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Miwa, Shuhei; Ducros, G.*; Hanus, E.*; Bottomley, P. D. W.*; Van Winckel, S.*; Osaka, Masahiko
Nuclear Engineering and Design, 326, p.143 - 149, 2018/01
Times Cited Count：3 Percentile：29.78(Nuclear Science & Technology)The release and transport behaviors of 13 non-gamma-emitting fission products (FPs) and actinides in steam and hydrogen atmospheres were investigated based on the chemical analysis of their deposits on the components of VERCORS test loops. The new findings were obtained; strontium release was significantly enhanced in hydrogen atmosphere and a part of released strontium was transported towards the lower temperature region, uranium release was enhanced in steam atmosphere but most of released uranium deposited at high temperature region.
Osaka, Masahiko; Nakajima, Kunihisa; Miwa, Shuhei; Di Lemma, F. G.*; Miyahara, Naoya; Suzuki, Chikashi; Suzuki, Eriko; Okane, Tetsuo; Kobata, Masaaki
Proceedings of 8th European Review Meeting on Severe Accident Research (ERMSAR 2017) (Internet), 11 Pages, 2017/05
Fundamental research on fission product (FP) chemistry is underway at Japan Atomic Energy Agency. The purpose is to establish a FP chemistry database in each region of a LWR under severe accident conditions. Improvement of FP chemical models based on this database is also an important task of the research. Research outputs are reflected to the research and development of decommissioning of Fukushima Daiichi Nuclear Power Station (1F) and the enhancement of LWR safety. Four research items have thus been established considering the specific issues of 1F and the priority in the source term research area, as follows: - Effects of boron (B) release kinetics and thermal-hydraulic conditions on FP behavior, - Cesium (Cs) chemisorption and reactions with structural materials, - Establishment of a thermodynamic and thermophysical properties database for FP compounds, - Development of experimental and analytical techniques for the reproduction of FP behavior. In this paper, results and progress of the research are presented.
Osaka, Masahiko; Miwa, Shuhei; Nakajima, Kunihisa; Suzuki, Chikashi
no journal, ,
Research outline for fission product chemistry is introduced. Research plan, experiment, analysis and evaluation, together with subject and procedure of the FP-chemistry, are given. The purpose is to construct a database for FP chemistry at each stage of reactor under SA conditions and improvement of FP chemical model. Acquisition of experimental data for FP chemical form are carried out and their chemical kinetic analysis is performed for the database construction.
Osaka, Masahiko; Miwa, Shuhei; Nakajima, Kunihisa; Di Lemma, F. G.; Suzuki, Chikashi; Nagase, Fumihisa
no journal, ,
Chemical behavior of fission product (FP) are of crucial importance for the improvement of FP release and transport behavior under the severe accident. Fundamental research on FP sorption behavior and evaluation of FP chemical composition in the reactor are introduced.
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.
Miyahara, Naoya; Suzuki, Eriko; Uesawa, Shinichiro; Sato, Isamu*; Matsuura, Haruaki*; Hagura, Naoto*; Koshigoe, Koki*; Osaka, Masahiko
no journal, ,
We have started the fundamental research on detailed aerosol deposition phenomena at the walls of containment vessel and reactor building to develop a reasonable evaluation model of aerosol deposition amount which have a large influence on release amount to the environment. In this study, an aerosol deposition test onto various materials was conducted to investigate the physical and chemical phenomena related to aerosol deposition. As a result, important phenomena such as aerosol penetration into concrete pore were observed, which should be considered in the aerosol deposition model.
