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Suzuki, Eriko; Takase, Gaku; Nakajima, Kunihisa; Nishioka, Shunichiro; Hashimoto, Naoyuki*; Isobe, Shigehito*; Osaka, Masahiko
Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR 2019) (Internet), 4 Pages, 2019/05
In order to acquire the knowledge of the Cs chemisorption behaviour in the lower temperature region, the Cs chemisorbed compounds and the surface reaction rates were investigated by conducting the Cs chemisorption tests onto stainless steel at 873 and 973 K. As a result, The cesium ferrate compounds were revealed to be formed at this temperatures. It was seen that the dependences of surface reaction rate constant on this temperature were different from that at the higher temperature region. This behaviour leads to the conclusion that the Cs chemisorption model in the low temperature region should be newly constructed.
Hasegawa, Shin; Koshikawa, Hiroshi; Sawada, Shinichi; Maekawa, Yasunari; Hashimoto, Naoyuki*; Isobe, Shigehito*
no journal, ,
For establishing a safe and non-electric power type explosion prevention system with hydrogen storage materials, hydrogen permselective membranes against oxygen and water vapor have been developed. Using a radiation-induced grafting method, 4-trimethoxysilylstyrene (TMSS) and acrylic acid (AAc) monomers were introduced onto porous poly(vinylidene fluoride) (PVDF) films to obtain TMSS- and AAc-grafted PVDF membranes with grafting degrees of 29 and 24%. The TMSS- and AAc-grafted PVDF membranes showed permeabilities of hydrogen 3.5 and 12 time higher than those of water vapor. The above results indicated that radiation-grafting of porous films should be very effective method to obtain hydrogen permselective membranes.
Hasegawa, Shin; Azami, Shinya*; Sawada, Shinichi; Hino, Satoshi*; Isobe, Shigehito*; Hashimoto, Naoyuki*; Maekawa, Yasunari
no journal, ,
Hydrogen permselective membranes, which have high hydrogen permeability (approximately 10
10
mol/(m
s Pa) with selectivity against water and nitrogen, have been developed by radiation-induced graft polymerization (RIGP) of an acrylic acid (AAc), tetramethoxysirylstyrene (TMSS), and styrene(St) monomers into porous poly(vinylidene fluoride) (PVDF) films. The porosity of the prepared porous grafted PVDF were almost constant against grafting degrees. Thus, by hot press compression, the porosity of the grafted membranes was reduced to a 20-40% level. The hydrogen permeability of the compressed grafted PVDF is 10 10 mol/(m s Pa) with the hydrogen permselectivity of 3.2 and 3.5 against water and nitrogen, respectively. The above results indicate that RIGP of porous films with a hot press process is a very effective method to prepare hydrogen permselective membranes.
Suzuki, Eriko; Ogawa, Hiroaki; Nakajima, Kunihisa; Nishioka, Shunichiro; Osaka, Masahiko; Yamashita, Shinichiro; Kurishiba, Ryoko*; Endo, Takashi*; Isobe, Shigehito*; Hashimoto, Naoyuki*
no journal, ,
To elucidate Cs chemisorption behaviour onto stainless steel under LWR severe accident condition, elemental distribution measurement at microlevel was performed by using XPS and TEM. As a result, it was found that Cs-(Fe)-Si-O compounds, which have different composition, could be distributed.
Maekawa, Yasunari; Hasegawa, Shin; Sawada, Shinichi; Chen, J.; Hashimoto, Naoyuki*; Isobe, Shigehito*
no journal, ,
no abstracts in English
Suzuki, Eriko; Ogawa, Hiroaki; Nakajima, Kunihisa; Nishioka, Shunichiro; Osaka, Masahiko; Yamashita, Shinichiro; Kurishiba, Ryoko*; Endo, Takashi*; Isobe, Shigehito*; Hashimoto, Naoyuki*
no journal, ,
To elucidate Cs chemisorption behaviour onto stainless steel under LWR severe accident condition, elemental distribution measurement at microlevel was performed by using XPS and TEM. As a result, it was found that Cs-(Fe)-Si-O compounds, which have different composition, could be distributed.
Suzuki, Eriko; Nakajima, Kunihisa; Miwa, Shuhei; Osaka, Masahiko; Hashimoto, Naoyuki*; Isobe, Shigehito*
no journal, ,
In order to clarify the revaporization behaviour of cesium (Cs) chemisorbed onto stainless steel under severe accident conditions, the chemical form and distribution of fine Cs chemisorbed compounds were investigated using microscopic analytical methods. It was found that the chemical form and crystal structure differed according to the temperature of Cs chemisorption and depth from the surface. The difference can affect the revaporization rate and revaporized species.
Suzuki, Eriko; Nakajima, Kunihisa; Miwa, Shuhei; Osaka, Masahiko; Hashimoto, Naoyuki*; Isobe, Shigehito*
no journal, ,
In order to improve the cesium (Cs) chemisorption model onto stainless steel (SUS), the chemical forms and distributions of Cs compounds formed inside of the SUS oxide layer at 873-1273 K were evaluated based on the microscopic observation. It was revealed that compositions of Cs compounds varies alonbg depth from the oxide layer surface on SUS, which was tested in 1073-1273 K. In addition, an amorphous phase containing Cs was observed inside of the oxide layer on the SUS tested in 873-973 K. These results suggest that the chemical reactions occurred inside of the SUS oxide layer are different from that in the nearest region of the SUS oxide layer surface.
Suzuki, Eriko; Nakajima, Kunihisa; Miwa, Shuhei; Osaka, Masahiko; Hashimoto, Naoyuki*; Isobe, Shigehito*; Oka, Hiroshi*
no journal, ,
In order to evaluate the properties of chemisorbed cesium (Cs) onto the structural materials in nuclear reactors during severe accidents, temperature dependency of the chemical forms of Cs chemisorbed compounds was investigated based on the compilation of previous studies, the simulation tests of Cs chemisorption onto stainless steel, the acquisition of thermodynamic data and the thermodynamic equilibrium calculations, and the microstructure observation of chemical forms inside the oxide layer. It was revealed that the different Cs chemisorbed compounds were formed depending on the temperature conditions, such as Cs-Fe-O at 873-973 K, Cs-Fe-Si-O at 973-1273 K and Cs-Si-O at 1073-1273 K.
Hashimoto, Naoyuki*; Isobe, Shigehito*; Oka, Hiroshi*; Hayashi, Shigenari*; Ueda, Mikito*; Yamashita, Shinichiro; Itakura, Mitsuhiro; Tsuru, Tomohito
no journal, ,
Owing to the reduced defects, low cost, and high efficiency, the additive manufacturing (AM) technique has attracted increasingly attention and has been applied in high-entropy alloys (HEAs) in recent years. For the purpose of creating new materials which show no radiation damage or prompt recovery of radiation damage, we launched a new program in which additive-manufactured HEAs are target materials and their fundamental properties are under investigation. In this presentation, we reported the some of new test results which are conducted in the program.
Yamashita, Shinichiro; Ioka, Ikuo; Oka, Hiroshi*; Isobe, Shigehito*; Hashimoto, Naoyuki*
no journal, ,
The objective of this work is the development of new reduced activation HEAs applicable to next generation small module reactor components by using additive manufacturing (3D printing) method under the support of the 2020 MEXT Innovative Nuclear Research and Development Program. In the third presentation, we will share the highlighted results on radiation properties of the newly developed HEAs in this work.
Hashimoto, Naoyuki*; Ueda, Mikito*; Hayashi, Shigenari*; Oka, Hiroshi*; Isobe, Shigehito*; Yamashita, Shinichiro; Itakura, Mitsuhiro; Tsuru, Tomohito
no journal, ,
The objective of this work is the development of new reduced activation HEAs applicable to next generation small module reactor components by using additive manufacturing (3D printing) method under the support of the 2020 MEXT Innovative Nuclear Research and Development Program. We firstly introduce the outline of this work as a part of the series presentation.
Oka, Hiroshi*; Sato, Motoki*; Hashimoto, Naoyuki*; Isobe, Shigehito*; Yamashita, Shinichiro
no journal, ,
The objective of this work is the development of new reduced activation HEAs applicable to next generation small module reactor components by using additive manufacturing (3D printing) method under the support of the 2020 MEXT Innovative Nuclear Research and Development Program. In the second presentation, we will share the highlighted results on mechanical properties as well as microstructure of the newly developed HEAs in this work.
Suzuki, Eriko; Nakajima, Kunihisa; Miwa, Shuhei; Osaka, Masahiko; Hashimoto, Naoyuki*; Isobe, Shigehito*; Oka, Hiroshi*
no journal, ,
In order to evaluate the properties of chemisorbed cesium (Cs) onto the structural materials in nuclear reactors during severe accidents, temperature dependency of the chemical forms of Cs chemisorbed compounds was investigated based on the compilation of previous studies, the simulation tests of Cs chemisorption onto stainless steel, the acquisition of thermodynamic data and the thermodynamic equilibrium calculations, and the microstructure observation of chemical forms inside the oxide layer. It was revealed that the different Cs chemisorbed compounds were formed depending on the temperature conditions, such as Cs-Fe-O at 873-973 K,Cs-Fe-Si-O at 973-1273 K and Cs-Si-O at 1073-1273 K.
Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro; Hashimoto, Naoyuki*; Isobe, Shigehito*
no journal, ,
JAEA has been proceeding the simulation of hydrogen behavior which performed as a part of development of the safe and non-electric power type explosion prevention system with hydrogen storage materials for facilities, especially nuclear reactor building. This reports that simulation results of hydrogen storage test which was performed by Hokkaido University.
Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro; Hashimoto, Naoyuki*; Isobe, Shigehito*
no journal, ,
no abstracts in English
Suzuki, Eriko; Nakajima, Kunihisa; Miwa, Shuhei; Osaka, Masahiko; Hashimoto, Naoyuki*; Isobe, Shigehito*
no journal, ,
In order to study the cesium (Cs) chemisorption behavior onto stainless steel (SUS) under severe accident conditions, the chemical form and distribution of Cs compounds formed inside of the SUS oxide layer were investigated based on the microscopic observation such as TEM/EDS. As a result, it was revealed that chemical forms of Cs compounds varies along chemisorption temperature and depth from the SUS oxide layer surface.
Maekawa, Yasunari; Hasegawa, Shin; Sawada, Shinichi; Chen, J.; Hashimoto, Naoyuki*; Isobe, Shigehito*
no journal, ,
For establishing a safe and non-electric power type explosion prevention system with hydrogen storage materials, hydrogen permselective membranes against oxygen and water vapor have been developed. Using a radiation-induced grafting method, 4-trimethoxysilylstyrene (STMS) and acrylic acid (AAc) monomers were introduced onto porous poly(vinylidene fluoride) (PVDF) films to obtain STMS- and AAc-grafted PVDF membranes with grafting degrees of 23 and 24%. The STMS- and AAc-grafted PVDF membranes showed permeabilities of hydrogen 8.1 and 12 time higher than those of water vapor. The above results indicated that radiation-grafting of porous films should be very effective method to obtain hydrogen permselective membranes.
Yamashita, Shinichiro; Ioka, Ikuo; Abe, Yosuke; Oka, Hiroshi*; Isobe, Shigehito*; Hashimoto, Naoyuki*
no journal, ,
The objective of this work is the development of new reduced activation HEAs applicable to next generation small module reactor components by using additive manufacturing (3D printing) method under the support of the 2020 MEXT Innovative Nuclear Research and Development Program. In the third presentation, we will share the highlighted results on radiation properties of the newly developed HEAs in this work.