JAEA-Review 2020-006, 261 Pages, 2020/09
A literature review was conducted on the increase in surface area of vitrified products of HLW due to the fracturing caused by cooling during glass pouring process and by mechanical impact, from the perspective of a parameter of the radionuclide release model in the performance assessment of geological disposal system studied overseas. The review was focused on the value of surface area increase factor set as a parameter in the model, the experimental work to evaluate an increase in surface area, and how the parameters on surface area were determined based on the experimental results. The surface area obtained from the experiments executed in Japan was also discussed in comparison with the overseas studies. On the basis of the investigation, the effects of various conditions on the surface area were studied, such as a diameter of vitrified product, cooling condition during and after the glass pouring, impact on vitrified products during their handling, environment after the closure of disposal facility, and others. The causes of fracturing are associated with the phenomena or events in the waste management process such as production, transport, storage, and disposal. The surface area increase factors set in the nuclide release model of the glass and their bases were reviewed. In addition, the measured values and the experimental methods for surface increase factors published so far were compared. Accordingly, the methods for measuring surface area as the bases were identified for these factors set in the models. The causes of fracturing and features of these factors were studied with respect to the relation with the waste management process. The results from the review and assessment can contribute to the expanding the knowledge for the conservative and realistic application of these factors to performance assessment, and to the developing and upgrading of safety case as a consequence.
Takeuchi, Tetsuya*; Haga, Yoshinori; Taniguchi, Toshifumi*; Iha, Wataru*; Ashitomi, Yosuke*; Yara, Tomoyuki*; Kida, Takanori*; Tahara, Taimu*; Hagiwara, Masayuki*; Nakashima, Miho*; et al.
Journal of the Physical Society of Japan, 89(3), p.034705_1 - 034705_15, 2020/03
Inoue, Rintaro*; Kanaya, Toshiji*; Yamada, Takeshi*; Shibata, Kaoru; Fukao, Koji*
Physical Review E, 97(1), p.012501_1 - 012501_6, 2018/01
In this study, we investigate the process of a polystyrene thin film using inelastic neutron scattering (INS), dielectric relaxation spectroscopy (DRS), and thermal expansion spectroscopy (TES). The DRS and TES measurements exhibited a decrease in glass transition temperature () with film thickness. On the other hand, an increase in was observed in INS studies. In order to interpret this contradiction, we investigated the temperature dependence of the peak frequency () of the process probed by DRS and TES. The experiments revealed an increase in the peak frequency () with decreasing film thickness in the frequency region. This observation is consistent with the observed decrease in with thickness. The discrepancy between INS and DRS or TES descriptions of the process is likely to be attributed to a decrease in the apparent activation energy with film thickness and reduced mobility, due to the impenetrable wall effect.
Fukui, Toshiki*; Maki, Takashi*; Miura, Nobuyuki; Tsukada, Takeshi*
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(2), p.169 - 173, 2016/12
The basic research programs for the next generation vitrification technology, which are commissioned project from Ministry of Economy, Trade and Industry of Japan, have been implemented from 2014 until 2018 for developing the advanced vitrification technology of low level wastes and high level liquid wastes.
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(2), p.201 - 202, 2016/12
This paper reports an overview of a planed session, "How is the ability of the waste form glass?; Current status of the performance assessment of the waste form glass in the geological disposal system", held by the NUCE in 2016 AESJ Fall Meeting. Five panelists respectively introduced case studies and/or aspects from the view point of performance assessment, current status in the world including Japan, basic sciences and computation sciences.
Amamoto, Ippei; Kobayashi, Hidekazu; Kitamura, Naoto*; Takebe, Hiromichi*; Mitamura, Naoki*; Tsuzuki, Tatsuya*; Fukayama, Daigen*; Nagano, Yuichi*; Jantzen, T.*; Hack, K.*
Journal of Nuclear Science and Technology, 53(10), p.1467 - 1475, 2016/10
The iron phosphate glass (IPG) medium is known to be a high-efficiency glass medium, therefore we try to evaluate its applicability to immobilize sludge bearing radioactive nuclides arising from treatment of contaminated water at the stricken Fukushima Daiichi Nuclear Power Plant. For this study, many physical and chemical properties of target materials are necessary to evaluate the behaviours of IPG medium and its waste forms. Inevitably, it will entail the need for many and varied types of experiments to be carried out under high temperature. It is therefore rational to apply appropriate theoretical analysis first so as to reduce the number of experimental run. For this reason, some necessary thermodynamic values for theoretical analysis were estimated by CALPHAD approach followed by making up the calculated phase diagrams. By comparison with experimental results, they were found to be reliable for evaluating the behaviours of IPG medium and its waste forms.
Stellhorn, J. R.*; Hosokawa, Shinya*; Pilgrim, W.-C.*; Kawakita, Yukinobu; Kamimura, Kenji*; Kimura, Koji*; Blanc, N.*; Boudet, N.*
Zeitschrift fr Physikalische Chemie, 230(3), p.369 - 386, 2016/03
Stellhorn, J. R.*; Hosokawa, Shinya*; Kawakita, Yukinobu; Gies, D.*; Pilgrim, W.-C.*; Hayashi, Koichi*; Oyama, Kenji*; Blanc, N.*; Boudet, N.*
Journal of Non-Crystalline Solids, 431, p.68 - 71, 2016/01
Ruan, Y.*; Gibson, B. C.*; Lau, D. W. M.*; Greentree, A. D.*; Ji, H.*; Ebendorff-Heidepriem, H.*; Johnson, B. C.*; Oshima, Takeshi; Monro, T. M.*
Scientific Reports (Internet), 5, p.11486_1 - 11486_7, 2015/06
Ruan, Y.*; Ji, H.*; Johnson, B. C.*; Oshima, Takeshi; Greentree, A. D.*; Gibson, B. C.*; Monro, T. M.*; Ebendorff-Heidepriem, H.*
Optical Materials Express (Internet), 5(1), p.73 - 87, 2015/01
Physica A, 363(2), p.161 - 170, 2006/03
Within a class of cluster approximations, the Ising spin glass model on a d-dimensional hypercubic lattice is solved near the spin glass transition temperature. Spin glass order parameter function and Almeida-Thouless line are obtained.
Chemical Physics Letters, 417(4-6), p.550 - 554, 2006/01
no abstracts in English
Nishitani, Takeo; Sugie, Tatsuo; Morishita, Norio; Yokoo, Noriko*
Fusion Engineering and Design, 74(1-4), p.871 - 874, 2005/11
no abstracts in English
Oigawa, Hiroyuki; Yokoo, Takeshi*; Nishihara, Kenji; Morita, Yasuji; Ikeda, Takao*; Takaki, Naoyuki*
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10
The benefit of implementing Partitioning and Transmutation (P&T) of high-level wastes was parametrically surveyed. The possible reduction of the geological repository area was estimated. By recycling minor actinides (MA), the repository area required for unit spent fuel was reduced significantly in the case of MOX-LWR. This effect was caused by removal of Am which is a long-term heat source. By partitioning the fission products, in addition to MA recycling, further 70-80% reduction from the MA-recovery case can be expected for both UO and MOX. This significant reduction was independent of the cooling time before the partitioning process.
Otani, Eiji*; Suzuki, Akio*; Ando, Ryota*; Urakawa, Satoru*; Funakoshi, Kenichi*; Katayama, Yoshinori
Advances in High-Pressure Technology for Geophysical Applications, p.195 - 209, 2005/09
This paper summarizes the techniques for the viscosity and density measurements of silicate melt and glasses at high pressure and temperature by using the X-ray radiography and absorption techniques in the third generation synchrotron radiation facility, SPring-8, Japan. The falling sphere method using in situ X-ray radiography makes it possible to measure the viscosity of silicate melts to the pressures above 6 GPa at high temperature. We summarize the details of the experimental technique of the viscosity measurement, and the results of the measurements of some silicate melts such as the albite and diopside-jadeite systems. X-ray absorption method is applied to measure the density of the silicate glasses such as the basaltic glass and iron sodium disilicate glass up to 5 GPa at high temperature. A diamond capsule, which is not reactive with the glass, is used for the density measurement of the glasses. The present density measurement of the glasses indicates that this method is useful for measurement of the density of silicate melts at high pressure and temperature.
Physics Letters A, 344(2-4), p.211 - 219, 2005/09
The infinite-range -state Potts glass model is studied in the presence of a field. Stability of the replica symmetric solution for the longitudinal order parameter is investigated. Instability appears at higher temperature than the transverse freezing temperature for . Replica symmetry breaking pattern is obtained.
Katayama, Yoshinori; Inamura, Yasuhiro*
Nuclear Instruments and Methods in Physics Research B, 238(1-4), p.154 - 159, 2005/08
It is well know that many substances have different structures in the crystalline state and they exhibit first-order structural phase transitions by a change in pressure. On the other hand, pressure-induced structural changes in the liquid and glassy states were supposed to be monotonous. The recent development of synchrotron radiation sources enables us to perform structural studies on liquids and glasses under high pressure and high temperature conditions. These studies revealed that the changes in the liquid and glassy states are not necessarily monotonous. We will present recent results on liquid phosphorus and silica glass.
Progress of Theoretical Physics Supplement, (157), p.90 - 93, 2005/06
The mean-field p-state Potts glass model is studied in the presence of a field. As effective ferromagnetic interaction in the Potts glass model grows as temperature decreases, uniform part of the interaction is set to make effective ferromagnetic interaction zero at the continuous glass transition temperature without field. Replica symmetry breaking pattern is obtained analytically near the freezing of the transverse components for small fields. Replica symmetry breaking is continuous for p3.4, which is similar to the symmetry breaking for the Ising spin glass model. One step replica symmetry breaking is stable for 4.6p3.4. The transition to the transverse freezing phase is discontinuous for p4.6. This threshold is larger than 4 that is the threshold for the zero field case. These results show that qualitative feature of the transition in a field is similar to that without field if the number of the Potts components is shifted accordingly.
Physical Review B, 70(17), p.174422_1 - 174422_14, 2004/11
Phase transitions in the infinite-range p-state Potts glass model is studied in the presence of a field. Phase transition line into the transverse ordered phase is a straight line in a field-temperature phase diagram for small field and small effective ferromagnetic interaction. This is in contrast with the Gabay-Toulouse line for the vector spin-glass model. Replica symmetry breaking pattern is discussed near the phase transition line. Replica symmetry for the longitudinal order parameter is weakly broken at higher temperature than the transition line to the transverse ordered phase for p3.2. For p4.6, the transition to the transverse ordered phase reveals discontinuity in the order parameter just as the p4 case without a field.
Japanese Journal of Applied Physics, 43(9A), p.6473 - 6474, 2004/09
The output pattern of He-Ne laser that passes through the optical glass fiber bundle used for free electron laser etc. depends on the weight of load (modulation of transverse mode). The increment of pattern radius exponentially increases with the load. It is considered that the micro bending causes this increment. Next, the estimated delay time also exponentially increases with the weight of load, and the estimated delay time is the extent of pico-second.