolution. Overview When an object's velocity is held constant at one metre per second against a constant opposing force of one newton, the rate at which work is done is one watt. : \mathrm In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V), meaning the watt is equivalent to the volt-ampere (the latter unit, however, is used for a different quantity from the real power of an electrical circuit). : \mathrm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between the Baltic and North seas to the north, and the Alps to the south; it covers an area of , with a population of almost 84 million within its 16 constituent states. Germany borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its financial centre is Frankfurt; the largest urban area is the Ruhr. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. In 962, the Kingdom of Germany formed the bulk of the Holy Roman Empire. During the 16th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dragon Reactor
DRAGON Reactor Experiment (DRE) was an experimental high temperature gas-cooled reactor at Winfrith in Dorset, England, an experimental reactor of the Organisation for Economic Co-operation and Development (O.E.C.D) High Temperature Reactor Project. The site extended to of heathland in rural south Dorset, and nine different experimental reactors were located there. Many designs of the 1960s and 70s were based on this general tristructural-isotropic (TRISO) fuel concept, including "prismatic" designs with fixed fuel layouts like Dragon, and the pebble-bed reactor designs being developed in Germany. , these concepts have been used in several further research reactors, including Peach Bottom, AVR, HTTR, and HTR-10 as well as for commercial reactors Fort St. Vrain and THTR-300. The HTR-PM in China is under construction, with one unit at Shidao Bay connected to the grid as of December 2021. Of the nine experimental reactors at Winfrith, only the Dragon Reactor and the Steam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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