A5071600763- Radioactive contamination and transfer
- Nuclear and radioactivity studies
- Magnetic Properties and Applications
- Nuclear Materials and Properties
- Graphite, nuclear technology, radiation studies
- Nuclear reactor physics and engineering
- Non-Destructive Testing Techniques
- Microstructure and Mechanical Properties of Steels
- Risk and Safety Analysis
- Power Transformer Diagnostics and Insulation
- Nuclear Engineering Thermal-Hydraulics
- Radioactive element chemistry and processing
- Metallurgical Processes and Thermodynamics
- Electric Motor Design and Analysis
- Power Quality and Harmonics
- Radiation Detection and Scintillator Technologies
- Combustion and Detonation Processes
- Magnetic Properties of Alloys
- Particle Detector Development and Performance
- Induction Heating and Inverter Technology
- Physics of Superconductivity and Magnetism
- High-Temperature Coating Behaviors
- Particle physics theoretical and experimental studies
- Superconducting Materials and Applications
- Nuclear Physics and Applications
TEPCO (Japan)
2016-2025
Tokyo Electron (Japan)
2023
Nippon Steel (Japan)
1995-2015
Nippon Steel (Germany)
2014
Teikyo University
2005
Kyushu University
1998-1999
Fukuoka Prefecture Education Center
1998
The estimation and understanding of the state fuel debris fission products inside plant is an essential step in decommissioning Tokyo Electric Power Company Holdings Fukushima Daiichi Nuclear Station (1F). However, direct observation interior, which under a high radiation environment, difficult limited. Therefore, order to understand interior conditions, comprehensive analysis evaluation are necessary, based on various measurement data from plant, during accident progression phase,...
A new system for analyzing ac magnetostriction of electrical steel sheets, has been developed. This the following advantages: (a) AC waveforms can be precisely measured up to 4 kHz, and analyzed harmonic components. (b) Non-sinusoidal flux density excited simulate distorted waveform in an actual transformer core.
In order to study the acoustic noise generated by transformer cores, impacts of types core joint and number laminations per layer on levels were investigated. addition, localized magnetostrictions cores measured with strain gages, differences caused The following obtained as results. step-lap configuration reduced in comparison conventional lap. An increase raised levels. occurred higher harmonic components than fundamental component. There was a certain connection between magnetostriction...
Noise generated by a transformer core has been reduced improving material and design, but further reduction is still required. To obtain the reduction, comprehension of noise generating mechanism important. It achieved detailed investigation vibration. A vibration measuring system utilizing laser Doppler meter was developed, 3-phase 3-limb measured. The following results were obtained. on front back two or three times higher than other surfaces. occurred mainly in limbs core, direction...
Abstract We have investigated the status of nuclear debris in Unit-2 Nuclear Reactor Fukushima Daiichi Power plant by method called Cosmic Muon Radiography. In this measurement, muon detector was placed outside reactor building, as case measurement for Unit-1 Reactor. Compared to previous measurements, down-sized, which made it possible us locate closer and investigate lower part fuel loading zone particular. identified inner structures such containment vessel, pressure vessel other objects...
A melt-textured YBCO bulk material was employed to obtain high current transport characteristics of a temperature superconductor. disk-shaped 65 mm in diameter and 15 thick fabricated by modified quench melt growth (QMG) process. An "H" shaped conductor cut from the disk. The cross sectional area length were 7 mm/spl times/7 20 mm, respectively. mounted bus line with conductor-holder which allows feed mechanical support against thermal stress electromagnetic force. Both ends soldered...
In order to study the acoustic noise generated by transformer cores, impacts of types core joint and number laminations per layer on levels were investigated. addition, localized magnetostrictions cores measured with strain gages, differences caused The followings obtained as results. step-lap configuration reduced in comparison conventional lap. increase raised levels. occurred higher harmonic components than fundamental component. There was a certain connection between magnetostriction...
Research has been carried out on the magnetostriction measured in changing direction of grain oriented silicon steel sheets. When magnetic field is applied a 45° off rolling normally parallel to Goss texture orientation, indicated negative value regardless compressive stress specimen and showed favourably smaller poor coating condition rather than good one, which had not easily imagined by experience concerning direction. This was explained fact that 90° supplementary domains followed strain...
The magnetic properties of electrical steel sheets and plates at high flux density near saturation magnetization were investigated. have nearly the same curves as theoretical ones calculated with anisotropy rotation. slopes iron losses to on log scales are almost constant sinusoidal density. Those hysteresis two also those eddy current effective obtained from induced voltages magnetization.
Doubly oriented 3% Si-Fe having high permeability was prepared by a cross-rolling method and secondary recrystallization. We examined two applications of this doubly material. One application is three-phase power transformer. Watt loss the transformer using in yokes found to be lower than that singly Si-Fe, especially at induction. The explained magnetic domain wall movement observation FEM calculation. flux can rotate more smoothly those parts also effective decrease ‘‘hot point.’’ Another...
Noise produced by a transformer core has been reduced improving material and design of the, core. Further reduction is required for the trend toward amenity. The comprehension mechanism producing noise necessary one measures detail investigation vibration. We developed vibration measuring system utilizing laser Doppler meter we measured 3-phase 3-limb on front back was two or three times higher than other surfaces. occurred mainly in limbs direction perpendicular to surface. waveforms were...
This paper presents the effect of magnetic flux distribution on properties a core and its materials. The anisotropies depend not only material texture, but also neighboring crystalline grains, that is, flow through grain boundary. A with high coercive force magnetostriction constant exhibits large deterioration in core. because internal stresses are induced by due to distribution.
Magnetic and mechanical characteristics of adhesive coating non-oriented electrical steel sheet cores were measured in the conditions motor, comparing with those welded cores. The deteriorations iron losses exciting currents by adhesion are less than welding. noise levels vibrating about 10dB lower results modal analysis core one support vibration tests. heat conductivities lamination direction higher.
福島第一原子力発電所1~3号機の原子炉・格納容器内の状態推定や事故分析を進めるに当たっては,現場から取得される情報が重要である。当社では廃炉作業を円滑に進めつつ,必要な情報を取りこぼさないことを目的に事故調査中長期計画を作成した。また,現場で取得される汚染物サンプルにはα汚染を含むものがあり,燃料成分であるウランを含む粒子が検出され,事故時の原子炉・格納容器内の状況を推定する上でのヒントとなり得る。本稿では,燃料デブリの性状把握・推定技術に関する取り組みとして,事故調査中長期計画と採取サンプルの分析状況について述べる。
The early phase of the core degradation at Fukushima Daiichi Nuclear Power Station Unit 2 was investigated in terms a fuel-component by materials interaction carrying out accident analysis, evaluation chemical conditions and experimental works. First, scenario evaluated to specify target period (from 18:40 22:40 on NaN Invalid Date NaN), then temperature H2/H2O pressure ratio region during this were calculated based plant parameters. Subsequently, semi-integral experiments performed using...