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Journal articles on the topic 'Reactor block'

Author: Grafiati

Published: 25 May 2024

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1

Kalyuzhnyi, Sergey, and Vyacheslav Fedorovich. "Integrated mathematical model of UASB reactor for competition between sulphate reduction and methanogenesis." Water Science and Technology 36, no. 6-7 (September 1, 1997): 201–8. http://dx.doi.org/10.2166/wst.1997.0592.

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The existing mathematical models of anaerobic treatment processes were mainly developed for ideally mixed reactors with no concentration gradients on substrates, intermediates, products and bacteria inside the reactor. But for conventional UASB reactors with low upward velocity, the distribution of these components along the reactor height is very far from uniform. This paper presents an integrated mathematical model of the functioning of UASB reactor taking into account this non-uniformity as well as multiple-reaction stoichiometry and kinetics. In general, our integrated model includes the following blocks: a) kinetic block, including the growth and metabolism of acidogenic, acetogenic, methanogenic and sulphate-reducing bacteria; b) physico-chemical block, for the calculation of pH in each compartment of the liquid phase; c) hydrodynamic block, describing liquid flow as well as the transport and distribution of the components along the reactor height; d) transfer block, describing a mass transfer of gaseous components from the liquid to gas phase. This model was calibrated to some experimental studies of the functioning of UASB reactors made by in 1994. Hypothetical computer simulations are presented to illustrate the influence of different factors (recycle number, hydraulic retention time, quality of seed sludge, SO42−:COD ratio etc.) on the operation performance of UASB reactor.

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2

Nikolaev, A. "FRIGATE CODE TO THE COMPLEX SCENARIZED CORE AND SHIELDING CALCULATIONS IN GROUPWISED APPROXIMATION: BACKGROUND OF CREATION, ORGANIZATION STRUCTURE, FUNCTIONALITY." PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY. SERIES: NUCLEAR AND REACTOR CONSTANTS 2020, no. 1 (March 26, 2020): 37–49. http://dx.doi.org/10.55176/2414-1038-2020-1-37-49.

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The short information about destination and abilities of program FRIGATE, structure description and program characteristics are presented. The FRIGATE program implements the methodology developed by the authors of a free programmable organization of complex interconnected multicomponent calculations to justify the design characteristics of reactors and protect reactor installations in a group approximation. The FRIGATE program within the framework of a single executable file allows the user to organize arbitrary chains of standard calculations to solve the main tasks of the design support of reactor installation design. The structure of the FRIGATE program is organized according to the principle of a set of interacting process units. Each program block performs a separate logically closed task. The program includes the following blocks: a geometric block, an SN block (based on the PMSNSYS-II program), a block group block preparation block, point kinetics parameter calculation block, a perturbation theory calculator of reactivity effects, a unit for working with ionizing radiation field functionals, isotope kinetics calculation unit, as well as other computational and / or service subroutine blocks. The program has no restrictions on the number of nuclides, the number of physical zones, cells, the number of nuclides in the zone, and the like. Parallelization of lengthy calculations in the current version of the program is organized using the OpenMP 3.0 standard. A set of software documents has been released for the program.

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3

TERAI, Yuzo. "Block Metal-Fuel Fast Reactor." Proceedings of the National Symposium on Power and Energy Systems 2019.24 (2019): B113. http://dx.doi.org/10.1299/jsmepes.2019.24.b113.

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4

Branchu, Joël, and Charles Gigarel. "Superphénix 1 Reactor Block Fabrication." Nuclear Technology 68, no. 2 (February 1985): 135–45. http://dx.doi.org/10.13182/nt85-a33549.

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5

Morozenko, Andrey, and Alexey Shashkov. "Labor costs management in the large-block construction of NPP." E3S Web of Conferences 263 (2021): 02040. http://dx.doi.org/10.1051/e3sconf/202126302040.

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The article continues the research of the features of the use of prefabricated cast-in-place structures in the construction of nuclear power plants (NPP), the organizational and economic feasibility of the use of prefabricated cast-in-place structures in the implementation of new projects for the construction of nuclear power plants. The estimation of labor costs and resource costs of installation of large-block structures for the reactor building of the NPP was made. The dependence of labor costs for the installation of reinforced blocks, depending on the share of using reinforced blocks during the construction of the reactor building of a nuclear power plant, was obtained. The dependence of the overall labor costs for the industrial production and installation of reinforced blocks, depending on the share of using reinforced blocks during the construction of the reactor building of a nuclear power plant, was obtained. Graphical representations of dependencies are illustrated. The main daily resource consumption for the installation of reinforced blocks during large-block construction has been analytically calculated. The data on the required shares of labor costs at industrial enterprises and at the construction site in percentage terms were obtained. The conclusion is made about the rational use of large-block construction in the implementation of NPP construction projects.

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6

Shamanin, Igor, Sergey Bedenko, Yuriy Chertkov, and Ildar Gubaydulin. "Gas-Cooled Thorium Reactor with Fuel Block of the Unified Design." Advances in Materials Science and Engineering 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/392721.

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Scientific researches of new technological platform realization carried out in Russia are based on ideas of nuclear fuel breeding in closed fuel cycle and physical principles of fast neutron reactors. Innovative projects of low-power reactor systems correspond to the new technological platform. High-temperature gas-cooled thorium reactors with good transportability properties, small installation time, and operation without overloading for a long time are considered perspective. Such small modular reactor systems at good commercial, competitive level are capable of creating the basis of the regional power industry of the Russian Federation. The analysis of information about application of thorium as fuel in reactor systems and its perspective use is presented in the work. The results of the first stage of neutron-physical researches of a 3D model of the high-temperature gas-cooled thorium reactor based on the fuel block of the unified design are given. The calculation 3D model for the program code of MCU-5 series was developed. According to the comparison results of neutron-physical characteristics, several optimum reactor core compositions were chosen. The results of calculations of the reactivity margins, neutron flux distribution, and power density in the reactor core for the chosen core compositions are presented in the work.

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7

Trinh, Dinh Hai, Van Tai Vo, Van Diep Le, and Nhi Dien Nguyen. "Design and Construction of a Preamplifier for Research Reactor Control System Using Russia’s Neutron Detectors." Nuclear Science and Technology 6, no. 3 (September 30, 2016): 8–15. http://dx.doi.org/10.53747/jnst.v6i3.159.

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This paper presents the design and construction of a preamplifier device for Research Reactor Control System, using Russia’s Neutron Detectors of ionization and fission chambers. In this work, the preamplifier device which consists of a wide range Current to Frequency Converter block used with a compensation ionization chamber type KNK-3 to measure the thermal neutron flux in the range of 1x106 ¸ 1x1011 n/cm2.s, a Pulse Preamplifier block used with a fission chamber type KNK-15 to measure the thermal neutron flux in the range of 1x100 ¸ 1x106 n/cm2.s, and a Power Supply block, was designed and tested in different conditions in the laboratory and at Dalat Nuclear Research Reactor (DNRR). Obtained results show that, the above blocks have almost design specifications as equivalent or better in comparison with the same function blocks of the DNRR’s Control System which were designed by the former Soviet Union. They also meet the utilization requirements as well as the experimental and training purposes.

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8

Rizki, M., Oktavian, Volkan Seker, Brendan Kochunas, and Yunlin Xu. "Accurate Nodal Diffusion Modelling on the High Temperature Test Reactor (HTTR)." Journal of Physics: Conference Series 2048, no. 1 (October 1, 2021): 012023. http://dx.doi.org/10.1088/1742-6596/2048/1/012023.

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Abstract The High Temperature Test Reactor is a 30-MWth helium-cooled, graphite-moderated, prismatic-type gas reactor developed by the Japan Atomic Energy Agency (JAEA). The hexagonal shape of fuel blocks in the HTTR core combined with complex inner structures containing TRISO particles results in the double-heterogeneity effect that increases the simulation challenge of the reactor. This research has a goal to accurately model the HTTR fuel blocks employing the standard two-step procedure of a reactor analysis: employ a lattice physics calculation to generate homogeneous cross sections and use them in a nodal diffusion calculation. The implementation of the diffusion approximation results in a faster calculation with acceptable accuracy compared to the high-resolution lattice calculation. An advanced method called Triangular Polynomial Expansion Nodal (TriPEN) method was used in this work for the nodal diffusion calculation to accurately model the flux discontinuity effect between blocks by generating discontinuity factors in each surface and corner point. To do this, the heterogeneous solutions obtained from the lattice physics calculation, which is done by Serpent Monte Carlo in this case, are utilized by TriPEN to generate the discontinuity factors. Due to its capability to simulate any reactor geometry with a high-resolution, the results generated from Serpent calculation were also used as the reference cases for this work. In this work, the TriPEN method is implemented in the PARCS core neutronic module inside AGREE, a U.S. N.R.C. Multiphysics code system for the High Temperature Reactor (HTR). Test cases conducted for this method involved the original design of the HTTR. The 4-hex model built consisted of the central control-rod block of HTTR together with 6 of the half-fuel-blocks surround it. The differences in material composition in each assembly block in HTTR resulted in flux discontinuity effects on the assembly block interfaces. To correct this discrepancy, discontinuity factors were applied in order to make the homogenous solutions from the nodal calculation agree with the heterogeneous solutions from the lattice physics calculation. Applying this procedure to the HTTR nodal models, TriPEN is able to produce exact results in the eigenvalue compared to Serpent calculation, the rod worth calculated perfectly matched the reference, and the flux and power distribution only has negligible discrepancies.

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9

TERAI, Yuzo. "Piled Block Metal-Fuel Fast Breeder Reactor." Proceedings of the National Symposium on Power and Energy Systems 2018.23 (2018): A235. http://dx.doi.org/10.1299/jsmepes.2018.23.a235.

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10

Peltan, Tomas, Eva Vilimova, Tomas Czakoj, Zdenek Matej, Filip Mravec, Frantisek Cvachovec, Jan Simon, Vlastimil Juricek, and Michal Kostal. "Specially developed LR-0 reactor graphite environment for gen IV reactor support and cross-section measurement." EPJ Web of Conferences 288 (2023): 04024. http://dx.doi.org/10.1051/epjconf/202328804024.

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This paper is focused on the development of the experimental environment connected to reactor graphite. Regarding its very good neutronic and mechanical properties, graphite will be very important in some new reactor designs, such as high-temperature or molten salt SMR reactors. These new reactor concepts require a new experimental environment as support for further research. In the laboratories of the Research Centre Řež and at the LR-0 reactor, the new experimentally validated graphite environment was created. This large graphite insertion is the largest graphite mono-block, which is possible to assemble at the LR-0 reactor. Sets of experiments for measuring reaction rates of different activation detectors for neutron field mapping were performed. This approach was used for thermal and epithermal region descriptions. For the fast neutron spectrum evaluation, the stilbene scintillation detector was used. All parameters, such as criticality height of moderator level, neutron spectrum, and other parameters for all experiments, were performed using Monte Carlo neutronic codes Serpent and MCNP. The obtained results were finally compared to the measurement of neutron leakage spectra from the graphite cube and graphite cylinder. These specially developed graphite-shaped neutron fields, reactor insertions, and external cube and cylinder with Cf neutron source can be used in the future for validation of not only materials used in SMR reactors but for arbitrary cross-section verification.

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11

Wessels, J. "Inservice inspection of the reactor block of sodium-cooled fast breeder reactors." Nuclear Engineering and Design 130, no. 1 (September 1991): 33–42. http://dx.doi.org/10.1016/0029-5493(91)90190-s.

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12

Shakiryanov, E. D. "Computer simulation of block polymerization of 1,6-Hexanediol Diacrylate." Journal of Physics: Conference Series 2131, no. 2 (December 1, 2021): 022006. http://dx.doi.org/10.1088/1742-6596/2131/2/022006.

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Abstract In this paper, a computer model of the block three-dimensional free-radical polymerization of 1,6-Hexanediol Diacrylate (HDDA) is proposed. The model of the reaction system is based on an ideal mixing reactor. The reaction process is modeled by the Monte Carlo method. Accounting for the diffusion inhibition of the reaction is described using the free volume model. An adequate description of the experimental data of the calculated conversion rate curve is obtained. The nature of the change in the rate constant of the growth reaction with increasing conversion is shown.

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13

Chaudhari, Ashok R. "KINETIC STUDY COMPARISON OF IMMOBILIZED GLUCOSE ISOMERASE (GENSWEET AND SWEETZYME IT) IN STIRRED TANK REACTOR AND PACKED BED REACTOR." Journal of Medical pharmaceutical and allied sciences 10, no. 4 (October 15, 2021): 3354–58. http://dx.doi.org/10.22270/jmpas.v10i4.1196.

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Various additives have been employed to extend the brachial plexus block. Dexamethasone, when added to local anesthetic block prolongation with analgesic and anti-inflammatory effects has been seen. Group I (Control group) received Inj. Lignocaine 1.5% plus adrenaline (1:200000) max safe dose of 7mg/kg+ NS- 2ml while group II (Dexa group) received Inj. Lignocaine 1.5% plus adrenaline (1:200000) max safe dose of 7mg/kg + Inj. Dexamethasone - 2ml (8mg). Total volume in each group ranged between 25-32ml considering the patients individual body weight. Block characteristics, duration and quality of analgesia in the post-operative period were noted. Dexamethasone hastens the onset and prolonged the duration of motor and sensory blockade. The mean duration of postoperative analgesia was prolonged till 8th hour in the dexamethasone group while in the control group it was continued till 3hrs, the role of rescue analgesia commenced after 3rd hour. Dexamethasone provides better hemodynamic stability and profound analgesia without any untoward side effects in the perioperative period. In the supraclavicular method of brachial plexus block, the addition of dexamethasone to lignocaine adrenaline offers excellent anesthetic and analgesia.

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14

ONISHI, Nobuaki. "One-piece removal of JRR-3 reactor block." Journal of the Atomic Energy Society of Japan / Atomic Energy Society of Japan 29, no. 7 (1987): 593–602. http://dx.doi.org/10.3327/jaesj.29.593.

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15

Pan, Qing, Jin Zhu Tan, Qiu Yue Feng, Yun Li, and Ri Dong He. "The Study on Degradation of Stainless Steel Clad Plate Used for a Shift Reactor in Coal Chemical Plant." Applied Mechanics and Materials 853 (September 2016): 311–16. http://dx.doi.org/10.4028/www.scientific.net/amm.853.311.

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Shift reactors are widely used in the petroleum and chemical industries, and especially in the coal chemical plants. The degradation of the reactor is critical to the safe operation of coal chemical plant. In this paper, a shift reactor after 8 year service was chosen. The test block taken from the reactor cylinder with the stainless steel clad plate was used and the test samples from the test block were prepared. And then, chemical composition analysis, metallographic examination, tensile and hardness tests were performed. The scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) method were used to study the degradation and degradation mechanism of the reactor. The metallographic analysis results show that there were a large number of carbides segregated in the grain boundary and the intergranular cracks were observed for the samples in the weld zone of the stainless steel clad plate. The SEM and EDS results indicate that the corrosion medium (i.e. polythionic acid) was found in the fracture surface of the samples from the weld zone of the stainless steel clad plate. The XRD test results show that the tensile residual stress occurred for the welding of the stainless steel clad plates. It is found that the degradation mechanism of the shift reactor was due to the polythionic acid stress corrosion cracking.

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16

Shamanin, Igor V., Andrey V. Arzhannikov, Vadim V. Prikhodko, Vladimir M. Shmakov, Dmitry G. Modestov, Igor O. Lutsik, Sergey D. Polozkov, and Sergey V. Bedenko. "Hybrid “Fusion-Fission” Reactor Facility on Thorium Fuel with a Source of Additional Thermonuclear Neutrons." Siberian Journal of Physics 16, no. 1 (2021): 21–43. http://dx.doi.org/10.25205/2541-9447-2021-16-1-21-43.

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The results of full-scale numerical experiments of a hybrid thorium-containing fuel cell facility operating in a close-to-critical state due to a controlled source of fusion neutrons are discussed in this work. The facility under study was a complex consisting of two blocks. The first block was based on the concept of a high-temperature gas-cooled thorium reactor core. The second block was an axially symmetrical extended plasma generator of additional neutrons that was placed in the near-axial zone of the facility blanket. The calculated models of the blanket and the plasma generator of D-T neutrons created within the work allowed for research of the neutronic parameters of the facility in stationary and pulse-periodic operation modes. This research will make it possible to construct a safe facility and investigate the properties of thorium fuel, which can be continuously used in the epithermal spectrum of the considered hybrid fusion-fission reactor.

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17

Lee, Jang Won, and Young Shin Lee. "The Effects of Fluid Structure Interactions on the Dynamic Characteristics of the Reactor Internals Structure of SMART." Applied Mechanics and Materials 752-753 (April 2015): 851–58. http://dx.doi.org/10.4028/www.scientific.net/amm.752-753.851.

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The Korea Atomic Energy Research Institutes has been developing the SMART (System integrated Modular Advanced ReacTor), an environment-friendly nuclear reactor, for the generation of electricity, and to perform desalination. SMART reactors can be exposed to various external and internal loads caused by seismic and coolant flows. Reactor structures need to be maintained for the reactor’s safety and integrity against these loads during the operational time of the SMART. This paper presents two FE-models, 3-D solid models of the reactor internals in the air and in the coolant, and then compares the results of the dynamic characteristic for the two FE-models using a commercial Finite Element tool, ANSYS V12. A solver was selected by the Block Lanczos method. These FE-models are looking forward to being executed in various researches concerning the SMART in further studies.

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18

Velasco, Ion, Oihane Sanz, Iñigo Pérez-Miqueo, Iñigo Legorburu, and Mario Montes. "Design and Test of a Miniature Hydrogen Production Integrated Reactor." Reactions 2, no. 2 (April 16, 2021): 78–93. http://dx.doi.org/10.3390/reactions2020007.

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A detailed study of the experimental issues involved in the design and operation of a methanol steam microreformer is presented in this paper. Micromachining technology was utilized to fabricate a metallic microchannel block coupling the exothermic and endothermic process. The microchannel block was coated with a Pd/ZnO catalyst in the reforming channels and with Pd/Al2O3 in the combustion channels by washcoating. An experimental system had been designed and fine-tuned allowing estimation of the heat losses of the system and to compensate for them by means of electric heating cartridges. In this way, the heat necessary for the reforming reaction is provided by methanol combustion, thanks to the temperature and flow cascade controller we developed. Thus, the coupling of both reactions in a block of microchannels without the interference caused by significant heat loss due to the small size of the laboratory microreactor could be studied. Runs of this microreformer device were carried out, varying the deposited catalyst amount, methanol steam reforming temperature and space velocity. When the reforming reaction was compensated by the combustion reaction and the heat losses by the electric heating, an almost isothermal behavior of the microchannel reactor was observed. In the less favorable case, with a 460 mg catalyst load, ΔTMSR was about 8 K and ΔTCOMB was about 16 K. This confirmed good coupling of the methanol steam reforming and the methanol combustion.

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19

Hora, Heinrich, Shalom Eliezer, Jiaxiang Wang, Georg Korn, Noaz Nissim, Yan-Xia Xu, Paraskevas Lalousis, Gotz J. Kirchhoff, and George H. Miley. "Laser Boron Fusion Reactor With Picosecond Petawatt Block Ignition." IEEE Transactions on Plasma Science 46, no. 5 (May 2018): 1191–97. http://dx.doi.org/10.1109/tps.2017.2787670.

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20

Chia, Ee-Sunn J., Jay B. Benziger, and Ioannis G. Kevrekidis. "STR-PEM fuel cell as a reactor building block." AIChE Journal 52, no. 11 (2006): 3902–10. http://dx.doi.org/10.1002/aic.10987.

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21

Camera-Roda, Giovanni, Francesco Parrino, Vittorio Loddo, and Leonardo Palmisano. "A Dialysis Photocatalytic Reactor for the Green Production of Vanillin." Catalysts 10, no. 3 (March 14, 2020): 326. http://dx.doi.org/10.3390/catal10030326.

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In the present work, dialysis was used to recover vanillin while being produced by partial photocatalytic oxidation of ferulic acid in an aqueous solution at ambient temperature. The relatively high value of the permeate flux through a dense polyether-block amide membrane allowed continuously extracting vanillin from the reacting solution, thus avoiding its successive oxidation. The rate of vanillin formation was improved, compared to other reactor configurations, because intermediate compounds permeated from the reacting solution and did not hinder the reaction, while ferulic acid permeated in the opposite direction to partially replenish the reactor with the substrate. The photocatalytic membrane reactor obtained by the effective coupling of dialysis with the photocatalytic reaction improved the production yield. For instance, with the utilized experimental set up, the total amount of vanillin produced after 5 h in the membrane reactor was more than one-third higher than in the photocatalytic reactor without dialysis. The results obtained with a mathematical model agree with the experimentally observed behavior. The model allowed estimating vanillin diffusivity in the membrane and showed that concentration polarization might limit the process.

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22

Seungsu, Yuk, Tak Nam-il, and Chang Jo Keun. "DEVELOPMENT OF PIN-LEVEL NEUTRONICS/THERMAL-FLUID ANALYSIS COUPLED CODE SYSTEM FOR A BLOCK-TYPE HTGR CORE." EPJ Web of Conferences 247 (2021): 02041. http://dx.doi.org/10.1051/epjconf/202124702041.

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Recently, the coupling between computer codes that simulate different physical phenomena has attracted for more accurate analysis. In the case of high-temperature gas-cooled reactor (HTGR), the coupling between neutronics and thermal-fluid analysis is necessary because of large change of temperature in the reactor core. Korea Atomic Energy Research Institute (KAERI) has developed the coupled code system between a reactor physics analysis code CAPP and a thermal-fluid system safety analysis code GAMMA+ for a block-type HTGR. The CAPP/GAMMA+ coupled code system provides more accurate block-wise distribution data than CAPP or GAMMA+ stand-alone analysis. However, the block-wise distribution data has the limitation in order to predict safety parameters such as the maximum temperature of the nuclear fuel. It is necessary to calculate refined distribution, for example, pin-level (fuel compact level) distribution. In this study, we tried to solve this problem by coupling CAPP and a high-fidelity thermal-fluid analysis code CORONA. CORONA can perform a high-fidelity thermal-fluid analysis of Computational Fluid Dynamics (CFD) level by dividing a block-type HTGR core into small lattices. On the other hand, CAPP can provide a pin power distribution. It is expected that the refined, more accurate distribution data for a block-type HTGR can be obtained by coupling these two codes. This paper presents the development of coupled code system between CAPP and CORONA, and then it is tested on a simple HTGR column problem with encouraging results.

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23

Pavliuk, A. O., S. G. Kotlyarevsky, E. V. Bespala, A. E. Rif, and R. I. Kan. "Graphite Removal from Uranium-Graphite Reactors: International Experience and Approaches." Radioactive Waste 23, no. 2 (2023): 41–55. http://dx.doi.org/10.25283/2587-9707-2023-2-41-55.

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The article explores the best practices for graphite removal from the stacks of uranium-graphite reactors (GLEEP, WAGR, BGRR, HTGR) and reactors with graphite reflectors (DIORIT, DR 1) operated abroad. Based on several case studies, it considers different approaches, in particular: graphite crushing; underwater stack demolition by reactor shaft flooding and upper biological shield dismantling; dismantlement of the upper biological shield and layer-bylayer graphite block removal. It discusses current trends, existing challenges and long-term plans for the practical implementation of advanced approaches under international projects.

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24

Baier, Silvio, Emil Fridman, Soeren Kliem, and Ulrich Rohde. "Extension and application of the reactor dynamics code DYN3D for Block-type High Temperature Reactors." Nuclear Engineering and Design 271 (May 2014): 431–36. http://dx.doi.org/10.1016/j.nucengdes.2013.12.013.

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25

Hornung, Christian H., Xuan Nguyen, Stella Kyi, John Chiefari, and Simon Saubern. "Synthesis of RAFT Block Copolymers in a Multi-Stage Continuous Flow Process Inside a Tubular Reactor." Australian Journal of Chemistry 66, no. 2 (2013): 192. http://dx.doi.org/10.1071/ch12479.

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This work describes a multi-stage continuous flow polymerisation process for the synthesis of block copolymers using the RAFT polymerization method. The process retains all the benefits and versatility of the RAFT method and has been adapted for a series of monomer combinations, including acrylates, acrylamides, and vinyl monomers. It resulted in polymers with molecular weights between 13500 and 34100 g mol–1, and dispersities typically between 1.21 and 1.58. Different architectures were prepared (including combinations of hydrophilic and hydrophobic blocks) which are soluble in a range of different solvents including aqueous and organic media.

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26

Shirali Zadeh, Niloofar, Morgan J. Cooze, Nathaniel R. Barr, and Robin A. Hutchinson. "An efficient process for the Cu(0)-mediated synthesis and subsequent chain extension of poly(methyl acrylate) macroinitiator." Reaction Chemistry & Engineering 4, no. 11 (2019): 2000–2010. http://dx.doi.org/10.1039/c9re00224c.

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27

Seubert, A. "A 3-D FINITE ELEMENT FEW-GROUP DIFFUSION CODE AND ITS APPLICATION TO GENERATION IV REACTOR CONCEPTS." EPJ Web of Conferences 247 (2021): 02010. http://dx.doi.org/10.1051/epjconf/202124702010.

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In this paper, a recently developed 3-d few-group finite element-based diffusion code is de-scribed. Its geometrical flexibility allows future modeling of complex and irregular geometries of (very) small and medium size reactor concepts –(v)SMRs –being in the spotlight for energy provision in remote residential and industrial regions or for space applications, and also liquid metal cooled Generation IV reactors where thermally induced core deformation results in localized assembly lattice distortions which cannot be treated by traditional 3-d neutron kinetics codes devoted to the regular lattices of LWR and Generation IV systems. The description of the implemented FEM solution method is followed by first applications to a prismatic (or block type) high-temperature reactor MHTGR-350MW within an OECD/NEA benchmark activity and to the sodium cooled fast reactor concept ASTRID within the past EU project ESNII+. Finally, an outlook to planned further code development activities is given.

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28

Carreño, Amanda, Luca Bergamaschi, Angeles Martinez, Antoni Vidal-Ferrándiz, Damian Ginestar, and Gumersindo Verdú. "Block Preconditioning Matrices for the Newton Method to Compute the Dominant λ-Modes Associated with the Neutron Diffusion Equation." Mathematical and Computational Applications 24, no. 1 (January 15, 2019): 9. http://dx.doi.org/10.3390/mca24010009.

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In nuclear engineering, the λ -modes associated with the neutron diffusion equation are applied to study the criticality of reactors and to develop modal methods for the transient analysis. The differential eigenvalue problem that needs to be solved is discretized using a finite element method, obtaining a generalized algebraic eigenvalue problem whose associated matrices are large and sparse. Then, efficient methods are needed to solve this problem. In this work, we used a block generalized Newton method implemented with a matrix-free technique that does not store all matrices explicitly. This technique reduces mainly the computational memory and, in some cases, when the assembly of the matrices is an expensive task, the computational time. The main problem is that the block Newton method requires solving linear systems, which need to be preconditioned. The construction of preconditioners such as ILU or ICC based on a fully-assembled matrix is not efficient in terms of the memory with the matrix-free implementation. As an alternative, several block preconditioners are studied that only save a few block matrices in comparison with the full problem. To test the performance of these methodologies, different reactor problems are studied.

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29

Petik, T. V., and M. V. Lobachev. "SEARCHING FOR THE BOUNDARIES OF REPRESENTATION OF INTERNAL DISTURBANCES OF THE VVER-1000 CORE IN THE FORM OF PHYSICAL-MATHEMATICAL AND APPROXIMATION MODELS." ELECTRICAL AND COMPUTER SYSTEMS, no. 39(115) (2024): 55–64. http://dx.doi.org/10.15276/eltecs.39.115.2024.6.

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Abstract. The scientific article is devoted to the study of the use of physical-mathematical and approximation models for simulation of the power change control system at nuclear power plants with VVER-1000. Methods for controlling energy release have been studied, problem of optimal reactor control has been solved, and block diagram of the automatic control system has been developed. The limits of using models to ensure the stability of control processes are clarified. Keywords: Automatic control system, control programs, reactor power, boundaries search, pressurized water reactor.

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Shamanin, Igor’ Vladimirovich, Sergej Vladimirovich Bedenko, Yurij Borisovich Chertkov, and Il’dar Mukharamovich Gubaydulin. "Gas-cooled thorium reactor with fuel block of the unified design." Izvestiya Wysshikh Uchebnykh Zawedeniy, Yadernaya Energetika 2015, no. 3 (October 2015): 124–34. http://dx.doi.org/10.26583/npe.2015.3.13.

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Nie, Yisu, Lorenz T. Biegler, Carlos M. Villa, and John M. Wassick. "Reactor Modeling and Recipe Optimization of Ring-Opening Polymerization: Block Copolymers." Industrial & Engineering Chemistry Research 53, no. 18 (November 14, 2013): 7434–46. http://dx.doi.org/10.1021/ie402770k.

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Shamanin, I. V., S. V. Bedenko, Yu B. Chertkov, and I. M. Gubaydulin. "Gas-cooled thorium reactor with fuel block of the unified design." Nuclear Energy and Technology 1, no. 3 (November 2015): 184–90. http://dx.doi.org/10.1016/j.nucet.2016.01.012.

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Solyar, B. Z., L. Sh Glazov, E. A. Klimtseva, I. M. Liberzon, E. P. Dvurekov, O. B. Alseitov, and A. A. Anikin. "Revamping the reactor block of the KT-1 unit cat cracker." Chemistry and Technology of Fuels and Oils 43, no. 3 (May 2007): 201–5. http://dx.doi.org/10.1007/s10553-007-0035-5.

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Yang, Yu‐Cheng, Xiao‐Hui Yu, Qing‐Jie Yu, Shi‐Ying Yang, and Moses Arowo. "Micromixing efficiency in a multiphase reactor with a foam block stirrer." Canadian Journal of Chemical Engineering 97, S1 (January 25, 2019): 1560–67. http://dx.doi.org/10.1002/cjce.23407.

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35

Tkachenko, D. N., N. V. Lopukhov, and K. G. Pluzyan. "Dynamic deformation calculations of block NB-1p of reactor BR-K1M." Вопросы атомной науки и техники. Серия: Физика ядерных реакторов, no. 4 (2022): 17–34. http://dx.doi.org/10.53403/02054671_2022_3_17.

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Aguado, D., M. Zarzo, A. Seco, and A. Ferrer. "Process understanding of a wastewater batch reactor with block-wise PLS." Environmetrics 18, no. 5 (2007): 551–60. http://dx.doi.org/10.1002/env.828.

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Carreño, A., A. Vidal-Ferrándiz, D. Ginestar, and G. Verdú. "Multilevel method to compute the lambda modes of the neutron diffusion equation." Applied Mathematics and Nonlinear Sciences 2, no. 1 (June 24, 2017): 225–36. http://dx.doi.org/10.21042/amns.2017.1.00019.

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AbstractDetermination of the reactor kinetic characteristics is very important for the design and development of a new reactor system. In this sense, the computation of lambda modes associated to a nuclear power reactor has interest since these modes can be used to analyze the reactor criticality and to develop modal methods to analyze transient situations in the reactor. In this paper, the lambda problem has been discretized using a high order finite element method to obtain a generalized algebraic eigenvalue problem. A multilevel method is proposed to solve this generalized eigenvalue problem combining a hierarchy of meshes with a Modified Block Newton method. The Krylov-Schur method is used to compare the efficiency of the multilevel method solving several benchmark problems.

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Drobyshevsky, Yuri V., Ilya M. Anfimov, Valery A. Varlachev, Svetlana P. Kobeleva, Sergey A. Nekrasov, and Sergey N. Stolbov. "Experimental confirmation of a new method for selective neutron separation." Nuclear Energy and Technology 6, no. 4 (November 18, 2020): 235–41. http://dx.doi.org/10.3897/nucet.6.60294.

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The article presents an experimental confirmation of the operability of neutron concentrators in devices that form and use directed high-intensity thermal neutron beams with elliptical channels made as blocks of profiled graphite and aluminum plates. The effect of neutron reflection from the surface of materials is the basis of a device capable of selecting neutrons by their directions in space. The study experimentally confirmed the efficiency of a moderating-focusing structure (MFS) based on a pack of elliptical neutron mirrors, which makes it possible to form oriented thermal neutron beams from the outgoing neutron flux. To record the effects of selective thermal neutron separation, silicon single-crystal wafers were used, due to which it was possible to obtain portraits of integral neutron fluxes in the reactor. The experiments were carried out in a horizontal experimental channel (HEC-4) at the IRT-T reactor of the National Research Tomsk Polytechnic University. The integral neutron flux was (2.3–3.02)·1017 cm–2. The neutron flux was detected by the change in the specific electrical resistivity of the single-crystal silicon wafers. The effect of concentration of thermal neutrons was recorded both on the block of graphite neutron mirrors and on the block of aluminum thin-walled elliptical mirrors. In the near future, on this basis, it will be possible to solve such problems as extending the reactor life by reducing the hydrogen uptake in the inner walls. In addition, the experiments have proved the possibility of creating anisotropic structures that lie outside the formalism of Liouville’s theorem, in which the surfaces of thermal neutron sinks are formed with subsequent concentration in the areas separated by aluminum or graphite plates.

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Li, Zhen, Weijie Chen, Lifen Zhang, Zhenping Cheng, and Xiulin Zhu. "Fast RAFT aqueous polymerization in a continuous tubular reactor: consecutive synthesis of a double hydrophilic block copolymer." Polymer Chemistry 6, no. 28 (2015): 5030–35. http://dx.doi.org/10.1039/c5py00847f.

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Utilizing a continuous tubular reactor, well-defined double hydrophilic block copolymer PSPMA-b-PPEGMA was successfully synthesized with an extremely high monomer conversion in water without handling the intermediate macro-RAFT agent.

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Zhao, Bo Ya, Song Yang, Zhe Zhang, and Ri Sheng Sun. "Control Improvement of the Reactor Protection System." Applied Mechanics and Materials 71-78 (July 2011): 4199–202. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.4199.

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In this paper an optimal maintenance policy for a Reactor Protection System (RPS) for a nuclear plant was developed. RPS consists of continuously operating sub-systems that were subject to random failures. A block system diagram for RPS had been proposed that facilitates analyzing of individual sub-systems separately. The proposed maintenance policy is the Age Replacement model, which incorporated both corrective and preventive maintenances. A Markov model was used to optimize the preventive maintenance interval of those sub-systems whose failure and repair rates were exponentially distributed. Finally, a sensitivity analysis had been performed and recommendations for maintaining the required RPS availability have been suggested.

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Zhang, Yin Hui, Jin Hui Peng, and Zi Fen He. "Stereo Reconstruction of Infrared Images Captured in Microwave Reactor." Advanced Materials Research 846-847 (November 2013): 1007–10. http://dx.doi.org/10.4028/www.scientific.net/amr.846-847.1007.

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During metallurgy and food processing it is always necessary for real-time detection of stereo temperature distribution in reaction cavity of microwave. We focus on the stereo reconstruction of temperature distribution of the microwave reaction chamber using real-time image data captured by infrared sensor during heating process. Due to the stereo depth of the scene in humans vision system is mapped through disparity, thus the key technology stereo reconsturction of temperature is to find the corresponding points in the image pair. We employ the block matching algorithm to search the correspondence by minimizing a cost function derived on a hierarchical tree structured pyramid probabilistic graph. The study result shows that in the back projection of the depth map, the walls, ceiling, and floor of the microwave reactor all appear mutually orthogonal, which illustrates that the stereo temperature field is well reconstructed.

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Selivanov, A. A., O. V. Afanaseva, A. N. Mrakin, G. K. Zhanaev, and A. Yu Kamaev. "THE OPTIMIZATION OF THE REACTOR BLOCK OPERATING PARAMETERS OF UNIT WITH A SOLID HEATING AGENT." Proceedings of the higher educational institutions. ENERGY SECTOR PROBLEMS 20, no. 7-8 (September 8, 2018): 47–54. http://dx.doi.org/10.30724/1998-9903-2018-20-7-8-47-54.

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In the article the questions of optimization of technological parameters of mutual functioning of the system of apparatuses of the reactor block of semi-coking of slate with a solid heating agent (UTT) are considered.

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Rahim, Muhammad Roslan, Annisa Palupi Trisasongko, Mohammad Nazri Mohd Jaafar, Norazila Othman, Yahaya Ramli, Muhammad Syahiran Abdul Malik, and Mazlan Said. "ULASAN: PEMBANGUNAN TEKNOLOGI PENGGASAN DAN PENGGUNAAN." Jurnal Teknologi 84, no. 1 (November 22, 2021): 193–210. http://dx.doi.org/10.11113/jurnalteknologi.v84.17709.

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Gasification technologies have the potential to produce clean and efficient energy sources. This technology is capable of producing synthesis gas from low or negative carbon -based raw materials such as coal, petroleum coke, high sulfur fuel oil, waste or waste materials and biomass. The gas produced from the process is used to replace natural gas to generate electrical power, or acts as basic raw material for producing chemicals and liquid fuels. Gasification is a process which utilizes heat, pressure, and steam to convert materials directly into gases, such as carbon monoxide and hydrogen gases. Despite differing in various aspects, gasification technologies have four common engineering factors such as atmospheric gasification reactors (oxygen or air content level), internal and external heating, reactor design and operating temperature. Raw materials, either in dry form or small granules, are fed into the reactor chamber called gasifier. Raw materials subjected to heat, pressure as well as an environment with rich or low oxygen content. Hydrocarbon gas (also known as Syngas), liquid hydrocarbon (oil) and coal (carbon black and ash) are the three main products of gasification. Syngas can be used as a fuel to produce electricity or steam, or acts as a basic block for various types of chemicals. When mixed with air, Syngas can be used in petrol or diesel engines with slight modifications to the engine.

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Annunziata, Francesca, Alessandra Guaglio, Paola Conti, Lucia Tamborini, and Raffaella Gandolfi. "Continuous-flow stereoselective reduction of prochiral ketones in a whole cell bioreactor with natural deep eutectic solvents." Green Chemistry 24, no. 2 (2022): 950–56. http://dx.doi.org/10.1039/d1gc03786b.

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Immobilized whole cells of Rhodotorula rubra MIM147 were used in a packed bed flow reactor for the enantioselective reduction of β-ketonitriles and for the obtainment of a key building block for the synthesis of the antidepressant drug duloxetine.

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Ohoka, Y., and H. Sekimoto. "Application of CANDLE burnup to block-type high temperature gas cooled reactor." Nuclear Engineering and Design 229, no. 1 (April 2004): 15–23. http://dx.doi.org/10.1016/j.nucengdes.2003.12.001.

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Solyar, B. Z., L. Sh Tlazov, I. M. Libezon, E. A. Klimtseva, E. Z. Aladysheva, and V. N. Popov. "Modernizing Cat Cracker Reactor Block Units on the G-43-107M/1." Chemistry and Technology of Fuels and Oils 41, no. 3 (May 2005): 179–83. http://dx.doi.org/10.1007/s10553-005-0043-2.

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Elshin, A. I., B. Z. Solyar, L. Sh Glazov, I. M. Liberzon, V. M. Moiseev, I. E. Sidorov, I. V. Kuks, and S. L. Kryachek. "Revamping of the Cat Cracker Reactor Block in the GK–3 Complex." Chemistry and Technology of Fuels and Oils 40, no. 4 (July 2004): 222–26. http://dx.doi.org/10.1023/b:cafo.0000041218.48666.f0.

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Altarawneh, Ibrahem S., Vincent G. Gomes, and Mourtada H. Srour. "Block Copolymers From Living Emulsion Polymerization: Reactor Operating Strategies and Blocking Efficiency." Macromolecular Reaction Engineering 6, no. 1 (November 25, 2011): 8–16. http://dx.doi.org/10.1002/mren.201100052.

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49

Li, Rui, Xu Sheng Deng, Jin Sheng Gou, and Zhao Lin Lv. "Vacuum Paddle Fast Pyrolysis Reactor Design and Internal Heat Transfer Investigation." Materials Science Forum 704-705 (December 2011): 468–74. http://dx.doi.org/10.4028/www.scientific.net/msf.704-705.468.

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Fast pyrolysis is cracking process in which macromolecule of biomass is broken into small molecular under moderate temperature and at high heating speed. Bio-oil produced by the process can be used as potential alternatives of diesel oil and other chemicals. By investigate different kinds of reactor, a new type reactor called vacuum paddle fast pryoysis reactor is developed with low manufacture cost and operating fee and more stable performance. Two stage condensing system composed of 1st quench stage and 2nd cooling heat exchanger is designed, which is proven effective in avoiding secondary cracking of biomass oil and eliminating block of equipment by tar. At same time, a model describing heat transfer in new reactor is established and solved by unsteady heat conduction equation, which give conclusion on minimum agitating speed and therefore, provide basic theoretical foundation. Keywords: fast pyrolysis, vacuum paddle reactor, condenser, heat transfer

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Pieńkowski, Ludwik, Marek Jaszczur, Michał Dudek, and Katarzyna Skolik. "CCGT and small nuclear SMR hybrids system for flexible energy generation." E3S Web of Conferences 108 (2019): 01023. http://dx.doi.org/10.1051/e3sconf/201910801023.

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Future development of the energy conversion systems will be based on second and third generation technology. Additionally, modern power plants are expected to be able to work in a very wide range of power output. At the same time, frequent and rapid changes in generated power reduce systems lifetime, their average efficiency, and in the case of nuclear energy, introduce additional issues related to nuclear safety. The hybrid energy systems can give at least a partial solution to such challenges. In the present work, a thermodynamic analysis of a hybrid system consisting of a nuclear block powered by Small Modular Reactor (SMR) and a gas-steam block Gas Turbine Combined Cycle (GTCC) was performed. The coupling was made by means of a compressor in a gas block powered by an electric motor and using steam from a nuclear block in the Gas Turbine Combined Cycle steam power plant block. Some promising and challenging results are shown and discussed.

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