The Verification of SONG Library

2017 ◽  
Author(s):  
Hua Bei ◽  
Jinkun Zhao ◽  
Qichang Chen ◽  
Shengyi Si
Keyword(s):  
Layer Structure ◽  
Resonance Effect ◽  
Fission Products ◽  
Reaction Rates ◽  
Monte Carlo Code ◽  
Personal Factors ◽  
Operation Condition ◽  
Pressurized Water ◽  
Fission Rate ◽  
Wide Range

We have developed the 293-group cross-section library SONGLIB with complete reaction pathes, broad-spectrum solving ability and wide range isotopes, which is adopted in the lattice code SONG, the next generation reactor lattice calculation and analysis code. SONGLIB provides the multi-group data for the transport calculation, resonance calculation and burnup calculation of SONG. So the precision and reliability of data is very important. However, the size of the data is very large and there are still a lot of personal factors in determination of the processing parameters and methods. In order to evaluate the library, it’s necessary to carry out the test work comprehensively. Amount of test work is then undertaken based on three kinds of reactors such as pressurized water reactor with UO2 fuel, sodium cooled fast reactor and new-type molten salt reactor with none-beryllium core. In order to test the adaptivity of the library, 39 cases are designed totally, changing the fuel composition, the absorber compositon, the burnup depth and the working temperature. Only the results of a few cases are given in details to shorten the length of this article. For comparison, the Monte Carlo code MCNP is chosen and the library source of evaluated nuclear data is ensured to be the same. The model that has been calculated is simple, the cell with “fuel-cladding-modulator” the three-layer structure and total reflection boundary for the aim of minimizing the differences between the codes. From the macroscopic angle, the results of infinite multiplication factor fit well with each other in total. From the microscopic angle, the absorption rate for actinides, fission products and absorbers, the fission rate for fissile isotopes and scattering rate for moderators are compared with that of MCNP whose output is normalized to the actual cell power. The difference between the reaction rates for most isotopes can be neglected. But there still exist some obvious differences for some isotopes whose resonance effect should have been considered, such as Fe56, ZrNat and W, which might affect the macoscopic results to some extent. As a conclusion, the data of SONGLIB can be expected with high precision and reliability. And SONGLIB is adapted in solving various problems for reactors with different spectrum, depth of burnup, operation condition or fuel cycling. Nevertheless, there still exist some factors that may affect the final results during the process and use of the library, which should be paid attention to while taking a further step in optimizing and updating the library.

scholarly journals Actinides induced irradiation damage and swelling effect in irradiated Zircaloy-4 after 30 years of storage

2021 ◽  
Vol 1 ◽  
pp. 7-8
Author(s):  
Mara Marchetti ◽  
Michel Herm ◽  
Tobias König ◽  
Simone Manenti ◽  
Volker Metz
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Reactor Core ◽  
Fission Products ◽  
Alpha Decay ◽  
Irradiation Damage ◽  
Monte Carlo Code ◽  
Pressurized Water ◽  
Dry Storage ◽  
Inner Surface

Abstract. After several years in the reactor core, irradiated nuclear fuel is handled and subsequently stored for a few years under water next to the core, to achieve thermal cooling and decay of very short-lived radionuclides. Thereafter, it might be sent to dry-cask interim storage before final disposal in a deep geological repository. Here, the spent nuclear fuel (SNF) is subject to a series of physicochemical phenomena which are of concern for the integrity of the nuclear fuel cladding. After moving the SNF from wet to dry storage, the temperature increases, then slowly decreases, leading the hydrogen in solid solution in the cladding to precipitate radially with consequent hydride growth and cladding embrittlement (Kim, 2020). Another phenomenon affecting the physical properties of the cladding during interim dry storage is the irradiation damage produced in the inner surface of the cladding by the alpha decay of the actinides present at the periphery of the pellet, particularly when the burnup at discharge is high. SNF pellets with high average burnup present larger fuel volumes at the end of their useful life due to accumulation of insoluble solid fission products and noble gases, which leads to disappearance of the as-fabricated pellet–clad gap. Further swelling is expected as a consequence of actinide decay and the accumulation of helium. This leads to larger cladding hoop stress and larger alpha decay damage. The present work first investigates the variation in diameter caused by pellet swelling in an irradiated Zircaloy-4 cladding after chemical digestion of the uranium oxide (UOx) pellet. Second, the irradiation damage produced during the 30 years elapsed since the end of irradiation in terms of displacements per atom (dpa) is studied by means of the FLUKA Monte Carlo code. The irradiation damage produced by the decay of actinides in the inner surface of the cladding extends for less than 3 % in depth. The considered cladded UOx pellet was extracted from a pressurized water reactor (PWR) fuel rod consisting of five segments, with an average burnup at discharge of 50.4 GWd (tHM)−1.

Neutron Physics Characterization & Optimization Analysis of the ACPR100 Small Modular Reactor

2021 ◽  
Author(s):  
Songyang Liu ◽  
Xiang Wang
Keyword(s):  
Life Cycle ◽  
Reactor Core ◽  
Fission Products ◽  
Negative Temperature ◽  
Design Parameters ◽  
Monte Carlo Code ◽  
Time Step ◽  
Optimization Analysis ◽  
Insertion Depth ◽  
Pressurized Water

Abstract The ACPR100 is a small modular pressurized water reactor design proposed by China General Nuclear Power Corporation which integrates most important components of the reactor into one pressure vessel. This paper aims to model the reactor core by Monte Carlo code Serpent. Firstly, the steady-state characterization and optimization analysis within different temperature, pin-pitch and other design parameters are performed. Secondly, the loading pattern of fuel assemblies with Gd-doped fuel rods was assessed. Thirdly, based on the reference research, the temperature coefficients of fuel and coolant are calculated. The influence of control rod insertion depth was simulated additionally. Besides, to show the life cycle and the change of inventory directly, we performed burnup calculation based on pre-defined time step and discussed the fission products including radioactive minor actinides and radiopharmaceutical isotopes during the life cycle. The results show that the ACPR100 achieved more stable performance using high abundance boric acid, and the negative temperature reactivity coefficient is sufficient to maintain the stability of the reactor operation, but the ACPR100 is not suitable for massive production of radiopharmaceutical isotopes.

scholarly journals Mass and Heat Transfer Coefficients in Automotive Exhaust Catalytic Converter Channels

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 507
Author(s):  
Chrysovalantis C. Templis ◽  
Nikos G. Papayannakos
Keyword(s):  
Heat Transfer ◽  
Flow Reactor ◽  
Catalytic Converter ◽  
Reaction Rates ◽  
Cfd Model ◽  
Automotive Exhaust ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Wide Range ◽  
Mass And Heat Transfer

Mass and heat transfer coefficients (MTC and HTC) in automotive exhaust catalytic monolith channels are estimated and correlated for a wide range of gas velocities and prevailing conditions of small up to real size converters. The coefficient estimation is based on a two dimensional computational fluid dynamic (2-D CFD) model developed in Comsol Multiphysics, taking into account catalytic rates of a real catalytic converter. The effect of channel size and reaction rates on mass and heat transfer coefficients and the applicability of the proposed correlations at different conditions are discussed. The correlations proposed predict very satisfactorily the mass and heat transfer coefficients calculated from the 2-D CFD model along the channel length. The use of a one dimensional (1-D) simplified model that couples a plug flow reactor (PFR) with mass transport and heat transport effects using the mass and heat transfer correlations of this study is proved to be appropriate for the simulation of the monolith channel operation.

scholarly journals Novel Bloch wave excitation platform based on few-layer photonic crystal deposited on D-shaped optical fiber

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Esteban Gonzalez-Valencia ◽  
Ignacio Del Villar ◽  
Pedro Torres
Keyword(s):  
Optical Fibers ◽  
High Performance ◽  
Light Propagation ◽  
Fiber Optic ◽  
Layer Structure ◽  
Optical Network ◽  
Building Blocks ◽  
Bloch Wave ◽  
Nanophotonic Devices ◽  
Wide Range

AbstractWith the goal of ultimate control over the light propagation, photonic crystals currently represent the primary building blocks for novel nanophotonic devices. Bloch surface waves (BSWs) in periodic dielectric multilayer structures with a surface defect is a well-known phenomenon, which implies new opportunities for controlling the light propagation and has many applications in the physical and biological science. However, most of the reported structures based on BSWs require depositing a large number of alternating layers or exploiting a large refractive index (RI) contrast between the materials constituting the multilayer structure, thereby increasing the complexity and costs of manufacturing. The combination of fiber–optic-based platforms with nanotechnology is opening the opportunity for the development of high-performance photonic devices that enhance the light-matter interaction in a strong way compared to other optical platforms. Here, we report a BSW-supporting platform that uses geometrically modified commercial optical fibers such as D-shaped optical fibers, where a few-layer structure is deposited on its flat surface using metal oxides with a moderate difference in RI. In this novel fiber optic platform, BSWs are excited through the evanescent field of the core-guided fundamental mode, which indicates that the structure proposed here can be used as a sensing probe, along with other intrinsic properties of fiber optic sensors, as lightness, multiplexing capacity and easiness of integration in an optical network. As a demonstration, fiber optic BSW excitation is shown to be suitable for measuring RI variations. The designed structure is easy to manufacture and could be adapted to a wide range of applications in the fields of telecommunications, environment, health, and material characterization.

scholarly journals Single particle dual plasmonic effect for efficient organic solar cells

2021 ◽  
Author(s):  
Adi Prasetio ◽  
Soyeon Kim ◽  
Muhammad Jahandar ◽  
Dong Chan Lim
Keyword(s):  
Solar Cells ◽  
Organic Solar Cells ◽  
Light Absorption ◽  
Resonance Effect ◽  
Localized Surface Plasmon ◽  
Main Role ◽  
Charge Generation ◽  
One Pot ◽  
Wide Range ◽  
Light Reflectance

AbstractIncorporating localized surface plasmon resonance (LSPR) into organic solar cells (OSCs) is a popular method for improving the power conversion efficiency (PCE) by introducing better light absorption. In this work, we designed a one-pot synthesis of Ag@SiO2@AuNPs dual plasmons and observed an immense increase in light absorption over a wide range of wavelengths. Ag@SiO2 plays the main role in enhancing light absorption near the ultraviolet band. The silica shell can also further enhance the LSP resonance effect and prevent recombination on the surface of AgNPs. The AuNPs on the Ag@SiO2 shell exhibited strong broad visible-light absorption due to LSP resonance and decreased light reflectance. By utilizing Ag@SiO2@AuNPs, we could enhance the light absorption and photoinduced charge generation, thereby increasing the device PCE to 8.57% and Jsc to 17.67 mA cm−2, which can be attributed to the enhanced optical properties. Meanwhile, devices without LSPR nanoparticles and Ag@SiO2 LSPR only showed PCEs of 7.36% and 8.18%, respectively.

scholarly journals Ureido Functionalization through Amine-Urea Transamidation under Mild Reaction Conditions

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1583
Author(s):  
Natalia Guerrero-Alburquerque ◽  
Shanyu Zhao ◽  
Daniel Rentsch ◽  
Matthias M. Koebel ◽  
Marco Lattuada ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Reaction Times ◽  
Reaction Rates ◽  
Secondary Amines ◽  
Isocyanic Acid ◽  
Advantages And Disadvantages ◽  
Major Disadvantage ◽  
Wide Range ◽  
Potential Alternative ◽  
Full Conversion

Ureido-functionalized compounds play an indispensable role in important biochemical processes, as well as chemical synthesis and production. Isocyanates, and KOCN in particular, are the preferred reagents for the ureido functionalization of amine-bearing compounds. In this study, we evaluate the potential of urea as a reagent to graft ureido groups onto amines at relatively low temperatures (<100 °C) in aqueous media. Urea is an inexpensive, non-toxic and biocompatible potential alternative to KOCN for ureido functionalization. From as early as 1864, urea was the go-to reagent for polyurea polycondensation, before falling into disuse after the advent of isocyanate chemistry. We systematically re-investigate the advantages and disadvantages of urea for amine transamidation. High ureido-functionalization conversion was obtained for a wide range of substrates, including primary and secondary amines and amino acids. Reaction times are nearly independent of substrate and pH, but excess urea is required for practically feasible reaction rates. Near full conversion of amines into ureido can be achieved within 10 h at 90 °C and within 24 h at 80 °C, and much slower reaction rates were determined at lower temperatures. The importance of the urea/amine ratio and the temperature dependence of the reaction rates indicate that urea decomposition into an isocyanic acid or a carbamate intermediate is the rate-limiting step. The presence of water leads to a modest increase in reaction rates, but the full conversion of amino groups into ureido groups is also possible in the absence of water in neat alcohol, consistent with a reaction mechanism mediated by an isocyanic acid intermediate (where the water assists in the proton transfer). Hence, the reaction with urea avoids the use of toxic isocyanate reagents by in situ generation of the reactive isocyanate intermediate, but the requirement to separate the excess urea from the reaction product remains a major disadvantage.

3D Calculations of PWR Vessels Neutron Fluence With EFLUVE 3D Code

2013 ◽  
Author(s):  
Cécile-Aline Gosmain ◽  
Sylvain Rollet ◽  
Damien Schmitt
Keyword(s):  
Monte Carlo ◽  
Fast Neutron ◽  
Pressure Vessel ◽  
Reaction Rate ◽  
Neutron Fluence ◽  
Neutron Transport ◽  
Reaction Rates ◽  
Surveillance Program ◽  
Monte Carlo Code ◽  
Neutron Sources

In the framework of surveillance program dosimetry, the main parameter in the determination of the fracture toughness and the integrity of the reactor pressure vessel (RPV) is the fast neutron fluence on pressure vessel. Its calculated value is extrapolated using neutron transport codes from measured reaction rate value on dosimeters located on the core barrel. EDF R&D has developed a new 3D tool called EFLUVE3D based on the adjoint flux theory. This tool is able to reproduce on a given configuration the neutron flux, fast neutron fluence and reaction rate or dpa results of an exact Monte Carlo calculation with nearly the same accuracy. These EFLUVE3D calculations does the Source*Importance product which allows the calculation of the flux, the neutronic fluence (flux over 1MeV integrated on time) received at any point of the interface between the skin and the pressure vessel but also at the capsules of the pressurized water reactor vessels surveillance program and the dpa and reaction rates at different axial positions and different azimuthal positions of the vessel as well as at the surveillance capsules. Moreover, these calculations can be carried out monthly for each of the 58 reactors of the French current fleet in challenging time (less than 10mn for the total fluence and reaction rates calculations considering 14 different neutron sources of a classical power plant unit compared to more than 2 days for a classic Monte Carlo flux calculation at a given neutron source). The code needs as input: - for each reaction rate, the geometric importance matrix produced for a 3D pin by pin mesh on the basis of Green’s functions calculated by the Monte Carlo code TRIPOLI; - the neutron sources calculated on assemblies data (enrichment, position, fission fraction as a function of evolution), pin by pin power and irradiation. These last terms are based on local in-core activities measurements extrapolated to the whole core by use of the EDF core calculation scheme and a pin by pin power reconstruction methodology. This paper presents the fundamental principles of the code and its validation comparing its results to the direct Monte Carlo TRIPOLI results. Theses comparisons show a discrepancy of less than 0,5% between the two codes equivalent to the order of magnitude of the stochastic convergence of Monte Carlo results.

Reactions of the radical cation derived from 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+) with amino acids. Kinetics and mechanism

2000 ◽  
Vol 78 (8) ◽  
pp. 1052-1059 ◽  
Author(s):  
C Aliaga ◽  
E A Lissi
Keyword(s):  
Amino Acids ◽  
Radical Cation ◽  
Sulfonic Acid ◽  
Biological Fluids ◽  
Reaction Rates ◽  
Kinetics And Mechanism ◽  
Specific Rate ◽  
Wide Range ◽  
Initial Ph ◽  
Secondary Reactions

Stable free radicals derived from 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+) have been extensively employed to monitor the antioxidant capacity of biological fluids and beverages. Besides reacting with typical antioxidants (such as phenols or thiols) these radicals react with a variety of hydrogen or electron donors. The present work reports on the kinetics and mechanism of these radical reactions with several amino acids. Reaction rates notably increase when the pH of the media increases and, when measured under similar conditions, follows the ordercysteine > > tryptophan > tyrosine > histidine > cystineThe kinetics of the process is interpreted in terms of a mechanism comprising an initial pH dependent reversible step, followed by secondary reactions of the substrate derived radical with itself or with another ABTS·+; this simple three-step mechanism leads to very complex kinetic expressions. The specific rate constants of several of the elementary steps were determined by working under a wide range of substrate, radical, and ABTS concentrations. The values obtained for the initial interaction between the ABTS derived radical and the substrate range from 0.5 M–1 s–1 to 1.9 × 106 M–1 s–1 for histidine and cysteine, respectively.Key words: ABTS radical cation, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), amino acids, kinetics.

scholarly journals A comprehensive Monte Carlo study to design a novel multi-nanoparticle loaded nanocomposites for augmentation of attenuation coefficient in the energy range of diagnostic X-rays

2021 ◽  
Vol 27 (4) ◽  
pp. 279-289
Author(s):  
Elahe Sayyadi ◽  
Asghar Mesbahi ◽  
Reza Eghdam Zamiri ◽  
Farshad Seyyed Nejad
Keyword(s):  
Monte Carlo ◽  
Energy Range ◽  
Radiation Protection ◽  
Experimental Studies ◽  
Rubber Matrix ◽  
Photon Flux ◽  
Monte Carlo Code ◽  
X Rays ◽  
Wide Range ◽  
Shielding Properties

Abstract Introduction: The present study aimed to investigate the radiation protection properties of silicon-based composites doped with nano-sized Bi2O3, PbO, Sm2O3, Gd2O3, WO3, and IrO2 particles. Radiation shielding properties of Sm2O3 and IrO2 nanoparticles were investigated for the first time in the current study. Material and methods: The MCNPX (2.7.0) Monte Carlo code was utilized to calculate the linear attenuation coefficients of single and multi-nano structured composites over the X-ray energy range of 10–140 keV. Homogenous distribution of spherical nanoparticles with a diameter of 100 nm in a silicon rubber matrix was simulated. The narrow beam geometry was used to calculate the photon flux after attenuation by designed nanocomposites. Results: Based on results obtained for single nanoparticle composites, three combinations of different nano-sized fillers Sm2O3+WO3+Bi2O3, Gd2O3+WO3+Bi2O3, and Sm2O3+WO3+PbO were selected, and their shielding properties were estimated. In the energy range of 20-60 keV Sm2O3 and Gd2O3 nanoparticles, in 70-100 keV energy range WO3 and for photons energy higher than 90 keV, PbO and Bi2O3 nanoparticles showed higher attenuation. Despite its higher density, IrO2 had lower attenuation compared to other nanocomposites. The results showed that the nanocomposite containing Sm2O3, WO3, and Bi2O3 nanoparticles provided better shielding among the studied samples. Conclusions: All studied multi-nanoparticle nanocomposites provided optimum shielding properties and almost 8% higher attenuation relative to single nano-based composites over a wide range of photon energy used in diagnostic radiology. Application of these new composites is recommended in radiation protection. Further experimental studies are suggested to validate our findings.

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