检索结果-南通市图书馆

Prediction of the cross-sections of isotopes produced in deuteron-induced spallation of long-lived fission products

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2019年第10期43卷 61-68页

作者： Guanming Yang Suyang Xu Mengting Jin Jun Su sino-french institute of nuclear engineering and technology Sun Yat-sen University

The spallation cross-section data for the long-lived fission products (LLFPs) are scarce but required for the design of accelerator driven systems. In this paper, the isospin dependent quantum molecular dynamics model and the statistical code GEMINI are applied to simulate deuteron-induced spallation in the energy region of GeV/nucleon. By comparing the calculations with the experimental data, the applicability of the model is verified. The model is then applied to simulate the spallation of 90Sr, 93Zr, 107Pd, and 137Cs induced by deuterons at 200, 500 and 1000 MeV/nucleon. The cross-sections of isotopes, the cross-sections of long-lived nuclei, and the reaction energy are presented. Using the above observables, the feasibility of LLFP transmutation by spallation is discussed.

关键词： deuteron-induced spallation transmutation long-lived fission product

Experimental investigation on the characteristics of molten lead–bismuth non-eutectic alloy fragmentation in water

在线全文

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2022年第9期33卷 59-79页

作者： Shao-Jie Tan Yu-Bao Zhong Hui Cheng Song-Bai Cheng sino-french institute of nuclear engineering and technology Sun Yat-Sen UniversityZhuhai 519082China

To study the interaction between molten noneutectic alloys and subcooled water during severe nuclear accidents,an experimental investigation was carried out by injecting molten lead–bismuth non-eutectic alloy(LBNE,70%Pb-30%Bi)into the water in a free-fall style using the visualized thermo-hydraulic characteristics in melt coolant interaction(VTMCI)*** effects of various experimental parameters,including water temperature,melt temperature,melt penetration velocity,and water depth,on the molten LBNE jet fragmentation characteristics were *** research shows that compared with lead–bismuth eutectic,larger fragments,less spherical fragments,and more porous debris beds are generated for *** water or melt temperatures facilitate molten LBNE fragmentation,resulting in higher debris bed sphericity and lower debris bed porosity.A higher melt temperature leads to smaller fragment sizes,except that a cake-like debris bed is formed for very high alloy superheat and very low water *** approximate spherical particles were generated in the film boiling zone than in the thermal interaction *** size decreases with an increase in the melt penetration velocity,but the debris bed porosity and sphericity variation was not *** effect of water depth on molten LBNE fragmentation behavior was not obvious under the current experimental *** with other fragmentation theories,the Weber number theory better predicted the fragment volume mean *** addition,a melt-jet behavior mode diagram that describes the competition between the hydrodynamic and thermal interactions and diagrams of debris bed porosity and sphericity that show the influence of thermal factors were analyzed in this study.

关键词： Fuel-coolant interaction Coolant-coolant interaction Debris bed Lead-bismuth non-eutectic alloy-water interaction Fragmentation behavior

Interdiffusion behavior between Cr and Zr and its effect on the microcracking behavior in the Cr-coated Zr-4 alloy

在线全文

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2021年第12期32卷 1-12页

作者： Ji-Shen Jiang Dong-Qing Wang Ming-Yue Du Xian-Feng Ma Chen-Xue Wang Xiu-Jie He sino-french institute of nuclear engineering and technology Sun Yat-Sen UniversityZhuhai 519082China

High-temperature chromium(Cr)-zirconium(Zr)interdiffusion commonly occurs in Cr-coated zircaloys applied for enhanced accident-tolerant fuel(ATF)clad*** interdiffusion changes the interfacial microstructure and thus the fracture mechanism of the coating under external *** this study,the interdiffusion behavior in a magnetron sputtered Cr coating deposited on a Zr-4 alloy was studied in a vacuum environment at 1160*** addition,the effect of interdiffusion on the microcracking behavior of the Cr coating was determined by in situ three-point bending *** experimental results show that the interdiffusion behavior resulted in the formation of a ZrCr2 layer,accompanied by the consumption of Cr coating and interfacial *** growth of the diffusion layer followed a nearly parabolic law with respect to annealing time,and the residual stress of the annealed coating decreased with increasing annealing *** external loading,a large number of cracks were generated in the brittle interlayer,and some interfacial cracks were formed and grew at the ZrCr2/Zr-4 *** the remarkable microcracks in the ZrCr2 layer,the vacuum-annealed Cr coating has significantly fewer cracks than the original coating,mainly because of the recrystallization of the coating during annealing.

关键词： Accident-tolerant fuel Surface coating Interdiffusion Three-point bending test Crack propagation

Experimental study on the mechanism of flow blockage formation in fast reactor

在线全文

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2023年第6期34卷 171-182页

作者： Wen-Hui Jin Song-Bai Cheng Xiao-Xing Liu sino-french institute of nuclear engineering and technology Sun Yat-Sen UniversityZhuhai519082China

Various sources of solid particles might exist in the coolant flow of a liquid metal cooled fast reactor(e.g.,through chemical interaction between the coolant and impurities,air,or water,through corrosion of structural materials,or from damaged/molten fuel).Such particles may cause flow blockage accidents in a fuel assembly,resulting in a reduction in coolant flow,which potentially causes a local temperature rise in the fuel cladding,cladding failure,and fuel *** understand the blockage formation mechanism,in this study,a series of simulated experiments was conducted by releasing different solid particles from a release device into a reducer pipe using *** detailed analyses,the influence of various experimental parameters(e.g.,particle diameter,capacity,shape,and static friction coefficient,and the diameter and height of the particle release nozzle)on the blockage characteristics(i.e.,blockage probability and position)was *** the current range of experimental conditions,the blockage was significantly influenced by the aforementioned *** ratio between the particle diameter and outlet size of the reducer pipe might be one of the determining factors governing the occurrence of ***,increasing the ratio enhanced blockage(i.e.,larger probability and higher position within the reducer pipe).Increasing the particle size,particle capacity,particle static friction coefficient,and particle release nozzle diameter led to a rise in the blockage probability;however,increasing the particle release nozzle height had a downward influence on the blockage ***,blockage was more likely to occur in non-spherical particles case than that of spherical *** study provides a large experimental database to promote an understanding of the flow blockage mechanism and improve the validation process of fast reactor safety analysis codes.

关键词： Liquid metal cooled fast reactor Flow blockage Granular jamming Experimental study

Reduced-order method for nuclear reactor primary circuit calculation

在线全文

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2024年第11期35卷 28-45页

作者： Ze-Long Zhao Ya-Hui Wang Zhe-Xian Liu Hong-Hang Chi Yu Ma sino‑french institute of nuclear engineering and technology Sun Yat-sen UniversityZhuhai 519082China

Accurate real-time simulations of nuclear reactor circuit systems are particularly important for system safety analysis and *** effectively improve computational efficiency without reducing accuracy,this study establishes a thermal-hydraulics reduced-order model(ROM)for nuclear reactor circuit *** full-order circuit system calculation model is first established and verified and then used to calculate the thermal-hydraulic properties of the circuit system under different states as *** proper orthogonal decomposition method is used to extract the basis functions from snapshots,and the ROM is constructed using the least-squares method,effectively reducing the difficulty in constructing the ROM.A comparison between the full-order simulation and ROM prediction results of the AP1000 circuit system shows that the proposed ROM can improve computational efficiency by 1500 times while achieving a maximum relative error of 0.223%.This research develops a new direction and perspective for the digital twin modeling of nuclear reactor system circuits.

关键词： Reactor system model Primary circuit Reduced-order Proper orthogonal decomposition Least-squares method

Investigation of nuclear Binding Energy and Charge Radius Based on Random Forest Algorithm

在线全文

学校读者我要写书评

暂无评论

原子能科学技术 2023年第4期57卷 704-712页

作者： CAI Boshuai YU Tianjun LIN Xuan ZHANG Jilong WANG Zhixuan YUAN Cenxi sino-french institute of nuclear engineering and technology Sun Yat-sen UniversityZhuhai 519082China

The random forest algorithm was applied to study the nuclear binding energy and charge *** regularized root-mean-square of error(RMSE)was proposed to avoid overfitting during the training of random *** for nuclides with Z,N>7 is reduced to 0.816 MeV and 0.0200 fm compared with the six-term liquid drop model and a three-term nuclear charge radius formula,*** interest is in the possible(sub)shells among the superheavy region,which is important for searching for new elements and the island of *** significance of shell features estimated by the so-called shapely additive explanation method suggests(Z,N)=(92,142)and(98,156)as possible subshells indicated by the binding *** the present observed data is far from the N=184 shell,which is suggested by mean-field investigations,its shell effect is not predicted based on present *** significance analysis of the nuclear charge radius suggests Z=92 and N=136 as possible *** effect is verified by the shell-corrected nuclear charge radius model.

关键词： nuclear binding energy nuclear charge radius random forest algorithm

Experimental investigation on pressure-buildup characteristics of a water lump immerged in a molten lead pool

在线全文

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2023年第3期34卷 25-39页

作者： Zi-Jian Deng Song-Bai Cheng Hui Cheng sino-french institute of nuclear engineering and technology Sun Yat-Sen UniversityZhuhai 519082China

Motivated to understand the pressure-buildup characteristics in a circumstance of a water droplet immerged inside a heavy liquid metal pool,which is a key phenomenon during a Steam Generator Tube Rupture accident of Lead-cooled Fast Reactor,many experiments have been conducted by injecting water lumps into a molten lead pool at sun yat-sen *** order to deepen the understanding of the influence of melt material,this lead experiment was compared with a Lead-Bismuth-Eutectic(LBE)experiment in the *** both experiments,a steam explosion occurred in a small part of the experi-mental runs,which generally leads to strengthened pressure *** the non-explosion experimental cases,the impact of all parameters employed in lead experiments(i.e.,water lump volume,water lump shape,molten pool depth,and temperature of water and melt)on the pressure buildup is non-negligible and similar to that in our previous experiments using ***,limited pressure buildup with an increase in water lump volume was also observed.A slightly more violent pressure buildup tends to appear in the lead experiments than in the LBE experiments under the same experimental conditions,which may be due to the higher thermal conductivity of lead than of *** a few experimental runs with a relatively low melt temperature close to the melting point of lead,local solidification of liquid lead was observed,restricting pressure *** the lead and LBE experiments,the calculated melt kinetic energy conversion efficiencyηhas a relatively small value(not exceeding 1.6%),and theηvalues have an overall positive correlation with the impulse on the molten pool.

关键词： Lead-cooled fast reactor Steam generator tube rupture accident Pressure-buildup characteristics Experimental study Melt material

Theoretical analysis of long-lived radioactive waste in pressurized water reactor

在线全文

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2021年第7期32卷 55-71页

作者： Ze-Xin Fang Meng Yu Ying-Ge Huang Jin-Bei Chen Jun Su Long Zhu sino-french institute of nuclear engineering and technology Sun Yat-sen UniversityZhuhai 519082China

Background The accelerator-driven subcritical transmutation system(ADS)is an advanced technology for the harmless disposal of nuclear waste.A theoretical analysis of the ingredients and content of nuclear waste,particularly long-lived waste in a pressurized water reactor(PWR),will provide important information for future spent fuel *** The present study is an attempt to investigate the yields of isotopes in the neutron-induced fission process and estimate the content of long-lived ingredients of nuclear waste in a *** We combined an approximation of the mass distribution of five Gaussians with the most probable charge model(Zp model)to obtain the isotope yields in the^(235)U(n,f)and^(239)Pu(n,f)*** potential energy surface based on the concept of a di-nuclear system model was applied to an approximation using five Gaussian functions.A mathematical formula for the neutron spectrum in a PWR was established,and sets of differential equations were solved to calculate the content of long-lived nuclides in a *** The calculated isotopic fission yields were in good agreement with the experimental *** for 238U,the contents of^(239)Pu,^(240)Pu,^(241)Pu,^(242)Pu,^(237)Np,^(235)U,and^(236)U are predominant in the PWR after reaching a discharge *** addition,some isotope pairs of heavy nuclei reach a similar value after stabilization,which can be explained by the decay chain and effective fission *** fission fragments,we simulated the content evolution of some long-lived nuclides^(90)Sr,^(107)Pd,^(135)Cs,and their isobars^(90)Rb,^(107)Rh,and^(135)Xe during a fuel cycle in a *** variations in the inventories of uranium and plutonium were in good agreement with the data in Daya *** A new method is proposed for the prediction of the isotopic fission *** inventory of long-lived nuclides was analyzed and predicted after reaching a discharge burnup.

关键词： Radiotoxicity PWR Five Gaussians Long-lived nuclides Fissionfragmentsyields

Neutronic analysis of deuteron-driven spallation target

在线全文

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2021年第9期32卷 52-60页

作者： Wei-Wei Qiu Wu sun Jun Su sino-french institute of nuclear engineering and technology Sun Yat-sen UniversityZhuhai 519082China

Deuteron-driven spallation targets have garnered attention recently because they can provide high-energy neutrons to transmute long-lifetime fission *** this study,the Geant4 toolkit was used to simulate the inter-action between a deuteron beam at 500 MeV and a com-posite target composed of alternating lead-bismuth eutectic(LBE)and *** water was used because it may be employed as a target *** energy spectrum,neu-tron yield,average energy,and total energy of the emitted neutrons were calculated for different thicknesses and thickness ratios between the LBE and *** a constant target thickness,the neutron yield increases with an increasing thickness ratio of LBE to H 2 O,while the aver-age energy of the emitted neutrons decreases with an increasing in the aforementioned thickness *** two aspects support the use of a pure target,either LBE or ***,with an increasing LBE-to-H 2 O thickness ratio,the total energy of the emitted neutrons increases and then *** result supports the addition of water into the LBE *** angular distributions of the emitted neutrons show that the rear of the target is suit-able for loading nuclear waste containing minor actinides and long-lifetime fission products.

关键词： Long-lived nuclear waste product Accelerator-driven sub-critical system Deuteron-induced spallation target Neutron spectrum