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Journal Articles

Evaluation of temperature dependence of viscosity and crystallization time for Japanese HLW glass

Kawamura, Kazuhiro; Koide, Manabu*; Matsushita, Kazumasa*

Nihon Genshiryoku Gakkai Wabun Rombunshi, 13(1), p.27 - 33, 2014/03

https://doi.org/10.3327/taesj.J13.014

The temperature dependence of viscosity below and above the glass transition temperature (Tg) of simulated high-level radioactive waste (HLW) glass was measured by the fibre bending method and the parallel plate method. The ratio of activation energy for viscous flow below Tg to that above Tg was found to be 0.1, which is significantly smaller than the generally accepted value of 0.5. The long-term crystallization time of HLW glass below Tg was estimated from measured crystallization and viscosity data. A formula of the long-term crystallization time was evaluated with the assistance of a TTT diagram. The HLW glass was evaluated to have a sufficiently long-term stability, even if it is exposed to a maximum temperature of 150 $^{circ}$ C during the disposal period.

JAEA Reports

Report on Collaboration Reseaech Meeting with Belgian Nuclear Research Center(SCK/CEN); CORALUS: An Integrated in Situ Corrosion Test on Alpha Active HLW Glass

Kawamura, Kazuhiro

JNC TN8200 2005-002, 39 Pages, 2005/07

JNC-TN8200-2005-002.pdf:77.9MB

The final meeting of CORALUS project was held at Mol, Belgium, on June 14,15 in 2005. JNC presented the results of nuclide migration modeling. The other institutes also presented and discussed about the contents. Then I could visit the underground research facility and the surface hot laboratory. The results of an integrated in situ corrosion test on alpha active HLW glass will be open on the other papers.

Journal Articles

Status of studies on HLW glass performance for confirming its validity in assessment

Inagaki, Yaohiro*; Mitsui, Seiichiro*; Makino, Hitoshi*; Ishiguro, Katsuhiko*; Kamei, Gento*; Kawamura, Kazuhiro*; Maeda, Toshikatsu; Ueno, Kenichi*; Bamba, Tsunetaka*; Yui, Mikazu*

Genshiryoku Bakkuendo Kenkyu, 10(1-2), p.69 - 84, 2004/03

https://doi.org/10.3327/jnuce.10.69

no abstracts in English

JAEA Reports

Status of Studies on HLW Glass Performance for Increasing Its Validity in Assessment

Inagaki, Yaohiro*; Mitsui, Seiichiro; Makino, Hitoshi; Ishiguro, Katsuhiko; Kamei, Gento; Kawamura, Kazuhiro; Maeda, Toshikatsu*

JNC TN8400 2003-036, 53 Pages, 2003/12

JNC-TN8400-2003-036.pdf:0.51MB

Obtain of sufficient data for the performance of high-level radioactive waste(HLW) glass and verification of a model for the radionuclide release from the HLW glass in the disposal condition are required in order to show the objective reliability. In this paper, some reports about performance assessment of HLW glass are reviewed and we clarify the problems to raise reliability comparing these reports.

JAEA Reports

Report on Collaboration Research Meeting with Belgian Nuclear Research Center(SCK/CEN) -CORALUS:An Integrated in Situ Corrosion Test on Alpha Active HLW Glass-

Kawamura, Kazuhiro; Ueno, Kenichi

JNC TN8200 2003-002, 248 Pages, 2003/11

JNC-TN8200-2003-002.pdf:21.8MB

Collaboration Research Meeting with Belgian Nuclear Research Center(SCK/CEN) -CORALUS:An integrated in situ corrosion test on alpha active HLW glass- was held on October 29 and 30th, 2003 at Avignon, France. Scientific achievements obtained in the last year were presented and results on modelling of nuclide migration were discussed. It is necessary to get data in situ tests and to compare with the modelling results.

Journal Articles

Oxidation-Reduction Equilibrium of Fe3+/Fe2 in a Candidate Glass for Immobilization of High Level Nuclear Waste

Kawamura, Kazuhiro; Miyamoto, Yoichi; Ouchi, Jin

Glass Technology, 39(4), p.142 - 148, 2002/00

None

Journal Articles

Effect of MgO and BaO on Fe3+/Fe2+ equilibrium in a Candidate Glass for Immobilization o

Kawamura, Kazuhiro; Miyamoto, Yoichi

High Temperature Materials and Processes, 16(3), p.169 - 172, 2002/00

None

JAEA Reports

Evaluation of soluble organic compounds generated by radiological degradation of asphalt

Fukumoto, Masahiro; Nishikawa, Yoshiaki*; Kagawa, Akio; Kawamura, Kazuhiro

JNC TN8400 2001-002, 23 Pages, 2000/12

JNC-TN8400-2001-002.pdf:0.55MB

The soluble organic compounds generated by radiological degradation of asphalt ( ray) were confirmed as a part of influence of the bituminized waste degradation in the TRU waste repository. Especially, the influence of the nitrate was focused on. As a result, the concentration of the soluble organic compounds generated by radiological degradation of asphalt (10MGy, ray which is correspond to absorbed dose of asphalt for 1,000,000 years) were lower (each formic acid : about 50mg/dm $^{3}$ , acetic acid : about 30mg/dm $^{3}$ and oxalic acid : about 2mg/dm $^{3}$ ) than that of the formic acid, the acetic acid and the oxalic acid which Valcke et al. had shown (the influence of the organic at the solubility examination which uses Pu and Am). Moreover, the change in the concentration of TOC and the soluble organic compounds (formic acid, acetic acid and oxalic acid) is little under the existence of nitrate ion. That is, the formic acid and acetic acid which can be organic ligands were generated little by oxidative decomposition of asphalt in the process that nitrate ion becomes nitrite ion by radiation. The influence of the soluble organic compounds by the radiological degradation of the asphalt ( ray) on adsorption and solubility by the complexation of radionuclides in the performance assessment can be limited.

Journal Articles

Influence of Chemical and Radiolytic Degradation of Bitumen on Its Performance for Disposal

Kagawa, Akio; Kawamura, Kazuhiro;

Journal of Nuclear Science and Technology, 37(10), p.934 - 937, 2000/10

https://doi.org/10.3327/jnst.37.934

None

JAEA Reports

Nuclide migration study in the QUALITY; Data acquisitions for the second progress report

Ashida, Takashi; ; Sato, Haruo; ; Kitamura, Akira; Kawamura, Kazuhiro

JNC TN8400 99-083, 63 Pages, 1999/11

JNC-TN8400-99-083.pdf:5.36MB

Studies on the chemical and migration behaviour of radionuclides were carried out in the Quantitative Assessment Radionuclide Migration Experimental Facility (QUALITY)for assuring the relaiability and for improving the propriety of data concerning nuclide migration used in the Second Progress Report for the geoloical disposal of high-level radioactive waste. Five studies for solubility, sorption and diffusion concerning nuclide migration were carried out. The overview of each study and the result is as follows: (1)Study on Effect of Carbonate on Np Solubility. Solubilities of Np(IV) were measured as functions of pH and carbonate concentration under reducing conditions. The obtained data could be well described by considering two hydroxo-carbonate complexes, and those stability constants were estimated and compared with the literature data. Consequently, the data obtained in this study were similar to the literature data. (2)Study on Effect of Carbonate on Np Sorption on Bentonite. Distribution coefficients (Kd) of Np(IV) on smectite were measured as a function of carbonate concentration. The obtained Kd values were approximately constant over the carbonate concentration (total carbon concentration 0.04-0.15M). The results of desorption tests by 1M KCl and HCl at the end of sorption experiments showed two different desorption behaviour; Np(IV) was well removed by HCl for the experiments in low carbonate concentration and by KCl for those in high carbonate concentration. (3)Distribution Coefficient Measurements for Cs, Pb and Cm on Rocks. Distribution Coefficients for Cs, Pb and Cm on Japanese major rocks (basalt, mudstone, sandstone, granodiorite and tuff) were measured as a function of ionic strength. The obtained Kd values were either the same orders or higher compared with data used to both fresh and saline groundwater systems in the Second Progress Report. This indicates that the Kd data used in the Second Progress Report are either proper or conservative. ...

JAEA Reports