Simulation of Lagrangian pollutant in Jakarta urban district using Lattice Boltzmann method

Yokouchi, Hiroshi*; Inagaki, Atsushi*; Kanda, Manabu*; Onodera, Naoyuki

Doboku Gakkai Rombunshu, B1 (Suikogaku) (Internet), 76(2), p.I_253 - I_258, 2020/00

https://doi.org/10.2208/jscejhe.76.2_I_253

Hight-resolution pollutant model embedded into Lattice Boltzmann method (LBM) is constructed. We focuses on Particle pollutants. Flow field is calculated using D3Q27 model of LBM and particle is calculated by Lagrangian method. Using this model, we discuss the change in concentration distribution when there is a huge building (GARUDA) in Jakarta as a application. As a result, we can find the relation of differences in particle density and differences in flow velocity due to GARUDA. When the velocity in the case w/o GARUDA is faster than the other, particle velocity in the case w/o GARUDA is reduced. And also, we can find the velocity near the solid boundary is underestimated and the particle density is higher than theoretical value. However, this model is valid far away from the solid boundary.

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 2; Progress report on NUMO-JAEA collaborative research in FY2012 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Hayano, Akira; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.

JAEA-Research 2013-037, 455 Pages, 2013/12

JAEA-Research-2013-037.pdf:42.0MB

Following FY2011, JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, the tree diagram of methodology of groundwater travel time has been extended for crystalline rock, in addition, tree diagram for sedimentary rock newly has been organized. With regard to (2) study on scenario development, the existing approach has been improved in terms of a practical task, and applied and tested for near field focusing on the buffer. In addition, the uncertainty of some important processes and its impact on safety functions are discussed though analysis. With regard to (3) study on setting radionuclide migration parameters, the approaches for parameter setting have been developed for sorption for rocks and solubility, and applied and tested through parameter setting exercises for key radionuclides.

Development of methodology of groundwater flow and solute transport analysis in the Horonobe area, Hokkaido, Japan

Maekawa, Keisuke; Makino, Hitoshi; Kurikami, Hiroshi; Niizato, Tadafumi; Inagaki, Manabu; Kawamura, Makoto*

Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.71 - 80, 2010/10

https://doi.org/10.1115/ICEM2010-40041

It is important for establishing safety assessment techniques of HLW geological disposal to understand groundwater flow and solute transport. We have carried out groundwater flow and solute transport analysis using geological and hydrological information from surface-based investigations in the Horonobe area. From this study, a methodology to integrate activities from site investigations and evaluation to solute transport analysis was tested. We have been also carrying out a simulation of groundwater flow and salinity concentration distribution using information on geological evolution considering the impacts of natural events and processes. From the result, we could outline the impacts of natural events and processes on geological environments. We plan to apply a methodology of groundwater flow and solute transport analysis to the shallow part, the Horonobe coastal area. It must be important techniques in support of generic safety assessment for future geologic disposal in Japan.

Electron spin resonance study on H, HD, HD, and HD in solid parahydrogen

Kumagai, Jun*; Inagaki, Hiroshi*; Kariya, Susumu*; Ushida, Takahiro*; Shimizu, Yuta*; Kumada, Takayuki

Journal of Chemical Physics, 127(2), p.024505_1 - 024505_13, 2007/07

https://doi.org/10.1063/1.2748046

We carried out an electron spin resonance (ESR) study on hydrogen ion radicals produced by radiolysis of solid parahydrogen. In addition to quartet ESR lines proposed to be H-core H ions in solid parahydrogen, we newly observed totally more than fifty resolved lines in -ray irradiated solid para-H-ortho-D (1 mol %) and para-H-HD (1 mol %) mixtures. We assigned these lines to be isotope substituents of H-core H ions such as HD, HD, and HD throughout comparison of their ESR parameters with theoretical results.

An Estimation of microorganisms impacts on geological disposal system for TRU waste.

Kato, Takashi; Honda, Akira; Nakanishi, Hiroshi; Inagaki, Manabu; Tsukamoto, Masaki*

JNC TN8400 2005-022, 52 Pages, 2005/09

JNC-TN8400-2005-022.pdf:1.34MB

(1) The denitrifying bacteria, the sulfate restoration bacteria, the methanation bacteria and the organic substrate (the cement admixture, the cellulose and the asphalt, TBP) decomposing bacteria were extracted as the important microbes which can be active on the basis of both previous studies on the microbes in deep underground and coexisting substrate. (2) The total amount of calcium hydrate in the repository exceeded the equivalent amount of that for reacting the total Co generated from microbial decomposition of organic substrate and phosphate generated from the microbial decomposition of TBP. Therefore, the impacts of lowering pH by the metabolic products was not considered to be significant. Furthermore, impacts of alteration of both bentonite and cementitious materials and metal corrosion due to the drop of pH are not considered to be significant. (3) The N gas evolution rate due to the denitrifying reaction by microorganisms dominated the total gas evolution rate, if time dependent reduction of corrosion rate was employed. However, the H gas evolution rate in the case is similar to those of N gas due to the denitrifying reaction mentioned above, if time dependent reduction of corrosion rate was neglected. (4) The information of the impacts of the complex formation between nuclides and metabolic products of microbes, colloid formation (including the colloidal behavior of microbes) and CH formation due to microbial activities is limited. The impacts are also considered to depend on the site character. Therefore the limited availability of information and site dependency prevent us from assessing the previous impacts at present. The further accumulation of knowledge is necessary for the assessments.

Completion of the ITER CS model coil-outer module fabrication

Ando, Toshinari; Hiyama, Tadao; Takahashi, Yoshikazu; Nakajima, Hideo; Kato, Takashi; Isono, Takaaki; Sugimoto, Makoto; Kawano, Katsumi; Koizumi, Norikiyo; Nunoya, Yoshihiko; et al.

IEEE Transactions on Applied Superconductivity, 10(1), p.568 - 571, 2000/03

https://doi.org/10.1109/77.828298

no abstracts in English

Preliminary analysis for evolution of redox conditions in the near field

Chiba, Tamotsu*; Sasamoto, Hiroshi; Miki, Takahito*; Inagaki, Manabu*; Yui, Mikazu

JNC TN8400 99-027, 144 Pages, 1999/06

JNC-TN8400-99-027.pdf:19.19MB

It is planned that high level radioactive waste is going to be disposed under deep geological environment. It is believed that the chemical condition of deep groundwater is generally anoxic and reducing. However, during construction and operation phase of repository, oxygen will diffuse some distance into the surrounding rock mass, and diffused oxygen may remain in the surrounding rock mass even after repository closure. In such a case, the transitional redox condition around the drift is not preferable in view point of safety assessment for HLW disposal. Hence, it is very important to evaluate evolution of redox conditions in the near field. This report describes results of preliminary analysis for evolution of redox conditions in the near field rock mass and buffer after repository closure based on the model developed by Chiba et al. (1999). The results of preliminary analysis are summalized as follows : (1)The decrease of oxygen in the near field rock mass and buffer are affected by pH of groundwater and surface area of iron-bearing minerals. (2)The decrease of oxygen in the near field rock mass takes place at time scales lower than 500 years in considering the hypothetical reference groundwater pH range for H12 report. It is implicated that the redox conditions in the near field rock mass will recover to reducing conditions. (3)The decrease of oxygen in the buffer takes place at time scales lower several tens years under neutral to weakly alkaline pH values of porewater in the buffer, even if it is assumed that residual oxygen in the near field rock mass after repository closure will diffuse into the buffer. On the other hand, under weakly acid pH values of porewater in the buffer, it may be presumed that oxygen remain in the buffer at time scale more than 500 years.

Model development to evaluate evolution of redox conditions in the near field

Sasamoto, Hiroshi; Yui, Mikazu; Chiba, Tamotsu*; Miki, Takahito*; Inagaki, Manabu*

JNC TN8400 99-019, 30 Pages, 1999/02

JNC-TN8400-99-019.pdf:2.34MB

Deep underground is thought to be a potential place for high level radioactive waste repository. It is believed that the chemical condition of deep groundwater is generally anoxic and reducing. However, during construction and operation phase of repository, oxygen will diffuse some distance into the surrounding rock mass, and diffused oxygen may remain in the surrounding rock mass even after repository closure. In such a case, the transitional redox condition around the drift is not preferable in view point of safety assessment for HLM disposal. Hence, it is very important to evaluate evolution of redox conditions in the near field. This report describes the status of model development to evaluate evolution of redox conditions in the near field. We use the commercial solver to equate the mathematical equations which mean evolution of redox condition in the near field. The target area modeled in this report are near field rock mass and engineered barrier (buffer). In case of near field rock mass, we consider the following two geological media : (1) porous media for sedimentary rock, (2)fractured media for crystalline rock. In case of the engineered barrier, we the regard buffer as porous media. We simulate the behavior of dissolved oxygen and Fe in groundwater during evolution of redox condition in the near field rock mass and the buffer. In case of the porous media, we consider diffusion of chemical species as dominant transport mechanism. On the other hand, in case of the fractured media, we consider diffusion of chemical species in rock matrix and advection of that (only dissolved oxygen considered in this model) in fracture as transport mechanism. We also use the rate raw of iron oxidation reaction and dissolution of Fe-bearing minerals in this model besides.

None

Nagaki, Hiroshi; Asano, Takashi*; ;

PNC TN8410 89-019, 27 Pages, 1989/03

PNC-TN8410-89-019.pdf:0.96MB

None

None

Nagaki, Hiroshi; ; Ishiguro, Katsuhiko; ; ; Sasaki, Noriaki

PNC TN841 83-28, 35 Pages, 1983/04

PNC-TN841-83-28.pdf:1.76MB

no abstracts in English