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Yokoi, Shinobu*; Kamishima, Yoshio*; Sadahiro, Daisuke*; Takaya, Shigeru
JAEA-Data/Code 2016-002, 38 Pages, 2016/07
JAEA-Data-Code-2016-002.pdf:1.51MB
Many efforts have been made to implement the System Based Code concept aiming at optimizing margins dispersed in existing codes and standards. Failure probability calculated based on statistical information such as a type of probability distribution, mean (or median) and variance (or standard deviation) for random variables is expected to be a promising quantitative index for margin optimization. Statistical information on material strength, which is also required to calculate the failure probability, has been already reported in JAEA-Data/Code 2015-002 "Structural Properties of Material Strength for Reliability Evaluation of Components of Fast Reactors -Austenitic Stainless Steels-" whereas others have not been identified yet. This report provides methodologies and basic ideas to determine statistical parameters of other random variables, especially variable loads, necessary for reliability evaluation.
Chikazawa, Yoshitaka; Usui, Shinichi; Konomura, Mamoru; Sadahiro, Daisuke*; Tozawa, Katsuhiro*; Hori, Toru*; Toda, Mikio*; Kotake, Shoji*
Proceedings of 14th International Conference on Nuclear Engineering (ICONE-14) (CD-ROM), 7 Pages, 2006/07
A seismic analysis has been performed showing that the seismic interaction between the UIS and the FHM can be avoided adopting gapless bearings at the FHM arm joint. An angular contact ball bearing is suitable for the new FHM since it can eliminate gaps by preload pressure. A major problem of the FHM bearings is lubrication since the contact pressure between steel rings and ball increases because of ball bearing. Additionally, FHM operating temperature is about 200 deg-C and normal grease is not applicable under argon gas with sodium vapor. A endurance test with 1/10 scale bearings in the air has been performed to show applicability of angular contact ball bearings to the FHM arm joint. The results with 20,000 cycle showed that bearings with combination of MoS
coating steel rings and ceramics balls can be tolerable as the FHM operating condition. A real scale bearing test in argon gas with sodium vapor has also been demonstrated to reveal bearing size and sodium vapor effects.
Nagashima, Hedeaki; Shibamoto, Hiroshi; Inoue, Kazuhiko; kasahara, Naoto; Sadahiro, Daisuke*
Proceedings of 2005 ASME International Mechanical Engineering Congress and Exposition (CD-ROM), 0 Pages, 2005/08
Focusing on the cover layer materials (as the Radon Barrier Materials), which could have the effect to restrain the radon from scattering into the air and the effect of the radiation shielding, we produced the radon barrier materials with crude bentonite on an experimental basis, using the rotary type comprehensive unit for grinding and mixing, through which we carried out the evaluation of the characteristics thereof.
Sadahiro, Daisuke*
JNC TJ9400 2001-020, 91 Pages, 2002/03
JNC-TJ9400-2001-020.pdf:4.01MB
Plant economics is one of important items in FBR development. In present FBR design, large design factor provided in design standards is considered to be one of restriction for the improvement of FBR economics. From such a background, FBR Integrity System Code (FISC), which is for settlement of appropriate design margin, is now under development. Aim of this study is to contribute to the development of this code, and investigation study on inspection technique and flame of code for inspection has been performed. The results of this studyare as follows. (1)Study of position of code for inspection. The present code and standard for inspection and evaluation examples for risk assessment, which is one of method fbr margin exchange, have been investigated, and inspection accuracy, inspection interval, type of inspection and inspection procedure etc. have been extracted as the standardization item. In these items, first two items, in particular, have a large contribution to rationalization. (2)Investigation of inspection technique. Because the inspection accuracy is one of important item from study item (1), present status of Ultrasonic Testing (UT) technique, which is the one of the method used for ISI, has been investigated. And, monitoring technique, which is effective for rationalization of inspection, has been also investigated. Concerning UT, estimation of detection limit is difficult, but it is considered that detection of 1-2mm depth crack can be detected by present UT technique. On monitoring technique, fatigue or crack monitoring can contribute to maintenance schedule. (3)Study of flame of code for inspection. Based on the above study results, the standardization items in code for inspection have been extractcd, and area and flame of this code have been studied. Because FISC is considered to provide the concrete design procedures, present code and guideline such JEAC and JEAG is considered to be covered in this code. Material inspection included ...
Usui, Shinichi; Chikazawa, Yoshitaka; Konomura, Mamoru; Sadahiro, Daisuke*; Tozawa, Katsuhiro*; Hori, Toru*
no journal, ,
no abstracts in English
Tsukimori, Kazuyuki; Moriizumi, Makoto; Abe, Masato; Sadahiro, Daisuke*; Ishigaki, Yoshinobu*
no journal, ,
The elastic limit and the collapse load of a rectangular or circular cross-section beam subjected to both bending moment and shear force are derived analytically with partially approximation. According to the result, there is no interaction between bending moment and shear force in the region of elastic, however, there is an interaction between them with some relation, which is complicated but seems to be close to oval shape. The validity of this relation is examined by FEM analysis.