This paper discusses and presents figures about the future power consumption in the world and, especially in Brazil, based on the current world and Brazilian’s energy scenarios. Emphasis is given to the scenarios of ...This paper discusses and presents figures about the future power consumption in the world and, especially in Brazil, based on the current world and Brazilian’s energy scenarios. Emphasis is given to the scenarios of nuclear power and uranium resources demand. A discussion on the future roles of thorium and uranium fuels in the replacement of the traditional resources like oil and gas is also presented, as it is the role of the new nuclear power plants, planned to be built in a short term time horizon. This paper considers two different indexes for future projections, and the results obtained indicated a strong dependence on them. The time horizon for the analysis was fixed on the time estimated for Brazil to reach its maximum in population, and parameters evaluated were taken from the Brazilian’s governmental and world data on the population growth, energy consumption and energy consumption per capita. Calculations show that the power consumption projections for Brazil, for the adopted time horizon and working with global indexes, become overestimated, when compared with the results considering the national indexes. According to our approach, power consumption estimates using global indexes becomes approximately 4.5 times higher than the estimates presented by the Brazilian indexes. This was the motivation to the discussion between the Brazilian and world energy demand scenarios, and also the roles of nuclear energy in the future transition from the current conventional to alternative sources.展开更多
The whole concept and relative value of nuclear energy is being reassessed against the juxtaposed background of climate change induced by global warming versus the imperatives of international energy security.This res...The whole concept and relative value of nuclear energy is being reassessed against the juxtaposed background of climate change induced by global warming versus the imperatives of international energy security.This research focuses on the new trends and developments of nuclear energy against the guidelines being set for attaining carbon neutrality and the demands for energy security.展开更多
The Monte Carlo(MC)method offers significant advantages in handling complex geometries and physical processes in particle transport problems and has become a widely used approach in reactor physics analysis,radiation ...The Monte Carlo(MC)method offers significant advantages in handling complex geometries and physical processes in particle transport problems and has become a widely used approach in reactor physics analysis,radiation shielding design,and medical physics.However,with the rapid advancement of new nuclear energy systems,the Monte Carlo method faces challenges in efficiency,accuracy,and adaptability,limiting its effectiveness in meeting modern design requirements.Overcoming technical obstacles related to high-fidelity coupling,high-resolution computation,and intelligent design is essential for using the Monte Carlo method as a reliable tool in numerical analysis for these new nuclear energy systems.To address these challenges,the Nuclear Energy and Application Laboratory(NEAL)team at the University of South China developed a multifunctional and generalized intelligent code platform called MagicMC,based on the Monte Carlo particle transport method.MagicMC is a developing tool dedicated to nuclear applications,incorporating intelligent methodologies.It consists of two primary components:a basic unit and a functional unit.The basic unit,which functions similarly to a standard Monte Carlo particle transport code,includes seven modules:geometry,source,transport,database,tally,output,and auxiliary.The functional unit builds on the basic unit by adding functional modules to address complex and diverse applications in nuclear analysis.MagicMC introduces a dynamic Monte Carlo particle transport algorithm to address time-space particle transport problems within emerging nuclear energy systems and incorporates a CPU-GPU heterogeneous parallel framework to enable high-efficiency,high-resolution simulations for large-scale computational problems.Anticipating future trends in intelligent design,MagicMC integrates several advanced features,including CAD-based geometry modeling,global variance reduction methods,multi-objective shielding optimization,high-resolution activation analysis,multi-physics coupling,and radiation therapy.In this paper,various numerical benchmarks-spanning reactor transient simulations,material activation analysis,radiation shielding optimization,and medical dosimetry analysis-are presented to validate MagicMC.The numerical results demonstrate MagicMC's efficiency,accuracy,and reliability in these preliminary applications,underscoring its potential to support technological advancements in developing high-fidelity,high-resolution,and high-intelligence MC-based tools for advanced nuclear applications.展开更多
Additive manufacturing(AM)is an innovative technique that enables the flexible design and construction of three-dimensional objects.In the nuclear industry,AM enables the use of advanced materials and high-performance...Additive manufacturing(AM)is an innovative technique that enables the flexible design and construction of three-dimensional objects.In the nuclear industry,AM enables the use of advanced materials and high-performance components.Although AM processing has been extensively investigated,the corresponding mechanical properties and structural integrity issues of AM parts have received less attention.This study reviews the mechanical behavior and key challenges of typical AM materials,fuel components,compact heat exchangers with complex geometries,and additive repair of damaged reactor components.The findings of this review will guide the efficient and reliable implementation of AM techniques in nuclear reactors.展开更多
In this study,the dosimetric characteristics(thickness applicability,preheating time,temperature and humidity dependence,in-batch uniformity,readout reproducibility,dose linearity,self-decay,and electron energy respon...In this study,the dosimetric characteristics(thickness applicability,preheating time,temperature and humidity dependence,in-batch uniformity,readout reproducibility,dose linearity,self-decay,and electron energy response)of engineered polycarbonate films irradiated with an electron beam(0–600 kGy)were investigated using photoluminescence spectroscopy.The results show a linear relationship between photoluminescence intensity and radiation dose when the thickness of the polycarbonate film is 0.3 mm.A higher fluorescence intensity can be obtained by preheating at 60℃ for 180 min before photoluminescence spectrum analysis.As the temperature during spectral testing and the ambient humidity(during and after irradiation)increased,the photoluminescence intensity of the polycarbonate films decreased.The photoluminescence intensity deviation of the polycarbonate films produced within the same batch at 100 kGy is 2.73%.After ten times of repeated excitations and readouts,the coefficients of variation in photoluminescence intensity are less than 8.6%,and the linear correlation coefficient between photoluminescence intensity and irradiation dose is 0.965 in the dose capture range of 20–600 kGy.Within 60 days of irradiation,the photoluminescence intensity of the polycarbonate film decreased to 60%of the initial value.The response of the 0.3 mm polycarbonate films to electron beams with energies exceeding 3.5 MeV does not differ significantly.This comprehensive analysis indicates the potential of polycarbonate films as a high-radiation dose detection material.展开更多
A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete...A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition.展开更多
Under normal water chemistry conditions, the oxygen and hydrogen peroxide produced by water radiolysis in the coolant of boiling water reactors(BWRs) can lead to intergranular stress corrosion cracking in the constitu...Under normal water chemistry conditions, the oxygen and hydrogen peroxide produced by water radiolysis in the coolant of boiling water reactors(BWRs) can lead to intergranular stress corrosion cracking in the constituent materials of plant components. This fact has led to the wide-scale adoption of hydrogen water chemistry(HWC) in the nuclear industry to counteract these effects.This study seeks to characterize the metallic composition and the surface properties of the constituent materials of plant components in order to determine their effects on the accumulation of chalk river unidentified deposits(crud) on fuel rods in the BWR Unit-1 of the Kuosheng Nuclear Power Plant in Taiwan. Inductively coupled plasma-atomic emission spectroscopy was used to calculate the concentrations of surface crud and gamma spectrometry was used to determine the radioactivity of the corrosion products, as well as their axial distribution across the surface of the fuel rods. X-ray diffraction analysis and scanning electron microscopy/energy-dispersive X-ray spectroscopy were used to identify the crystalline phase and morphology of the crud as irregular shapes and flakes. The amount of crud deposited during the fourth fuel cycle exceeded that of the third fuel cycle due to extended burn-up time. Our analytical results indicate that the implementation of HWC had no significant effect on the characteristics of subsequent crud.展开更多
The HTR-PM600 high-temperature gas-cooled reactor nuclear power plant is based on the technology of the high-temperature gas-cooled reactor pebble-bed module(HTR-PM)demonstration project.It utilizes proven HTR-PM reac...The HTR-PM600 high-temperature gas-cooled reactor nuclear power plant is based on the technology of the high-temperature gas-cooled reactor pebble-bed module(HTR-PM)demonstration project.It utilizes proven HTR-PM reactor and steam generator modules with a thermal power of 250 MW_(th)and power generation of approximately 100 MW_(e)per module.Six modules in parallel,connected to a steam turbine,form a 600-MW_(e)nuclear power plant.In addition,its system configuration in the nuclear island is identical to that of the HTR-PM in which the technical risks are minimized.Under this principle,the HTR-PM600 achieves the same level of inherent safety as the HTR-PM.The concept of a ventilated lowpressure containment(VLPC)is unchanged;however,a large circular VLPC accommodating all six reactor modules is adopted rather than the previous small-cavity-type VLPC,which contains only one module,as defined for the HTR-PM.The layout of the nuclear island and its associated systems refer to single-unit pressurized water reactor(PWR)practices.With this layout,the HTR-PM600achieves a volume size of the nuclear island that is comparable to a domestic PWR of the same power level.This will be a GenerationⅣnuclear energy technology that is economically competitive.展开更多
The components from spent fuel are discharged from the core and then stored in the framework of the spent fuel pool for cooling. However, it is of great significance to save the storage space of the spent fuel pool by...The components from spent fuel are discharged from the core and then stored in the framework of the spent fuel pool for cooling. However, it is of great significance to save the storage space of the spent fuel pool by shrinkage and shearing work to increase the spare fuel lattice number. In order to solve the problem of shrinkage and shearing work of spent fuel involving the problem of radioactive safety, the radioactive source item is calculated by ORIGEN2 program base on Unit 1 Ⅱ of Lingao Nuclear Power Plant(NPP), and the radiation dose rate of the related component shrinkage operation scene is simulated by the MCNP5 program. In addition, the effectiveness of shielding measures is discussed, and the maximum dose rate is within 0.35 μSv/h at the distance of 2.5 m from component center, and the maximum dose rate is almost 0 at the distance of 3.2 m from the component center. The intensity of the radiation dose produced by the related components is very low and can be neglected, which belong to the green area of NPP. The program calculation system from source term calculation to shielding calculation is established, and an engineering example is referenced, and its application and analysis are carried out. It provides a basis for radioactive safety analysis and evaluation for the shrinkage operation of spent fuel and makes the shrinkage technology of fuel-related components safer and more reliable.展开更多
The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by ...The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by combining scattering and transmission nuclear resonance fluorescence(s NRF and t NRF)spectroscopy.In s NRF spectroscopy,SNMs such as^(235,238)U are excited by a wide-band photon beam of appropriate energy and exhibit unique NRF signatures.Monte Carlo simulations show that one-dimensional scans can realize isotopic identification of concealed^(235,238)U when the detector array used for interrogation has sufficiently high energy resolution.The simulated isotopic ratio^(235U/238)U is in good agreement with the theoretical value when the SNMs are enclosed in relatively thin iron.This interrogation is followed by t NRF spectroscopy using a narrow-band photon beam with the goal of obtaining tomographic images of the concealed SNMs.The reconstructed image clearly reveals the position of the isotope^(235)U inside an iron rod.It is shown that the interrogation time of s NRF and t NRF spectroscopy is one order of magnitude lower than that when only t NRF spectroscopy is used and results in a missed-detection rate of 10^(-3).The proposed method can also be applied for isotopic imaging of other SNMs such as^(239,240)Pu and^(237)Np.展开更多
A detector setup for the measurement of angular distribution of heavy-ion elastic scattering at energies around Coulomb barrier on the radioactive ion beam line in Lanzhou at the heavy-ion research facility in Lanzhou...A detector setup for the measurement of angular distribution of heavy-ion elastic scattering at energies around Coulomb barrier on the radioactive ion beam line in Lanzhou at the heavy-ion research facility in Lanzhou is designed.The beam profile and the scattering angles on the target are deduced by two parallel plate avalanche counters,and four sets of detector telescopes(including doublesided silicon strip detectors) are placed systematically with the beam line,incorporating with Monte Carlo simulations.The data of ^(16)O on ^(89)Y target were analyzed to compare with the simulation results.It is found that the simulated distribution is agreeable with the experimental data.By assuming the pure Rutherford scattering at small scattering angles,the angular distribution of elastic scattering of^(16)O+^(89)Y at low energies can be reasonably obtained.It indicates that this set of detector setup can be used for the measurement of angular distributions of heavy-ion elastic scattering at energies around Coulomb barrier.展开更多
NG-CT-10 and NG-CT-20 are newly developed grades of nuclear-grade graphite from China.In this study,their oxidation behaviors were experimentally investigated using thermal gravimetric analysis.Microstructural evoluti...NG-CT-10 and NG-CT-20 are newly developed grades of nuclear-grade graphite from China.In this study,their oxidation behaviors were experimentally investigated using thermal gravimetric analysis.Microstructural evolution before and after oxidation was investigated using scanning electron microscope,mercury intrusion,and Raman spectroscopy.The apparent activation energy of NG-CT-10 nuclear graphite is 161.4 kJ/mol in a reaction temperature range of 550–700℃and that of NG-CT-20 is 153.5 kJ/mol in a temperature range of 550–650℃.The activation energy in the inner diffusion control regime is approximately half that in the kinetics control regime.At high temperatures,the binder phase is preferentially oxidized over the filler particles and small pores are generated in the binder.No new large or deep pores are generated on the graphite surfaces.Oxygen can diffuse along the boundaries of filler particles and through the binder phase,but cannot diffuse into the spaces between the nanocrystallites in the filler particles.Filler particles are oxidized starting at their outer surfaces,and the sizes of nanocrystallites do not decrease following oxidation.展开更多
It is necessary to develop an automatic fault diagnosis system to avoid a possible nuclear disaster caused by an inaccurate fault diagnosis in the nuclear power plant by the operator. Because Radial Basis Function Neu...It is necessary to develop an automatic fault diagnosis system to avoid a possible nuclear disaster caused by an inaccurate fault diagnosis in the nuclear power plant by the operator. Because Radial Basis Function Neural Network (RBFNN) has the characteristics of optimal approximation and global approximation. The mixed coding of binary system and decimal system is introduced to the structure and parameters of RBFNN, which is trained in course of the genetic optimization. Finally, a fault diagnosis system according to the frequent faults in condensation and feed water system of nuclear power plant is set up. As a result, Genetic-RBF Neural Network (GRBFNN) makes the neural network smaller in size and higher in generalization ability. The diagnosis speed and accuracy are also improved.展开更多
Interventional radiology has been beneficial for patients for over 30 years of age with the combination of diagnostic and therapeutic methods. The radiation affecting occupationally exposed workers should be evaluated...Interventional radiology has been beneficial for patients for over 30 years of age with the combination of diagnostic and therapeutic methods. The radiation affecting occupationally exposed workers should be evaluated by means of the energy spectra and flux of X-rays in the treatment room. The present study aims to obtain the energy spectra of interventional procedures and study the capability of some detectors to evaluate the dose in interventional procedures. These measurements were taken by silicon-drift, CdTe, and CdZnTe detectors. The energy spectra were corrected by the energy-response curve of each detector. The energy-response curves of silicon-drift and CdTe detectors provided by the manufacturers specification were used. The energy response of the CdZnTe detector was measured by 133Ba and 152Eu γ sources. The experimental data were compared with the simulation results, and their perfect agreement provides a way to correct the energy or dose response, which can be used for the personal dosimeter developed by our group. Moreover, the measured energy spectra can be used in individual radiation protection. The present study shows that the CdZnTe detector is a good candidate detector in interventional procedures.展开更多
In this work,a life cycle analysis is accomplished for flat plate solar collectors.The purpose of this investigation is to predict the energy consumption during the manufacturing processes that results in carbon dioxi...In this work,a life cycle analysis is accomplished for flat plate solar collectors.The purpose of this investigation is to predict the energy consumption during the manufacturing processes that results in carbon dioxide emissions.Energy consumption and system efficiency enhancement will be studied and predicted.CES EduPack software is used to perform the analysis of the currently commercial system,and the suggested changes are implemented to increase the efficiency and make the comparison.Even though cost analysis is done,the priority of selection is given to the most energy conserving and environmentally friendly alternative.However,if the compared alternatives result in the same energy consumption and CO_(2)emissions,the cost analysis would be a better approach.It can be stated that flat plate solar collectors are sustainable and renewable energy systems that do not produce CO_(2)emissions during their active usage,but the manufacturing processes they undergo during the design contribute to the greenhouse gasses emission.展开更多
A method for analyzing the dynamic energy spectrum of intense pulsed ion beam(IPIB) was proposed.Its influence on beam energy deposition in metal target was studied with IPIB produced by two types of magnetically insu...A method for analyzing the dynamic energy spectrum of intense pulsed ion beam(IPIB) was proposed.Its influence on beam energy deposition in metal target was studied with IPIB produced by two types of magnetically insulated diodes(MID).The emission of IPIB was described with space charge limitation model,and the dynamic energy spectrum was further analyzed with time-of-flight method.IPIBs generated by pulsed accelerators of BIPPAB-450(active MID) and TEMP-4M(passive MID) were studied.The dynamic energy spectrum was used to deduce the power density distribution of IPIB in the target with Monte Carlo simulation and infrared imaging diagnostics.The effect on the distribution and evolution of thermal field induced by the characteristics of IPIB dynamic energy spectrum was discussed.展开更多
Gas irradiation in research nuclear reactors is an important way to produce radionuclides. Although some nuclear reactors centers offer this type of service, there are few publications about capsules to irradiation of...Gas irradiation in research nuclear reactors is an important way to produce radionuclides. Although some nuclear reactors centers offer this type of service, there are few publications about capsules to irradiation of gaseous samples. This paper describes a method to fabricate and evaluate aluminum capsules to irradiate gaseous samples in nuclear reactor. A semi-circular slotted die from a hydraulic presshead was modified to seal aluminum tubes. The aluminum capsules were subjected to leak detection tests, which demonstrated the accordance with standard ISO 9978.展开更多
The microscopic c.m. correction energies for nuclei ranging from oxygen to calcium are systematically calculated by both spherical and axially deformed relativistic mean-field （RMF） models with the effective interac...The microscopic c.m. correction energies for nuclei ranging from oxygen to calcium are systematically calculated by both spherical and axially deformed relativistic mean-field （RMF） models with the effective interaction PK1. The microscopic c.m. correction energies strongly depend on the isospin as well as deformation and deviate from the phenomenological ones. The deformation effect is discussed in detail by comparing the deformed with the spherical RMF calculation. It is found that the direct and exchange terms of the c.m. correction energies are strongly correlated with the density distribution of nuclei and are suppressed in the deformed case.展开更多
In this work,neodymium(Nd)and samarium(Sm)codoped lead lanthanum zirconate titanate(PLZT)ceramics were prepared by a high-temperature solid-state method.The samples were characterized by X-ray diffraction,scanning ele...In this work,neodymium(Nd)and samarium(Sm)codoped lead lanthanum zirconate titanate(PLZT)ceramics were prepared by a high-temperature solid-state method.The samples were characterized by X-ray diffraction,scanning electron microscopy and ferroelectric analysis.Rare earth-doped PLZT ceramics show good phase formation.An appropriate rare earth element doping amount increases the densities of PLZT ceramics and reduces their resistivities,which is due to the role of rare earth elements in grain refinement.However,the increase in the amount of grain boundaries caused by grain refinement also affects domain inversion.Therefore,with increasing doping concentration,the remnant polarization of PLZT gradually decreases,and the doping of rare earth elements also slightly reduces the band gap of PLZT.Under irradiation with an X-ray simulated beta source with a particle energy of 10 keV(between the average energies of the beta particles of^3H and^(63)Ni),the ceramic sheets in this work produce current densities of up to 1.38 nA/cm^2.This indicates that Nd and Sm codoped PLZT ceramics have a certain potential for application in betavoltaic batteries.展开更多
Recent astrophysical measurements strongly suggest the existence of a missing energy component dubbed dark energy that is responsible for the current accelerated expansion of the universe.A new class of modified gravi...Recent astrophysical measurements strongly suggest the existence of a missing energy component dubbed dark energy that is responsible for the current accelerated expansion of the universe.A new class of modified gravity theory is introduced which yields a universe accelerating in time and dominated by dark energy.The new modified gravity model constructed here concurrently includes a Gauss-Bonnet invariant term,barotropic fluid with a time-dependent equation of state parameter,a Coleman-Weinberg（CW） potential-like expression V（φ） =ξφm lnφn and a new Einstein-Hilbert term f（R,φ） =E（φ） R which depends on both the scalar curvature and the scalar fieldφthrough a generic logarithmic function E（φ） =lnφ.Here m and n take different values from the standard CW potential andξis a real parameter. It was shown that the presence of these terms provides many useful features which are discussed in some detail.展开更多
文摘This paper discusses and presents figures about the future power consumption in the world and, especially in Brazil, based on the current world and Brazilian’s energy scenarios. Emphasis is given to the scenarios of nuclear power and uranium resources demand. A discussion on the future roles of thorium and uranium fuels in the replacement of the traditional resources like oil and gas is also presented, as it is the role of the new nuclear power plants, planned to be built in a short term time horizon. This paper considers two different indexes for future projections, and the results obtained indicated a strong dependence on them. The time horizon for the analysis was fixed on the time estimated for Brazil to reach its maximum in population, and parameters evaluated were taken from the Brazilian’s governmental and world data on the population growth, energy consumption and energy consumption per capita. Calculations show that the power consumption projections for Brazil, for the adopted time horizon and working with global indexes, become overestimated, when compared with the results considering the national indexes. According to our approach, power consumption estimates using global indexes becomes approximately 4.5 times higher than the estimates presented by the Brazilian indexes. This was the motivation to the discussion between the Brazilian and world energy demand scenarios, and also the roles of nuclear energy in the future transition from the current conventional to alternative sources.
文摘The whole concept and relative value of nuclear energy is being reassessed against the juxtaposed background of climate change induced by global warming versus the imperatives of international energy security.This research focuses on the new trends and developments of nuclear energy against the guidelines being set for attaining carbon neutrality and the demands for energy security.
基金supported by the National Natural Science Foundation of China(Nos.12475174 and U2267207)YueLuShan Center Industrial Innovation(No.2024YCII0108)+2 种基金Natural Science Foundation of Hunan Province(No.2022JJ40345)Science and Technology Innovation Project of Hengyang(No.202250045336)the Project of State Key Laboratory of Radiation Medicine and Protection,Soochow University(No.GZK12023031)。
文摘The Monte Carlo(MC)method offers significant advantages in handling complex geometries and physical processes in particle transport problems and has become a widely used approach in reactor physics analysis,radiation shielding design,and medical physics.However,with the rapid advancement of new nuclear energy systems,the Monte Carlo method faces challenges in efficiency,accuracy,and adaptability,limiting its effectiveness in meeting modern design requirements.Overcoming technical obstacles related to high-fidelity coupling,high-resolution computation,and intelligent design is essential for using the Monte Carlo method as a reliable tool in numerical analysis for these new nuclear energy systems.To address these challenges,the Nuclear Energy and Application Laboratory(NEAL)team at the University of South China developed a multifunctional and generalized intelligent code platform called MagicMC,based on the Monte Carlo particle transport method.MagicMC is a developing tool dedicated to nuclear applications,incorporating intelligent methodologies.It consists of two primary components:a basic unit and a functional unit.The basic unit,which functions similarly to a standard Monte Carlo particle transport code,includes seven modules:geometry,source,transport,database,tally,output,and auxiliary.The functional unit builds on the basic unit by adding functional modules to address complex and diverse applications in nuclear analysis.MagicMC introduces a dynamic Monte Carlo particle transport algorithm to address time-space particle transport problems within emerging nuclear energy systems and incorporates a CPU-GPU heterogeneous parallel framework to enable high-efficiency,high-resolution simulations for large-scale computational problems.Anticipating future trends in intelligent design,MagicMC integrates several advanced features,including CAD-based geometry modeling,global variance reduction methods,multi-objective shielding optimization,high-resolution activation analysis,multi-physics coupling,and radiation therapy.In this paper,various numerical benchmarks-spanning reactor transient simulations,material activation analysis,radiation shielding optimization,and medical dosimetry analysis-are presented to validate MagicMC.The numerical results demonstrate MagicMC's efficiency,accuracy,and reliability in these preliminary applications,underscoring its potential to support technological advancements in developing high-fidelity,high-resolution,and high-intelligence MC-based tools for advanced nuclear applications.
基金supported by Stable Support Initiative of the State Key Laboratory of Advanced Nuclear Energy Technology(Grant No.YNSW-0124-0101-03)the author Cheng Zhang would like to thank the support by Stable Support Program for Scientific Research of China(Grant No.WDZC-2023-02-02-05).
文摘Additive manufacturing(AM)is an innovative technique that enables the flexible design and construction of three-dimensional objects.In the nuclear industry,AM enables the use of advanced materials and high-performance components.Although AM processing has been extensively investigated,the corresponding mechanical properties and structural integrity issues of AM parts have received less attention.This study reviews the mechanical behavior and key challenges of typical AM materials,fuel components,compact heat exchangers with complex geometries,and additive repair of damaged reactor components.The findings of this review will guide the efficient and reliable implementation of AM techniques in nuclear reactors.
基金supported by the National Natural Science Foundation of China(No.12305385)Key Projects of Scientific Research of the Hunan Provincial Department of Education(22A0310)the Research Startup Project of University of South China(220XQD025).
文摘In this study,the dosimetric characteristics(thickness applicability,preheating time,temperature and humidity dependence,in-batch uniformity,readout reproducibility,dose linearity,self-decay,and electron energy response)of engineered polycarbonate films irradiated with an electron beam(0–600 kGy)were investigated using photoluminescence spectroscopy.The results show a linear relationship between photoluminescence intensity and radiation dose when the thickness of the polycarbonate film is 0.3 mm.A higher fluorescence intensity can be obtained by preheating at 60℃ for 180 min before photoluminescence spectrum analysis.As the temperature during spectral testing and the ambient humidity(during and after irradiation)increased,the photoluminescence intensity of the polycarbonate films decreased.The photoluminescence intensity deviation of the polycarbonate films produced within the same batch at 100 kGy is 2.73%.After ten times of repeated excitations and readouts,the coefficients of variation in photoluminescence intensity are less than 8.6%,and the linear correlation coefficient between photoluminescence intensity and irradiation dose is 0.965 in the dose capture range of 20–600 kGy.Within 60 days of irradiation,the photoluminescence intensity of the polycarbonate film decreased to 60%of the initial value.The response of the 0.3 mm polycarbonate films to electron beams with energies exceeding 3.5 MeV does not differ significantly.This comprehensive analysis indicates the potential of polycarbonate films as a high-radiation dose detection material.
基金supported by the National Natural Science Foundation of China(Nos.U2167202,12225504,12005276)the Natural Science Foundation of Shandong Province(No.ZR2024QA172)the Fundamental Research Funds of Shandong University.
文摘A 32-channel charge-sensitive amplifier(CSA)is designed for fast timing in the delay-line readout of a parallel plate avalanche counter(PPAC)array.It is realized on a PCB with operational amplifiers and other discrete components.Each channel consists of an integrator,a pole-zero cancellation net,and a linear amplification stage,which can be adapted to accommodate either positive or negative input signals.The RMS equivalent input noise charges are 3.3 fC,the conversion gains are approximately±2 mV∕fC,and the intrinsic time resolution reaches 32 ps.In the prototype PPAC application,the CSA performs as well as the commercial FTA820A amplifier,providing a position resolution as good as 0.17 mm,and exhibiting reliable stability during several hours of continuous data acquisition.
文摘Under normal water chemistry conditions, the oxygen and hydrogen peroxide produced by water radiolysis in the coolant of boiling water reactors(BWRs) can lead to intergranular stress corrosion cracking in the constituent materials of plant components. This fact has led to the wide-scale adoption of hydrogen water chemistry(HWC) in the nuclear industry to counteract these effects.This study seeks to characterize the metallic composition and the surface properties of the constituent materials of plant components in order to determine their effects on the accumulation of chalk river unidentified deposits(crud) on fuel rods in the BWR Unit-1 of the Kuosheng Nuclear Power Plant in Taiwan. Inductively coupled plasma-atomic emission spectroscopy was used to calculate the concentrations of surface crud and gamma spectrometry was used to determine the radioactivity of the corrosion products, as well as their axial distribution across the surface of the fuel rods. X-ray diffraction analysis and scanning electron microscopy/energy-dispersive X-ray spectroscopy were used to identify the crystalline phase and morphology of the crud as irregular shapes and flakes. The amount of crud deposited during the fourth fuel cycle exceeded that of the third fuel cycle due to extended burn-up time. Our analytical results indicate that the implementation of HWC had no significant effect on the characteristics of subsequent crud.
基金supported by the National S&T Major Project (No.ZX069)
文摘The HTR-PM600 high-temperature gas-cooled reactor nuclear power plant is based on the technology of the high-temperature gas-cooled reactor pebble-bed module(HTR-PM)demonstration project.It utilizes proven HTR-PM reactor and steam generator modules with a thermal power of 250 MW_(th)and power generation of approximately 100 MW_(e)per module.Six modules in parallel,connected to a steam turbine,form a 600-MW_(e)nuclear power plant.In addition,its system configuration in the nuclear island is identical to that of the HTR-PM in which the technical risks are minimized.Under this principle,the HTR-PM600 achieves the same level of inherent safety as the HTR-PM.The concept of a ventilated lowpressure containment(VLPC)is unchanged;however,a large circular VLPC accommodating all six reactor modules is adopted rather than the previous small-cavity-type VLPC,which contains only one module,as defined for the HTR-PM.The layout of the nuclear island and its associated systems refer to single-unit pressurized water reactor(PWR)practices.With this layout,the HTR-PM600achieves a volume size of the nuclear island that is comparable to a domestic PWR of the same power level.This will be a GenerationⅣnuclear energy technology that is economically competitive.
基金Supported by the Project of Radiation Shielding Calculation Based on Unit 1 Ⅱ of Lingao Nuclear Power Plant of China
文摘The components from spent fuel are discharged from the core and then stored in the framework of the spent fuel pool for cooling. However, it is of great significance to save the storage space of the spent fuel pool by shrinkage and shearing work to increase the spare fuel lattice number. In order to solve the problem of shrinkage and shearing work of spent fuel involving the problem of radioactive safety, the radioactive source item is calculated by ORIGEN2 program base on Unit 1 Ⅱ of Lingao Nuclear Power Plant(NPP), and the radiation dose rate of the related component shrinkage operation scene is simulated by the MCNP5 program. In addition, the effectiveness of shielding measures is discussed, and the maximum dose rate is within 0.35 μSv/h at the distance of 2.5 m from component center, and the maximum dose rate is almost 0 at the distance of 3.2 m from the component center. The intensity of the radiation dose produced by the related components is very low and can be neglected, which belong to the green area of NPP. The program calculation system from source term calculation to shielding calculation is established, and an engineering example is referenced, and its application and analysis are carried out. It provides a basis for radioactive safety analysis and evaluation for the shrinkage operation of spent fuel and makes the shrinkage technology of fuel-related components safer and more reliable.
基金supported by the National Natural Science Foundation of China(No.11675075)Youth Talent Project of Hunan Province,China(No.2018RS3096)+1 种基金Independent Research Project of Key Laboratory of Plasma Physics,CAEP(No.JCKYS2020212006)Innovation and Entrepreneurship Training Program for College Students of University of South China(No.X2019083)。
文摘The smuggling of special nuclear materials(SNMs)across national borders is becoming a serious threat to nuclear nonproliferation.This paper presents a feasibility study on the rapid interrogation of concealed SNMs by combining scattering and transmission nuclear resonance fluorescence(s NRF and t NRF)spectroscopy.In s NRF spectroscopy,SNMs such as^(235,238)U are excited by a wide-band photon beam of appropriate energy and exhibit unique NRF signatures.Monte Carlo simulations show that one-dimensional scans can realize isotopic identification of concealed^(235,238)U when the detector array used for interrogation has sufficiently high energy resolution.The simulated isotopic ratio^(235U/238)U is in good agreement with the theoretical value when the SNMs are enclosed in relatively thin iron.This interrogation is followed by t NRF spectroscopy using a narrow-band photon beam with the goal of obtaining tomographic images of the concealed SNMs.The reconstructed image clearly reveals the position of the isotope^(235)U inside an iron rod.It is shown that the interrogation time of s NRF and t NRF spectroscopy is one order of magnitude lower than that when only t NRF spectroscopy is used and results in a missed-detection rate of 10^(-3).The proposed method can also be applied for isotopic imaging of other SNMs such as^(239,240)Pu and^(237)Np.
基金Supported by the National Natural Science Foundation of China(Nos.11475013,11175011,11035007)
文摘A detector setup for the measurement of angular distribution of heavy-ion elastic scattering at energies around Coulomb barrier on the radioactive ion beam line in Lanzhou at the heavy-ion research facility in Lanzhou is designed.The beam profile and the scattering angles on the target are deduced by two parallel plate avalanche counters,and four sets of detector telescopes(including doublesided silicon strip detectors) are placed systematically with the beam line,incorporating with Monte Carlo simulations.The data of ^(16)O on ^(89)Y target were analyzed to compare with the simulation results.It is found that the simulated distribution is agreeable with the experimental data.By assuming the pure Rutherford scattering at small scattering angles,the angular distribution of elastic scattering of^(16)O+^(89)Y at low energies can be reasonably obtained.It indicates that this set of detector setup can be used for the measurement of angular distributions of heavy-ion elastic scattering at energies around Coulomb barrier.
基金financially supported by the National Natural Science Foundation of China(No.51576103)the National S&T Major Project(No.ZX06901)
文摘NG-CT-10 and NG-CT-20 are newly developed grades of nuclear-grade graphite from China.In this study,their oxidation behaviors were experimentally investigated using thermal gravimetric analysis.Microstructural evolution before and after oxidation was investigated using scanning electron microscope,mercury intrusion,and Raman spectroscopy.The apparent activation energy of NG-CT-10 nuclear graphite is 161.4 kJ/mol in a reaction temperature range of 550–700℃and that of NG-CT-20 is 153.5 kJ/mol in a temperature range of 550–650℃.The activation energy in the inner diffusion control regime is approximately half that in the kinetics control regime.At high temperatures,the binder phase is preferentially oxidized over the filler particles and small pores are generated in the binder.No new large or deep pores are generated on the graphite surfaces.Oxygen can diffuse along the boundaries of filler particles and through the binder phase,but cannot diffuse into the spaces between the nanocrystallites in the filler particles.Filler particles are oxidized starting at their outer surfaces,and the sizes of nanocrystallites do not decrease following oxidation.
文摘It is necessary to develop an automatic fault diagnosis system to avoid a possible nuclear disaster caused by an inaccurate fault diagnosis in the nuclear power plant by the operator. Because Radial Basis Function Neural Network (RBFNN) has the characteristics of optimal approximation and global approximation. The mixed coding of binary system and decimal system is introduced to the structure and parameters of RBFNN, which is trained in course of the genetic optimization. Finally, a fault diagnosis system according to the frequent faults in condensation and feed water system of nuclear power plant is set up. As a result, Genetic-RBF Neural Network (GRBFNN) makes the neural network smaller in size and higher in generalization ability. The diagnosis speed and accuracy are also improved.
基金supported by the National Natural Science Foundation of China(No.11705123)Natural Science Foundation of Jiangsu Province(No.BK20160306)+1 种基金China Postdoctoral Science Foundation(No.2016M591911)the Project of the State Key Laboratory of Radiation Medicine and Protection,Soochow University(No.GZN1201801)
文摘Interventional radiology has been beneficial for patients for over 30 years of age with the combination of diagnostic and therapeutic methods. The radiation affecting occupationally exposed workers should be evaluated by means of the energy spectra and flux of X-rays in the treatment room. The present study aims to obtain the energy spectra of interventional procedures and study the capability of some detectors to evaluate the dose in interventional procedures. These measurements were taken by silicon-drift, CdTe, and CdZnTe detectors. The energy spectra were corrected by the energy-response curve of each detector. The energy-response curves of silicon-drift and CdTe detectors provided by the manufacturers specification were used. The energy response of the CdZnTe detector was measured by 133Ba and 152Eu γ sources. The experimental data were compared with the simulation results, and their perfect agreement provides a way to correct the energy or dose response, which can be used for the personal dosimeter developed by our group. Moreover, the measured energy spectra can be used in individual radiation protection. The present study shows that the CdZnTe detector is a good candidate detector in interventional procedures.
文摘In this work,a life cycle analysis is accomplished for flat plate solar collectors.The purpose of this investigation is to predict the energy consumption during the manufacturing processes that results in carbon dioxide emissions.Energy consumption and system efficiency enhancement will be studied and predicted.CES EduPack software is used to perform the analysis of the currently commercial system,and the suggested changes are implemented to increase the efficiency and make the comparison.Even though cost analysis is done,the priority of selection is given to the most energy conserving and environmentally friendly alternative.However,if the compared alternatives result in the same energy consumption and CO_(2)emissions,the cost analysis would be a better approach.It can be stated that flat plate solar collectors are sustainable and renewable energy systems that do not produce CO_(2)emissions during their active usage,but the manufacturing processes they undergo during the design contribute to the greenhouse gasses emission.
基金supported by the National Natural Science Foundation of China(No.11175012)the National Magnetic Confinement Fusion Program(No.2013GB109004)
文摘A method for analyzing the dynamic energy spectrum of intense pulsed ion beam(IPIB) was proposed.Its influence on beam energy deposition in metal target was studied with IPIB produced by two types of magnetically insulated diodes(MID).The emission of IPIB was described with space charge limitation model,and the dynamic energy spectrum was further analyzed with time-of-flight method.IPIBs generated by pulsed accelerators of BIPPAB-450(active MID) and TEMP-4M(passive MID) were studied.The dynamic energy spectrum was used to deduce the power density distribution of IPIB in the target with Monte Carlo simulation and infrared imaging diagnostics.The effect on the distribution and evolution of thermal field induced by the characteristics of IPIB dynamic energy spectrum was discussed.
文摘Gas irradiation in research nuclear reactors is an important way to produce radionuclides. Although some nuclear reactors centers offer this type of service, there are few publications about capsules to irradiation of gaseous samples. This paper describes a method to fabricate and evaluate aluminum capsules to irradiate gaseous samples in nuclear reactor. A semi-circular slotted die from a hydraulic presshead was modified to seal aluminum tubes. The aluminum capsules were subjected to leak detection tests, which demonstrated the accordance with standard ISO 9978.
基金Supported by the National Basic Research Program （2007CB815000）, and the National Natural Science Foundation of China （10775004 and 10975008）.
文摘The microscopic c.m. correction energies for nuclei ranging from oxygen to calcium are systematically calculated by both spherical and axially deformed relativistic mean-field （RMF） models with the effective interaction PK1. The microscopic c.m. correction energies strongly depend on the isospin as well as deformation and deviate from the phenomenological ones. The deformation effect is discussed in detail by comparing the deformed with the spherical RMF calculation. It is found that the direct and exchange terms of the c.m. correction energies are strongly correlated with the density distribution of nuclei and are suppressed in the deformed case.
基金the Independent Deployment Project of Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZZ109)the National Key Research and Development Program of China(2019YFC0605000)+2 种基金the Independent Deployment Project of Ganjiang Innovation Research Institute of Chinese Academy of Sciences(E055A002)the Key Deployment Project of the Chinese Academy of Sciences(ZDRW-CN-2021-3)the Fujian Provincial Natural Fund Project(2021J05101)。
文摘In this work,neodymium(Nd)and samarium(Sm)codoped lead lanthanum zirconate titanate(PLZT)ceramics were prepared by a high-temperature solid-state method.The samples were characterized by X-ray diffraction,scanning electron microscopy and ferroelectric analysis.Rare earth-doped PLZT ceramics show good phase formation.An appropriate rare earth element doping amount increases the densities of PLZT ceramics and reduces their resistivities,which is due to the role of rare earth elements in grain refinement.However,the increase in the amount of grain boundaries caused by grain refinement also affects domain inversion.Therefore,with increasing doping concentration,the remnant polarization of PLZT gradually decreases,and the doping of rare earth elements also slightly reduces the band gap of PLZT.Under irradiation with an X-ray simulated beta source with a particle energy of 10 keV(between the average energies of the beta particles of^3H and^(63)Ni),the ceramic sheets in this work produce current densities of up to 1.38 nA/cm^2.This indicates that Nd and Sm codoped PLZT ceramics have a certain potential for application in betavoltaic batteries.
文摘Recent astrophysical measurements strongly suggest the existence of a missing energy component dubbed dark energy that is responsible for the current accelerated expansion of the universe.A new class of modified gravity theory is introduced which yields a universe accelerating in time and dominated by dark energy.The new modified gravity model constructed here concurrently includes a Gauss-Bonnet invariant term,barotropic fluid with a time-dependent equation of state parameter,a Coleman-Weinberg（CW） potential-like expression V（φ） =ξφm lnφn and a new Einstein-Hilbert term f（R,φ） =E（φ） R which depends on both the scalar curvature and the scalar fieldφthrough a generic logarithmic function E（φ） =lnφ.Here m and n take different values from the standard CW potential andξis a real parameter. It was shown that the presence of these terms provides many useful features which are discussed in some detail.
