In this study, we proposed a double exposure method using synchrotron white X-rays (DEM-WX) to measure strains of coarse-grained materials, and examined its feasibility. The X-ray diffractions were measured by a CdTe pixel detector. The CdTe pixel detector can resolve photon energy by changing a threshold voltage. Calibrating each pixel of the detector using characteristic X-rays of Pb and W foils, the images by threshold X-ray energy were obtained. The difference image, which is like a diffraction image wi...
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Feasibility Study on Stress Measurements using CdTe Pixel Detector and Synchrotron White X-Rays

In order to assure the reliability of advanced gas turbine systems, it is very important to evaluate the damage of high temperature materials such as Ni-ba sed superalloys under creep and fatigue conditions quantitatively. The refractive index of the gamma-prime phase was found to be smaller than that of the g amma phase in the Ni-based superalloy, when the wavelength of an irradiated laser beam is shorter than 500 nm. Therefore, it is possible to evaluate the cr eep damage of this material quantitatively ...
英字タイトル:
Basic Study of Non-destructive Evaluation of Creep or Fatigue Damage of Ni-based Superalloy

In Japan, the decommissioning of a number of nuclear power plant is planned or underway. In order to implement the decommissioning safely and rationally, not only the nuclear industry but also a wide range of stakeholders, such as the local governments where the plants are located, must cooperate to solve the issues that are barriers to the safe and rational implementation of the decommissioning. For this background, Mitsubishi Research Institute carried out to identify the cross-industry issues of decommis...
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Issues and Solution for Safe and Rational Decommissioning of Nuclear Power Plants

Regarding the nuclear regulatory inspection system that came into effect in April 2020, the authors conducted a questionnaire and interview surveys with NRA staff involved in inspection work for the purpose of improving inspection capability and efficient operation of inspections. As a result of the investigation, it became clear that the inspector's conceptual understanding of nuclear regulatory inspection has permeated. In particular, it was confirmed that the understanding of the four concepts of nuclear...
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Research on the efficient operation of nuclear regulatory inspections and the improvement of inspectors' abilities Part1

Regarding the nuclear regulatory inspection system that came into effect in April 2020, we conducted a questionnaire survey and interview survey with NRA staff involved in inspection activities for the purpose of improving inspection competence and efficient operation of inspection system. As a result of the survey, it became clear that the inspectors' understanding of the concept of nuclear regulatory inspection system was pervasive, while improvements related to the improvement of the inspector's competen...
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Research on the efficient operation of nuclear regulatory inspection system and inspectors' capabilities Part 2

For predicting the fuel debris distribution in Fukushima Daiichi Nuclear Power Plants (1FNPPs), it is essential to figure out the melt spreading behavior on primary containment vessel (PCV) floor. In this paper, we analyzed VULCANO spreading experiment programs using a particle method called “Moving Particle Full-Implicit method (MPFI)” which conserves an angular momentum. Phase change model was installed into MPFI method. two experiments having different corium characteristics were analyzed to confirm the ...
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Evaluation of spreading-solidification behavior of high-temperature and highly viscous fluid by particle method with angular momentum conservation

A new research program of irradiation effects on LWR concrete member has been started since 2017. The previous research results indicate the reference level of neutron irradiation degradation on concrete should be set at 1 x 1019 n/cm2 which is one order of magnitude lower than the conventional reference level used in Japan. Several issues remain after the previous research and the objectives for clarifying the issues are set in the new project which is scheduled for five and half years. And international c...
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The Research Plan on Development of Evaluation Method of LWR Concrete Irradiation Effect

In this study, we propose a novel EMAT-ECT multi sensor aiming at advanced structural health monitoring. For the purpose, proto-type EMAT-ECT multi-sensor was developed and their functions both as ECT and EMAT prove were evaluated. Experimental results of pulse ECT using the EMAT-ECT multi-sensor showed that the pr oposed sensor has a capability of detection and sizing of flaws. Experimental results of EMAT evaluation using the EMAT-ECT multi-sensor showed that ultrasoni c wave was transmitted by EMAT-ECT ...
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Development of novel EMAT-ECT multi-sensor and verification of its feasibility

In this study, stress measurements were performed using a double exposure method with hard synchrotron monochromatic X-rays, and its validity was proved. The diffractions of the shrink-?tted ring of austenitic stainless steel SUS304 were measured by the CdTe pixel detector. The used X-rays were 70, 80 and 90 keV. The measured stress distributions with the 311 diffraction of γ-Fe corresponded to the predicted result. In addition, The stress distribution of the shrink-?tted ring was measured by the CCD camera...
英字タイトル:
Stress Measurements of Austenitic Stainless Steel using Hard Synchrotron X-Rays