Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya*; Aketagawa, Yasushi*; Takahashi, Makikatsu*; Yoshii, Akihiro*; Tsunoda, Yasuhiko*; Seko, Noriaki
Radiation Physics and Chemistry, 81(8), p.1033 - 1035, 2012/08
Endo, Kiyoshi*; Shibata, Yasushi*; Yamamoto, Tetsuya*; Nakai, Kei*; Matsumura, Akira*; Sato, Takahiro; Yokoyama, Akihito; Koka, Masashi; Okubo, Takeru; Yamazaki, Akiyoshi; et al.
JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 86, 2012/01
Shibuta, Yasushi*; Unoura, Seiji*; Sato, Takumi; Shibata, Hiroki; Kurata, Masaki*; Suzuki, Toshio*
Journal of Nuclear Materials, 414(2), p.114 - 119, 2011/07
The uranium dendrite growth on cathode during pyroprocessing of uranium is investigated using a novel phase-field model, in which electrodeposition of uranium and zirconium from molten-salt is taken into account. The threshold concentration of zirconium in molten salt demarcating the dendritic and planar growth is then estimated as a function of the current density. Moreover, growth process of both the dendritic and planar electrodeposits has been demonstrated by way of varying the mobility of the phase field, which consists of the effect of attachment kinetics and diffusion.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.
Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06
Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.
Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.
Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04
Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.
Takigami, Machiko*; Nagasawa, Naotsugu; Hiroki, Akihiro; Kasai, Noboru; Yoshii, Fumio; Tamada, Masao; Takigami, Shoji*; Shibata, Takuya*; Aketagawa, Yasushi*; Ozaki, Masuo*
Transactions of the Materials Research Society of Japan, 35(3), p.647 - 650, 2010/09
There are many livestock farmers in Gunma Prefecture. Many of the farms are located under Mt. Akagi and Haruna, which attract tourists. Furthermore, rivers around the mountains are source of water supply to metropolitan area. Therefore, the waste treatments are very important. Regulations of smell and COD (chemical oxygen demand) are severe in Gunma Prefecture. Although there is no regulation for color of drain water, color in secondary treated water from livestock urine waste has been one of the major concerns for livestock farmers. The color is a metabolite of microorganisms and not easy to be removed. People have tried to remove the color by ozone treatment, absorption using activated carbon or soils. An absorbent was prepared by radiation grafting; fibers were irradiated with Co -rays and some kinds of monomers were grafted onto the fibers. The absorbent thus prepared were used to decolorize the secondary treated water. The color and COD were removed by the absorbent, however, COD removal was more difficult than decolorization. Degree of grafting (weight increase expressed in % by grafting reaction to initial weight of the fiber), treated water/absorbent ratio, flow rate of treated water, and direction of flow affected color and COD removal. The used absorbent could be used repeatedly after washing.
Fujita, Tomo; Taniguchi, Naoki; Matsui, Hiroya; Tanai, Kenji; Nishimura, Mayuka; Kobayashi, Yasushi; Hiramoto, Masayuki; Maekawa, Keisuke; Sawada, Atsushi; Makino, Hitoshi; et al.
JAEA-Research 2007-045, 140 Pages, 2007/03
This report summarizes the progress of research and development on geological disposal during the surface-based investigation phase (2001-2005) in the Horonobe Underground Research Laboratory project (HOR), of which aims are to apply the design methods of geological disposal and mass transport analysis to actual geological environments and derive future subjects based on the results. The design methods of geological disposal were reviewed based on the recent knowledge and the advertences were identified. Then the parameters for virtual design of engineered barrier system, backfill deposition hole and tunnel were set up based on actual geological conditions obtained from the surface-based investigations in HOR as an example of actual geological environment. The conceptual structure from site investigation and evaluation to mass transport analysis was represented as a work flow at first. Then following this work flow a series of procedures for mass transport analysis were carried out based on actual geological conditions obtained from the surface-based investigations in HOR to illustrate the functioning of the work flow and the applicability of this methodology. Consequently, knowledge that will help follow-up or future execution and planning activities was obtained.
Yoshikawa, Hideki; Shibata, Masahiro; Sasamoto, Hiroshi; Iijima, Kazuki; Sato, Haruo; Kitamura, Akira; Ishidera, Takamitsu; Fujiwara, Kenso; Kurosawa, Susumu; Xia, X.; et al.
Hoshasei Haikibutsu Anzen Kenkyu Nenji Keikaku (Heisei-13-NendoHeisei-17-Nendo) Kenkyu Seika Hokokushu, p.153 - 170, 2006/03
no abstracts in English
Sasamoto, Hiroshi; Yoshida, Yasushi*; Isogai, Takeshi*; Suyama, Tadahiro*; Jintoku, Takashi*; Shibata, Masahiro; Yui, Mikazu
Saikuru Kiko Giho, (28), p.27 - 33, 2005/09
JNC has developed the databases of nuclides migration for safety assessment of high-level radioactive waste (HLW), and the databases have been used in the second progress report to present the technical reliability of HLW geological disposal in Japan. The technical level and applicability of databases developed by JNC have been evaluated highly not only in Japan but also in overseas. Thus we have performed the followings in order to provide the databases broadly in the word and to promote the use of databases; 1) development of tools to convert the database format from geochemical code PHREEQE to PHREEQC, GWB and EQ3/6, 2) open the web site including the databases to the public. As a result, a down-load system of databases from web site has been applied and the database users have significantly increased. Additionally it has been performed that we consider the useful comments from database user for modification and/or update of databases.
Arthur, R. C.*; Sasamoto, Hiroshi; Oda, Chie; Honda, Akira; Shibata, Masahiro; Yoshida, Yasushi*; Yui, Mikazu
JNC TN8400 2005-010, 234 Pages, 2005/07
This report describes three thermodynamic databases for minerals, gases, aqueous species and reactions of relevance to bentonite and cement barriers in geologic repositories for transuranic (TRU) and other nuclear wastes. The databases support calculations using the SUPCRT, PHREEQC and GWB geochemical codes, and are referred to as SPRONS.TRU (SUPCRT), JNC-TDB.TRU (PHREEQC) and THERMO_ JNCTRU (GWB). The reliability of these databases should be considered in the context of basic limitations in current conceptual models of clay-bearing, high-pH systems. Minerals that are important in such systems tend to be complex, possibly metastable solid solutions having highly variable compositions that have not been well characterized experimentally or thermodynamically. There is also considerable uncertainty regarding important aqueous species in such systems due to the paucity of relevant experimental data presently available. With these limitations in mind, the databases developed in this study are considered to be reliable insofar as they include data for minerals that are known to be important or representative of hyperalkaline, argillaceous systems, and because the data are in general demonstrably accurate in cases where comparisons can be made between calculated values and their experimental counterparts. The databases may not meet the ideal standard of an internally consistent database because more weight has been given in this study to the accuracy and completeness of the data than to their internal consistency. An approach recommended for future improvements and revisions of the databases described in this report includes the development of a consistent set of empirical methods permitting routine estimation of thermodynamic properties in cases where reliable experimental data are lacking, combined with uncertainty analyses to assess the importance of conceptual and parameter uncertainties on models of the long-term behavior of bentonite and cementitious barriers.
Yoshida, Yasushi*; Shibata, Masahiro
JNC TN8400 2004-025, 23 Pages, 2005/03
Thermodynamic data base for compounds and complexes of actinides and fission products with auxiliary species specialized in modeling requirements for safety assessments of radioactive waste disposal systems are being developed by NEA TDB project of OECD/NEA. In this project, relevant data bases for compounds and complexes of U, Am, Tc, Np and Pu with auxiliary species were updated and published in 2003. JNC established the data base files available for geochemical calculation codes using these updated data. The procedure for establishment and contents of data base files are described in this report. These data base files were prepared as the formats of major geochemical codes PHREEQE, PHREEQC, EQ3/6 and Geochemist's workbench.Additionally modification for data in the thermodynamica data base files which had been already published by JNC was also done. This procedure and revised data bases are shown in the appendix of this report.
Shibata, Yasushi*; Yamamoto, Kazuyoshi; Matsumura, Akira*; Yamamoto, Tetsuya*; Hori, Naohiko; Kishi, Toshiaki; Kumada, Hiroaki; Akutsu, Hiroyoshi*; Yasuda, Susumu*; Nakai, Kei*; et al.
JAERI-Research 2005-009, 41 Pages, 2005/03
The measurement of neutron flux and boron concentration in the blood during medical irradiation is indispensable in order to evaluate the radiation in boron neutron capture therapy. It is, however, difficult to measure the blood boron concentration during neutron irradiation because access to the patient is limited. Therefore we prospectively investigated the predictability of blood boron concentrations using the data obtained at the first craniotomy after infusion of a low dosage of BSH. When the test could not be carried out, the blood boron concentration during irradiation was also predicted by using the 2-compartment model. If the final boron concentration after the end of the infusion is within 95% confidence interval of the prediction, direct prediction from biexponential fit will reduce the error of blood boron concentrations during irradiation to around 6%. If the final boron concentration at 6 or 9 hours after the end of infusion is out of 95% confidence interval of the prediction, proportional adjustment will reduce error and expected error after adjustment to around 12%.
Yamamoto, Tetsuya*; Matsumura, Akira*; Nakai, Kei*; Shibata, Yasushi*; Endo, Kiyoshi*; Sakurai, Fumio; Kishi, Toshiaki; Kumada, Hiroaki; Yamamoto, Kazuyoshi; Torii, Yoshiya
Applied Radiation and Isotopes, 61(5), p.1089 - 1093, 2004/11
no abstracts in English
Endo, Kiyoshi*; Shibata, Yasushi*; Yoshida, Fumiyo*; Nakai, Kei*; Yamamoto, Tetsuya*; Matsumura, Akira*; Ishii, Keizo*; Sakai, Takuro; Sato, Takahiro; Oikawa, Masakazu*; et al.
Proceedings of 11th World Congress on Neutron Capture Therapy (ISNCT-11) (CD-ROM), 2 Pages, 2004/10
Micro PIXE, which is installed in a single end accelerator in JAERI, was used for quantitative analysis of boron and gadolinium distribution in a cell level. The micro beam of 1 m diameter is possible to observe the distribution. In the adjustment procedure of the sample, first is a fix of mylar film by using a glass ring and a bite ring of 2cm diameter. Next the 9L cells were scattered on the washed film, and is cultivated on 37C in medium until they form the mono-layer. After the Gd-BOPTA was added, it incubates for the 24-72 hour on 37C. The film is washed in the THAM liquid, and is directly put on liquid nitrogen. A vacuum drying for 24 hours is conducted in order to fix a film on holder. It is important to uniformly fix the cell in distribution analysis in the cell using Micro PIXE. In recent result, it became possible that the distribution of P, S, Gd, etc. was analyzed. But we could not distinguish whether K and Gd exist in the cell or whether it exists around the cell. It was indicated that these elements was leaked by the reason of cell breaking or other on the cytoplasm.
Jintoku, Takashi; Shibata, Masahiro; Yoshida, Yasushi*; Suyama, Tadahiro*
JNC TN8400 2003-048, 40 Pages, 2004/03
We attended the OECD/NEA Sorption Project in which sorption modeling study and applicability study for sorption experimental results on minerals was held. In this study, JNC selected the sorption modeling of Ni, Np onto Montmorillonite and U onto Weathered Shist, adopted the surface complexation model and/or ion exchange model, and carried out modeling for the experimental results by using the fitting procedure. In this procedure, PHREEQC geochemical calculation code was used. Based on the modeling results which can explain experimental results, the equilibrium constants were fixed.Following the modeling, the applicability study which applies the modeling results to other sorption experiments presented that the errors of Kd value between them were within approximately one order. For the future, validation procedures for this model are needed.
Jintoku, Takashi; Shibata, Masahiro; Yoshida, Yasushi*; Suyama, Tadahiro*
Saikuru Kiko Giho, (21), p.65 - 77, 2003/12
We attended the OECD/NEA Sorption Project in which sorption modeling study and applicability study for other experimental results on minerals was held. In this study, JNC selected the sorption modeling of Ni, Np onto Montmorillonite and U onto Weathered Shist, adopted the surface complexation model and/or ion exchange model, and carried out mainly by using the fitting procedure for the experimental results. In this modeling procedure, PHREEQC geochemical calculation code is used. Based on the analytical results similar to experimental results, the equilibrium constants were fixed.From the applicability study, the trend of the analytical result and experimental one are similar. For the future, validation procedures for this model are needed.
Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Hori, Naohiko; Torii, Yoshiya; Shibata, Yasushi*; Nose, Tadao*
Radiation Research, 160(1), p.70 - 76, 2003/07
The survival curves and the RBE for the dose components generated in boron neutron capture therapy (BNCT) were determined separately in neutron beams at JRR-4. The surviving fractions of V79 cells with or without 10B were obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal (TNB-2) neutron beam. The cell killing effect of the neutron beam in the presence or absence of 10B was highly dependent on the neutron beam used and depended on the epithermal and fast-neutron content of the beam. The RBEs of the boron capture reaction were 4.07, 2.98 and 1.42, and the RBEs of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50, 2.34 and 2.17 for ENB, TNB-1 and TNB-2, respectively. The approach to the experimental determination of RBEs allows the RBE-weighted dose calculation for each dose component of the neutron beams and contributes to an accurate inter-beam comparison of the neutron beams at the different facilities employed in ongoing and planned BNCT clinical trials.
Shibata, Yasushi*; Matsumura, Akira*; Yamamoto, Tetsuya*; Akutsu, Hiroyoshi*; Yasuda, Susumu*; Nakai, Kei*; Nose, Tadao*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Hori, Naohiko; et al.
Research and Development in Neutron Capture Therapy, p.1055 - 1060, 2002/09
We prospectively investigated the predictability of blood boron concentrations using the data obtained at the first craniotomy after infusion of a low dose of sodium undecahydroclosododecaborate (BSH). Nine patients with malignant glial tumors underwent Boron neutron capture therapy (BNCT) at the Japan Atomic Energy Research Institute (JAERI) between 1995 and 2001. In 7 patients, 1g of BSH was infused before the first tumor removal and boron concentrations were determined using prompt gamma ray analysis (PGA). Then, 12 hours before BNCT, patients were infused at a dose of 100mg/kg BSH, and the boron concentrations were determined again. The boron biodistribution data showed a biexponential pharmacokinetic profile. If the final boron concentration at 6 or 9 hours after the end of the infusion is within the 95% confidence interval of the prediction, direct prediction from biexponential fit will reduce the error of blood boron concentrations during irradiation to around 6%.
Matsumura, Akira*; Yamamoto, Tetsuya*; Shibata, Yasushi*; Nakai, Kei*; Zhang, T.*; Matsushita, Akira*; Takano, Shingo*; Endo, Kiyoshi*; Akutsu, Hiroyoshi*; Yamamoto, Kazuyoshi; et al.
Research and Development in Neutron Capture Therapy, p.1073 - 1078, 2002/09
Since 1998 to 2002, a new clinical trial of an intraoperative boron neutron capture therapy (IOBNCT) at JRR-4 of Japan Atomic Energy Institute (JAERI) using BSH with mixed thermal/epithermal neutron beam has been accomplished. There have been 9 patients included in this study. The median survival time (MST) in GBM was 19.8 months and 16.8 months in AA. IOBNCT with mixed thermal/epithermal neutron beam provide better primary radiation effect than conventional therapy in selected cases. Our phase I/II clinical trial was effective in local tumor control. Further clinical trial with new design should be performed to prove the efficacy of IOBNCT.
Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Torii, Yoshiya; Endo, Kiyoshi*; Matsushita, Akira*; Shibata, Yasushi*; Nose, Tadao*
Research and Development in Neutron Capture Therapy, p.415 - 418, 2002/09
Dose measurements in a patient's brain undergoing intraoperative BNCT (IOBNCT) were compared with calculations by a JAERI computational dosimetry system (JCDS). The maximum thermal neutron flux on the brain surface from the postirradiation measurement averaged 2.330.37(10cms) and the vascular boron dose averaged 11.41.2 (9.6-12.7) Gy. Using JCDS, the maximum thermal neutron flux in the irradiated volume averaged 2.210.33(10cms), while the target vascular dose averaged 5.7 Gy and varied from 3.5 to 7.8 Gy. As such, in the dose planning for intra-operative irradiation, practical use of JCDS is recommended for uniform volume-dose control of postsurgical brain in IOBNCT.