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Mishima, Ria; Inaba, Yusuke*; Tachioka, Sotaro*; Harigai, Miki*; Watanabe, Shinta*; Onoe, Jun*; Nakase, Masahiko*; Matsumura, Tatsuro; Takeshita, Kenji*
Chemistry Letters, 49(1), p.83 - 86, 2020/01
Times Cited Count：4 Percentile：21.18(Chemistry, Multidisciplinary)Separation of platinum group metals (PGMs) from high-level liquid waste generated from the reprocessing of spent nuclear fuels is important to produce good quality vitrified glass for final disposal. A new sorbent, Aluminum hexacyanoferrate (AlHCF), was synthesized and the general sorption behavior of PGMs from concentrated nitric acid was examined. Nitric acid caused substantial elution of AlHCF but the sorption of Pd stabilized the structure. Consequently, Rh was sorbed in the presence of Pd, whereas single Rh sorption caused complete dissolution of AlHCF. Relation between sorbed mount of Pd vs eluted Al and Fe revealed that the elution ratio of Al and Fe was not the same as molar ratio of synthesized AlHCF, indicating the re-sorption of Fe resulted in formation of new structure. The sorption mechanism of PGMs by this new sorbent, AlHCF, not only the simple ion exchange, but also oxidation reduction reaction as well as kinetics play important rule. Understanding the general sorption and dissolution behavior will help improve the sorption performance of PGMs by AlHCF.
Hamamoto, Takafumi*; Matsubara, Ryuta*; Shibutani, Sanae*; Suyama, Tadahiro*; Tachi, Yukio
JAEA-Data/Code 2017-014, 31 Pages, 2018/03
JAEA-Data-Code-2017-014.pdf:2.1MB
JAEA-Data-Code-2017-014-appendix(CD-ROM).zip:0.61MB
NUMO and JAEA have developed the methodology of post-closure safety assessment for the geological disposal. For this purpose, NUMO and JAEA have conducted a collaborative research project for developing the safety assessment methodology based on international state of the art knowledge. The present report focuses on investigation of sorption and diffusion data reported and their QA evaluation for updating sorption and diffusion database (SDB and DDB) as the collaborative research project between NUMO and JAEA. This report includes sorption and diffusion data for mainly sedimentary rocks and cement materials. As a result, 1,746 sorption data from 19 references and 593 diffusion data from 25 references were extracted and prepared in the datasheet of SDB and DDB.
setting approaches for rocks for the performance assessment of geological disposal; Application for granitic rocksTachi, Yukio; Suyama, Tadahiro*; Shibutani, Sanae*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 24(2), p.109 - 133, 2017/12
For performance assessment (PA), the distribution coefficient (K) need to be determined taking into account the specific PA conditions, including geochemical variability or uncertainty. The K setting approach for rocks was developed by integrating three methods; (i) direct use of measured K data extracted from the sorption database, (ii) semi-quantitative estimation by scaling differences between experimental and PA conditions, and (iii) thermodynamic sorption models. This approach was tested for granitic rock by comparing K values and their uncertainties of Cs and Am. The results indicated that K can be quantitatively evaluated by all approaches when adequate data and models are available. The K dataset for safety-relevant 25 radionuclides was developed based on the direct use of measured data, and compared with the recent K dataset in European PA projects. This K setting approaches allowed to estimate the K values and their uncertainties under the expected site conditions.
Kurikami, Hiroshi; Malins, A.; Takeishi, Minoru; Saito, Kimiaki; Iijima, Kazuki
Journal of Environmental Radioactivity, 171, p.99 - 109, 2017/05
Times Cited Count：15 Percentile：43.57(Environmental Sciences)A modified diffusion-sorption-fixation model (mDSF) is proposed to describe the vertical migration of radiocesium in soils following fallout. The model introduces kinetics for reversible sites, meaning that the exponential-shape radiocesium distribution can be reproduced immediately following fallout. The initial relaxation mass depth of the distribution is determined by the diffusion length, which depends on the distribution coefficient, sorption rate and dispersion coefficient. The model captures the long tails of the radiocesium distribution at large depths. These tails are caused by different rates for kinetic sorption and desorption.
Hemmi, Ko
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(1), P. 113, 2016/06
no abstracts in English
Yamaguchi, Tetsuji; Shimada, Taro; Ishibashi, Makoto*; Akagi, Yosuke*; Kurosawa, Mitsuru*; Matsubara, Akiyoshi*; Matsuda, Yuki*; Sato, Shigeyoshi*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 22(2), p.21 - 27, 2015/12
It is predictable from previous studies that radiocesium hardly migrate into surrounding soils and groundwater from soils contaminated by the Fukushima Daiichi Nuclear Power Plant accident if they are buried and covered with indigenous soils. This study demonstrated the prediction by performing in-situ migration experiments over a year in a public park in Miho, Ibaraki prefecture and in two public parks in Misato, Saitama prefecture. Contaminated soils were buried at a depth range of 0.3 - 1.0 m or at 0.3 - 1.3 m and covered with indigenous soil layer of 0.3 m, and were sprinkled with water to accelerate the radiocesium migration. Migration of radiocesium was not observed from radiometric analyses of boring cores and soil water samples. Laboratory column and sorption experiments revealed that the radiocesium hardly leach out of the soil and even if they leach out from the contaminated soil, radiocesium is sorbed on surrounding soils and hardly migrate through the soli layer. Simulation of Cs-137 migration for 100 years by an advection-diffusion model showed that Cs-137 hardly migrate and decay out in the contaminated soil.
, Na, I
and HTO in granodiorite; Laboratory-scale results and their extrapolation to the in situ conditionTachi, Yukio; Ebina, Takanori*; Takeda, Chizuko*; Saito, Toshihiko*; Takahashi, Hiroaki*; Ouchi, Yuji*; Martin, A. J.*
Journal of Contaminant Hydrology, 179, p.10 - 24, 2015/08
Times Cited Count：29 Percentile：73.48(Environmental Sciences)Matrix diffusion and sorption are important processes in the assessment of radionuclide transport in crystalline rocks. Diffusion and sorption parameters for Cs, Na, I and HTO were determined by through-diffusion and batch sorption experiments using granodiorite samples from the Grimsel Test Site, Switzerland. The De values were in the order Cs, Na, HTO, I. The capacity factor and Kd values show the same trends. The dual depth profiles for Cs and Na can be interpreted by a near-surface Kd increment. The microscopic analysis indicated that this is caused by high porosity and sorption capacities in disturbed biotite minerals on the sample surface. The Kd values derived from the dual profiles are likely to correspond to Kd dependence on the grain sizes of crushed samples in the batch experiments. The results of the in situ LTD experiments were interpreted reasonably well by using transport parameters derived from laboratory data and extrapolating them to in situ conditions.
Hemmi, Ko; Yamaguchi, Tetsuji; Iida, Yoshihisa
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 22(1), p.3 - 10, 2015/06
Iodine and tin are important elements in performance assessment of geological disposal of radioactive wastes. Sorption experiments of iodine were carried out under varying nitrate concentration with a range of 0 to 5 mol dm
at neutral pH range in order to determine the distribution coefficient of iodine was zero or non-zero value. The experimental results with estimated statistical errors showed non-zero values for tuffaceous sandstone except for NaNO
concentration 0.5 mol dm. Non-zero values were also obtained under NaNO concentrations higher than 0.5 mol dm for granodiorite. Sorption experiments of tin were carried out at high pH range in order to check whether the distribution coefficient of tin decreases significantly with pH as a result of formation of anionic hydrolysis species of tin. The distribution coefficients of tin on granodiorite decreased from 9.79
10
m
kg
at pH10.4 to 2.4610 m kg at pH12.4. The distribution coefficient of tin on tuffaceous sandstone was about one order of magnitude higher (about 210 m kg) than that of granodiorite at pH around 12.4.
Yamaguchi, Tetsuji; Sakamoto, Yoshifumi; Iida, Yoshihisa; Negishi, Kumi; Taki, Hiroshi; Akai, Masanobu; Jinno, Fumika; Kimura, Yuichiro; Ueda, Masato; Tanaka, Tadao; et al.
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10
no abstracts in English
Tanaka, Tadao; Mukai, Masayuki; Nakayama, Shinichi
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10
no abstracts in English
Fukushi, Keisuke*; Sato, Tsutomu*; Yanase, Nobuyuki; Minato, Junichi*; Yamada, Hirohisa*
American Mineralogist, 89(11-12), p.1728 - 1734, 2004/11
The sorption mechanism of As(V) on schwertmannite was investigated by both a batch sorption experiment and crystallographic considerations. The batch experiment was carried out as a function of As(V) concentration in acidic solution at 25 
C. Crystallographic considerations indicate surface sites of schwertmannite comprise varied surface oxygen (hydroxyl) and SO
groups. Sorption experiments showed reactive surface sites for As(V) sorption are surface SO groups. As(V) sorption mechanism involves ligand exchange with solid phase SO. Results also suggest monodentate As(V) coordination with surface adsorbed SO sites and bidentate As(V) coordination in structural originated SO sites. Estimated equilibrium constant for ligand exchange reaction describes the observed As(V) sorption behavior. The surface structure approach in this study reveals reactive surface sites in As(V) sorption on schwertmannite comprise surface SO group instead of surface hydroxyl groups identified by former views.
Tanaka, Tadao; Mukai, Masayuki; Li, Z.*; Li, S.*
JAERI-Conf 2003-010, p.142 - 149, 2003/09
An environmental migration test of Sr-85 was carried out in natural unsaturated loess zone at the field test site of China Institute for Radiation Protection, China, and the migratory mobility of Sr was observed during 2 years. As laboratory experiments, the migration experiment of Sr by a column system and the sorption experiment of Sr by a batch system were carried out by using the loess taken from the field test site. We discussed about applicability of sorption data determined from the laboratory experiments to evaluating the Sr migration behavior investigated at the field test site. The Sr migration behavior at the field test site could be expressed by the equilibrium sorption model using distribution coefficients determined from the laboratory experiments. This supports that the valid distribution coefficient for the evaluation of Sr migration in natural environment is predicted from the laboratory experiments.
Onuki, Toshihiko; Sakamoto, Fuminori; Kozai, Naofumi; Sakai, Takuro; Kamiya, Tomihiro; Sato, Takahiro; Oikawa, Masakazu*
Nuclear Instruments and Methods in Physics Research B, 210, p.407 - 411, 2003/09
Times Cited Count：13 Percentile：64.66(Instruments & Instrumentation)Sorption behavior of Co by lichen biomass has been studied in the foliose lichen Permotrema tinctorum in solution between pH 3 and 5. Sorption of Co by P. tinctorum reached equilibrium within 24 hours. Co uptake was independent of solution pHs between 3 and 5. Two-dimensional distribution of Co indicates that the sorbed Co is distributed in upper and lower surfaces, and medullary layers at 1 day after contact with P. tinctorum. Highest density in the two-dimensional distribution of Co is obtained in the lower surface suggesting that Co is sorbed by melanin-like pigment contained in the lower surface. Interestingly, the density of Co in algal layer is lower than those in medullary layer. Two-dimensional distribution of Co does not correspond to Fe indicating that Co is not adsorbed on the Fe-containing minerals trapped on P. tinctorum. It is concluded that high accumulation of Co by P. tinctorum is caused by the sorption on not only both surfaces, but medullary layer.
Fukushi, Keisuke*; Sato, Tsutomu*; Yanase, Nobuyuki
Environmental Science & Technology, 37(16), p.3581 - 3586, 2003/07
Times Cited Count：71 Percentile：79.91(Engineering, Environmental)The mechanism of As(V) sorption on schwertmannite was investigated by a batch sorption experiment as a function of solution As(V) concentration under acidic conditions (pH 3.3 
0.1) at 25 C. The reacted solution chemistry and mineralogy showed that the mechanism of As(V) sorption was ligand exchange with solid phase SO in schwertmannite. Two processes presumably occur simultaneously within the reaction period. i.e., ligand exchange of As(V) with surface site SO and subsequent transfer of As(V) to the structure and ligand exchange with tunnel site SO. The exchange ratio between As(V) sorption and SO release, and the SO coordination environment in schwertmannite indicates that monodentate As(V) coordination occurs in surface sites while bidentate binuclear As(V) coordination occurs in tunnel sites. Sorption modeling that considers the different types of reactive sites successfully described the observed As(V) sorption behavior.
Takebe, Shinichi; Fujiwara, Keiji*; Moriyama, Hirotake*
Nihon Genshiryoku Gakkai "Shisetsu, Kankyo Hoshano Dotai" Kenkyu Senmon Iinkai Hokokusho, p.1 - 9, 2003/03
no abstracts in English
Ohashi, Hiroshi*; Sato, Seichi*; Kozaki, Tamotsu*
JAERI-Tech 2002-021, 52 Pages, 2002/03
JAERI-Tech-2002-021.pdf:2.95MB
no abstracts in English
*; Mihara, Morihiro;
JNC TN8430 2001-007, 56 Pages, 2002/01
JNC-TN8430-2001-007.pdf:13.13MB
In the geological disposal concept of radioactive wastes, a kind of clay with sorption ability and low permeability, called bentonite, is envisaged as an engineered barrier system in the geological repository. Also, the cemetitious material is envisaged as the backfill material in the vaults and the structure material of the vaults. The groundwater in contact with the cementitious material will promote hyperalkaline conditions in the repository environment and these conditions will affect the performance of the bentonite. Therefore, it is necessary to investigate the interaction between the cementitious material and the bentonite for the evaluation of long term stability of the disposal system. In this study, for the identification and the investigation of the secondary minerals, the batch immersion experiments of the powder bentonite were carried out using synthetic cement leachates (pH=7, 12.5, 14) at 200C. As the results, it was confirmed that Na as exchangeable cations in the bentonite can exchange relatively easily with Ca in the solution from the experiment results. And the ratio of cation exchange was estimated to be about 25% based on the amount of exchangeable cations Ca
between layers. Furthermore, it was concretely shown that the generation of analcime might be affected by the Na concentration from results of the solution analyses and a stability analysis of analcime using the chemical equilibrium model, in addition to the pH in the solution.
Kato, Hiroshige*; Mine, Tatsuya*; Mihara, Morihiro; Oi, Takao; Honda, Akira
JNC TN8400 2001-029, 63 Pages, 2002/01
JNC-TN8400-2001-029.pdf:1.81MB
Cementitious materials will be used for the TRU waste repository as a component of engineered barrier system. The distribution coefficients which represent the retardation of radionuclides migration for the cementitious materials would be one of the important parameter for the safety assessment. The much information of radionuclide sorption onto the cementitious materials has been accumulated through the study in the world. Therefore it is necessary to compile the information and Kd of the radionuclides reported in previous studies. In this report, the Kd of the important radionuclides, such as C, Ni, Se, Sr, Zr, Nb, Mo, Tc, Sn, I, Cs, Sm, Pb, Ra, Ac, Th, Pa, U, Np, Pu, Am, Cm, for the cementitious materials were compiled as the Sorption Database (SDB). For radionuclides to be sensitive to the redox potential, e.g. Se, Tc, Pa, U, Pu and Np, some Kds measured under the controlled atmosphere had been reported, and few Kds measured under the controlled redox potential had been reported. For Se, Mo, Sm, Cm and Ac, the distribution coefficients had not been reported, therefore distribution coefficients of Se and Mo for OPC (Ordinary Portland Cement) pastes were measured by batch sorption experiments and these data were added into the SDB.
Onuki, Toshihiko; Kozai, Naofumi; Samadfam, M.; Yamamoto, Shunya; Narumi, Kazumasa; Naramoto, Hiroshi; Kamiya, Tomihiro; Sakai, Takuro; Murakami, Takashi*
Nuclear Instruments and Methods in Physics Research B, 181(1-4), p.644 - 648, 2001/07
Times Cited Count：4 Percentile：33.81(Instruments & Instrumentation)no abstracts in English
Hirabayashi, Takakuni
Radioisotopes, 49(4), p.57 - 58, 2000/04
no abstracts in English
