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Tatsumi M.,Nuclear Engineering Ltd. | Tsujita K.,Nuclear Engineering Ltd. | Tamari Y.,Nuclear Engineering Ltd.
International Conference on Nuclear Engineering, Proceedings, ICONE | Year: 2015

This paper describes recent activity on development of the Micro-Physics Nuclear Reactor Simulator™ and its application to introductory educations of nuclear engineering at high schools and university. The simulator has been continuously improved with active feedbacks from existing and potential users through its applications to exercises in classes/seminars. A newly developed reactor core transient analysis code, RAMBO-T has been adopted in the simulator along with SIMULATE-3K by Studsvik Scandpower Inc. (Borkowski, 1994) The internal data structure has been revised so that any combinations of the target reactor type, the core transient analysis code and the display language can be established. A new graphical user interface was implemented to realize the intuitive and easy-to-understand operations by novice users. The improved version of the Micro-Physics Nuclear Reactor Simulator has been practically used at educational institutions. In order to contribute to the activities on human resource development in the field of nuclear engineering, it is planned to donate the Micro-Physics Simulator™ Lite, a variation of the simulator that supports the only transient core analysis with RAMBO-T, to IAEA, the International Atomic Energy Agency. It will be included into the "NPP Simulators suite for Education" where complimentary copies are distributed to the member states countries. Copyright © 2015 by JSME.


Sato K.,Nuclear Engineering Ltd | Tabuchi M.,Nuclear Engineering Ltd | Sugimura N.,Nuclear Engineering Ltd | Tatsumi M.,Nuclear Engineering Ltd
AIP Conference Proceedings | Year: 2015

After the Fukushima accidents, all nuclear power plants in Japan have gradually stopped their operations and have long periods of shutdown. During those periods, reactivity of fuels continues to change significantly especially for high-burnup UO2 fuels and MOX fuels due to radioactive decays. It is necessary to consider these isotopic changes precisely, to predict neutronics characteristics accurately. In this paper, shutdown cooling (SDC) effects of UO2 and MOX fuels that have unusual operation histories are confirmed by the advanced lattice code, AEGIS. The calculation results show that the effects need to be considered even after nuclear power plants come back to normal operation. © 2015 AIP Publishing LLC.


Yamamoto A.,Nagoya University | Endo T.,Nagoya University | Tabuchi M.,Nuclear Engineering Ltd | Sugimura N.,Nuclear Engineering Ltd | And 4 more authors.
Nuclear Engineering and Technology | Year: 2010

AEGIS is a lattice physics code incorporating the latest advances in lattice physics computation, innovative calculation models and efficient numerical algorithms and is mainly used for light water reactor analyses. Though the primary objective of the AEGIS code is the preparation of a cross section set for SCOPE2 that is a three-dimensional pin-by-pin core analysis code, the AEGIS code can handle not only a fuel assembly but also multi-assemblies and a whole core geometry in twodimensional geometry. The present paper summarizes the major calculation models and part of the verification/validation efforts related to the AEGIS code.


Narumiya Y.,Kansai Electric Power Co. | Kuramoto T.,Nuclear Engineering Ltd.
International Conference on Nuclear Engineering, Proceedings, ICONE | Year: 2012

The safety of NPPs has to be maintained in any condition which has to be considered. Rational criteria are especially needed for adequate classification of external hazards. Characteristics of external hazards, e.g. Tsunami, Earthquake, Land slide etc, are changed by features of the site. It is necessary to make a rational and clear process of classification to appropriate method of risk assessment. This study treated of various external hazards included natural phenomena and man-made events. Much disaster information was gathered from historical documents these one thousand and five hundred years (1). Published standards of US and IAEA were referred. This study provided some viewpoints for classification, e.g. hazard frequency, range of impact, basic design, and difficulty of accident management etc. The classification included several paths; a full-scope PRA, a hazard analysis, or a comparison between an impact of the hazard and the design condition against it. Copyright © 2012 by ASME.


The invention provides a biodegradable film or sheet having water resistance and strength sufficiently. Respective components are mixed so as to form a mixture containing 0% by mass or more and 35% by mass or less of starch, 20% by mass or more and 70% by mass or less of protein, 15% by mass or more and 60% by mass or less of cellulose fibers and 1% by mass or more and 15% by mass or less of urea, then adding 10 or more and 100 or less parts by mass of water to 100 parts by mass of the mixture, kneading the mixture sufficiently with a twin-screw mixer or the like, and rolling the kneaded product under heating at about 120C to give a film or sheet with several tens m to about 300 m in thickness.


The prevent invention provides a processed biodegradable article having excellent water resistance and rigidity, which can be used as a food container, and a biodegradable composition required to produce the processed biodegradable article. The respective components are mixed such that the content of starch is 15% by mass or more and 75% by mass or less, the content of protein is 5% by mass or more and 50% by mass or less, the content of cellulose fiber is 3% by mass or more and 50% by mass or less, the content of polyphenols is 0.5% by mass or more and 20% by mass or less, and the content of sodium chloride is 0% by mass or more and 5% by mass or less, and then water is added in the amount of 10 parts by mass or more and 100 parts by mass or less based on 100 parts by mass of the mixture, followed by kneading the mixture using a mixer. Then, the kneaded mixture is press-molded into a predetermined shape such as a cup or a dish, and heat-treated at 120C or higher and 180C or lower to obtain a processed article having excellent biodegradability.


An eddy-current flaw detection device is provided that improves spatial resolution of flaw detection signals and signal reproducibility during redetection of flaws, and reduces interference signals with simple circuit construction. The eddy-current flaw detection device comprises a magnetic element group of which a specified number of magnetic elements are evenly spaced in each of at least two rows that are formed around the surface of a column shaped casing that is formed such that it can be inserted into a conductive pipe (not shown in the figures), with one row 11 to 18 being located at a position that differs from the other row 21 to 28 by 1/2 the even spacing in the row direction, and switching circuits for switching the magnetic elements in the respective row of the magnetic element group at time-division. The magnetic elements 11 to 18 of one row function as magnetic field excitation elements that excite a magnetic field by being switched at time-division, the magnetic elements 21 to 28 of the other row function as magnetic field detection elements that detect a magnetic field by being switched at time-division, and the eddy-current flaw detection device performs eddy-current flaw detection of the conductive pipe by detecting each magnetic field that is excited by each magnetic field excitation element 11 to 18 by two magnetic field detection elements 21 to 28 that are each located at positions that differs from the magnetic field excitation elements 11 to 18 by 3/2 the even spacing in the row direction.


Patent
Nuclear Engineering LTD. | Date: 2015-03-25

There is provided a lightweight strain gauge holder having a simple structure. A strain gauge holder 1 includes a holder body 10 mounted on a side surface of a pipe 3, a gauge pressing member 21 for pressing a strain gauge 2 against the side surface of the pipe 3, and a feed mechanism for giving a pressing force to the gauge pressing member 21. The holder body 10 is provided with guide grooves 12 for guiding the gauge pressing members 21. The feed mechanism feeds the gauge pressing member 21 in the guide groove 12 to press the strain gauge 2 against the side surface of the pipe 3. The feed mechanism includes a cylindrical portion 32a having a thread formed on the inner surface thereof, a bushing 32 having a flange 32b provided on a tip end of the cylindrical portion 32a, and a feed screw 31 which is threadedly inserted into a back surface of the gauge pressing member 21. Each of the feed screws 31 threadedly inserted into the bushing 32 mounted on the holder body 10 is threadedly inserted to feed the gauge pressing member 21.


Patent
Nuclear Engineering Ltd. | Date: 2013-05-08

The strain gauge holder 1 includes a holder body 10 on a side surface of a pipe 3, a gauge pressing member 21 for pressing a strain gauge 2 against the side surface of the pipe, and a feed mechanism for giving a pressing force to the gauge pressing member. The guide grooves 12 guide the gauge pressing members. The feed mechanism feeds the gauge pressing member in the guide groove to press the strain gauge 2 against the side surface of the pipe 3. The feed mechanism includes cylindrical portion 32a, bushing 32, and feed screw 31. Each of the feed screws 31 threadedly inserted into the bushing mounted on the holder body is threadedly inserted to feed the gauge pressing member.


Tatsumi M.,Nuclear Engineering Ltd. | Chiba G.,Hokkaido University
Journal of Nuclear Science and Technology | Year: 2014

As the basis and fundamentals of nuclear technology, reactor physics has an important role to play; recent requirements for reliability and accountability to realize a higher level of safety have been encouraging researchers and engineers to study and develop more advanced and sophisticated numerical methods and calculation codes. Many of the outstanding research and developments are presented in scientific journals, including the Journal of Nuclear Science and Technology. Some topics have been covered in this summary from the latest activities in the field of reactor physics. © 2014 Atomic Energy Society of Japan.

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