CHEMKEq; Evaluation code for chemical composition based on partial mixed model with Chemical Equilibrium and Reaction Kinetics (Contract research)

Ito, Hiroto*; Shiotsu, Hiroyuki; Tanaka, Yoichi*; Nishihara, Satomichi*; Sugiyama, Tomoyuki; Maruyama, Yu

JAEA-Data/Code 2018-012, 42 Pages, 2018/10

JAEA-Data-Code-2018-012.pdf:4.93MB

Chemical composition of fission products transported in nuclear facilities in severe accidents is controlled by slower chemical reaction rates, therefore, it could be different from that evaluated on the chemical equilibrium assumption. Hence, it is necessary to evaluate the chemical composition with reaction kinetics. On the other hand, databases applicable to the analysis of nuclear facilities have not been constructed because knowledge of reaction rates of complex chemical reactions in severe accidents is currently limited. Accordingly, we have developed the CHEMKEq code based on a partial mixed model with chemical equilibrium and reaction kinetics to decrease uncertainties of the chemical composition caused by the reaction rate. The CHEMKEq code, under mass conservation law, firstly evaluates chemical species obeying the chemical equilibrium model, and then, relatively slow reactions are solved by the reaction kinetics model. Moreover, the CHEMKEq code has a multiplicity of use in evaluations of chemical composition because general chemical equilibrium and reaction kinetics models are also available and databases required to calculation are external file formats. This report is the user's guide of the CHEMKEq code, showing models, solution methods, structure of the code and calculation examples. And information to run the CHEMKEq code is summarized in appendixes.

Structural kinetics studies on phase transitions of the Bi UPD layer between the (2 2) and ( ) structures using surface X-ray diffraction

Tamura, Kazuhisa; Mizuki, Junichiro

Journal of Physical Chemistry B, 109(26), p.12832 - 12836, 2005/07

https://doi.org/10.1021/jp0455632

The kinetics of the phase transition between the (2 2) and ( )-Bi structures on Au(111) was investigated using electrochemical methods and time-resolved surface X-ray diffraction. The temporal changes in the current value and the diffracted X-ray intensity that originated from the (2 2)-Bi overlayer were monitored during the phase transitions at various overpotentials. For the ( ) (2 2) phase transition, the phase transition models determined by the X-ray and electrochemical measurements were a surface-diffusion controlled instantaneous nucleation-growth process and a Langmuir process, respectively. For the reverse transition, the phase transition models determined by X-ray and electrochemical measurements were a Langmuir adsorption process and a surface diffusion controlled nucleation-growth process, respectively.

Effect of solute atoms on swelling in Ni alloys and pure Ni under He ion irradiation

Wakai, Eiichi; Ezawa, Tadashi*; Imamura, Junko*; Takenaka, Tsuyoshi*; Tanabe, Tetsuo*; Oshima, Ryuichiro*

Journal of Nuclear Materials, 307-311(Part.1), p.367 - 373, 2002/12

https://doi.org/10.1016/S0022-3115(02)01192-3

no abstracts in English

Compilation of Kinetic Data for Geochemical Calculations

Arthur, R. C,*; Savage, D.*; Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu

JNC TN8400 2000-005, 61 Pages, 2000/01

JNC-TN8400-2000-005.pdf:2.83MB

Kinetic data, including rate constants, reaction orders and activation energies, are compiled for 34 hydrolysis reactions involving feldspars, sheet silicates, zeolites, oxides, pyroxenes and amphiboles, and for similar reactions involving calcite and pyrite. The data are compatible with a rate law consistent with surface reaction control and transition-state theoly, which is incorporated in the geochemieal software package EQ3/6 and GWB. Kinetic data for the reactions noted above are strictly compatible with the transition-state rate law only under far-from-equilibrium conditions. It is possiblethat the data are conceptually consistent with this rate law under both far-from-equilibrium and near-to-equilibrium conditions, but this should be confirmed whenever possible through analysis of original experimental results, Due to limitations in the availability of kinetic data for mineral-water reactions, and in order to simplify evaluations of geochemical models of groundwater evolution, it is convenient to assume local-equilibrium in such models whenever possible. To assess whether this assumption is reasonable, a modeling approach accounting for coupled fluid flow and water-rock interaction is described that can be used to estimate spatial and temporal scale of local equiliblium. The approach is demonstrated for conditions involving groundwater flow in fractures at JNC's Kamaishi in-situ tests site, and is also used to estimate the travel time necessary for oxidizing surface waters to migrate to the level of a HLW repository in crystalline rock. The question of whether local equilibrium is a reasonable assumption must be addressed using an appropriate modeling approach. To be appropriate for conditions at the Kamaishi site using the modeling approach noted above, the fracture fill must closely approximate a porous medium, groundwater flow must be purely advective and diffusion of solutes across the fracture-host rock boundary must not occur. Moreover, the ...

None

Mukai, Satoru*; Kitao, Hideo*; Tachikawa, Hirokazu*; Fusaeda, Shigeki*; Yanagisawa, Ichiro*; Doi, Motoo*; *

PNC TJ1216 96-003, 106 Pages, 1996/03

PNC-TJ1216-96-003.pdf:2.44MB

None

Radiation-induced polymerization of a phospholipid for developing artificial red blood cells

Hosoi, Fumio; Omichi, Hideki; Akama, Kazuhiko*; Awai, K.*; Tokuyama, S.*; Sato, T.*

Nuclear Instruments and Methods in Physics Research B, 105(1-4), p.318 - 321, 1995/11

https://doi.org/10.1016/0168-583X(95)00575-7

no abstracts in English

Field test of radionuclide migration; Cooperative research between JAERI and CIRP

*; Yamamoto, Tadatoshi; ; Takebe, Shinichi; Ogawa, Hiromichi; Tanaka, Tadao; Mukai, Masayuki; Komiya, Tomokazu; S.Li*; Z.Wang*; et al.

JAERI-Research 94-009, 44 Pages, 1994/07

JAERI-Research-94-009.pdf:1.69MB

no abstracts in English

Formation of Tc(III) complexes with EDTA and HEDTA

Hashimoto, Masashi; *; *; *

Radiochimica Acta, 63, p.173 - 177, 1993/00

https://doi.org/10.1524/ract.1993.63.special-issue.173

no abstracts in English

Chemical kinetic analysis on the degradation of insulating materials exposed to LOCA simulating environments

; ; ; ; ; Yoshida, Kenzo

EIM-82-111, p.27 - 36, 1982/00

no abstracts in English

Radiation-induced seeded copolymerization of tetrafluoroethylene with propylene, II; Kinetic analysis

; ;

J.Appl.Polym.Sci., 26, p.2751 - 2762, 1981/00

https://doi.org/10.1002/app.1981.070260822

no abstracts in English