Construction Of Reactor Research Articles

Foundations for a Fission Battery Digital Twin

As the nuclear industry moves toward construction of microreactors and next-generation reactors, these efforts pose new challenges. A digital-twin tool will reduce costs and risk through integration of the disparate systems used in the design, construction, and operation of these reactors. Recent investments at Idaho National Laboratory (INL) in open-source digital engineering and multiphysics framework development provide a foundation from which to create and evaluate a digital twin for nuclear reactors. This digital-twin tool will use the Single Primary Heat Pipe Extraction and Removal Emulator (SPHERE) and Microreactor AGile Non-nuclear Experimental Testbed (MAGNET) as case studies to develop a digital twin with both single and 37 heat pipe test articles. The digital twin will provide the capabilities of remote monitoring and unattended operation (autonomous control) of these systems. A digital twin is a digital replica of an operating asset that can display data received from live sensors, update a physics model for the asset with the received data, compute predictive results of operational status with artificial intelligence (AI) to aid in optimizing asset use, and apply asset control accordingly. This twin will be developed through integration of the open-source technologies Deep Lynx (a data-warehouse technology) and the Multiphysics Object-Oriented Simulation Environment (MOOSE), physical-asset sensors, and physical-asset controls. Specifically, the general AI will successfully predict the events described as MAGNET heat pipe article test cases (such as heat pipe failure) using integrated data from the MAGNET sensors and physics-based models, including developed meta models. The integration of open-source INL software and AI assets with sensor data from a test bed will lead to a repeatable framework and guide for the creation of future digital twins. The team will also perform AI model training and experimentation to determine what models and features are most important to enable intelligent, autonomous control as well as to evaluate and determine best practices for digital-twin cybersecurity.

NUCLEAR GEOSTRATEGY OF THE POST-COLD WAR ERA

The use of nuclear energy has changed the world's geopolitical and geostrategic landscape irreversibly, distinguishing another attribute of "high power", namely that of nuclear power, which not only means the possession of a nuclear arsenal, but also trade in civil nuclear technology (nuclear reactors for electricity generation) placing the selling state and the buyer in a geopolitical relationship. What's new? The emergence of a new nuclear military power, China, perceived as a "growing tiger", and new exporters of civil nuclear technology, Russia and China, which now concentrate 2/3 of reactor construction in the world after the long period of the Cold War when the global civilian nuclear energy market was dominated by the US.

Effects of cold work on the corrosion behavior of Alloy 800H exposed to aerated supercritical water

• Cold work reduces the corrosion resistance of Alloy 800H in supercritical water containing 200 ppb oxygen. • At initial corrosion stage, the corrosion behavior of as-received and cold-worked materials is similar. • The formation of a continuous chromia layer reduces the oxygen partial pressure at the oxide scale-matrix interface, which contributes to the later internal oxidation and selective oxidation of the elements. • With the increase of exposure time, the microstructure of the cold worked materials becomes more complicated and is further subdivided into Fe 3 O 4 /Ni x Fe 3- x O 4 /Ni x Fe y Cr 3- x - y O 4 /Cr 2 O 3 / NiO/Fe x Cr 2- x O 4 +pure Ni multi-layer structure. • Through observation of the oxidation process and the calculation of thermodynamic equilibria, the oxide scale differences were explained through the hypothesis that diffusion barriers were created by the prevailing oxides. Revealing the corrosion mechanism of materials in supercritical water (SCW) is a key issue for the development of a supercritical water reactor (SCWR). Considering cold work is inevitable in the construction of nuclear reactors and its effect on the corrosion behavior of materials in SCW is still unclear, the corrosion behavior of solution-annealed (as-received) and 30% cold-worked Alloy 800H were studied at 600 °C in aerated SCW for 1500 h. The microstructure of the oxide scale was studied by a variety of characterization techniques. The results indicate that cold work increases the corrosion rate of the materials, promotes selective oxidation and internal oxidation, and this was attributed to the high diffusion rate of different ions along “short-circuit paths”. The oxide scale composition and structure of the cold-worked material, which is subdivided to Fe 3 O 4 /Ni x Fe 3- x O 4 /Ni x Fe y Cr 3- x - y O 4 /Cr 2 O 3 /NiO/ Fe x Cr 2- x O 4 + pure Ni multi-layer structure, are much more complicated than the as-received material after 1500 h exposure. Combined with the thermo-dynamic equilibrium calculation, the oxidation processes of the as-received and cold-worked materials were analyzed to reveal the effect of cold work on the corrosion behavior of Alloy 800H.

Preparation of nitrogen-doped porous carbon by urea–formaldehyde resin for the construction of membrane adsorption reactor to remove refractory pollutant

• UFCA was prepared by carbonization and activation of urea-formaldehyde resin. • UFCA-900 was used to adsorb quinoline, phenol and pyridine with high capacities. • Membrane adsorption reactor with UFCA-900 continuously remove quinoline. • The mechanism is electrostatic interactions, π-π interactions and hydrogen bonds. Considering the highly toxic by-products generation and environmental friendliness, the adsorption process is a suitable solution as the end of pipe treatment for refractory organics in coking wastewater. Nitrogen-doped micro-mesoporous carbon prepared by carbonization and KOH activation of urea–formaldehyde resin (UFCA) realized effective adsorption of quinoline, phenol and pyridine in coking wastewater. Among them, UFCA-900 has large specific surface area (S BET = 1469.94 m 2 g −1 ) and excellent adsorption properties: the adsorption removal rate of quinoline reached 98.40% about 16 min, and the maximum adsorption capacity of quinoline was 721.90 mg·g −1 at 318 K, the adsorption capacity of phenol and pyridine at 298 K were 341.59 mg·g −1 and 225.08 mg·g −1 , respectively. The adsorption kinetics of UFCA-900 obeyed the pseudo-second-order model, and the adsorption process was endothermic. The membrane adsorption reactor demonstrated efficient adsorption, well separation, and negligibly irreversible membrane fouling. The adsorption mechanism included electrostatic interactions, π-π interactions and hydrogen bonds. Regeneration test proved that the removal rate of the chemically regenerated UFCA-900 was similar to the fresh adsorbent after six cycles. Taken together, a simple strategy for in-situ nitrogen-doped porous carbon has been developed and the resultant composite UFCA-900 has promising application prospect in coking wastewater treatment.

MATHEMATICAL RELATIONS OF MODELS OF SINGLE-PHASE FLOWS IN THE CHANNELS OF REACTORS AND STEAM GENERATORS OF NPP’s FOR CALCULATION OF HEAT TRANSFER PROCESSES AND HYDRODYNAMIC CHARACTERISTICS

The article presents the mathematical relationships of models of single-phase flows in channels of a other design for calculating the parameters of heat transfer processes and hydrodynamic (gas-dynamic) characteristics of flows. A comparative analysis of these ratios and their differences are indicated depending on the design of the channels. To calculate the processes of heat exchange in steam generators of nuclear power plants during the movement of single-phase flows of the coolant and working substance, the criterion equations of the similarity theory are used, which describe the generalized relationships between the quantities characterizing the processes that are similar to each other. These are the criteria for Re; Nu; Pr; Pe, et al. The article provides generalized relationships between similarity criteria for single-phase flows of different types of coolants (water, gas, liquid metals) and working substances that are used in the design and construction of reactors and steam generators.

Peptide modification on the interior surface of red blood cell ghosts for construction of catalytic reactors.

We have succeeded in in situ synthesis of gold nanoparticles (Au NPs) on the interior surfaces of red blood cell ghosts (RBCGs) with a cytoskeleton chemically conjugated to a gold-binding peptide. The Au NP-deposited RBCG with the peptide exhibits enhanced catalytic reactivity for the reduction of 4-nitrophenol due to the uniform distribution of the Au NPs on the inner surface and the coverage of the Au NPs surface with the peptide.

The statistical analysis and prediction associated with nuclear meltdown accidents risk evaluation

The relevant safety property associated with nuclear meltdown is evaluated from both reactors' internal and external factors using three statistical models: logistic regression model, linear discriminant model, and support vector machines (SVM). For each statistical model, the relevant factors that affect the nuclear reactors and probability of nuclear meltdown are evaluated by mathematical statistical analytics. Through the study, the phenomena are found that external factors have the trend to overwhelm inner factors and play a dominate role in the accident. The model analysis and their prediction results presented here could potentially provide nuclear engineers and relevant decision-makers with suggestions on selecting appropriate locations, designs and relevant construction and operation strategy for nuclear reactors from a statistical perspective.

Study on Nitrate Removal from Water by Micro-Electrolysis and Construction of Iron-Carbon Micro-Electrolysis Reactor (Icmer)

Study on Nitrate Removal from Water by Micro-Electrolysis and Construction of Iron-Carbon Micro-Electrolysis Reactor (Icmer)

Određivanje biometanskog potencijala za različite vrste sirovina

The design and construction of anaerobic reactors for a wide range of substrates from one or more sources require a good understanding of each substrate's physical and biochemical characteristics. Tests of biological or biochemical methane potential (BMP), i.e., anaerobic biodegradability analyses, are used to determine anaerobic biodegradability and total methane potential of waste or biomass, as well as the velocity of the process in laboratory conditions. This paper presents the use of an automated methane production potential testing system (AMPTS). AMPTS was developed for online measurements of ultra-low flows of biogas and bio-methane produced from the anaerobic fermentation of any biodegradable substrate (both solid and liquid form) at the laboratory level. Specific measurements and analysis of the results were performed for different raw materials: sludge from treated wastewater, animal manure, corn silage, straw, and their combinations.

Соотношение радиационно-обусловленных потенциальных канцерогенных рисков ОЯТ реактора ВВЭР-1000 и РАО реактора БРЕСТ-1200 при выработке 1 ГВт х год электроэнергии. Часть 2. Радиологическая миграционная эквивалентность

Currently it is acknowledged that the problem of disposal of radioactive waste (RW) from the nu-clear reactors largely depends on the use of fast neutron reactors (fast reactors) in nuclear power industry. These reactors are able to burn and transmutate long-lived radionuclides in closed nu-clear fuel cycle (NFC). In an open NFC with thermal neutron reactors (thermal reactors), unpro-cessed spent nuclear fuel (SNF) is buried. In a closed NFC with fast reactors the reprocessed SNF is disposed. In this paper, the feasibility and possibility of closing the NFC in a two-component nuclear power industry with thermal and fast reactors are studied. Potential biological hazard (PBH) to the public from unprocessed SNF from the thermal reactor WWER-1000 and re-processed SNF from the fast reactor BR-1200, were evaluated with account of relevant radionu-clides migration from the deep disposal to the earth surface. PBH values were expressed in terms of committed effective dose and lifetime attributable risk (LAR) of malignant neoplasms, normalized to 1 GW of generated electricity. PBH of RW from BR-1200 is about 100 times lower than risk from unprocessed SNF from WWER-1000. Comparative evaluation of PBH from BR-1200 and unprocessed SNF from WWER-1000 demonstrated that the committed effective doses from the dwell-water used by the public from the time of radionuclides appearance at the earth surface are 0.7 µSv and 80 µSv/year respectively, and LAR values are 6∙10-9 and 7.74∙10-6 re-spectively. At the same time, PBH of reprocessed SNF from WWER-1000, from the time of radio-nuclides appearance on the earth’s surface is an order less than PBH of RW from BR-1200. In accordance with the principle of radiological equivalence of RW disposal, it was established that the RW from BR-1200 satisfies the time limit for achievement of the equality with the PBH of the equivalent mass of uranium raw material will be within the range of 300 years. If PBH is ex-pressed in terms of LAR the radiological migration equivalence is achieved even earlier. Thus, when reprocessing SNF from thermal reactors and operating thermal reactors with simultaneous construction and operation of fast reactors (in a two-component nuclear power industry), it is ad-visable to use a closed NFC and dispose of RW, considering the principle of radiation-migration equivalence.

Металофізичні проблеми надійності зварювальних з’єднань корпусів реакторів ВВЕР

The prospects and possibilities of replacing the capacities of nuclear power units of Ukrainian nuclear power plants, which are currently almost completely depleting their operational life, as well as the possibility of extending the guaranteed service life are analyzed and generalized. Based on the study of reactor construction trends and proposals on the world market, a basic promising modern model of a high-capacity 3+ AP1000 nuclear water reactor manufactured by Westinghouse El. Corp. was selected and recommended as a basic promising for use in Ukraine. The results of new studies on the dynamics of strength loss of reactor steels of WWER reactors and their welding joints under the action of radiation are considered. The main attention is paid to the presence and processes of migration and segregation in the crystal structure of reactor steels of harmful impurities, in particular phosphorus and nickel. It is concluded that there are significant advantages of new foreign metallurgical technologies, the use of which in vessel steels provides reliability and increased guaranteed life of safe operation of PWR reactors, in particular, AP1000 type made in the USA. The urgent problems of commissioning additional shunting capacities in the National Unified Energy System of Ukraine were assessed and the conclusion was made that they can be solved by improving the shunting characteristics of existing high-capacity nuclear power units and (mainly) by accelerating construction and commissioning of small modular reactors with high shunting characteristics, in particular the SMR-160 model manufactured by SMR LLC (USA).

Design and Construction of an ALD Reactor by Growth of Al2O3 Nanostructure Films

Objective: This project focuses on designing, building and commissioning work the atomic layer deposition (ALD) reactor for Al2O3 ultrathin film, which it will be contain specific components and a system's own control unit. Methodology: The ALD reactor was designed under a system to minimize components, flow lines and connections; to reduce manufacturing costs, volume of precursors, among others. Currently, ALD reactors are expensive to sell, maintain and replace parts. The design and manufacture of the ALD reactor manufactured at the University of Sonora (UNISON) is based on the state art with sequential binary reactions of the precursors, for the proposal for the manufacture of solar cells. Contribution: It was possible to build and commission the ALD reactor for the deposition of ultra-thin films, with the characteristics of being reproducible and scalable, which makes it attractive for commercialization. The homemade ALD reactor at UNISON is considered a very interesting equipment for the semiconductor research area, since it is possible to combine different types of materials in the form of films such as oxides and nitrides in the order of Angstroms (Ǻ).

Design of a photocatalytic reactor (uv-a) for the study of the chemical degradation of 1,2- dihydroxybenzene and inactivation of e. coli in simulated water

For water disinfection, conventional methods have been applied with some drawbacks towards the formation of potentially dangerous disinfection products. Advanced oxidation processes such as photocatalysis are less expensive, using fluorescent ultraviolet light lamps. The intense oxidation and mineralization reactions of contaminants can be increased in the presence of molecular oxygen or H2O2, resulting in a highly efficient process due to the formation of reactive oxygen species, which leads to an efficient degradation of contaminants in an aqueous medium to form compounds or residues. with low toxicity. The photocatalytic remediation of 1,2-dihydroxybenzene and the inactivation of E. coli in simulated waters was carried out after the construction of a photocatalytic reactor with a 10W UV light source at 365 nm based on the LED light emitting diode - UV energetically. efficient due to direct light incidence and the reduction of electron-hole recombination that increases photonic efficiency. To carry out the degradation process of 1,2-dihydroxybenzene, a three-level 3k factorial design was applied for the catalyst concentration (TiO2), pH level and H2O2 concentration, showing favorable results for acid pH and low amount of catalyst. . To evaluate the inactivation of E. coli, the bacterial growth curve of the ATCC 25922 strain was studied in Nutrient culture medium, using the UV-vis technique. Spectral scanning was performed from 200 to 800nm, obtaining the maximum absorption at 300nm and an exponential growth phase of 4 to 5 hours at 37°C and pH 7.0.

Progress and prospects on tritium safety for fusion energy

<p indent=0mm>Tritium safety is a key safety issue for a fusion reactor, and it is one of the most important problems that should be solved before the construction of a fusion reactor. Progress of tritium safety research including tritium distribution in fusion reactors, tritium confinement, tritium disposal, tritium-induced environmental problems, and human radiation effects, has been discussed in this article. Considering the roadmap of fusion energy development via magnetic confinement, we also propose the roadmap for tritium safety. Key issues related to science, technology, and also engineering are also suggested.

On similarity scaling of tokamak fusion plasmas with different aspect ratio

Previously, tokamak research has been focused mainly on large aspect ratio devices where the vessel/plasma major radius is about a factor three larger than the plasma radius. This research culminated in the design and construction of the international thermonuclear experimental reactor, ITER. Spherical tokamaks (ST), with aspect ratio below two, represent an attractive alternative to large aspect ratio tokamaks as, in our opinion, provide a faster, more economical and compact solution on the path to a fusion reactor. STs are the focus of research at Tokamak Energy Ltd with its present device ST40 in operation and the first ST reactor being designed, taking advantage of the high temperature superconductor (HTS) technology. HTS allow to design a ST with magnetic field/comparable or exceeding that of present-day large aspect ratio tokamaks. However, plasma studies carried out so far on compact, low aspect ratio tokamaks have been limited to small, low magnetic field, low plasma-current devices and therefore the data available for extrapolating to large scale ST plasmas is limited. This paper addresses the problem of scaling the results of large aspect ratio tokamak and existing ST plasmas to a high field ST reactor using plasma-similarity arguments in order to mitigate its design and operational risks. The role of the plasma aspect ratio in scaling burning plasmas as well as conventional experiments in deuterium is highlighted. We find that the scaling for fusion-reactor plasmas exhibit a stronger dependence on the magnetic field and aspect ratio than the one of conventional non-burning plasmas. The parameters of a ST having the same fusion gain Q fus of ITER under different confinement assumptions and for different aspect ratios are presented and discussed.

Simultaneous carbon and nitrogen removal in a structured bed reactor subjected to intermittent aeration (SBRIA): effect of support material diameter and bed porosity

AbstractBACKGROUNDA structured bed reactor subjected to intermittent aeration (SBRIA) is a new reactor configuration that simultaneously promotes the removal of COD and nitrogen in a single reactor. Although studies have shown positive results with this reactor model, some reactor construction and operation parameters remain empirical. This study aimed to optimise the support material diameter and bed porosity for simultaneous COD and total nitrogen (TN) removal in an SBRIA.RESULTSSupport material diameter and bed porosity did not affect COD removal and nitrification efficiencies, which achieved average values of 80% and 90%, respectively. However, the denitrification and TN removal efficiencies were significantly affected. The highest denitrification and TN removal were achieved by adopting a support material diameter of 3 cm and 60% of bed porosity.CONCLUSIONThe response surface methodology demonstrated that the increase in the support material diameter had a positive effect on denitrification due to the existence of an anoxic zone inside the PU foam. Conversely, when the system was operated at low support material diameters, the increase in the bed porosity increased the denitrification process, improving the overall TN removal. © 2021 Society of Chemical Industry (SCI).

Capillary-Bound Dense Micelle Brush Supports for Continuous Flow Catalysis.

Flow reactors are appealing alternatives to conventional batch reactors for heterogeneous catalysis. However, it remains a key challenge to firmly immobilize the catalysts in a facile and flexible manner and to simultaneously maintain a high catalytic efficiency and throughput. Herein, we introduce a dense cylindrical micelle brush support in glass capillary flow reactors through a living crystallization-driven self-assembly process initiated by pre-immobilized short micelle seeds. The active hairy corona of these micellar brushes allows the flexible decoration of a diverse array of nanocatalysts, either through a direct capture process or an in situ growth method. The resulting flow reactors reveal excellent catalytic efficiency for a broad range of frequently utilized transformations, including organic reductions, Suzuki couplings, photolytic degradations, and multistep cascade reactions, and the system was both recyclable and durable. Significantly, this approach is readily applicable to long capillaries, which enables the construction of flow reactors with remarkably higher throughput.

Capillary‐Bound Dense Micelle Brush Supports for Continuous Flow Catalysis

AbstractFlow reactors are appealing alternatives to conventional batch reactors for heterogeneous catalysis. However, it remains a key challenge to firmly immobilize the catalysts in a facile and flexible manner and to simultaneously maintain a high catalytic efficiency and throughput. Herein, we introduce a dense cylindrical micelle brush support in glass capillary flow reactors through a living crystallization‐driven self‐assembly process initiated by pre‐immobilized short micelle seeds. The active hairy corona of these micellar brushes allows the flexible decoration of a diverse array of nanocatalysts, either through a direct capture process or an in situ growth method. The resulting flow reactors reveal excellent catalytic efficiency for a broad range of frequently utilized transformations, including organic reductions, Suzuki couplings, photolytic degradations, and multistep cascade reactions, and the system was both recyclable and durable. Significantly, this approach is readily applicable to long capillaries, which enables the construction of flow reactors with remarkably higher throughput.

Novel design of reactor to grow CuSbS2 films by chalcogenisation of metal precursors sequentially evaporated

This article presents details of the design, construction and operation of a low cost reactor for growth of thin films of Chalcogenide Materials used for Photovoltaic applications. This reactor allows growing any type of chalcogenide compound by chalcogenisation of their metal precursors. However its performance was tested by depositing CuSbS2 films by chalcogenisation of metal precursors sequentially deposited by evaporation. The sulfurization process includes soft annealing of the Sb/Cu stacked precursor in a controlled atmosphere mixture of argon and hydrogen gas (95% Ar and 5% H2) followed by heating in the presence of elemental sulfur, using a tubular furnace heated with infrared lamps. Chalcogenisation process is carried out by controlling the heating rate of the furnace with the help of algorithms developed using LabVIEW programming environment. Through a study of deposition parameters that included the variables, furnace heating rate, final annealing target temperature and annealing time, conditions were found to grow single-phase CuSbS2 films with good structural, optical and morphological properties. This indicates that the CuSbS2 films prepared by means the chalcogenisation routine developed in this work, could be used later as an absorbent layer in solar cells.

Drilling Force Characterization during Inconel 718 Drilling: A Comparative Study between Numerical and Analytical Approaches.

In drilling operations, cutting forces are one of the major machinability indicators that contribute significantly towards the deviations in workpiece form and surface tolerances. The ability to predict and model forces in such operations is also essential as the cutting forces play a key role in the induced vibrations and wear on the cutting tool. More specifically, Inconel 718—a nickel-based super alloy that is primarily used in the construction of jet engine turbines, nuclear reactors, submarines and steam power plants—is the workpiece material used in the work presented here. In this study, both mechanistic and finite element models were developed. The finite element model uses the power law that has the ability to incorporate strain hardening, strain rate sensitivity as well as thermal softening phenomena in the workpiece materials. The model was validated by comparing it against an analytical mechanistic model that considers the three drilling stages associated with the drilling operation on a workpiece containing a pilot hole. Both analytical and FE models were compared and the results were found to be in good agreement at different cutting speeds and feed rates. Comparing the average forces of stage II and stage III of the two approaches revealed a discrepancy of 11% and 7% at most. This study can be utilized in various virtual drilling scenarios to investigate the influence of different process and geometric parameters.