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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.
Takai, Toshihide; Sato, Isamu*; Yamashita, Shinichiro; Furukawa, Tomohiro
JAEA-Technology 2015-043, 56 Pages, 2016/02
JAEA-Technology-2015-043.pdf:23.14MB
Fundamental research on FP-chemistry for fission product release behaviors under severe accident was carried out for reinforcement of source term evaluation, and implementation of the 1F decommissioning R&D project. There were subjects to clarified (1) FP chemistry behavior between vapor species release and aerosol formation and (2) physical parameters which would be affect subsequent aerosol's chemical behavior, for improvement of FP transport model. Applicability of measuring/analyzing techniques presently used was studied for evaluating foregoing properties. And the validity was verified by trial measurements. In conclusion, Raman spectrometry and high temperature X-ray diffraction were hopeful to determine FP-chemical form against vapor/aerosol species and aerosol species, respectively. Combination use of cascade impactor and scanning type electron microscope with energy-dispersive X-ray spectrometry was hopeful to determine physical parameters of aerosol.
Osaka, Masahiko
no journal, ,
Research program for chemical behavior of fission products during severe accident is introduced. The goal is to construct a database for FP chemistry at each stage of the nuclear power station. In-situ measurement techniques of the FP chemical form are developed for those just after release from fuel and deposited onto the structural materials. Reproduction test for FP release and transport behaviors are performed using irradiated fuels for the chemical form determination by means of the developed techniques for in-situ chemical form determination. Several preliminary results such as B effects on deposited FP are also given.
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.
Takai, Toshihide; Sato, Isamu; Yamashita, Shinichiro; Furukawa, Tomohiro; Osaka, Masahiko
no journal, ,
Property evaluation methods of aerosol, which was released from the simulated FP release test apparatus, were considered, as part of the direct measurement technique of FP's chemical form. It is important to prevent thermal flow from having an effect by installing instruments, for evaluating aerosol property (chemical form, particle diameter distribution, and shape) under simulated severe accident conditions correctly. A low flow cascade impactor with a gas flow control system was installed to the test apparatus, and applicability for aerosol property evaluation was confirmed by heating test using simulated CsI.
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.
Takai, Toshihide; Sato, Isamu*; Furukawa, Tomohiro; Osaka, Masahiko
no journal, ,
Fundamental research to clarify FP's chemical behavior under severe accident was carried out for reinforcement of source term evaluation and implementation of the Fukushima Daiichi Nuclear Power Station decommissioning R&D. Vapor species, which was released form over heated nuclear fuel under severe accident, was cooled and aerosol was produced during transition from release to reactor cooling system. The transient behavior of the aerosol was assumed significantly different depending on the chemical forms. Evaluation technique for material property immediately after aerosol formation was extracted, and applicability was confirmed.
Ishikawa, Jun; Zheng, X.; Shiotsu, Hiroyuki; Sugiyama, Tomoyuki
no journal, ,
no abstracts in English
Shiotsu, Hiroyuki; Ito, Hiroto*; Sugiyama, Tomoyuki; Maruyama, Yu
no journal, ,
no abstracts in English