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Uchida, Masahiro; Hoshi, Katsuya; Yamazaki, Takumi; Tsujimura, Norio; Takada, Chie
no journal, ,
no abstracts in English
Okuda, Takahiro
no journal, ,
This study describes the setting of the material property equations of 316FR steel at an extremely high temperature which can be applied to severe accident conditions of generation IV fast reactors. After the severe accident in Fukushima Daiichi Nuclear Power Plants, the evaluation of structural integrity was found to be very important severe accident condition. The development of the generation IV fast reactors requires the material properties of 316FR steel at the extremely high temperature. However, such data has not been acquired. Therefore, tensile and creep tests were carried out in the temperature range over 700
C for 316FR steel. Based on the acquired data from the tests, the equations that can evaluate the material properties of 316FR steel at the extremely high temperature were set up. They are a creep rupture equation and a creep strain equation.
Matsushita, Kentaro; Ito, Kei*; Ezure, Toshiki; Tanaka, Masaaki
no journal, ,
A numerical simulation code named SYRENA has been developed in JAEA to analyze the behavior of entrained bubbles and dissolved gas in the primary coolant of sodium-cooled fast reactor (SFR). In the present study, a flow network model for a pool-type SFR was newly developed in SYRENA and the non-condensable gas behavior in the pool type SFR was analyzed. A dipped-plate (D/P) model was introduced into the flow network to investigate influences of D/P installation on the non-condensable behavior in the pool-type reactor. A parametric study was performed on the exchange flow rate through the D/P and the gas entrainment rate at the free surface existing above the D/P. The non-condensable gas behavior under various flow conditions, e.g. gas entrainment rate condition, was obtained. Especially, it was observed that the bubble volume in the primary coolant system changed with the exchange flow rate though the change ratio is dependent on the gas entrainment.
Kanda, Naoyuki; Kijima, Jun
no journal, ,
no abstracts in English
Kusaka, Ryoji; Watanabe, Masayuki
no journal, ,
We study extraction mechanism of metal elements from the aqueous phase to the organic phase to improve separation technology by solvent extraction. In the present presentation, we comprehensively show recent results about transfer mechanism of metal elements, studied by Vibrational Sum Frequency Generation (VSFG) spectroscopy. Based on the results, we propose a novel way for improvement of solvent extraction technology.
Yamashita, Hayato
no journal, ,
no abstracts in English
Kaneko, Masashi; Kato, Akane*; Nakashima, Satoru*; Kitatsuji, Yoshihiro; Watanabe, Masayuki
no journal, ,
Ruthenium exists as ruthenium nitrosyls, [Ru(NO)]
, in high-level radioactive liquid waste and shows various stabilities depending on concentrations of nitrate and hydroxide ions. The detailed stabilities, however, remain to be unclear. As the first step to understand the stabilities of ruthenium nitrosyls, the present study focuses on the structural and bonding properties of the nitrosylruthenium species with fundamental ligands, such as chloride ion and ammonia. We modeled the ruthenium species by referring the corresponding single crystal structures and calculated the stable geometries under aqueous condition. The result reproduced the ruthenium-ligand bond lengths and the stretching vibrational energies of nitrosyl group. We also estimated 
Ru M
ssbauer isomer shifts based on electron density analysis and succeeded in reproducing the ismoer shifts. In the presentation, we will indicate the correlation between the isomer shifts and ligand field splitting derived by molecular orbital analysis and discuss an origin of the stability of ruthenium nitrosyls.
Saegusa, Yu; Yamamoto, Masahiko; Inada, Satoshi; Kuno, Takehiko
no journal, ,
Selenium-79 in highly active liquid waste (HAW) is important nuclides due to abundance and dose evaluation in regards to treatment and disposal of vitrified glass. Iodine-129 shifts to shearing and dissolver off-gas so it is not included in HAW. However there are few analysis report of iodine in HAW. These are difficult to be analyzed by radioactivity method due to a long half-life nuclide and emits low energy beta ray. Accurate analysis by inductively coupled plasma mass spectrometry is difficult due to the isobaric interference. In this study, we investigated analytical method for selenium-79 and iodine-129 by inductively coupled plasma mass spectrometry with collision reaction cell technique. Reaction gas can be introduced into the cell and isobaric ion can be eliminated. We will report the fundamental experiment results to determine selenium-79 and iodine-129 by collision reaction cell typed ICP-MS in this presentation.
Miyazaki, Yasunori; Watanabe, So; Nakamura, Masahiro; Shibata, Atsuhiro; Nomura, Kazunori
no journal, ,
High-level liquid waste generated by reprocessing spent nuclear fuel is geologically disposed after vitrification, and partitioning and transmutation of minor actinide (MA: Am, Cm) is performed to minimize the volume and toxicity of radioactive waste. We have been developing extraction chromatography for selective MA partitioning. The calculation code that simulates partitioning behavior of ions is developed, but the chromatogram is not yet reproduced adequately. The resonance neutron imaging at J-PARC allows us to observe partitioning behavior of ions inside the column undestructively. The obtained diffusion and dispersion data is applied to upgrade the simulation code as well as increase of column partition property.
Sato, Junya; Irisawa, Keita; Nakazawa, Osamu; Takaoka, Masaki*
no journal, ,
no abstracts in English
Hashidate, Ryuta; Kato, Shoichi; Onizawa, Takashi; Wakai, Takashi; Kasahara, Naoto*
no journal, ,
Under the severe accident conditions, structural materials of nuclear power plants are subjected to excessive high temperature. Although it is very essential to clarify how the structure collapses under the severe accident conditions, the failure mechanisms in such high temperatures are not clarified. However, it is very difficult and expensive to perform structural tests using actual structural materials. Therefore, we propose to use lead alloys instead of actual structural materials. Because the strength of lead alloys is much poorer than that of the actual structural materials, failure can be observed at low temperature and by small load. For demonstration of analogy between the failure mechanisms of lead alloys structure at low temperature and those of the actual structures at high temperature, numerical analyses are required. So, we confirm the material characteristics of lead alloys and develop inelastic constitutive equations of lead alloy required for finite element analyses.
Hirota, Kenji
no journal, ,
no abstracts in English
Cm and 
Cm using high time-resolution neutron pulses at J-PARC MLFKawase, Shoichiro; Kimura, Atsushi; Harada, Hideo; Iwamoto, Nobuyuki; Iwamoto, Osamu; Nakamura, Shoji; Segawa, Mariko; Toh, Yosuke
no journal, ,
no abstracts in English
Takahashi, Akina; Sakashita, Satoshi; Yoshida, Tadayoshi; Shiba, Kozo
no journal, ,
no abstracts in English
Sakashita, Satoshi; Takahashi, Akina; Yoshida, Tadayoshi; Shiba, Kozo
no journal, ,
no abstracts in English
-ray irradiation on mechanical strength of polycarbonate materialKawasaki, Kohei
no journal, ,
no abstracts in English
Morishita, Kazuki; Onishi, Takashi; Maeda, Koji; Mizokami, Masato*; Ito, Kenichi*; Mizokami, Shinya*
no journal, ,
no abstracts in English
Shibanuma, Tomohiro
no journal, ,
no abstracts in English
Toyota, Kodai
no journal, ,
no abstracts in English
Ambai, Hiromu
no journal, ,
The fuel debris which generated in the severe accident of Fukushima Daiichi Nuclear Power Plant (1F) of the Tokyo Electric Power Company Holdings, Inc. are under the water. Thus, it is important to understand the elution behavior of nuclear species in water. It has been reported that fuel debris consist of a number of phase by studies for TMI-2 and 1F accident. We can get only averaged information about all phases using normal methods. It is expected to have a better understanding about the elution mechanism of debris. In this study, we tried the evaluation of the elution reaction on fuel debris by getting the electrochemical properties of each phase, using scanning electrochemical microscopy which can measure local electrochemical property.