Construction Of Reactor Research Articles

An action plan of Japan toward development of demo reactor

An action plan presented here is the plan toward construction of a Demo reactor in Japan. A Task-force for development strategy of Tokamak Demo Reactors was established and has considered an action plan to construct the Demo in the 2040s. The action plan will lead works in a Joint Special Design Team for Fusion Demo established for design and R&D of the Demo reactor in Japan. Although the first version of action plan was reported in March 2016, a revised version, presented here, is being drafted in order to correspond to the new schedule of the ITER project agreed in 2016, because the ITER progress is one of critical issues in the action plan.

Apocalypse adjourned: the rise and decline of cold war environmentalism in Germany

ABSTRACTNuclear energy was a defining topic of German environmentalism from the 1970s to 1990s. An analysis of the transformation of Naturschutzbund Deutschland (NABU) shows that anti-nuclear protests, which are frequently depicted as a prototypical example of ‘new’ social movement activism, were only a temporary phenomenon. From the 1970s, NABU gradually transformed from a traditional nature conservation organization into an environmental lobby organization that addressed nuclear energy, other health hazards and environmental risks. These topics were perceived through the notion of mutual assured destruction that emerged with the cold war nuclear arms race. With the end of the cold war and the government’s decision to phase-out nuclear energy, NABU began to rediscover its neglected focus on nature conservation. Nature walks and wildlife monitoring schemes replaced sit-ins, political rallies and civil disobedience against the construction of nuclear reactors. Since 2000, the goals and strategies of German environmentalism have increasingly turned back to the ‘old’ social movement activism of traditional nature conservation.

Thermal characterization of soda lime silicate glass-graphite composites for thermal energy storage

Solar technology operating at elevated temperature conditions demands accurate knowledge of the optical and thermal properties of the materials involved in the construction and operation of solar collectors, reactors, and energy storages, among many others. Thermal energy storage (TES) devices involve successive melting and crystallization processes, which result in high complexity materials where the morphology, composition, and porosity could be highly non-homogeneous. In these cases, contact techniques for determining the thermal properties are highly susceptible and do not provide reliable measurements. It is under these conditions that non-contact photothermal techniques can provide superior performance, because in this case, the heat inducing source is a laser beam and the detector is usually a photodiode or a thermographic camera which are in non-contact with samples. The materials applied as storage medium in a TES unit can be divided into four groups: metals and alloys, ceramics and glasses, polymers and elastomers, and composites that include natural materials. Soda lime silicate glass recyclable waste is a very promising material for storage medium due to its inexpensive and wide availability. In this paper, we examined soda lime silicate glass-graphite composites for use as storage medium in a TES unit. A simple one-dimensional model for thermal conductivity was developed based on equivalent thermal circuits for series-parallel composite walls, and we found that thermal conductivity values depend on the amount of graphite dispersed into the samples, the porous media, and their structure.

Magnetic confinement fusion: a brief review

Fusion energy is considered to be the ultimate energy source, which does not contribute to climate change compared with conventional fossil fuel. It is massive compared with unconventional renewable energy and demonstrates fewer safety features compared with unconventional fission energy. During the past several decades, never-ceasing efforts have been made to peacefully utilize the fusion energy in various approaches, especially inertial confinement and magnetic confinement. In this paper, the main developments of magnetic confinement fusion with emphasis on confinement systems as well as challenges of materials related to superconducting magnet and plasmafacing components are reviewed. The scientific feasibility of magnetic confinement fusion has been demonstrated in JET, TFTR, JT-60, and EAST, which instigates the construction of the International Thermonuclear Experimental Reactor (ITER). A fusion roadmap to DEMO and commercial fusion power plant has been established and steady progresses have been made to achieve the ultimate energy source.

The Simulator Development for RDE Reactor

BATAN is proposing the construction of experimental power reactor (RDE reactor) for increasing the public acceptance on NPP development plan, proofing the safety level of the most advanced reactor by performing safety demonstration on the accidents such as Chernobyl and Fukushima, and owning the generation fourth (G4) reactor technology. For owning the reactor technology, the one of research activities is RDE’s simulator development that employing standard equation. The development utilizes standard point kinetic and thermal equation. The examination of the simulator carried out comparison in which the simulation’s calculation result has good agreement with assumed parameters and ChemCAD calculation results. The transient simulation describes the characteristic of the simulator to respond the variation of power increase of 1.5%/min, 2.5%/min, and 3.5%/min.

Development of a modular microreactor for the partial hydrocarbon oxidation

ABSTRACTThe industrially important partial oxidation of hydrocarbons is frequently characterized by low conversions and yields, which are mostly related to mass and heat transfer problems. Due to the reaction conditions, such processes include also important safety risks and are still not sufficiently investigated. To study the influence of the process parameters on the product selectivity, a lab facility including a silicon-coated micro reactor of stainless steel has been developed and constructed. Due to its modular construction (e.g., replaceable capillary), it permits for the first time to perform catalyzed and noncatalyzed oxidations of hydrocarbons with oxygen as a two-phase process in a capillary reactor in a wide range of residence times (some minutes to 24 h), temperatures and pressures. Especially wide ranges of reactant ratios and concentrations of inert gas, initiator, and additive are also accessible. The challenges of the reactor construction and their solutions are discussed.

Fully Digital and White Rabbit-Synchronized Low-Level RF System for LIPAc

The International Fusion Materials Irradiation Facility (IFMIF) is an international project to study and qualify candidate materials for the construction of a future fusion reactor. One of the objectives of the IFMIF-Engineering Validation and Engineering Design Activity Project is to build a linear prototype accelerator (LIPAc) to validate the final IFMIF accelerator concept. LIPAc, which is currently under construction in Rokkasho (Japan), will generate a 9-MeV deuteron beam of 125-mA current with 100% duty cycle. CIEMAT (Spain) is in charge of providing the RF power system, including the low-level radio frequency (LLRF) system. Most of the developed LLRF systems are not completely digital, as they use analog front ends for intermediate frequency conversion before or after digitalization. However, the LIPAc LLRF system is a fully digital system: no analog frequency conversion is performed, the radio frequency (RF) signals are directly digitally synthesized and sampled by means of high-speed digital-to-analog converters and analog-to-digital converters. This is a clear advantage in terms of flexibility, reliability, reconfigurability, cost, and response time, as all the signal processing is performed in the digital domain. The other main advantages and novelties are the use of White Rabbit (WR) for timing synchronization and master oscillator distribution (distributed RF over WR). The LIPAc LLRF system is the first LLRF based on WR, and it has been designed and fabricated using the most advanced technology. This paper presents the detailed description of the LIPAc LLRF system and its advantages, performance evaluation, and verification.

Treatment and Energy Valorisation of an Agro-Industrial Effluent in Upflow Anaerobic Sludge Reactor (UASB)

The accelerated growth of the population brings with it an increase in the generation of agro-industrial effluents. The inadequate discharge of these effluents significantly affects the quality of water resources. In this way, it becomes important to invest in treatment processes for agro-industrial effluents, particularly low-cost ones. In this context, the present study includes the design and construction of an UASB reactor and optimization of the anaerobic digestion treatment of the raw effluent from sweet chestnut production in the agro-industrial company Sortegel. The efficiency of the system was evaluated through the determination / monitoring of oxygen chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended solids (TSS), biogas production rate and quality (% methane). The reactor was fed for 25 weeks and operated under mesophilic conditions (temperature 30-40 °C). Different values were tested for the hydraulic retention time (HRT) and volumetric flow rate (VF): 0.66 days (VF=1509 L.m-3.d-1); 1.33 days (VF=755 L.m-3.d-1); 2.41 d days (VF=415 L.m-3.d-1). The average COD removal efficiency reached values of 69%, 82% and 75%, respectively, and simultaneously the associated BOD5 removal efficiency was 84%, 91% and 70%. As regards TSS, removal values were 78%, 94% and 63%. In addition, high methane production rates were obtained, between 2500 and 4800 L CH4.kg-1 COD removed d-1. For all the hydraulic retention times tested, high concentrations of methane in the biogas were recorded: 66-75%, 70% and 75% for HRT of 0.66, 1.33 and 2.41 days, respectively.

The assembly and use of continuous flow systems for chemical synthesis.

The adoption of and opportunities in continuous flow synthesis ('flow chemistry') have increased significantly over the past several years. Continuous flow systems provide improved reaction safety and accelerated reaction kinetics, and have synthesised several active pharmaceutical ingredients in automated reconfigurable systems. Although continuous flow platforms are commercially available, systems constructed 'in-lab' provide researchers with a flexible, versatile, and cost-effective alternative. Herein, we describe the assembly and use of a modular continuous flow apparatus from readily available and affordable parts in as little as 30 min. Once assembled, the synthesis of a sulfonamide by reacting 4-chlorobenzenesulfonyl chloride with dibenzylamine in a single reactor coil with an in-line quench is presented. This example reaction offers the opportunity to learn several important skills including reactor construction, charging of a back-pressure regulator, assembly of stainless-steel syringes, assembly of a continuous flow system with multiple junctions, and yield determination. From our extensive experience of single-step and multistep continuous flow synthesis, we also describe solutions to commonly encountered technical problems such as precipitation of solids ('clogging') and reactor failure. Following this protocol, a nonspecialist can assemble a continuous flow system from reactor coils, syringes, pumps, in-line liquid-liquid separators, drying columns, back-pressure regulators, static mixers, and packed-bed reactors.

“One-Pot” Solar Fuels

Chemists have always taken great pride in simplifying a complex multistep chemical synthesis into a single step process, in just one reactor. The motivation for doing so, apart from demonstrating synthetic competency and elegance, is the pursuit of green and sustainable solutions to chemical problems, as single step strategies have the inherent advantage of being atomically, energetically and economically efficient, as well as environmentally friendly and responsible.

Quantitative Immobilization of Phthalocyanine onto Bacterial Cellulose for Construction of a High-Performance Catalytic Membrane Reactor

We report the fabrication of a tetra-amino cobalt (II) phthalocyanine (CoPc)-immobilized bacterial cellulose (BC) functional nanocomposite, CoPc@BC, by quantitative immobilization of CoPc onto a BC membrane. Lab-cultured BC was oxidized by NaIO4 to generate aldehyde groups on BC for the subsequent CoPc immobilization, the processing conditions were optimized by monitoring both the generated aldehyde content and the resulting CoPc loading. X-ray photoelectron spectroscopy (XPS) was employed to characterize the change of the element bonding environment during the functionalization processes. The CoPc@BC functional nanocomposite was utilized for the treatment of reactive red X-3B dye wastewater. The CoPc molecules in the CoPc@BC nanocomposite can function as an “antenna” to adsorb the target anionic dye molecules, the adsorption takes place both on the surface and in the interior of CoPc@BC. A catalytic membrane reactor (CMR) was assembled with the CoPc@BC nanocomposite, the performance of CMR was evaluated based on the catalytic oxidation behavior of reactive red X-3B, with H2O2 as an oxidant. Highly-reactive hydroxyl radical (OH) was involved in the catalytic oxidation process, as detected by electron paramagnetic resonance (EPR). Under optimal operating conditions of a flow rate of 6 mL/min, a reaction temperature of 50 °C, and an H2O2 concentration of 10 mmol/L, the decoloration rate of CMR was as high as 50 μmol⋅min−1⋅g−1.

PREFACE for the special issue on “progress in novel nuclear energy technologies”

This is an exclusively prepared special issue containing papers selected from two well-established events, namely, International Conference on Emerging Nuclear Energy Systems (ICENES) and International Conference on Nuclear and Renewable Energy Resources (NURER) and some invited papers in order to make a unique source to reflect the progress in the area of novel nuclear energy technologies. ICENES, with a long scientific tradition, started in 1978 as an autonomous, self-organized event by a group of independent nuclear scientists. The goal was to find unconventional new routes for improving the use of the atomic energy beyond the commercial grounds. It was evident that the field of “strong interactions” still has a broad way for further developments to harness the most powerful source of energy of our universe, in a safe way and with better use of natural resources. The Nuclear Field is plenty of opportunities, and no free from risks, and it is the spirit of human vocation to explore those domains where new findings can change some essential aspects of our world, as is the case of Energy. Nuclear energy is considered the ultimate energy to secure the future of the mankind. Hence, considerable research activities and international collaboration are continuing on innovative nuclear energy systems, such as fusion energy, fusion-fission hybrids, GEN-IV reactors, space nuclear reactors, and power systems and accelerator-driven systems. Asian countries are considerably progressing in the construction of new nuclear reactor as well as in the research and the development of innovative nuclear energy technologies. A sort of new international merging is needed to recover capability and potential in this field of Physics and Technology, which should play an important role in coping with the energy problem and its environmental effects. NURER is a relatively younger one, which was initiated in 2010 as an independent event to look inside the long-term future of energy problems, without forgetting to bridge the gap between the present time and the future, parallel to the ICENES series in alternating years. Both are unique conferences in their nature, considering that nuclear energy, and other newly emerging alternative and renewable energy technologies as complementing and not competing directions with each other. On that way, ICENES and NURER conferences represent two alternating fora, where present and future technologies and systems are discussed under the same umbrella and establish a bridge with closer communication and mutual understanding between nuclear and renewable energy communities. The mankind needs both of them. In that sense, both conferences cover a wide range of topics related to nuclear power production; nuclear hydrogen production; hydrogen energy, energy efficiency, and management; solar energy; wind energy; hydrogen production and storage; renewable energy; fuel cells; bio-energy, etc. In closing, this particular special issue aims to make a unique collection on “progress in novel nuclear energy technologies” from the papers selected from the above listed conferences along with some invited papers which have peer-reviewed, improved, enhanced, and accepted for publication in IJER. The guest editor would like to take this opportunity to warmly thank the editor-in-chief, Prof Dr Ibrahim Dincer; Journal Manager, Peter Creaton; and the authors of the special issue papers to make this special issue a fruitful outcome.

Reversible covalent enzyme immobilization methods for reuse of carriers

Reversible immobilization techniques which allow for multiple use of the carrier are relevant for applications, such as enzymatic microreactors, biosensors with specific setups and for expensive carriers such as superparamagnetic particles. The activity of immobilized enzymes reduces with time, so that the introduction of fresh immobilized enzyme becomes necessary. Thus, methods for reversible immobilization and multiple carrier reuse can help to reduce purchase costs and facilitate reactor construction. In this work, we present a method that makes use of the reduction and oxidation of cystamine, a cleavable linker with disulfide bond and amine functionality. For a proof of principle, α-chymotrypsin was immobilized on polyethylene glycol with terminal epoxy groups using cystamine as a crosslinker. The enzyme was highly active and could be used in repeated cycles. After the enzymatic reaction was demonstrated, α-chymotrypsin was cleaved off the particle by reducing agents. The resulting thiols on the particle surface were oxidized to disulfides by means of cysteamine, the reduction product of cystamine. This way, an almost complete oxidation of surface thiols with cysteamine was possible, restoring amine functionalization for further reactions. Reduction and oxidation were repeated several times without a decrease in the extent of amine coupling. Finally, immobilization of α-chymotrypsin could be repeated with results comparable to first run.

Continuous Photo-Oxidation in a Vortex Reactor: Efficient Operations Using Air Drawn from the Laboratory.

We report the construction and use of a vortex reactor which uses a rapidly rotating cylinder to generate Taylor vortices for continuous flow thermal and photochemical reactions. The reactor is designed to operate under conditions required for vortex generation. The flow pattern of the vortices has been represented using computational fluid dynamics, and the presence of the vortices can be easily visualized by observing streams of bubbles within the reactor. This approach presents certain advantages for reactions with added gases. For reactions with oxygen, the reactor offers an alternative to traditional setups as it efficiently draws in air from the lab without the need specifically to pressurize with oxygen. The rapid mixing generated by the vortices enables rapid mass transfer between the gas and the liquid phases allowing for a high efficiency dissolution of gases. The reactor has been applied to several photochemical reactions involving singlet oxygen (1O2) including the photo-oxidations of α-terpinene and furfuryl alcohol and the photodeborylation of phenyl boronic acid. The rotation speed of the cylinder proved to be key for reaction efficiency, and in the operation we found that the uptake of air was highest at 4000 rpm. The reactor has also been successfully applied to the synthesis of artemisinin, a potent antimalarial compound; and this three-step synthesis involving a Schenk-ene reaction with 1O2, Hock cleavage with H+, and an oxidative cyclization cascade with triplet oxygen (3O2), from dihydroartemisinic acid was carried out as a single process in the vortex reactor.

Calculations of Cross-Sections and Astrophysical S-factors for the (α,n) Reactions of Some Structural Fusion Materials

Structural material selection in design of fusion reactors is very crucial. These structural materials should satisfy the hard conditions such as high thermo-mechanical stresses, high heat loads and severe radiation damage without compromising on safety considerations. The materials such as titanium, vanadium and chromium are used in the construction of fusion reactors. Therefore, it is important to examine these materials. Obtained results from the nuclear reactions using structural materials can be used for developing of these structural materials. For this reason, in this study cross sections of the 46Ti(α,n) 49Cr, 50Cr(α,n) 53Fe and 51V(α,n) 54Mn reactions have been calculated at 2–20 MeV energy range. In these theoretical calculations, the TALYS 1.8 and NON-SMOKER codes were used. Also, the astrophysical S-factors which describe the possibility of reaction in low energies were calculated. Results of our calculations were checked to the experimental data obtained from EXFOR database.

MHD thermohydraulics analysis and supporting R&D for DCLL blanket in the FNSF

A Fusion Nuclear Science Facility (FNSF) has been recognized in the fusion community as a necessary facility to resolve the critical technology issues of in-vessel components prior to the construction of a DEMO reactor (Abdou et al., 1996) [1]. Among these components, development of a reliable, low-cost and safe blanket system that provides self-sufficient tritium breeding and efficient conversion of the extracted fusion energy to electricity, while meeting all material, design and configuration limitations is among the most important but still challenging goals. In the recent FNSF study in the US (Kesel et al., 2015) [2], a Dual-Coolant Lead-Lithium (DCLL) blanket has been selected as the main breeding blanket concept. This paper summarizes the most important details of the proposed DCLL blanket design, presents the MHD thermohydraulic analysis for the PbLi flows in the blanket conduits and introduces supporting R&D studies, which are presently ongoing at UCLA. We also discuss the required pre-FNSF R&D in the area of MHD Thermofluids to support the further work on the DCLL blanket design & analysis and its integration into the fusion facility.

Characterization of functional materials for liquid blanket systems by cathodoluminescence measurement

Applicability of cathodouminescence (CL) measurements in development of functional materials for advanced liquid blanket systems was investigated by using a conventional scanning microprobe and CCD spectrometer. Firstly, CL spectra of lithium compounds for tritium fuel breeding, oxide, nitride and carbide functional materials for advanced blanket systems, fluoride materials for coolants, etc. were obtained to construct a database. Relations between changes in the spectra and the crystallinities of specimens were examined for ZrO2, Y2O3 and TiO2 coatings baked at different temperatures. The specimens with lower crystallinities showed broader luminescence peak at longer wavelengths. Changes in CL spectra by irradiation damages were also examined for Y2O3 and SiC by ion beam irradiations. Since luminescence intensity decreased significantly for the specimens with low crystallinities, an SEM system which can control the electron beam current more than 2 orders while keeping the spatial resolution of <1μm is suitable for quick acquisition of CL spectra in the development of the functional materials. Once a database of CL spectra for candidate materials and their changes by crystallinities and irradiation damages is constructed, the CL measurement would be a reliable tool also in inspection and monitoring of materials during reactor construction and operation.

Technology of Producing the Contact Connections of Superconductor Metal-Sheathed Cable

Abstract The technology of producing the current contact connections on the superconductor cable edges is presented. This lead cable is used as one of the major elements of the magnetic system in thermonuclear reactor construction, actuality for modern world energy. The technology is realized by the radial draft of metal thin-walled tube on the conductor’s package. The filling of various profiles by round section wire is optimized. Geometrical characteristics of the dangerous crosssection (as a broken ring) of thin-walled tube injured by the sector cut-out are accounted. The comparative strength calculation of the solid and injured tubes at a longitudinal compression and lateral bending is acted. The radial draft mechanism of cylindrical thin-walled sheath with the wire packing is designed. The necessity to use the nonlinear theory for the sheaths calculate is set. The resilient co-operation of wires as the parallel located cylinders with the contact stripes of rectangular form is considered.

ECOLOGICAL AND ECONOMIC ASPECTS OF ElECTROCHEMICAL PURIFICATION OF QUARRY WATERS FROM THE IONS OF HEAVY METALS

In the paper the problems of purification of quarry waters from the ions of heavy metals by the use of electrochemical method are considered. The construction of electrochemical reactor is described allowing to perform the so-called channel electrolysis at high rate of liquid flow along of the electrodes in the conditions of limiting cathode current density (i k ). Technological schemes of complex processing of quarry waters for separation of useful components and estimation of their economic efficiency are presented.

Modeling of intensified glycerol steam reforming in a heat-exchange integrated microchannel reactor

The aim of this study is to investigate glycerol steam reforming in a heat exchange integrated microchannel reactor involving solid wall separated, rectangular-shaped, parallel reaction and heating channels by means of mathematical modeling techniques. Heat needed for endothermic glycerol steam reforming taking place in Co-Ni/Al2O3 coated channels is supplied by steam flowing in the adjacent channels separated by solid walls. Simultaneous catalytic reaction and heat exchange within the microchannel reactor are modeled by 2D Navier-Stokes equations which were solved by the finite volume method in ANSYS 16.0 platform to study the effects of operational parameters, namely molar inlet steam-to-carbon ratio (S/C) and temperature of the reactive mixture, inlet temperature and velocity of steam, flow configurations of the reactive mixture and steam, and of structural parameters, i.e. reactor wall material and thickness of the wall between the reaction and heating channels on temperature distribution and on glycerol conversion. The results show that increasing S/C from 1 to 6 promotes H2 and CO2 selectivity, having average values of 64.7% and 21.2%, respectively. The same effect, however, suppresses CO selectivity from 12.8% to 10.8% and resulted in CH4 selectivity below 2.7%. Product distribution is found to be in alignment with those of experimental studies reported in the literature. Heating by steam has an obvious contribution to glycerol conversion, which is found to be 73.3% and 63.8% in the presence and absence of steam heating, respectively. Counter- and co-current flow of steam with respect to reactive mixture, however, do not lead to a notable difference in conversion. Increasing steam inlet temperature from 663K to 783K improved conversion by 10.0%, whereas changing steam inlet velocity from 2 to 8m/s did not change reforming channel temperature significantly. Reactor performance is significantly affected by increasing feed temperature of the reactive mixture from 673K to 773K which improved conversion by 11.7%. Higher glycerol conversions are also obtained by using thicker separating walls and thermally conductive wall materials, both of which favor heat flux into the reforming channel. Changing the wall thickness from 4×10−4m to 1.2×10−3m elevates conversion by 1.3%. A similar response is noted upon using silicon carbide instead of AISI steel as the material of construction of the microchannel reactor. In general, selectivity towards H2 is positively correlated with the degree of uniformity of reaction channel temperature, which is also found to dampen undesired CH4 selectivity.