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Dragon Reactor
Dragon was an experimental high temperature gas-cooled reactor at Winfrith in Dorset, England, operated by the United Kingdom Atomic Energy Authority (UKAEA). Its purpose was to test fuel and materials for the European High Temperature Reactor programme, which was exploring the use of tristructural-isotropic (TRISO) fuel and gas cooling for future high-efficiency reactor designs. The project was built and managed as an Organisation for Economic Co-operation and Development/ Nuclear Energy Agency international project. In total, 13 countries were involved in its design and operation during the project lifetime. Originally conceived as a small research reactor, during the design phase it grew larger. The choice of helium coolant was made after a long debate within the UKAEA between proponents of helium and carbon dioxide, with helium ultimately selected. Groundbreaking occurred in 1960. It operated from 1965 to 1976, and is generally considered extremely successful. Dragon's con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winfrith
Winfrith Atomic Energy Establishment, or AEE Winfrith, was a United Kingdom Atomic Energy Authority site near Winfrith Newburgh in Dorset. It covered an area on Winfrith Heath to the west of the village of Wool between the A352 road and the South West Main Line. Winfrith was set up in order to test a variety of new nuclear reactor designs with the intention of selecting a new design for power generation and other tasks. The main design built at the site was the demonstration steam-generating heavy water reactor (SGHWR) providing power to the National Grid. A number of smaller designs were also constructed at the site. The site officially opened with the ZENITH reactor in 1960. SGHWR opened in 1967 and was shut down in 1990. All of the reactors have been shut down and are in various stages of removal. The site is now being re-used for other purposes while decommissioning continues. Nuclear research The initial steps that led to the formation of Winfrith began with the crea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Cross Section
The nuclear cross section of a nucleus is used to describe the probability that a nuclear reaction will occur. The concept of a nuclear cross section can be quantified physically in terms of "characteristic area" where a larger area means a larger probability of interaction. The standard unit for measuring a nuclear cross section (denoted as σ) is the barn, which is equal to , or . Cross sections can be measured for all possible interaction processes together, in which case they are called total cross sections, or for specific processes, distinguishing elastic scattering and inelastic scattering; of the latter, amongst neutron cross sections the absorption cross sections are of particular interest. In nuclear physics it is conventional to consider the impinging particles as point particles having negligible diameter. Cross sections can be computed for any nuclear process, such as capture scattering, production of neutrons, or nuclear fusion. In many cases, the number of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Criticality (status)
In the operation of a nuclear reactor, criticality or critical state is the state in which a nuclear chain reaction is self-sustaining but not growing. Subcriticality or subcritical state is the state in which a nuclear chain reaction is not self-sustaining. Supercriticality or supercritical state is the state in which a nuclear chain reaction is self-sustaining and growing. Sometimes, less preferably, criticality takes a wider definition, and refers to the any state in which a nuclear chain reaction is self-sustaining, no matter growing or not (encompassing criticality in strict definition and supercriticality). In terms of reactivity, reactivity is 0 in criticality, less than 0 in subcriticality, greater than 0 in supercriticality. In terms of effective neutron multiplication factor (), is 1 in criticality, less than 1 in subcriticality, greater than 1 in supercriticality. Applications Criticality is the normal operating condition of a nuclear reactor, in which nuclear fue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helium
Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the Chemical element, elements, and it does not have a melting point at standard pressures. It is the second-lightest and second-most Abundance of the chemical elements, abundant element in the observable universe, after hydrogen. It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and Jupiter, because of the very high nuclear binding energy (per nucleon) of helium-4 with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. The most common isotope of helium in the universe is helium-4, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shidao Bay Nuclear Power Plant
Shidao Bay Nuclear Power Plant (), commonly known as Shidaowan, is a nuclear power plant in Shandong province, China. The site is located near the Xiqianjia village in Ningjin subdistrict, Rongcheng, Weihai, Shandong. The plant is located about south of Rongcheng City, northwest of Shidao, and southeast of Weihai City. The plant has the first fourth-generation nuclear reactors in the world: the HTR-PM, a high-temperature gas-cooled reactor (HTGR) concept (). The plant will ultimately have ten 210 MWe ( megawatts electrical) units of this type. Each unit is made of two HTR-PM reactors driving a single 210 MWe steam turbine. The plant also hosts the construction of two 1500 MWe CAP1400 pressurized water reactors (), a design based on the AP1000 jointly developed by Westinghouse and China's State Nuclear Power Technology Corporation (SNPTC). Shidao Bay nuclear power plant is a joint venture by China Huaneng Group, China Nuclear Engineering & Constructio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after India, representing 17.4% of the world population. China spans the equivalent of five time zones and Borders of China, borders fourteen countries by land across an area of nearly , making it the list of countries and dependencies by area, third-largest country by land area. The country is divided into 33 Province-level divisions of China, province-level divisions: 22 provinces of China, provinces, 5 autonomous regions of China, autonomous regions, 4 direct-administered municipalities of China, municipalities, and 2 semi-autonomous special administrative regions. Beijing is the country's capital, while Shanghai is List of cities in China by population, its most populous city by urban area and largest financial center. Considered one of six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTR-PM
The HTR-PM ( zh, 球床模块式高温气冷堆核电站) is a Chinese small modular nuclear reactor. It is a high-temperature gas-cooled (HTGR) pebble-bed generation IV reactor evolved from the HTR-10 prototype. The technology is intended to replace coal-fired power plants in China's interior, in line with the country's plan to reach carbon neutrality by 2060. The first plant has an electrical output of 210 MW. It began producing power in December 2021 and started commercial operation in late 2023. Technology The HTR-PM is a high-temperature gas-cooled (HTGR) pebble-bed reactor. While the German AVR and THTR-300, operating from 1969 to 1988, were the first pebble-bed reactors and operated at similar temperatures, the HTR-PM is the first such design using modular construction and the second small modular reactor, following Russia's ''Akademik Lomonosov'' floating plant in 2019. It is a generation IV design. The technology is based on the HTR-10 prototype reactor. The ... [...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 on 1 September 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 fin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fort St
A fortification (also called a fort, fortress, fastness, or stronghold) is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from Latin ("strong") and ("to make"). From very early history to modern times, defensive walls have often been necessary for cities to survive in an ever-changing world of invasion and conquest. Some settlements in the Indus Valley Civilization were the first small cities to be fortified. In ancient Greece, large cyclopean stone walls fitted without mortar had been built in Mycenaean Greece, such as the ancient site of Mycenae. A Greek '' phrourion'' was a fortified collection of buildings used as a military garrison, and is the equivalent of the Roman castellum or fortress. These constructions mainly served the purpose of a watch tower, to guard certain roads, passes, and borders. Though smaller than a real fortress, they acted as a border ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HTR-10
HTR-10 is a 10 MWt prototype high-temperature gas-cooled, pebble-bed reactor at Tsinghua University in China. Construction began in 1995, achieving its first criticality in December 2000, and was operated in full power condition in January 2003. Two HTR-PM reactors, scaled up versions of the HTR-10 with 250-MWt capacity, were installed at the Shidao Bay Nuclear Power Plant near the city of Rongcheng in Shandong Province and achieved first criticality in September 2021. Development The Institute of Nuclear Energy Technology (INET) of Tsinghua University is the lead designer for the HTR-10 reactor. The project was approved by the State Council in March 1992. The Design Criteria and Safety Analysis Report for the HTR-10 were approved in August 1992 and March 1993. In August 1994, Siemens/Interatom reviewed the fundamental design of the HTR-10 and exchanged knowledge gained from their advanced design efforts on the HTR-MODUL with INET. Like the HTR-MODUL, HTR-10 is claimed t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-temperature Engineering Test Reactor
The high-temperature engineering 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 Hydrogen gas is produced by several industrial methods. Nearly all of the world's current supply of hydrogen is created from fossil fuels. Article in press. Most hydrogen is ''gray hydrogen'' made through steam methane reforming. In this process, ... via the sulfur-iodine cycle. Technical details The primary coolant is helium gas at a pressure of about , 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 References E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AVR Reactor
The AVR reactor () 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 15 MWe, 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 days. In 2014 the JRC and AVR publicly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
