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Journal Articles

Evolution of the reaction and alteration of granite with Ordinary Portland cement leachates; Sequential flow experiments and reactive transport modelling

Bateman, K.*; Murayama, Shota*; Hanamachi, Yuji*; Wilson, J.*; Seta, Takamasa*; Amano, Yuki; Kubota, Mitsuru*; Ouchi, Yuji*; Tachi, Yukio

Minerals (Internet), 12(7), p.883_1 - 883_20, 2022/07

 Times Cited Count:0 Percentile:0.02(Geochemistry & Geophysics)

Journal Articles

Evolution of the reaction and alteration of mudstone with ordinary Portland cement leachates; Sequential flow experiments and reactive-transport modelling

Bateman, K.; Murayama, Shota*; Hanamachi, Yuji*; Wilson, J.*; Seta, Takamasa*; Amano, Yuki; Kubota, Mitsuru*; Ouchi, Yuji*; Tachi, Yukio

Minerals (Internet), 11(9), p.1026_1 - 1026_23, 2021/09

 Times Cited Count:2 Percentile:25.31(Geochemistry & Geophysics)

Journal Articles

Reaction and alteration of mudstone with Ordinary Portland Cement and Low Alkali Cement pore fluids

Bateman, K.; Amano, Yuki; Kubota, Mitsuru*; Ouchi, Yuji*; Tachi, Yukio

Minerals (Internet), 11(6), p.588_1 - 588_19, 2021/06

 Times Cited Count:4 Percentile:48.4(Geochemistry & Geophysics)

Journal Articles

Optimization for SEU/SET immunity on 0.15 $$mu$$m fully depleted CMOS/SOI digital logic devices

Makihara, Akiko*; Asai, Hiroaki*; Tsuchiya, Yoshihisa*; Amano, Yukio*; Midorikawa, Masahiko*; Shindo, Hiroyuki*; Kuboyama, Satoshi*; Onoda, Shinobu; Hirao, Toshio; Nakajima, Yasuhito*; et al.

Proceedings of 7th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-7), p.95 - 98, 2006/10

no abstracts in English

Journal Articles

Field emission-type scanning electron microscope for examination of irradiated fuels

Yasuda, Ryo; Mita, Naoaki; Nishino, Yasuharu; Nakata, Masahito; Nozawa, Yukio; Harada, Katsuya; Kushida, Teruo; Amano, Hidetoshi

Nuclear Technology, 151(3), p.341 - 345, 2005/09

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

The Field Emission type Scanning Electron Microscope (FE-SEM), which is one of effective tools for observation of micr-structures, was installed at the Reactor Fuel Examination Facility (RFEF) in JAERI. The FE-SEM is equipped in a large shield vessel with remote handling systems to keep safety of operators and is modified to enable to manipulate high radioactive materials. The Energy Dispersive Spectrometer (EDS) with radiation-shielded collimators has been also equipped on the FE-SEM to determine element compositions of the observed material samples. Characterization tests were carried out using deposited gold film and Zircaloy cladding tubes with hydrides to confirm the machine performance after the modifications. In the results of the tests, high-resolution images without some noises and fogs were obtained with high magnification above 10,000. Those results show that the FE-SEM keeps the high performance after some improvements and modifications for shielding $$gamma$$-rays and handling radioactive samples.

JAEA Reports

Development of remote controlled type field-emission type scanning electron microscope

Yasuda, Ryo; Nishino, Yasuharu; Mita, Naoaki; Nakata, Masahito; Harada, Katsuya; Nozawa, Yukio; Amano, Hidetoshi

JAERI-Tech 2002-081, 34 Pages, 2002/10

JAERI-Tech-2002-081.pdf:11.76MB

Information about the fuel behavior under high burn-up operation is needed to assess the safety of the high burn-up fuels. Microstructures in irradiated fuel pellets and Zircaloy tubes influence on their integrity. The fundamental information about microstructures is necessary to estimate the formation mechanism and change in the properties of the fuels.The Field Emission type Scanning Electron Microscope (FE-SEM) has been hence installed at the Reactor Fuel Examination Facility (RFEF). FE-SEM is designed for the remote handling type to use high radioactive materials and has equipments to keep safety for operators. Charctarization tests were carried out using Zircaloy cladding tubes with oxide films and hydrides to confirm machine performance. In the results of the tests, high-resolution images with a magnification of 30,000 were obtained. Those results show that the apparatus is maintained high performance as well as standard type.

JAEA Reports

A Study of existing experimental data and validation process for evaluated high energy nuclear data; Report of task force on integral test for JENDEL high energy file in japanese nuclear data committee

Oyama, Yukio; *; Watanabe, Yukinobu*; Kawano, Toshihiko*; Numajiri, M.*; Ueki, Kotaro*; *; Yamano, Naoki*; Kosako, Kazuaki*; *; et al.

JAERI-Review 98-020, 130 Pages, 1998/11

JAERI-Review-98-020.pdf:6.4MB

no abstracts in English

Journal Articles

Production and verification of the MCNP cross section library FSXLIB-J3R2 based on JENDL-3.2

Kosako, Kazuaki*; Yamano, Naoki*; Maekawa, Fujio; Oyama, Yukio

Proc., 1996 Topical Meeting on Radiation Protection and Shielding, 1, p.1088 - 1095, 1996/00

no abstracts in English

JAEA Reports

Benchmark problems for intermediate and high energy accelerator shielding

; Sakamoto, Yukio; Tanaka, Shunichi; ; Fukahori, Tokio; ; Sasamoto, Nobuo; Tanaka, Susumu; Nakamura, Takashi*; Shin, Kazuo*; et al.

JAERI-Data/Code 94-012, 90 Pages, 1994/09

JAERI-Data-Code-94-012.pdf:2.26MB

no abstracts in English

Oral presentation

Optimization for SEU/SET immunity on 0.15$$mu$$m fully depleted CMOS/SOI digital logic devices

Makihara, Akiko*; Asai, Hiroaki*; Tsuchiya, Yoshihisa*; Amano, Yukio*; Midorikawa, Masahiko*; Shindo, Hiroyuki*; Kuboyama, Satoshi*; Onoda, Shinobu; Hirao, Toshio; Nakajima, Yasuhito*; et al.

no journal, , 

no abstracts in English

Oral presentation

Half-life measurements of neutron-deficient isotopes using laser Compton scattering $$gamma$$-rays at NewSUBARU

Hayakawa, Takehito; Shizuma, Toshiyuki; Miyamoto, Shuji*; Amano, Sho*; Horikawa, Ken*; Hayashi, Yukio; Kawase, Keigo; Kando, Masaki; Kikuzawa, Nobuhiro; Chiba, Satoshi; et al.

no journal, , 

no abstracts in English

Oral presentation

Study of complex magnetic structures in frustrated magnets by means of polarized neutrons

Kakurai, Kazuhisa; Wakimoto, Shuichi; Matsuda, Masaaki*; Ishiwata, Shintaro*; Okuyama, Daisuke*; Taguchi, Yasujiro*; Tokura, Yoshiki*; Nishi, Masakazu*; Nakajima, Taro*; Mitsuda, Setsuo*; et al.

no journal, , 

Oral presentation

An Analogue study for heavy metal adsorption onto biofilm in the deep subsurface environment of the Horonobe area, Hokkaido, Japan

Amano, Yuki; Ise, Kotaro; Ito, Tsuyoshi; Nemoto, Kazuaki; Tachi, Yukio

no journal, , 

We characterized the geochemical and microbial structures of biofilm samples formed with groundwater from boreholes in the subsurface environment at Horonobe area, Japan. The biofilm samples were grown naturally into the sampling tubes made by nylon under in-situ geochemical conditions. The heavy metal sorption capacities of these biofilms were also determined to evaluate the effects of microorganims on radionuclides transport in HLW systems. From the results of heavy metal analyses, it is revealed that high content of elements was accumulated in the biofilms, and each elements was not accumulated in quantity in the same proportion and had different sorption properties. We could find no discernible correlation between those elements accumulated in the biofilms and the composition of groundwaters. It is assumed that these differences depend on the microbial community structure that composed of biofilms. That is to say, it is possible that microorganims that compose the biofilms selectively accumulate heavy metals according to their metabolic activity. Analyses of 16S rDNA utilizing next generation sequencing indicates that the biofilms were dominated by the phylum Nitrospirae, Proteobacteria, and JS1 and SM1 as Candidate phylum. Over 40% of the detected sequences belong to groups of uncultured microorganisms. These results possibly show the similar characteristics of natural biofilms formed on fracture-surfaces in the subsurface environments. Hence, it is necessary to evaluate mechanisms of interaction between heavy metals, microbial community structure and metabolic activities of biofilms.

Oral presentation

Use of natural analogues to develop and test models of radionuclide release and transport in uplift / erosion scenarios

Klein, L.*; Hardie, S.*; McKinley, I.*; Tachi, Yukio; Shibata, Masahiro; Amano, Yuki; Takase, Hiroyasu*

no journal, , 

The uplift / erosion is treated as a special perturbation scenario for the safety assessment of the geological disposal, due to the Japanese tectonic setting, the impact of uplift must be considered as part of "likely" repository evolution. In an initial study, a simple uplift and erosion scenario was assessed with resultant changes in solubility and sorption of key radionuclides. A special challenge here is development of models and associated databases to quantify the impact of rock mechanical, hydrogeological and bio-geochemical changes on radionuclide migration both in the EBS and in the geosphere. There are great uncertainties with any laboratory studies to investigate the processes involved and therefore natural analogues have great potential here. The paper will list and discuss the key safety-relevant processes and potential analogue studies by considering both data mining of existing knowledge bases and also new projects that are specifically focused on this application.

Oral presentation

Microbial populations stimulated by lanthanoids in groundwater of Pliocene diatomaceous mudstone of northernmost Japan

Amano, Yuki; Endo, Takashi; Nemoto, Kazuaki; Tachi, Yukio

no journal, , 

High-level radioactive waste (HLW) from nuclear power generation must be disposed in a safe manner for at least 100,000 years until the radiation dose is reduced to the levels of natural radiation dose in subsurface environments. Interaction of long-lived radionuclides with subsurface microorganisms has been studied to evaluate the effect of radionuclides migration in subsurface environments. However, the microbial activities and their mechanisms of radionuclide transformation are poorly understood. In this study, we investigated microbial populations stimulated by lanthanoids as analogue elements for actinides in natural systems. Groundwater samples collected from boreholes in the subsurface environment at Horonobe Underground Research Laboratory, Japan, were incubated anaerobically with lanthanoids. During the incubation experiments, concentrations of lanthanoids, total Fe, Fe$$^{2+}$$, S$$^{2-}$$ were measured by absorption spectrophotometry and ICP-MS. Microbial community compositions were analyzed by next generation sequencing the V4 region of the 16S rRNA gene on an Illumina Miseq. Phylogenetic analyses obtained from the original and incubated groundwaters revealed that microbial populations were changed from the original one. The original groundwater showed diverse microbial community structure with the dominant phylotypes clustered within the phylum Firmicutes, Proteobacteria, and Chloroflexi. In the lanthanoids added systems, microorganisms related to Chlostridium, Georgfuchsia or Rodobacter spp. increased by the incubation. These results indicate that interaction between microorganisms and actinides may effect on radionuclide migration in HLW systems.

Oral presentation

Sorption property of natural colloids in groundwater of Horonobe area with rare earth

Endo, Takashi; Amano, Yuki; Nemoto, Kazuaki; Ito, Tsuyoshi; Tachi, Yukio

no journal, , 

no abstracts in English

Oral presentation

Reaction and alteration of mudstone with cement pore fluids

Bateman, K.; Amano, Yuki; Tachi, Yukio

no journal, , 

Oral presentation

In situ interactions of concretes with mudstones from Horonobe URL

Anraku, Sohtaro; Sato, Hisao*; Walker, C.*; Amano, Yuki; Sakurai, Akitaka; Nakayama, Masashi; Tachi, Yukio

no journal, , 

Oral presentation

Selenium speciation in sedimentary formations from Horonobe, Hokkaido

Dei, Shuntaro; Miyakawa, Kazuya; Sasamoto, Hiroshi; Tachi, Yukio; Amano, Yuki; Francisco, P. C. M.; Sugiura, Yuki; Takahashi, Yoshio*

no journal, , 

no abstracts in English

24 (Records 1-20 displayed on this page)