| 1. |
Romain Vauchy, Taku Matsumoto, Shun Hirooka, Hiroki Uno, Testuya Tamura, Tatsumi Arima, Yaohiro Inagaki, Kazuya Idemitsu, Hiroki Nakamura, Masahiko Machida, Tatsutoshi Murakamia, Masato Kato , Uranium–plutonium–americium cation interdiffusion in polycrystalline (U,Pu,Am)O2±x mixed oxides, Journal of Nuclear Materials, 588, 154786, 2024.01, Diffusion couples made of dense polycrystalline U1− αPuα− βAmβO2±γ/U1− yPuy− zAmzO2±x oxides were annealed in various thermodynamic conditions (temperature, oxygen partial pressure), and for different durations. The associated actinide redistribution was quantified using Electron Probe Micro-Analysis (EPMA). Average diffusion profiles were obtained from elemental U, Pu, and Am X-ray maps and the resulting interdiffusion coefficients were calculated, then analyzed at the light of our model of point defect chemistry.. |
| 2. |
Kazuya Idemitsu, Yaohiro Inagaki, Tatsumi Arima, Long-term diffusion of neptunium and other wlements in compacted bentonite reveals filtration, MRS Advances, 2023, Cambridge University Press, 2023.02. |
| 3. |
Kenta Furutani, Takahiro Ohkubo, Jincheng Du, Koji Ohara, Kenzo Deguchi, Shinobu Ohki, Tadashi Shimizu, Yaohiro Inagaki, Ryuta Matsubara, and Keisuke Ishida, Elucidating the Atomic Structures of the Gel Layer Formed during Aluminoborosilicate Glass Dissolution: An Integrated Experimental and Simulation Study, J. Phys. Chem. C 126, 18, 7999–8015., 2022.03. |
| 4. |
Kazuya Idemitsu, Hajime Arimitsu, Masayuki Hirakawa, Keisuke Yoshida, Yaohiro Inagaki, Tatsumi Arima
, Effect of carbonate on the migration behavior of neptunium in compacted bentonite, MRS Advances 2022, DOI: 10.1557/s43580-022-00210-9, 2022.01. |
| 5. |
Van Mao Pham, Tatsumi Arima, Yaohiro Inagaki, Kazuya Idemitsu, Daisuke Akiyama, Takayuki Nagai, Yoshihiro Okamoto
, Crystal structure of U1-yLnyO2-x (Ln=Gd, Er) solid solution, Journal of Nuclear Materials Vol.556, 2021.11. |
| 6. |
Kazuya Idemitsu, Keisuke Yoshida, Yaohiro Inagaki, Tatsumi Arima, Speciation by XANES of copper migrated into compacted bentonite using electromigration techniques, MRS Advances Vol.6 Issue 4 , pp.80-83 , April 2021, Cambridge University Press, DOI:10.1557/s43580-021-00026-z, 2021.03. |
| 7. |
Pham VAN MAO, Tatsumi ARIMA, Yaohiro INAGAKI, Kazuya IDEMITSU, Evaluation of Structural and Thermal Properties of Ce1-yGdyO2-x Solid Solution, International Journal of Thermophysics, 41, 111, 2020, 2020.06. |
| 8. |
Kazuya Idemitsu, Keisuke Yoshida, Yaohiro Inagaki, Tatsumi Arima, Migration Behavior of Copper in Compacted bentonite Using Electromigration Technique, MRS Advances Vol.5 Issue3-4, pp. 141-147, January 2020, Cambridge University Press,
DOI: 10.1557/adv.2020.55, DOI: 10.1557/adv.2020.55, Vol.5 Issue3-4, pp. 141-147, 2020.01. |
| 9. |
Tatsumi Arima, Junpei Miyachi, PhamVan Mao, Yaohiro Inagaki, Kazuya Idemitsu, Evaluation of melting behavior in the system UO2-ZrO2: Molecular dynamics simulation, International Conference on Nuclear Engineering, Proceedings, ICONE2019-May, DOI: 10.1299/jsmeicone.2019.27.2095, 2019.09. |
| 10. |
PhamVan Mao, Tatsumi Arima, Yaohiro Inagaki, Kazuya Idemitsu, Evaluation of Mechanical Properties of (Ce,Gd)O2-x as a surrogate for (U,Gd)O2-x solid solutions, International Conference on Nuclear Engineering, Proceedings, ICONE2019-May, DOI: 10.1299/jsmeicone.2019.27.1927, 2019.09. |
| 11. |
Kazuya Idemitsu, Ryota Yamada, Masayuki Hirakawa, Yuki Kakoi, Yaohiro Inagaki, Tatsumi Arima, Effect of Carbonate on the Migration Behavior of Strontium in Compacted Bentonite, MRS Advances, February 2019, Cambridge University Press DOI: 10.1557/adv.2019.81, DOI: 10.1557/adv.2019.81, 2019.02. |
| 12. |
R.Kimura, Y.Inagaki, K.Idemitsu, T.Arima, Vitrification processes of simulated cesium sorbing zeolite waste, Progress in Nuclear Energy, 108, 497-502, 2018.10. |
| 13. |
Kazuya Idemitsu, Kazuyuki Fujii, Noriyuki Maeda, Yuki Kakoi, Noriya Okubo, Yaohiro Inagaki, Tatsumi Arima, Effect of Carbonate on the Migration Behavior of Lanthanides in Compacted Bentonite, MRS Advances, February 2018, Cambridge University Press DOI: 10.1557/adv.2018.184, DOI: 10.1557/adv.2018.184, 2018.02. |
| 14. |
K.Kawai, H.Sagara, K.Takeshita, M.Kawakubo, H.Asano, Y.Inagaki, Y.Niibori, S.Sato, EFFECTS OF HIGH BURN-UP OPERATION OF LWR AND EXTENDED COOLING PERIOD OF SPENT FUEL ON HIGH-LEVEL WASTE PROPERTIES FOR VITRIFICATION AND STORAGE, Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP '17), 2017, 2017.10. |
| 15. |
Kazuya IDEMITSU, Hikaru KOZAKI, Masaru YUHARA, Tatsumi ARIMA, Yaohiro INAGAKI, Diffusion Behavior of Selenite in Purified Bentonite, Progress in Nuclear Energy, 92, 279-285, 2016, 92, 279-285, 2016, 2016.09. |
| 16. |
Tatsumi ARIMA, Kazuya IDEMITSU, Yaohiro INAGAKI, Katsuyuki KAWAMURA, YukioTACHI, Kenji YOTSUJI, Diffusion and Adsorption of uranyl ion in Clays: Molecular Dynamics Study, Progress in Nuclear Energy, 92, 286-297, 2016, 92, 286-297, 2016, 2016.09. |
| 17. |
Maxime Fournier, Aurelian Ull, Elodie Nicoleau, Yaohiro Inagaki, Glass dissolution rate measurement and calculation revisited, Journal of Nuclear Materials, 467, 140-154, 2016.03, Aqueous dissolution rate measurements of nuclear glasses are a key step in the long-term behavior study
of such waste forms. These rates are routinely normalized to the glass surface area in contact with solution,
and experiments are very often carried. |
| 18. |
Yaohiro Inagaki, Micro-channel as a new tool to investigate glass dissolution kinetics, Procedia Materials Science, 7, 172 -178, 2014.12, A reliable modeling of the long-term dissolution of HLW glass requires sufficient evaluation of the glass dissolution kinetics
including a sound understandings of reaction mechanism. For the evaluation of glass dissolution kinetics, we need much more
data on the glass dissolution rate measured precisely, consistently and systematically under various well-constrained test
conditions. The current standard test methods, unfortunately, cannot provide enough data for the kinetic evaluation. Therefore,
we should improve or develop the test methods to provide precise and consitent data for the kinetic evaluation. In the present
paper, therefore, major standard test methods currently applied to the measurement of glass dissolution are summarized with
their advantages and disadvantages, and some newly developed test methods are introduced. In addition, problems to be solved
are discussed to advance the kinetic evaluation.. |
| 19. |
JD Vienna, S Gin, JV Ryan, Yaohiro Inagaki, Current Understanding and Remaining Challenges in Modeling Long-Term Degradation of Borosilicate Nuclear Waste Glasses, International Journal of Applied Glass Science, 4, [4], 283-294, 2013.12, Chemical durability is not a single material property that can be uniquely measured. Instead it is the response to a host of coupled material and environmental processes whose rates are estimated by a combination of theory, experiment, and modeling. High-level nuclear waste (HLW) glass is perhaps the most studied of any material yet there remain significant technical gaps regarding their chemical durability. The phenomena affecting the long-term performance of HLW glasses in their disposal environment include surface reactions, transport properties to and from the reacting glass surface, and ion exchange between the solid glass and the surrounding solution and alteration products. The rates of these processes are strongly influenced and are coupled through the solution chemistry, which is in turn influenced by the reacting glass and also by reaction with the near-field materials and precipitation of alteration products. Therefore, those processes must be understood sufficiently well to estimate or bound the performance of HLW glass in its disposal environment over geologic time-scales. This article summarizes the current state of understanding of surface reactions, transport properties, and ion exchange along with the near-field materials and alteration products influences on solution chemistry and glass reaction rates. Also summarized are the remaining technical gaps along with recommended approaches to fill those technical gaps.. |
| 20. |
Yaohiro Inagaki, Taiki Kikunaga, Kazuya Idemitsu, tatsumi arima, Initial Dissolution Rate of the International Simple Glass as a Function of pH and Temperature Measured Using Microchannel Flow-Through Test Method, International Journal of Applied Glass Science, 4, [4], 317-327, 2013.12, International Simple Glass (ISG) is a six-component alumino-borosilicate glass developed as a reference benchmark glass for six nations collaborating study on high-level nuclear waste glass dissolution/corrosion mechanism. In the present study, aqueous dissolution tests were performed for the ISG by using Micro-Channel Flow-Through (MCFT) method to evaluate the initial dissolution rate of glass matrix, r0, precisely and systematically as a function of solution pH and temperature. The test results indicated that the r0 shows a “V-shaped” pH dependence with a bottom at around pH4 at each temperature. Compared to Japanese reference glass of P0798, for which the r0 showed a “U-shaped” pH dependence with a bottom at around pH6 in our previous study, the ISG shows the higher dissolution rate at basic pH, and lower dissolution rate at neutral to acidic pH. The results also indicated that the r0 increases with temperature according to an Arrhenius law, and the apparent activation energy evaluated from Arrhenius relation is 62-77 [kJ/mol] at any pH from 3 to 10, which suggests the initial dissolution of ISG proceeds controlled by a surface-reaction mechanism in this pH range. . |
| 21. |
Yaohiro Inagaki, Hikaru Makigaki, Kazuya Idemitsu, Tatsumi Arima, Sei-IchiroMitsui and Kenji Noshita, Initial dissolution rate of a Japanese simulated high-level waste glass P0798 as a function of pH and temperature measured by using micro-channel flow-through test method, Journal of Nuclear Science and Technology, Volume 49, No. 4, pp. 438–449, 2012.04, Aqueous dissolution tests were performed for a Japanese type of simulated high-level waste (HLW) glass
P0798 by using a newly developed test method of micro-channel flow-through (MCFT) method, and the
initial dissolution rate of glass matrix, r0, was measured as a function of solution pH (3–11) and
temperature (25–908C) precisely and consistently for systematic evaluation of the dissolution kinetics. The
MCFT method using a micro-channel reactor with a coupon shaped glass specimen has the following
features to provide precise and consistent data on the glass dissolution rate: (1) any controlled constant
solution condition can be provided over the test duration; (2) the glass surface area actually reacting with
solution can be determined accurately; and (3) direct and totally quantitative analyses of the reacted glass
surface can be performed for confirming consistency of the test results. The present test results indicated
that the r0 shows a ‘‘V-shaped’’ pHdependence with aminimumat around pH6 at 258C, but it changes to a
‘‘U-shaped’’ one with a flat bottom at neutral pH at elevated temperatures of up to 908C. The present
results also indicated that the r0 increases with temperature according to an Arrhenius law at any pH, and
the apparent activation energy evaluated from Arrhenius relation increases with pH from 54 kJ/mol at pH
3 to 76 kJ/mol at pH 10, which suggests that the dissolution mechanism changes depending on pH.. |
| 22. |
M.Tada, Y.Inagaki, K.Idemitsu, T.Arima, O.Kato, T.Sakuragi, Temperature Dependence of Aqueous Dissolution of Silver iodide under Reducing Condition with FeCl2 Solution, Proceedings of the10th International Conference GLOBAL2011, No.501272, 2011.12. |
| 23. |
Kazuya IDEMITSU, Daisuke AKIYAMA, Akira ETO, Yoshihiko MATSUKI, Yaohiro INAGAKI, Tatsumi ARIMA, Migration Behavior of Alkali Earth Ions in Compacted Bentonite with Iron Corrosion Product Using Electrochemical Method, Proceedings of Materials Research Society Symposium Vol.1265 ( Scientific Basis for Nuclear Waste Management XXXIV), pp.227-232, November, 2010, XXXIV, Vol.1265, pp.227-232, 2010.11. |
| 24. |
H.Makigaki, Y.Inagaki, K.Idemitsu, T.Arima, S.Mitsui, T.Banba, K.Noshita, Measurement of initial dissolution rate of P0798 simulated HLW glass by using micro-reactor flow-through test method, Scientific Basis for Nuclear Waste Management XXXIII (Mat.Res.Soc.Proc.Vol.1193), 307, 2009.12. |
| 25. |
Y,Inagaki, S.Mitsui, H.Makigaki, K.Idemitsu, T.Arima, T.Banba, K.Noshita, Measurement of HLW glass dissolution/alteration kinetics by using micro-reactor flow-through test method, Scientific Basis for Nuclear Waste Management XXXIII (Mat.Res.Soc.Symp.Proc.1193), 219, 2009.12. |
| 26. |
Yaohiro INAGAKI, Tomohiko IWASAKI, Seichi SATO, Toshiaki OHE, Kazuyuki KATO, Seishi TORIKAI, Yuichi NIIBORI, Shinya NAGASAKI, Kazumi KITAYAMA, LWR High Burn-Up Operation and MOX Introduction; Fuel Cycle Performance from the Viewpoint of Waste Management, Journal of NUCLEAR SCIENCE and TECHNOLOGY, Vol.46, No.7, pp.677-689, Vol.46, No.7, pp.677-689, 2009.07. |
| 27. |
Fumio HIRANO, Seichi SATO, Tamotsu KOZAKI, Yaohiro INAGAKI, Tomohiko IWASAKI, Toshiaki OHE, Mazuyuki KATO, Kazumi KITAYAMA, Seishi TORIKAI, Yuichi NIIBORI, Shinya NAGASAKI, Thermal Impact on Geological Disposal of Hull and End Piece Wastes Resulting from High-Burn-up Operation of LWR and Introduction of MOX Fuels in LWR, Journal of NUCLEAR SCIENCE and TECHNOLOGY, Vol.46, No.5, pp.443-452, Vol.46, No.5, pp.443-452, 2009.05. |
| 28. |
Yaohiro INAGAKI, Toshitaka IMAMURA , Kazuya IDEMITSU , Tatsumi ARIMA,Osamu KATO , Tsutomu NISHIMURA and Hidekazu ASANO, Aqueous Dissolution of Silver Iodide and Associated Iodine Release under Reducing Conditions with FeCl2 Solution , Journal of NUCLEAR SCIENCE and TECHNOLOGY, Vol. 45, No. 9, p. 859–866 (2008) , Vol. 45, No. 9, p. 859–866 (2008) , 2008.09. |
| 29. |
Y. INAGAKI , T.IMAMURA, K. IDEMITSU, T. ARIMA, O.KATO, H.ASANO, T.NISHIMURA, Aqueous Dissolution of Silver Iodine and Associated Iodine Release Under Reducing Conditions with Sulfide, Scientific Basis for Nuclear Waste Management XXX(Mat. Res. Soc. Symp. Proc. Vol.985), Vol.985, pp.431-436, 2007.07. |
| 30. |
K. IDEMITSU, Y. YAMASAKI, S. A. NESSA, Y. INAGAKI , T. ARIMA, T.MITSUGASHIRA, M.HARA, Y.SUZUKI, Migration Behavior of Plutonium in Compacted Bentonite Under Reducing Condition using Electromigration, Scientific Basis for Nuclear Waste Management XXX (Mat. Res. Soc. Symp. Proc. Vol.985), Vol.985, pp.443-448, 2007.07. |
| 31. |
Y.Inagaki, T.Saruwatari, K.Idemitsu, T.Arima, A.Shinkai, H.Yoshikawa, M.Yui, Temperature Dependence of Long-Term Alteration Rate for Aqueous Alteration of P0798 Simulated Waste Glass under Smectite Forming Conditions, Scientific Basis for Nuclear Waste Management (Mat. Res. Soc. Symp. Proceedings Vol.932), pp.321-328, 2006.08. |
| 32. |
K.Yamaguchi, Y.Inagaki, T.Saruwatari, K.Idemitsu, T.Arima, H.Yoshikawa, M.Yui, Kinetics of Aqueous Alteration of P0798 Simulated Waste Glass in the Presence of Bentonite, Scientific Basis for Nuclear Waste Management (Mat. Res. Soc. Symp. Proceedings Vol.932), pp.385-392, 2006.08. |
| 33. |
Y.Inagaki*, A.Shinkai, K.Idemistu, T.Arima, H.Yoshikawa, M.Yui, Aqueous alteration of Japanese simulated waste glass P0798: Effects of alteration-phase formation on alteration rate and cesium retention, Journal of Nuclear Materials, Vol.354, pp.171-184(2006), 2006.07. |
| 34. |
X.Xia, Y.Inagaki, A.Hattori, K. Idemitsu, T. Arima, Iodine Release from Silver Iodide under Reducing Condition with Iron-Bearing Minerals, Scientific Basis for Nuclear Waste Management XXV (Mat.Res.Soc.Symp.Proc., vol.713), 713, 783-790, pp783-790, 2002.01. |
| 35. |
A review is given of the performance assessment of high-level radioactive waste(HLW) glass in geological disposal in an aspect of its validity. In the last few decades much progress has been made in understanding elementary reactions of HLW glass dissolution in contact with aqueous solutions and of associated radionuclide release. On the basis of the present knowledge, a conservative assessment of the glass performance can be made in geological disposal. For confirming its validity, however, more progress is required to be made in understanding reaction mechanism of the glass dissolution for the long-term of disposal period and in evaluating effects of the specific disposal conditions on the glass dissolution for each country. In addition to sound understanding of scientific basis for the glass dissolution described above, it is also essential to develop the glass performance model taking the scientific basis into account. Progress in these fundamental studies on the glass performance is expected to contribute to a valid assessment of the total system performance of disposal, which can lead to the reasonable and economical disposal. Studies on the glass performance at the present in Japan are less advanced than those conducted widely in France and the United States. Further works are required for the valid assessment of the glass performance in Japan.. |
| 36. |
Y.Inagaki, E.Sasaki, H.Furuya, K.Idemitsu and T.Arima, MIGRATION OF Cs IN A SIMULATED ENGINEERED BARRIER SYSTEM CONSISTING OF HLW GLASS, MAGNETITE AND COMPACTED BENTONITE, Proceedings of the 7th International Conference on Radioactive Waste Management and Environmental Remediation(ICEM’99), 1999.01. |
| 37. |
Y.Inagaki, H.Furuya, K.Idemitsu and T.Arima, H.Osako, T. Banba, T.Maeda, I.Nomura, Leaching and migration of neptunium in a simulated engineered barrier system consisting of HLW glass and compacted bentonite, Journal of Nuclear Materials, 10.1016/S0022-3115(01)00588-8, 298, 1-2, 168-173, Vol.298, pp168-173, 2001.01. |
| 38. |
Y.Inagaki, K. Idemitsu, T. Arima, T.Maeda, H.Ogawa, F.Itonaga, ALTERATION-PHASE FORMATION AND ASSOCIATED CESIUM RELEASE DURING ALTERATION OF R7T7 WASTE GLASS, Scientific Basis for Nuclear Waste Management XXV (Mat.Res.Soc.Symp.Proc., vol.713), pp589-596, 2002.01. |
