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Yamamoto, Kazuyoshi; Kumada, Hiroaki; Torii, Yoshiya; Hori, Naohiko; Kishi, Toshiaki; Takada, Juntaro*; Otake, S.*
Proceedings of 9th International Symposium on Neutron Capture Therapy for Cancer, p.243 - 244, 2000/10
no abstracts in English
-ray analysis device at JRR-4Hori, Naohiko; Yamamoto, Tetsuya*; Matsumura, Akira*; Torii, Yoshiya; Yamamoto, Kazuyoshi; Kishi, Toshiaki; Takada, Juntaro*
Proceedings of 9th International Symposium on Neutron Capture Therapy for Cancer, p.263 - 264, 2000/10
no abstracts in English
Ishijima, Yasuhiro; Takada, Juntaro; Ueno, Fumiyoshi; Yamamoto, Masahiro; Uchiyama, Gunzo; Nojima, Yasuo*; Fujine, Sachio*; Kimura, Kazuhiro*
no journal, ,
Effect of ageing on mechanical properties of nickel based refractory alloy was evaluated for study on ageing behavior of nuclear fuel reprocessing plants. Solution treated and aged Alloy 625 was elected to test material. Creep tests and tensile tests were carried out at 1027 K. From test results, aged alloy 625 showed linear relationship between test stress and secondary creep rate. On the other hand, solution treated alloy 625 showed deformation behavior change at 100 MPa. This result indicates that the ageing behavior of reducing furnace can evaluate by straight line extrapolation. Aged alloy 625 showed remarkable decreasing of ductility at room temperature. This result suggests that room temperature embrittlement should be considered on the ageing behavior of reducing furnace.
Miwa, Shuhei; Nakajima, Kunihisa; Di Lemma, F. G.; Suzuki, Chikashi; Yamashita, Shinichiro; Okane, Tetsuo; Takai, Toshihide; Takada, Juntaro; Furukawa, Tomohiro; Osaka, Masahiko
no journal, ,
JAEA conducts a fundamental research on fission product (FP) chemistry to construct the database of FP chemistry at each stage of nuclear power plants and improve FP chemistry models which will be reflected to the improvement of FP release and transport models. Main target of FP elements are Cs and I, and the evaluation of FP and B release kinetics, development of direct measurement technique of FP chemical form, the evaluation of Cs chemisorption behavior to SS, upgrading the thermodynamic database are carried out with focuses on Mo and BWR control material, boron carbide (B
C).
Di Lemma, F. G.; Yamashita, Shinichiro; Nakajima, Kunihisa; Takada, Juntaro; Osaka, Masahiko; Nagase, Fumihisa
no journal, ,
Fission products chemisorption on reactor structural materials is an important phenomenon to be considered following an accident, as it can lead to retention of fission products in the containment, affecting the radioactive release to the environment and reactor decommissioning. The knowledge acquired from this study could help improve the models for cesium(Cs) chemisorption and could be applied to evaluate the distribution and properties of Cs deposits in the Fukushima-Daiichi Nuclear Power Plant, providing guidance for its decommissioning. Our studies were performed vaporizing CsOH over stainless steel samples, varying experimental parameters, such as temperature (800-1000
C) and atmosphere (H
/Ar, H/HO/Ar). Sample surfaces were analyzed by SEM/EDX, XRD to evaluate the deposit microstructure and chemical composition. The EDX characterization results demonstrate a congruent distribution between Cs and Si, and the XRD patterns indicate the formed Cs compound as CsFeSiO. These results show the importance of the presence of impurities in stainless steel, affecting the formation of stable Cs deposits.
Takai, Toshihide; Takada, Juntaro; Nakajima, Kunihisa; Furukawa, Tomohiro; Osaka, Masahiko
no journal, ,
Fundamental knowledge of the characteristics of the Cs-chemisorbed deposits was important for decommissioning of the Fukushima-Daiichi Nuclear Power Plant (1F). Some important information was obtained from foregoing experiments results. Nevertheless, it was not enough for covering 1F accident conditions. Purpose of this study was to confirm the Cs-chemisorption mechanism in a wider range of temperature and atmosphere. Synthesis results of Cesium silicates, which was expected to form under a severe accident, was described in this presentation.
C/SS/Zry mixed melts phasesDi Lemma, F. G.; Miwa, Shuhei; Takada, Juntaro; Takano, Masahide; Osaka, Masahiko
no journal, ,
Miyahara, Naoya; Miwa, Shuhei; Takada, Juntaro; Osaka, Masahiko
no journal, ,
A test facility for the reproduction of fission poroduct release and transport under a severe accident condition has been developed. It was confirmed that not only deposited but also airborne materials in the farnace of this facility under temperature condition of severe accident (1000 - 400 K at reactor coolant system) can be subjected to various analyses by measuring aerosol size distribution of airborne CsI aerosol.