Conversion of molten carbon-rich iron by blowing air through it. Oxidation of constituents supplies heat; early acidic converters required low-phosphorus feed.
Steel melted in a crucible to improve compositional uniformity relative to incompletely homogenized starting stock.
Historical production of blister steel by prolonged heating of wrought iron with carbonaceous material, allowing carburization of the bars.
The carburized bar product of the cementation process, historically showing surface blisters and an uneven carbon distribution.
Historical refining of molten carbon-rich iron in a reverberatory furnace by oxidation and stirring, commonly producing wrought iron.
The nonmetallic melt or solid product separating gangue and other constituents from a metal during extraction or refining.
Conversion of an iron-bearing ore into metallic iron, for example by carbon monoxide reduction in a blast furnace.
The carbon-rich first molten iron product of traditional blast furnace smelting, also containing other feed-dependent impurities.
A shaft furnace with a blast of hot air, in which descending ore and ascending gases exchange heat and react. In iron extraction it supplies molten pig iron and slag.
A naturally occurring material from which a useful constituent can be extracted under the relevant technical and economic conditions.
A vehicle propelled wholly or partly by electric motors. Operational emissions depend on electricity generation and energy use per distance, while manufacture and the wider supply chain require a life-cycle assessment.
A hybrid vehicle whose battery can be charged externally and which also carries another propulsion energy source, commonly liquid fuel. Its electric-distance fraction depends on charging and use patterns; possessing a plug does not ensure substantial electric operation.
Separation of carbon dioxide from a gas stream followed by transport and storage intended to prevent its atmospheric release. Post-combustion capture treats flue gas after fuel burning. Capture fraction differs from emissions reduction per unit delivered energy because capture, regeneration and compression consume energy. Storage integrity, monitoring and upstream emissions remain part of the assessment.
Assessment of environmental burdens over a stated product or process boundary, including production, operation and disposal. Comparisons require a common functional unit, such as delivered energy or passenger distance. For a fuel, tailpipe emissions alone omit feedstock cultivation or extraction, processing, transport and changes in land carbon stocks.
The design and construction of defensive works. Surveying, geometry and practical mechanics connected this work with early modern mathematical expertise.
An empirical production-cost model uses , with fractional learning per doubling . It is conditional on technology, inputs, design and cost boundary, and is not a physical guarantee that future deployment must lower system cost.
An instrument for determining mass or weight; a comparison balance matches the effect of an unknown load against known loads under comparable conditions.
A device combining sensing, local processing, a radio and a power subsystem. An energy budget must account for sleep leakage, active operation, startup and peak communication current; stored energy can bridge intermittent harvesting.
Manufacturer of scientific instruments, including atomic force microscopes.
Engineering of systems using nuclear reactions or managing radioactive materials, including reactor energy conversion, materials performance and waste management.
Attenuation of an ionising radiation field by intervening material. A shield can reduce external exposure without preventing contamination from a released radioactive substance.
A factor accounting for scattered radiation that contributes to a specified response beyond the uncollided exponential attenuation. It depends on material, geometry, spectrum and the response being counted; is a stipulated simple model, not a universal law.
Prevention of unwanted dispersal of radioactive material by barriers, enclosures and controlled transfers. It differs from shielding, which attenuates a radiation field without necessarily retaining the radioactive source.
The coupled analysis of heat generation, heat transfer and coolant fluid mechanics in a nuclear reactor. A change in fuel geometry can affect neutron moderation, hydraulic resistance and thermal margins together, so holding one quantity fixed does not generally hold the others fixed.
An accident involving loss of reactor coolant through a breach of its pressure boundary. Depressurization, loss of inventory and changes in heat removal require a transient assessment; stopping the fission chain reaction does not remove decay heat.
A system intended to supply emergency cooling to limit fuel damage and maintain heat removal following a coolant-loss event. Its performance depends on the accident conditions and flow paths as well as nominal injection capability.
Thermal power generated per unit axial fuel-rod length, measured in . At fixed rod radius and material state, it controls the conductive fuel-to-surface temperature rise; coolant conditions determine the surface temperature from which that rise begins.
Thermal power per active-core volume under a stated volume convention. Coolant channels can be included in that core volume even when excluded from fuel volume, so core and fuel power densities need not change together.
Recording and reconciliation of nuclear-material inventories and transfers. This is a management concept, not a procedure for producing or separating fissile material.
Unwanted radioactive material on or in an object, substance or environment. It is distinct from activation of the object itself.
Administrative and technical actions bringing a permanently shut-down nuclear facility to a demonstrated end state permitting removal of some or all regulatory controls. Waste management and site-release evidence are integral to completion.
The specified condition at completion of nuclear decommissioning, supported by final characterisation and records. It can permit unrestricted reuse or retain defined restrictions.
Removal of materials or objects from further radiological regulatory control under specified criteria. Absence of an obvious radiation signal is not sufficient evidence of clearance.
Encasement of radioactive structures in a long-lived material. Historical classifications included it as a third strategy; IAEA GSR Part 6 excludes it for planned permanent shutdown, allowing consideration only in exceptional circumstances.
A strategy maintaining a facility safely for a period before final dismantling. radioactive decay can reduce later dose, while surveillance, deterioration and knowledge retention remain obligations.
A strategy beginning dismantling and decontamination soon after permanent shutdown, making early use of operating knowledge and enabling earlier site reuse.
Control of radioactive wastes from generation through treatment, conditioning, storage and disposal. Concentrating a radionuclide in a smaller stream changes its location, not its radioactive decay law.
A liquid or gaseous outflow containing radionuclides. Its measured inventory and treatment history are distinct from whether release is authorised under the applicable discharge controls.
Removal of contamination from a surface or material. The cleaning residues and wash solutions become part of the waste inventory.
Prevention of an unintended self-sustaining nuclear fission chain reaction in waste management. neutron absorbers, fissile-isotope dilution and their long-term geochemical retention are relevant; a cross-section comparison is not a criticality assessment.
Storage that allows short-lived radioactive constituents to radioactive decay before subsequent handling or discharge. A clearance or discharge decision still requires the applicable measurement and acceptance criteria.
Temporary retention of radioactive gas so that nuclear radioactive decay lowers the radioactive activity released. A guaranteed minimum residence time, an average residence time and a tank filling time are different design quantities.
Separation or transformation of contaminants in liquid waste. evaporation, ion exchange and chemical precipitation concentrate radionuclides into residues that need further management.
Transfer of dissolved contaminants to separable solids by precipitation, coprecipitation or surface uptake. The resulting sludge requires separation and conditioning; residual dissolved radioactive activity must be measured.
Removal of water vapour to concentrate mainly nonvolatile contaminants. Entrainment and volatile radionuclides can contaminate the condensate; a smaller concentrate volume does not guarantee a clean distillate.
Operations producing a stable waste form and suitable package, for example immobilisation in cement, glass or ceramic. Treatment residues and secondary wastes must be included in the waste inventory.
A waste form together with its container and any associated internal barriers prepared for handling, storage or disposal.
Immobilisation of radioactive waste in a glass matrix. glass composition, durability, secondary phases and the complete package affect performance.
Interaction of waste glass with water through ion exchange, network dissolution and alteration-product formation. Dissolved-element release need not equal the total extent of glass alteration.
Formation of new solids during glass alteration. Such phases can retain selected elements or consume dissolved network constituents, changing the apparent release and reaction rate.
A glass-durability test with a finite initially specified leachant inventory. Dissolved products, pH and alteration layers evolve, so the test does not maintain the same conditions as continuous fresh-water flow.
Element release departing from bulk glass proportions. Selective ion exchange, retention in an alteration layer, sorption and secondary precipitation can all produce noncoincident normalised solution releases.
A low continuing rate after alteration products or solution chemistry have slowed the initial reaction. It need not be zero or represent thermodynamic equilibrium of the original glass.
A hydrated, compositionally modified interfacial layer formed during glass corrosion. Its porosity, transport properties and continuing reactions can affect the residual alteration rate.
The dilute-solution dissolution rate at specified temperature, pH and composition, before dissolved reaction products suppress the chemical driving force. It is not a maximum across all temperatures and pH values.
A continuously refreshed leach test used to measure dissolution under controlled dilute conditions. At steady state the elemental normalised rate is . Varying helps identify solution-affinity effects.
Dissolution releasing glass constituents in their bulk proportions. Element-normalised releases then coincide if precipitation, sorption and analytical losses do not selectively remove released constituents.
The solution-released mass of an element divided by its initial glass mass fraction and the exposed glass area: . It has units of glass-equivalent mass per area; it does not alone establish congruent dissolution.
The physical and chemical form in which radioactive waste is immobilised for handling, storage or disposal. Its durability is distinct from that of its container and surrounding engineered barriers.
A waste form designed using durable mineral structures as hosts. A natural analogue motivates a design but does not substitute for tests of the actual radioactive composition.
A titanate host represented by . strontium can replace calcium; other ions require suitable charge balance.
A tunnel-structured titanate host, represented by , used to incorporate large cations such as caesium with appropriate charge compensation in a crystal.
A family of mineral-analogue ceramic waste forms. Different titanate phases accept different waste ions by solid solution; phase assemblage is tailored to the waste inventory.
A multiphase Synroc formulation with zirconolite, hollandite, perovskite and titanium-oxide phases. The mineral hosts distribute different radionuclides rather than requiring one lattice to accept the entire inventory.
Material containing radionuclides for which no further use is foreseen and which is subject to radiological control under the applicable framework.
The linked production, use and subsequent management of nuclear fuel. A closed cycle recovers some material for reuse; it still generates radioactive wastes.
The operating interval between specified refuelling events. It must be distinguished from the full material nuclear fuel cycle and from an individual fuel batch's multi-cycle residence time. Reactivity history, thermal limits and fuel management constrain the achievable interval.
An increase in the fraction of a specified uranium isotope. Fuel-cycle accounting tracks feed, product, enrichment tails and separative work; it does not specify an uranium enrichment plant or its operating conditions.
A technology exploiting mass-dependent redistribution of gas under rotation. It became the dominant commercial uranium-enrichment technology with much lower electricity consumption than gaseous diffusion. No operating conditions or equipment specifications are supplied.
A historical isotope-enrichment technology using the different transport of isotopic gas molecules through a barrier. It was displaced commercially by much less electricity-intensive centrifuge technology. This is a historical principle, not a plant design or operating procedure.
A unit of isotope-separation work used in fuel-cycle accounting. If stream masses are in kilograms and is isotope mass fraction, is in kg-SWU, with . This is a resource-accounting relation, not equipment or cascade design.
The depleted material stream in isotope uranium enrichment. enrichment tails retain uranium, so gross feed demand exceeds the enriched product mass.
The stated mass or atom fraction of a selected fuel isotope. An isotope balance requires all streams to use the same convention; a mass fraction is not interchangeable with an atom fraction without conversion.
A concentrated uranium-bearing product of ore processing. Resource accounts must distinguish mass of uranium from gross mass of its oxide concentrate.
A fuel cycle returning recovered constituents to fuel manufacture. Recovery losses, additional waste streams and recycled-fuel specifications affect the resource and cost balance.
A once-through fuel cycle in which spent nuclear fuel is managed without recovering its constituents for a further fuel irradiation.
Chemical treatment of spent nuclear fuel to partition reusable constituents from wastes. Recovery does not eliminate the need for waste conditioning and disposal. This article concerns concepts and material accounting, not operational fissile-separation procedures.
uranium recovered from spent nuclear fuel. Its isotopic composition differs from natural uranium; uranium-236 can impose an additional fuel-performance penalty.
Irradiated nuclear fuel removed from a reactor. Residual actinides coexist with fission products and activation products; radioactivity and decay heat continue after shutdown.
Historical background on the replacement of gaseous diffusion by gas centrifuges and diffusion-plant closures. The later webpage is not used to assign present-day plant counts to 2019.
Articles were limited to the first 100 out of 513 total.
Articles by others on the same topic
Engineering is a disciplined and systematic approach to designing, building, and maintaining structures, machines, systems, and technologies. It applies principles of mathematics, physics, biology, chemistry, and other scientific fields to solve practical problems and create innovative solutions. Key aspects of engineering include: 1. **Problem Solving**: Engineers identify challenges and develop practical solutions through analysis, design, and testing.
