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Nuclear Reactor Safety
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Nejdet ERKANProject Associate Professor
Nuclear
Reactor
SafetyExperimental and Numerical Nuclear Thermal-Hydraulics for Nuclear Safety and Accidents
The technology of the experimental instruments has reached to very advanced levels recently. In parallel, the computational methods and resources gained tremendous capacity that can employ sophisticated modeling techniques for real-life problems. To validate the results of the digital world, a high-quality experimental data set (diverse, multi-dimensional, high-resolution, and accurate) is extremely needed. To understand the sophisticated dynamics of nuclear accidents and to enhance the nuclear safety, we perform experiments and numerical simulations related to thermal-hydraulics phenomena existing in nuclear systems. We use/develop advanced visualization and measurement techniques for fluid flow and heat flow (PIV, PIV/TSP, Shadowgraphy etc.) diagnostics to acquire high-quality real-world data. We use the computational tools such as OpenFOAM and other CFD codes, and validate their models with the experimental results which are obtained from small-scale setups, and extrapolate acquired knowledge to real-scale problems.
Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Keywords
Nuclear Thermal-Hydraulics, Nuclear Safety, Severe Accident, Particle Image Velocimetry (PIV), OpenFOAM
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Koji OKAMOTOProfessor
Nuclear
Reactor
SafetyVisualization and Nuclear Safety
"Visualization" is the key technology on 21 century. We focused on the Information Visualization and Quantitative Visualization. The huge amount of data will be visualized to understand the complex phenomena and/or to resolve the core mechanism of the complex systems. The laser and high-speed camera will resolve the invisible world with quantitative information. We are the world top class laboratory for quantitative visualization.
In the Nuclear Safety, visualization is also the key system. The complex huge system, e.g. Nuclear Power Plant, will be resolved using the visualization technology. The Nuclear Energy will be a promising source of energy to help the world, especially developing countries. However, public understandings will be needed, especially in Japan. Using the visualization technology, we will provide an open access of the Nuclear Energy. We really need a trailblazer for the complex future.Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and Management、Director, JAEA Collaborative Laboratories for Advanced Decommissioning ScienceKeywords
Visualization, Nuclear safety, Severe accident
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Naoto KASAHARAProfessor
Nuclear
Reactor
SafetyDesign by analysis for energy plants
Energy plants are complex systems related with thermal-fluid-structural mechanics. Understanding of essential mechanism of multi-physics phenomena will lead to development of systematic models on thermal load - structural response - material strength in plants. These enable superior design which can satisfy both plant safety and economics.
Most of them are joint research programs with external companies. They will give you educational chance to learn academic research organization and project management.
Through concrete research on structural design of fast breeder reactors, students can learn rational and general methodologies applicable to other fields.Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Other posts：JAXA Visiting ResearcherKeywords
Nuclear Structural Engineering, Elevated Temperature Structural Design, Fast Breeder Reactor
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Takumi SAITOAssociate Professor
Nuclear
Reactor
SafetyChemistry for Nuclear Waste Disposal and Environmental Behaviors of Radionuclides
It is duty of our generation to settle the issues of nuclear waste disposal. Geological disposal is a feasible option for high-level wastes or spent fuels, where various basic research and R&D are still needed to improve the reliability. Chemistry of radionuclides is a key foundation to realize a well-accepted disposal system. Thus, we are pursuing understanding and modeling of the chemistry that governs the interaction of radionuclides with materials of engineering barriers and the migration of radionuclides in subsurface environments, using sophisticated spectroscopy with X-ray, laser, and neutron, chromatographic techniques, and computer simulation. Knowledge obtained through the research has been applied to the modeling of chemodynamics of radionuclides released from the accident of the Fukushima Daiichi nuclear power plant or other non-radioactive pollutants in environments. Any student who has an interest in the issue of nuclear waste disposal are welcomed, no matter what academic backgrounds they have.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and ManagementKeywords
Nuclear waste disposal, Physical chemistry, Geochemistry, Actinide chemistry
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Shunichi SUZUKIProject Professor
Nuclear
Reactor
SafetyDecommissioning of Fukushima Dai-ichi NPP and project management
In order to complete the decommissioning of Fukushima Dai-ichi NPP, we need to challenge and overcome the difficulties which no one has ever experienced. The key technology for decommissioning of the accident plants is how to solve the unsteady state problems caused by remarkable changes of environment, circumstances and the states of the plant condition with the lapse of time. Main theme of this course is finding the tasks and their solutions for decommissioning through evaluation of phenomena which may occur in the future and also though making the scenario with experiments such as material and thermal-hydraulic tests. This course will not only deepen your skill & knowledge on decommissioning, but also give you an opportunity to understand the importance of the project management and the way of System Thinking for a complex world which you will face in the future.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and ManagementKeywords
Decommissioning, System dynamics, Risk assessment, Resilience engineering
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Naoto SEKIMURAProfessor
Nuclear
Reactor
SafetyNuclear Materials Engineering, Ageing Management of Light Water Reactors, Maintenance Engineering of Complex Systems, Multi-scale Simulation of Radiation Damage in Nuclear Materials, Systems Engineering for Nuclear Fuels, Knowledge-base for Nuclear Engineering
Multi-scale simulation and experimental studies on microscopic and macroscopic behaviors of nuclear materials under very severe conditions including energetic neutron irradiation are the major topics. I have been leading national projects for ageing management of nuclear reactors components and materials with other universities, national laboratories and industries. Our group is also working on international collaboration on safe long term operation of nuclear systems and seismic safety through intensive collaboration with IAEA and OECD/NEA .
Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Other posts：Vice-President, The University of Tokyo（International、Japanese Education)Keywords
Safety and Knowledge Management for Nuclear Systems, Multiscale Modeling of Materials
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Kazuyuki DEMACHIAssociate Professor
Nuclear
Reactor
SafetyAbnormality Detection Technology
Development of Plant Safety, Security, Maintenance for NPP and Medical Imaging Technology:
1) Hand and Body Motion Recognition using Fish-eye camera for NPP Safety and Security,
2) Failure Sign Detection of Devices for Predictive Maintenance,
3) Madical Imating Technology for Real-time Tracking Radiation Therapy (RTRT.)Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Other posts：Nuclear Professional SchoolKeywords
Maintenance, Medical Technology, Movie Prediction
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Akira YAMAGUCHIProfessor
Nuclear
Reactor
SafetyTrans-Science and Nuclear Risk
Science and technologies promise better life and more wealthy society in the future. Eventually, we gain benefits from the fruits. The idea does not adapt to the contemporary society. The societal value of the science and technology is closely concerned with the rational relationship of the technology and the society. Key words of science and technologies in the light of societal view are uncertainties, imaginary skill, unknowns, questioning attitude, rational decision making and so on. Contemporary science and technologies need to be established putting more emphasis on the societal acceptance in terms of risk and benefit, i.e. welfare of the society. Researches necessary to respond to the expectations are for: (1) simulating the technology (to understand phenomena), (2) perceiving the technology (to understand risk), and (3) assessing the technology (to make a decision rationally). Common baseline idea is to be developed by an academic field that deals with the lack of knowledge and unknowns, e.g. uncertainties. Energy is the source and foundation of social infrastructures. The dual aspect, light and shadow (safety and uncertainty), of the energy should be quantitatively understood in whole the society for a good and rational decision-making. Last but not least are, needless to say, the next generation researchers. It is a challenge for those living in Japan that have engraved the experience of nuclear disaster deeply in heart. Please join us for opening the door of risk and safety research.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and Management、Graduate School of Osaka University (Invited Professor)Keywords
Risk assessment, Simulation, Unknown, Uncertainty, Decision making, Nuclear safety
Radiation Sources , Detection & Measurement
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Kenichi ISHIKAWAProfessor
Radiation
Sources ,
Detection &
MeasurementAttosecond Science and Particle Cancer Therapy
We study the interaction of a laser pulse and an ion beam with matter through theory and simulations. Our research interest is a new field called high-field phenomena and attosecond science, which studies the quantum dynamics in an ultrashort intense laser field. Especially, we investigate highly nonlinear processes such as high-harmonic generation and tunneling ionization as well as attosecond electron dynamics in atoms and molecules, based on atomic and plasma physics as well as quantum chemistry. Also, we develop a sophisticated method of dose calculation for heavy-ion cancer therapy, which also runs on the K supercomputer.
Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Other posts：Photon Science Center、Department of Physics, School of ScienceKeywords
High-order harmonic generation, High-field physics, Ab initio simulations, Monte-Carlo method
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Mitsuru UESAKAProfessor
Radiation
Sources ,
Detection &
MeasurementAdvanced and Compact Accelerators and Medical Physics
We are developing advanced and compact accelerators/lasers such as S-band photocathode RF electron gun and linear accelerator (linac), X-band Compton scattering monochromatic X-ray source, portable X-band linac X-ray source for nondestructive evaluation, X-band linac for pinpoint cancer therapy, fiber laser accelerator for basic radiation biology. Further, we are performing research on X-ray drug deliver system (DDS) for high quality diagnosis and synergy effect of chemical and radiation-therapies. R&D based medical physics are performed.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and Management、Department of BioengineeringKeywords
Portable linear accelerator, Fiber laser, Radiation biology
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Masashi OHNOAssociate Professor
Radiation
Sources ,
Detection &
MeasurementInnovative analysis of nuclear material using superconducting radiation sensors
Our academic objective is to realize a new innovative high-energy-resolution spectroscopy for nuclear structure investigations, radioactive or non-radioactive nuclide identifications, material analyses, and radiotherapy. For example, non-destructive analysis of nuclear materials for safeguards and nuclear forensic requires improvement in accuracy and sensitivity. The precision spectroscopy of hard X-ray and gamma ray from the nuclear materials is powerful tool for the identification of the plutonium, uranium, actinide and their decay products. However it needs to resolve their X-ray or gamma ray peaks in the complex spectrum of around 100keV region, which cannot be resolved by the conventional detectors. Therefore, we have developed the superconducting radiation sensor with the ultra-high energy resolution. Now our research group has already obtained the world top energy resolution in high-energy gamma-ray region and also, tried to measure gamma-rays from fission products with this superconducting detector.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and ManagementKeywords
Superconductivity, Nanotechnology, Gamma-ray spectroscopy, Charge particle therapy
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Hisaaki KUDOAssociate Professor
Radiation
Sources ,
Detection &
MeasurementRadiation chemistry and application of polymer materials
I am working on radiation chemistry and irradiation effects of polymer materials by using ion and electron beam accelerators.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and ManagementKeywords
Radiation chemistry, Radiation application, Radiation degradation, Polymer material
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Kenji ShimazoeProject Lecturer
Radiation
Sources ,
Detection &
MeasurementNovel quantum imaging and application to environmental, nuclear and medical science
State-of-the-art technology of quantum detection and quantum imaging are strongly required in the field of environmental, space, nuclear and medical science. In nuclear medicine, PET (Positron Emission Tomography) is now widely used to detect early-stage cancer, which utilizes two gamma quanta emitted after positron-electron interaction. In our laboratory, the novel quantum detection method and application to medical and environmental science are investigated based on physics of interactions between quanta and materials. Novel biological/medical imaging method is one of our research topics based on sophisticated quantum imaging technology. Collaborative researches with university hospital, NIRS, KEK, AIST, UCB, TUM etc. are ongoing.
Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Keywords
Quantum Detection, Radiation Detection and Measurement, Medical Imaging, Quantum Imaging, Molecular Imaging
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Hiroyuki TAKAHASHIProfessor
Radiation
Sources ,
Detection &
MeasurementRadiation Measurements and Instrumentation
Radiation measurements are very important in many science and technology areas. We develop quantum radiation detectors for various applications in many areas such as medical imaging, industrial imaging, basic science, etc. Microfabrication techniques, microelectronics and computer hardware techniques, and simulation calculations are effectively used in our research.
Department/Institute/Research Center
Main post：Institute of Engineering Innovation
Other posts：Department Nuclear Engineering and Management、Department of BioengineeringKeywords
Radiation measurements, Gamma-ray imaging, Environmental radiation, Neutron detectors, Signal processing
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Shuichi HASEGAWAProfessor
Radiation
Sources ,
Detection &
MeasurementLaser photons controlling isotopic atoms to manipulate physical and chemical reactions for isotope engineering
Recent progress has been made in engineering solid state lasers to extend their wavelengths and intensities, which leads less photon-cost and narrower bandwidth of the laser wavelength. Laser manipulation of atoms and molecules is one of the fruitful fields due to it. In nuclear engineering, the isotope manipulation and measurement are fundamental technology to pursue. Measurement of rare isotopes is also important for nuclear security or forensic science. We investigate interactions between photons and atoms to extend capability of the laser manipulation for nuclear engineering.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and ManagementKeywords
laser science, Atomic and molecular science, Isotope engineering
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Hiroyuki MATSUZAKIProfessor
Radiation
Sources ,
Detection &
MeasurementAMS, Isotope System, Earth Environmental System
Accelerator Mass Spectrometry (AMS) can analyze extremely rare long-lived radio isotopes such as 10Be(half life = 1.36x106 yr), 14C(5,730 yr), 26Al(7.2x105 yr),36Cl(3.01x105 yr), 129I(1.57x107 yr). These rare isotopes form special isotope systems with their stable isotopes which have precise information about earth environment system. Most famous isotope system is the 14C/12C system well known to be used for dating. Our laboratory has a 5MV tandem accelerator and developed multi-nuclide AMS system of which the performance retains world's top level. While we are applying AMS to various interdisciplinary research fields from archaeological to earth environmental sciences, recently we especially focus on the 129I/127I system. As iodine has a close relation with organic matter and is often found with important carbon reservoir such as methane hydrates and soils, we consider 129I/127I system is an important clue to elucidate the total carbon dynamics.
Department/Institute/Research Center
Main post：The University Museum
Other posts：Department Nuclear Engineering and ManagementKeywords
Ion beam, AMS, Isotope geochemistry, Radioisotope environment assessment
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Shinichi YAMASHITAAssociate Professor
Radiation
Sources ,
Detection &
MeasurementWhat are induced by ionizing radiations? Utilization of advantages and overcome of disadvantages.
Ionizing radiations are closely related to most of the problems in nuclear engineering while they are utilized in practical fields such as cancer treatment in medical field, material processing in industrial field, etc. Understanding their features is essential in order to enhance their advantages as well as to overcome their disadvantages. Sequential events from pico- to microseconds (10−12-10−6 s)) induced by ionizing radiations are all our interest. Examples of research subjects are as follows: "Mechanism of radiation protection and enhancement caused by a tiny amount of chemicals", "water radiolysis (radiation-induced decomposition) with therapeutic high-energy heavy-ion beams", "radiation chemistry in gel matrix for development of polymer gel dosimeter", "effect of seawater constituents on water radiolysis", "gas evolutions from boiling water", etc. In addition, radiation effects at interfaces such as water-polymer (DNA, polysaccharides), water-metal/ceramic, and liquid water-water vapor have not been investigated well. I hope some students make breakthroughs in the frontier.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and ManagementKeywords
Radiation effect (physical chemistry, chemistry, and biochemistry), water chemistry in nuclear engineering, cancer therapy, industrial application of radiation, interfaces
Advanced Modeling & Simulation
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Tatsuya ITOIAssociate Professor
Advanced
Modeling &
SimulationSeismic Safety of Spatially-Distributed Systems including Nuclear Facilities
Our research focuses on modeling of risk due to natural hazards (earthquake, strong wind, etc.) and risk governance framework, from the standpoint of disaster prevention and mitigation of nuclear facilities, buildings and infrastructures:
(1) Risk analysis of spatially-distributed systems
(2) Ground motion prediction and probabilistic seismic hazard analysis
(3) Real-time earthquake disaster mitigation
(4) Risk governance framework of important facilities against natural hazardsDepartment/Institute/Research Center
Main post：Resilience Engineering Research Center
Other posts：Department Nuclear Engineering and ManagementKeywords
Natural disaster modeling, Earthquake engineering, Risk governance
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Ryoichi KOMIYAMAAssociate Professor
Advanced
Modeling &
SimulationQuantitative Analysis of Energy Security
Energy security is a key agenda to address for sustaining socioeconomic activities under various structural and contingency risks such as the depletion of fossil fuel and energy supply disruption. In order to formulate effective technical and political measures for enhancing energy security under those risks and constraints, we need to comprehensively understand economics and international energy market as well as the engineering aspect of energy technology. The research theme in our group is to develop a mathematical and computational energy-economic model to analyze the optimal strategy for the deployment of energy technologies and to discuss energy policy firmly based on the simulated results derived from the model.
Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Other posts：Resilience Engineering Research Center(講義)Keywords
Energy security, Energy-economic model, Mathematical optimization, Econometrics
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Mikio SAKAIAssociate Professor
Advanced
Modeling &
SimulationMultiphysics modeling for computational granular dynamics
We study multiphysics modeling for computational granular dynamics, namely, numerical simulations of solid-fluid and solid particle-elastic body interaction problems. We encounter these problems in various fields including nuclear engineering, chemical engineering, mechanical engineering, civil engineering, pharmaceutical, etc. Numerical studies on the problems were challenging since these were hardly simulated because of the complicated phenomena and excessive calculation cost. Accordingly, our research topics becomes wide ranging, for example, slurry suspension, magneto-rheological fluids, fluidized beds, debris flows, slope failure. At present, we develop new models to perform the simulations by using Lagrangian-Lagrangian or Eulerian-Lagrangian approaches. Our original technologies become important in engineering and science.
Department/Institute/Research Center
Main post：Resilience Engineering Research Center
Other posts：Department Nuclear Engineering and Management、Imperial College London (Visiting Associate Professor)Keywords
Computational granular dynamics, Discrete element method, Multiphiscs modeling
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Takeshi SATOAssociate Professor
Advanced
Modeling &
SimulationMultielectron dynamics in intense laser fields
High field physics and attosecond science are rapidly progressing, in which dynamics of electrons in matters are directly measured and even controlled, using ultra-short high-intensity laser pulses. We are developing state-of-the-art theoretical and computational methods to solve time-dependent Schrödinger equation of multielectron systems interacting with intense laser fields, aiming at ab initio study of nonlinearly nonperturbative phenomena such as tunneling ionization, high harmonic generation, and nonsequential multiple ionization.
Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Other posts：Photon Science CenterKeywords
High field physics, Attosecond science, Wave function theory, Density functional theory, Quantum chemistry
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Yasumasa FUJIIProfessor
Advanced
Modeling &
SimulationEnergy Systems Analysis for Policy and Technology Assessment
Fujii laboratory has been working on the research topics of the feasibility analysis of various alternative energy supply technologies, and policy evaluation for international energy security and environmental issues using a global energy system model built with large-scale mathematical programming on the computers. Moreover, research topics of energy management, such as institutional design of deregulated electricity markets and optimal strategy planning of energy procurement under uncertainty, have also been investigated using variety of analytical techniques of stochastic dynamic programming, financial engineering, and multi-agent simulation with reinforcement learning.
In Fujii laboratory, since we try to find the solutions for the energy problems of 100 years and for the social system which is not realized yet, we welcome students who have the interest to learn various fields, and those who have strong imagination to consider the future of foreign countries.Department/Institute/Research Center
Main post：Department Nuclear Engineering and Management
Other posts：Resilience Engineering Research CenterKeywords
Energy Economic Systems, Technology and Policy Assessment, Optimization, Stochastic Programming
Materials in Extreme Environments
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Hiroaki ABEProfessor
Materials in
Extreme
EnvironmentsNuclear Materials Engineering
As one of the expected solutions for the safe design and operation of nuclear power plants, the further improvements of nuclear materials and fuels are indispensable. We deal with research and development of materials for fusion reactors, advanced fission reactors (Generation IV), and current light water reactors (LWR). The main aspects are to reveal fundamental mechanism of the degradation process under extreme environments, such as irradiation, corrosion and hydrogenation, in Fe-based and Zr-based alloys. Developments of high-performance materials and testing methods are also of our interest. The following techniques are currently applied: microscopy like TEM, HVEM, TEM-accelerator, SEM/EBSD etc.; mechanical tests like advanced expansion-due-to-compression (A-EDC) test, tensile, creep and nano-hardness etc.; and computer simulations like FEM and MD.
Department/Institute/Research Center
Main post：Nuclear Professional School
Other posts：Department Nuclear Engineering and ManagementKeywords
Fission, Fusion, Nuclear materials, Nuclear fuels, Extreme environment, Degradation mechanism, Radiation effects
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Takayuki TERAIProfessor
Materials in
Extreme
EnvironmentsMaterials Science and Elemental Technology for Advanced Energy and Environment Systems
We study material science and chemical engineering for advanced energy systems including the next-generation fission reactor, fusion reactor and nuclear fuel reprocessing systems. Elemental techniques for hydrogen energy system including fuel cell, hydrogen storage, etc. are also investigated. In addition, material processing with high-energy particles such as neutrons, ions, electrons and plasma particles for advanced material preparation and property modification are our research targets.
Department/Institute/Research Center
Main post：Institute of Engineering Innovation
Other posts：Department Nuclear Engineering and ManagementKeywords
Reactor materials, Hydrogen energy,High-energy particles
