JAEA Abstracts

-Research results below have been sorted by order of journals name.

-Sorry, some research results below have no English abstract.

July 2010

38000841
Large-Eddy Simulation on turbulent flow and plume dispersion over a 2-dimensional hill
Nakayama, Hiromasa; Nagai, Haruyasu
Advances in Science & Research (Internet) 4, p.71-76(2010) ; (JAEA-J 07468)

The dispersion analysis of airborne contaminant including radioactive substances from industrial or nuclear facilities is the important issue for maintenance of air quality or safety assessment. Many studies on the plume dispersion behavior in the simulated atmospheric boundary layer flow over flat plain have been conducted mainly by wind tunnel experiments. However, many nuclear power plants are located at complex coastal terrains in Japan. In this case, topographical effects on the turbulent flow and plume dispersion should be investigated. Therefore, we perform Large-Eddy Simulations (LES) on turbulent flows and plume dispersions. As the first step of this study, we try it for a 2-dimensional hill flow and investigate the characteristics of mean and fluctuation concentrations.

38000842
Assessing the role of RecA protein in the radioresistant bacterium Deinococcus geothermalis
Sghaier, H.*; Sato, Katsuya; Oba, Hirofumi*; Narumi, Issei
African Journal of Biochemistry Research 4(4), p.111-118(2010) ; (JAEA-J 07469)

The moderately thermophilic bacterium Deinococcus geothermalis exhibits extraordinary resistance to ionizing radiation. RecA protein is considered to be one of the most important participants in radioresistance. To assess the role of the RecA protein in D. geothermalis, the recA gene was isolated from D. geothermalis and overexpressed in Escherichia coli. After the D. geothermalis RecA protein (GeoRecA) was purified, the recombination activity was investigated in vitro. GeoRecA most efficiently promoted the strand exchange reaction between homologous linear double-stranded DNA and circular single-stranded DNA substrates at 50°C. Like D. radiodurans RecA protein (DraRecA), GeoRecA could promote DNA strand exchange reaction via normal and inverse pathways. Furthermore, GeoRecA complemented the RecA deficiency of D. radiodurans. These results indicate that GeoRecA is a functional homologue of DraRecA and plays an important role in radioresistance. However, unlike DraRecA, GeoRecA could not complement the RecA deficiency of E. coli, suggesting that GeoRecA require more strict intracellular conditions than DraRecA does to fulfill its function.

38000843
Development of tritiated vapor absorbent applicable to the atmospheric detritiation system in a nuclear facility
Iwai, Yasunori; Yamanishi, Toshihiko
Applied Radiation and Isotopes 68(9), p.1642-1649(2010) ; (JAEA-J 07471)

The combination of hydrogen oxidation reactor and water vapor absorber has been applied to the atmospheric detritiation system of tritium handling facility. Application of CaY faujasite-type zeolite to the adsorbent was investigated. The dehydration behavior was significantly improved using CaY zeolite with a high framework silica-to-alumina ratio. In contrast, detritiation factor for a CaY zeolite depended on the space velocity through the absorber. To apply a CaY zeolite to the ADS absorbent, the space velocity less than 250 h^-1 was recommended to maintain the detritiation factor more than 1000. The steep increase in water adsorption at the relative pressure lower than 0.05 is a feature of synthetic zeolite with calcium-cation. However, such an increase was not observed in the water adsorption on CaY zeolite with a framework SiO₂/Al₂O₃ ratio more than 7.0. Consequently, the CaY zeolite with the framework SiO₂/Al₂O₃ ratio of 5.0 is a promising candidate for absorbent of ADS absorber.

38000844
Analysis of dynamical process with mass distribution of fission fragment in heavy ion reactions
Aritomo, Yoshihiro
EPJ Web of Conferences 2, p.07004_1-07004_4(2010) ; (JAEA-J 07472)

We analyzed experimental data obtained for the mass distribution of fission fragments in the reactions ³⁶S+²³⁸U and ³⁰Si+²³⁸U at several incident energies, which were performed by the JAEA group. Using the dynamical model with the Langevin equation, we precisely investigate the incident energy dependence of the mass distribution of fission fragments. We also consider the fine structures in the mass distribution of fission fragments caused by the nuclear structure at a low incident energy. It is explained why the mass distribution of fission fragments has different features in the two reactions. The fusion cross sections are also estimated.

38000845
Seasonal variation in metabolic syndrome prevalence
Kamezaki, Fumihiko; Sonoda, Shinjo*; Tomotsune, Yusuke; Yunaka, Hiromi; Otsuji, Yutaka*
Hypertension Research 33(6), p.568-572(2010) ; (JAEA-J 07479)

Accumulating evidences have demonstrated that seasonal variations exist in metabolic syndrome parameters. The aim of this study was to examine the hypothesis that there is seasonal variation in metabolic syndrome prevalence in Japanese subjects. We investigated a total of 1,202 male workers in our institution (44 ± 10 years), who underwent health checkups in both June (summer) and December (winter), 2008. In this study, metabolic syndrome was defined according to the criteria proposed by National Cholesterol Education Program (NCEP), International Diabetes Federation (IDF), and Japanese Society of Internal Medicine (JSIM). Serum levels of high-density lipoprotein-cholesterol and fasting glucose, and blood pressure (BP) were significantly higher in winter than in summer, whereas waist circumference and serum levels of triglyceride were little changed. Prevalence of NCEP-, IDF-, and JSIM- metabolic syndrome in this study was 3.8, 15.1 and 12.4% in winter, 3.2, 10.7 and 8.4% in summer, respectively. Out of the metabolic syndrome components, elevated BP component was mainly connected with the seasonal variation of metabolic syndrome prevalence. The present study demonstrated the seasonal variation in metabolic syndrome prevalence in Japanese male workers. This result indicates that season of health checkups may affect a clinical diagnosis and management of metabolic syndrome.

38000846
Deinococcus aetherius sp. nov., isolated from the stratosphere
Yang, Y.*; Ito, Takashi*; Yokobori, Shinichi*; Shimada, Haruo*; Itahashi, Shiho*; Sato, Katsuya; Oba, Hirofumi*; Narumi, Issei; Yamagishi, Akihiko*
International Journal of Systematic and Evolutionary Microbiology 60, p.776-779(2010) ; (JAEA-J 07482)

A pink pigmented, non-motile, coccoid bacterial strain, ST0316, was isolated from dust samples collected from the stratosphere in Japan. Phylogenetic analysis based on 16S rRNA gene sequences showed that it belonged to the genus Deinococcus. DNA G+C content, desiccation tolerance, and resistance to γ-rays and UV radiation supported the affiliation of strain ST0316 to the genus Deinococcus. Strain ST0316 diverged from recognized species of the genus Deinococcus, showing less than 93% similarity values to its closest relatives Deinococcus apachensis, D. aerius, D. geothermalis and D. murrayi. We propose a new species of the genus Deinococcus, Deinococcus aetherius sp. nov.

38000847
Diffusion behaviors of plutonium and americium in polycrystalline urania
Sato, Isamu; Tanaka, Kosuke; Arima, Tatsumi*
IOP Conference Series; Materials Science and Engineering 9, p.012005_1-012005_8(2010) ; (JAEA-J 07483)

UO₂ discs and Am containing MOX discs were prepared to be diffusion couples. They were annealed for 4.5 h at 1600°C in a furnace under the constant oxygen partial pressures, and then concentrations of Pu and Am across the interfaces of them were measured with EPMA. The average diffusion coefficients of Pu and Am were obtained from the concentration profiles and were between 10^-15 and 10^-13m/s², in which the difference between Pu and Am was undetermined. This indicates that the difference between redistributions of Pu and Am found in a PIE may not be caused by the diffusion but by the other transport phenomenon. Moreover, the diffusion behavior was affected by existence of grain boundaries and the oxygen partial pressure in the furnace during annealing. From the affection of the grain boundary to the diffusion, the "practical" diffusion estimation may need grain boundary modeling.

38000848
Oxygen potential of (Pu,Am,Nd)O_2-x
Miwa, Shuhei; Osaka, Masahiko
IOP Conference Series; Materials Science and Engineering 9, p.012013_1-012013_7(2010) ; (JAEA-J 07484)

For the evaluation of chemical behaviors of irradiated fuel and decontaminated fuel, the oxygen potential of (Pu_0.81Am_0.08Nd_0.11)O_2-x was experimentally investigated by thermogravimetric analysis with H₂O/H₂ and CO₂/H₂ gas equilibrium.

38000849
Oxygen potential measurements of Cm_0.09Pu_0.91O_2-x by EMF method
Otobe, Haruyoshi; Akabori, Mitsuo; Arai, Yasuo
IOP Conference Series; Materials Science and Engineering 9, p.012015_1-012015_7(2010) ; (JAEA-J 07485)

The dependence of the oxygen potentials on oxygen nonstoichiometry (x) and temperature of Cm_0.09Pu_0.91O_2-x was measured by electromotive force (EMF) measurements. The coulomb titration has been made for the sample at the intervals of 40 K between 1173 and 1333 K over the x range of 0.018 ≤ x ≤ 0.053. The oxygen potentials decreased gradually from -31.02 to -117.48 kJmol^-1 with increasing x from 0.018 to 0.045, and the rapidly decreased from -117.48 to -283.74 kJmol^-1 up to 0.053. The temperature dependence of the oxygen potentials was also measured between 1173 and 1333 K for several constant x values. The temperature dependence was almost linear over the x and temperature ranges concerned.

38000850
Thermalconductivities of (Np,Am)N and (Pu,Am)N solid solutions
Nishi, Tsuyoshi; Takano, Masahide; Ito, Akinori; Miyata, Seiichi; Akabori, Mitsuo; Arai, Yasuo; Minato, Kazuo
IOP Conference Series; Materials Science and Engineering 9, p.012017_1-012017_8(2010) ; (JAEA-J 07486)

The thermal diffusivities and heat capacities of transuranium nitride solid solutions, (Np,Am)N and (Pu,Am)N, were measured by using a laser flash method and a drop calorimetry, respectively. The thermal conductivities of these samples were determined from the measured thermal diffusivities, heat capacities and bulk densities. The thermal conductivities of (Np,Am)N and (Pu,Am)N increased with temperature over the temperature range investigated. The increases in the thermal conductivities were probably due to the increase of electrical components. In addition, the thermal conductivities of (Np,Am)N and (Pu,Am)N decreased with increasing Am contents. It could be considered that the decreases in the thermal conductivities correspond to the lowering of electronic contribution.

38000851
Basic actinide chemistry and physics research in close cooperation with hot laboratories; ACTILAB
Minato, Kazuo; Konashi, Kenji*; Fujii, Toshiyuki*; Uehara, Akihiro*; Nagasaki, Shinya*; Otori, Norikazu*; Tokunaga, Yo; Kambe, Shinsaku
IOP Conference Series; Materials Science and Engineering 9, p.012018_1-012018_7(2010) ; (JAEA-J 07487)

Basic research in actinide chemistry and physics is indispensable to maintain sustainable development of innovative nuclear technology. Actinides, especially minor actinides of americium and curium, need to be handled in special facilities with containment and radiation shields. To promote and facilitate the actinide research, close cooperation with the facilities and sharing of technical and scientific information must be very important and effective. A three-year-program "Basic actinide chemistry and physics research in close cooperation with hot laboratories", ACTILAB, was started to form the bases of sustainable development of innovative nuclear technology. In this program, researches on actinide solid-state physics, solution chemistry and solid-liquid interface chemistry are made using four main facilities in Japan in close cooperation with each other, where basic experiments with transuranium elements can be made. The ¹⁷O-NMR measurements were performed on (Pu_0.91Am_0.09)O₂ to study the electronic state and the chemical behaviour of Am and Cm ions in electrolyte solutions was studied by distribution experiments.

38000852
Development of a new extractant and a new extraction process for minor actinide separation
Morita, Yasuji; Sasaki, Yuji; Asakura, Toshihide; Kitatsuji, Yoshihiro; Sugo, Yumi; Kimura, Takaumi
IOP Conference Series; Materials Science and Engineering 9, p.012057_1-012057_11(2010) ; (JAEA-J 07488)

The authors have developed a new type of extractant for Am and Cm, N,N,N',N'-tetraoctyl-diglycolamide (TODGA), which gives very high distribution ratio at relatively high nitric acid concentration. To apply such a new extractant to the separation process for Am and Cm from HLLW, many criteria should be investigated and satisfied; e.g., separability against fission products (FP), chemical and radiolytic stability, extraction capacity, compatibility with hydrocarbon diluents, and so on. From a viewpoint of extraction capacity, TODGA is modified to N,N,N',N'-tetradodecyl-diglycolamide (TDdDGA). Since TDdDGA extract Zr and Pd, effective masking agents for them were examined and selected. With those achievements, a counter-current extraction test with 0.1 M TDdDGA in n-dodecane was carried out using a small-scale mixer-settler and simulated solution of HLLW. As results of the test, a very high recovery of Am, more than 99.96%, was obtained and good separation from FP was observed.

38000853
Unique extraction behavior of americium and curium in a system of TBP and calcium nitrate hydrate melt
Okude, Genki*; Fujii, Toshiyuki*; Uehara, Akihiro*; Sekimoto, Shun*; Minato, Kazuo; Yamana, Hajimu*
IOP Conference Series; Materials Science and Engineering 9, p.012067_1-012067_7(2010) ; (JAEA-J 07489)

Extraction of Am(III) and Cm(III) between tri-n-butyl phosphate solution and molten calcium nitrate hydrate Ca(NO₃)₂-RH₂O was investigated radiochemically. In the range of water content R = 3.5-8.0, the distribution ratio was found to increase with the decrease of water activity. The dependence of the distribution ratios on the water activity in the hydrate melt changes at around log a_H2O = -0.4, which corresponds to R = 5.0. The extraction behavior of Am(III) and Cm(III) was systematically discussed with the reported data of trivalent lanthanides.

38000854
Electrolytic reduction mechanism of Np(V) and the effect of coexisting nitric acid
Kitatsuji, Yoshihiro; Kimura, Takaumi; Kihara, Sorin*
IOP Conference Series; Materials Science and Engineering 9, p.012078_1-012078_7(2010) ; (JAEA-J 07490)

The behaviors of reduction of Np(V) by controlled potential electrolysis were studied, and a unique time course of electrolysis current was observed. It was conclude that Np(V) was reduced by two reduction processes that are the chemical reaction with Np(III) and the electrocatalytic reduction by adsorbed hydrogen atom on platinum electrode surface. The time course of current for controlled potential electrolysis of Np(V) under various condition of the solution was investigated, and the effects of the concentration of H⁺ and NO₃^- on electrolysis behaviour were shown.

38000855
Micrometer-sized magnetic patterning of FeRh films using an energetic ion microbeam
Fujita, Naoki*; Matsui, Toshiyuki*; Kosugi, Shinya*; Sato, Takahiro; Saito, Yuichi; Takano, Katsuyoshi; Koka, Masashi; Kamiya, Tomihiro; Seki, Shuhei*; Iwase, Akihiro*
Japanese Journal of Applied Physics 49(6), p.060211_1-060211_3(2010) ; (JAEA-J 07491)

FeRh thin films were irradiated with a focused 10 MeV I 2 × 2 μm² ion microbeam at intervals of several μm. After the irradiations, the magnetic state at the surface was observed by a magnetic force microscopy (MFM). The micrometer-sized regions which were irradiated with the microbeam show ferromagnetic, and the unirradiated regions remain antiferromagnetic. The present result indicates that the energetic ion microbeam can be used as a tool to produce the micrometer-sized modulation of lateral magnetic state of FeRh films.

38000856
Formation and crystal growth process of AlH₃ in Al-H system
Saito, Hiroyuki; Okajima, Yuka; Yoneda, Yasuhiro; Machida, Akihiko; Kawana, Daichi; Watanuki, Tetsu; Katayama, Yoshinori; Aoki, Katsutoshi
Journal of Alloys and Compounds 496(1-2), p.L25-L28(2010) ; (JAEA-J 07492)

The hydrogenation process of aluminum is observed at high pressure and temperature by angle-dispersive in situ X-ray diffraction method. At 10 GPa and 600 °C, single crystals of AlH₃ about 20 μm in size are found to grow through three steps: self-pulverization of aluminum, hydrogenation of pulverized aluminum, and solid-state grain growth of hydride. The self-pulverization seems to be the precursor of the hydrogenation reaction because it occurs at pressure temperature conditions where AlH₃ is thermodynamically stable.

38000857
High-temperature water under pressure
Ikeda, Takashi; Katayama, Yoshinori; Saito, Hiroyuki; Aoki, Katsutoshi
Journal of Chemical Physics 132(12), p.121102_1-121102_4(2010) ; (JAEA-J 07493)

The effects of temperature and pressure upon structural, dynamical, and electronic properties of liquid H₂O were systematically investigated via first principles molecular dynamics and in situ X-ray diffraction in the chosen isochore (1.00-1.61 g/cm³) and isotherm (300-900 K) conditions. Our study suggests that the crossover occurs between H-bonded and simple-liquid-like liquids by raising temperature in molecular liquid phase.

38000858
Equilibrium potential across cation exchange membrane in HI-I₂-H₂O solution
Tanaka, Nobuyuki; Onuki, Kaoru
Journal of Membrane Science 357(1-2), p.73-79(2010) ; (JAEA-J 07495)

The equilibrium potential across Nafion 117 in a HIx solution (HI-I₂-H₂O mixture) was measured for an electro-membrane process (electro-electrodialysis, EED) in the thermochemical water-splitting Iodine-Sulfur process. The experimental results were correlated with a theoretical formula derived on the basis of the electrochemical reaction, the Donnan equilibrium and the Nernst-Planck equation. The obtained empirical formula could reproduce the experimental equilibrium potential within ±0.03 V. Also, the obtained regression parameter agreed well with that calculated from the vapor liquid equilibrium data of a HIx solution reported by Hodotsuka et al. (2008).

38000859
Effect of tensile stress on cavitation damage formation in mercury
Naoe, Takashi; Kogawa, Hiroyuki; Yamaguchi, Yoshihito; Futakawa, Masatoshi
Journal of Nuclear Materials 398(1-3), p.199-206(2010) ; (JAEA-J 07497)

Pressure wave induced cavitation is a critical issue to realize a MW-class mercury target because structural integrity of the target vessel is remarkably degraded by the pitting damage. The target vessel suffers tensile stress by welding residual stress and/or thermal stress due to proton beam injection. In this study, in order to examine the effect of tensile stress on pitting damage formation, cavitation erosion test was performed using an ultrasonic homogenizer in mercury. The result showed that the damaged area was increased with increasing in tensile stress. The depth and diameter of pits were larger than that of no-stressed specimen, and the eroded area was increased. Indentation tests under tensile stress were carried out to quasi-statically simulate impact load. Vickers hardness was slightly decreased. Threshold stress of the deformation, i.e. pitting damage formation, was decreased by tensile stress.

38000860
Melting behavior of MgO-based inert matrix fuels containing (Pu,Am)O_2-x
Miwa, Shuhei; Sato, Isamu; Tanaka, Kosuke; Hirosawa, Takashi; Osaka, Masahiko
Journal of Nuclear Materials 400(1), p.32-36(2010) ; (JAEA-J 07498)

The melting behavior of MgO-based inert matrix fuels containing (Pu,Am)O_2-x ((Pu,Am)O_2-x-MgO fuels) was experimentally investigated. Heat-treatment tests were carried out at 2173 K, 2373 K and 2573 K. The fuel melted at about 2573 K in the eutectic reaction of the Pu-Am-Mg-O system. The (Pu,Am)O_2-x grains, MgO grains and pores grew with increasing temperature. In addition, Am-rich oxide phases were formed in the (Pu,Am)O_2-x phase by heat-treatment at high temperatures. The melting behavior was compared with behaviors of PuO_2-x-MgO and AmO_2-x-MgO fuels.

38000861
Helium release from the uranium-plutonium mixed oxide (MOX) fuel irradiated to high burn-up in a fast breeder reactor (FBR)
Katsuyama, Kozo; Ishimi, Akihiro; Maeda, Koji; Nagamine, Tsuyoshi; Asaga, Takeo
Journal of Nuclear Materials 401(1-3), p.86-90(2010) ; (JAEA-J 07499)

The helium releases were investigated in FBR fuel pins irradiated to high burn-up. The released amounts of helium gas increased with the increase of burn-up, but their data were scattered in the region of high burn-up region. This was understood to be caused by the differences of ²⁴¹Am contents among fuel pellets, because this nuclide generates ²⁴²Cm which undergoes alpha decay at a short half life.

38000862
Local and electronic structure of Am₂O₃ and AmO₂ with XAFS spectroscopy
Nishi, Tsuyoshi; Nakada, Masami; Suzuki, Chikashi; Shibata, Hiroki; Ito, Akinori; Akabori, Mitsuo; Hirata, Masaru
Journal of Nuclear Materials 401(1-3), p.138-142(2010) ; (JAEA-J 07500)

XAFS studies were performed in a study of americium sesquioxide (Am₂O₃) with A-type rare earth oxide structure and americium dioxide (AmO₂) with fluorite structure. EXAFS results for Am-L₃ absorption edge of Am₂O₃ and AmO₂ were good agreement with the crystallographic data from X-ray diffraction analysis. In order to characterize XANES in aspect of the electronic states, the theoretical assignments for the Am₂O₃ and AmO₂ were performed with the all-electron full potential linearized augmented plane wave (FP-LAPW) method. The theoretical XANES spectra of Am₂O₃ and AmO₂ well reproduced the experimental ones. In addition, it was found that the white line peak was created due to the interaction between Am-d and O-p components, and the broad peak and the tail peak were created due to the interaction between Am-d and O-d component.

38000863
Solubility of selenium at high ionic strength under anoxic conditions
Iida, Yoshihisa; Yamaguchi, Tetsuji; Tanaka, Tadao; Nakayama, Shinichi
Journal of Nuclear Science and Technology 47(5), p.431-438(2010) ; (JAEA-J 07505)

Solubility experiments for selenium were performed at high ionic strengths (1.0 and 2.0 M NaCl) under anoxic conditions. Dominant aqueous selenium species were identified as hydrogen selenide, HSe^-, at pH between 5 and 8, and polyselenide, Se₄^2- at pH between 9 and 13. A solubility-limiting solid was determined to be amorphous selenium at pH between 5 and 8, and crystalline selenium at pH between 9 and 13. The equilibrium constants of Se(am) + H⁺ + 2e^- = HSe^-, logK⁰ = -6.57±0.15, 4Se(cr) + 2e^- = Se₄^2- logK⁰ = -16.67±0.03 and ion interaction coefficients for HSe^- and Se₄^2- versus Na⁺, ε(HSe^-, Na⁺) = -0.01±0.10 and ε(Se₄^2-, Na⁺) = -0.03±0.02, were determined by specific ion interaction theory. The standard molar free energy of formation of amorphous selenium and polyselenide species were determined to be Δ_fG_m⁰ (Se(am)) = 6.0±2.2 kJ mol^-1, Δ_fG_m⁰(Se₂^2-) = 111.64±1.61 kJ mol^-1, Δ_fG_m⁰(Se₃^2-) = 98.68±1.02 kJ mol^-1 and Δ_fG_m⁰ (Se₄^2-) = 95.14±0.17 kJ mol^-1, respectively.

38000864
Local coordination about La³⁺ in molten LaCl₃ and its mixtures with alkali chlorides
Okamoto, Yoshihiro; Suzuki, Shinichi; Shiwaku, Hideaki; Ikeda, Atsushi; Yaita, Tsuyoshi; Madden, P. A.*
Journal of Physical Chemistry A 114(13), p.4664-4671(2010) ; (JAEA-J 07506)

The local structure around the La³⁺ ions in molten LaCl₃ and its mixtures with alkali and alkaline earth chlorides has been investigated by using extended X-ray absorption fine structure (XAFS) and molecular dynamics (MD) techniques. New experimental methods allow observations at the La K-absorption edge at the high temperatures of interest and the ability of the technique to obtain reliable information even at very low La³⁺ concentrations in multi-component mixtures is demonstrated. Both the mean La-Cl interionic separation and the mean La³⁺ coordination number are found to decrease as the concentration of La³⁺ in the mixture decreases. In dilute mixtures with such cations La³⁺ is able to adopt a very stable octahedral coordination geometry but this is inhibited by the presence of more strongly coordinating cations like Li⁺ and Mg²⁺.

38000865
Enhanced catalytic activity of Carbon Alloy Catalysts codoped with boron and nitrogen for oxygen reduction reaction
Ikeda, Takashi; Boero, M.*; Huang, S.-F.*; Terakura, Kiyoyuki*; Oshima, Masaharu*; Ozaki, Junichi*; Miyata, Seizo*
Journal of Physical Chemistry C 114(19), p.8933-8937(2010) ; (JAEA-J 07507)

Carbon Alloy Catalysts (CACs) have been attracting a growing interest as potential Pt-free electrode catalysts for polymer electrolyte fuel cell. In this computational study, we inspect possible oxygen adsorption and reduction processes on various models for exposed edges of these catalysts via first principles molecular dynamics. Our simulations suggest that the codoping of boron and nitrogen in CACs is a promising route to further enhancement of their catalytic activity with respect to both stability and reactivity.

38000866
CO₂ motion in carbon dioxide deuterohydrate determined by applying maximum entropy method to neutron powder diffraction data
Igawa, Naoki; Taguchi, Tomitsugu; Hoshikawa, Akinori*; Fukazawa, Hiroshi; Yamauchi, Hiroki; Utsumi, Wataru; Ishii, Yoshinobu*
Journal of Physics and Chemistry of Solids 71(6), p.899-905(2010) ; (JAEA-J 07509)

Crystal structures of carbon dioxide deuterohydrate were studied by neutron powder diffraction at temperatures from 10 to 200 K. Maps of scattering length density distribution were obtained using a maximum entropy method, which clarified the motion of CO₂ molecules in the hydrate. In small cages, the carbon atom of the CO₂ molecule is at the center of the cage, and the oxygen atoms of CO₂ revolve freely around the carbon atom. In large cages, the carbon atom also is at the center of the cage, but the oxygen atoms tend to revolve around the carbon atom along the plane parallel to the hexagonal facets of the cage.

38000867
Charge-spin-orbital dynamics of one-dimensional two-orbital Hubbard model
Onishi, Hiroaki
Journal of Physics; Conference Series 200, p.012152_1-012152_4(2010) ; (JAEA-J 07510)

We study the real-time evolution of excited states in a one-dimensional two-orbital Hubbard model, by a time-dependent density-matrix renormalization group method. When we consider e_g orbitals along the z direction, electrons can hop only between 3z²-r² orbitals due to the spatial anisotropy of the orbital shape. In such a case, creating a hole into the ground state, we observe that wavepackets of the spin density and the charge density propagate in opposite directions with its own individual velocity. Thus, the spin-charge separation is clearly observed. We will discuss the propagation of wavepackets of various types of excited states that possess hole, holon-doublon, magnon, and orbiton.

38000868
Magnetic transitions in YbCo₂Si₂
Kaneko, Koji; Stockert, O.*; Mufti, N.*; Kiefer, K.*; Klingner, C.*; Krellner, C.*; Geibel, C.*; Steglich, F.*
Journal of Physics; Conference Series 200, p.032031_1-032031_4(2010) ; (JAEA-J 07511)

YbCo₂Si₂ with the tetragonal ThCr₂Si₂-type structure is an isoelectronic compound to YbRh₂Si₂. At zero magnetic field YbCo₂Si₂ undergoes two magnetic transitions at T_{N, L}=0.9 K and T_{N, H}=1.7 K,and exhibits a complex magnetic phase diagram for small applied fields, lower than B=2 T. Therefore, YbCo₂Si₂ is not only a good reference to YbRh₂Si₂ but also an interesting system in its own to study its magnetic properties. In order to reveal the magnetic structure of YbCo₂Si₂, a neutron powder diffraction experiment was carried out. At zero field, several superlattice reflections were clearly observed at 0.5 K. By heating up to 1.1 K, to the intermediate phase, a substantial change in both, the peak position and the intensity ratio of the magnetic reflection was found. We will propose a possible magnetic structure for both phases.

38000869
High pressure experiments with the engineering materials diffractometer (BL-19) at J-PARC
Abe, Jun; Hattori, Takanori; Komatsu, Kazuki*; Arima, Hiroshi; Arakawa, Masashi*; Sano, Asami; Kagi, Hiroyuki; Harjo, S.; Ito, Takayoshi; Moriai, Atsushi; Aizawa, Kazuya; Arai, Masatoshi; Utsumi, Wataru
Journal of Physics; Conference Series 215, p.012023_1-012023_6(2010) ; (JAEA-J 07512)

A high-intensity proton accelerator facility named J-PARC has been constructed, and the first neutron beam at J-PARC/MLF was extracted in May of 2008, and user-operation commenced in December of the year. The fist feasibility test of high-pressure neutron experiments were performed with the engineering materials diffractometer "TAKUMI". As results, diffraction profiles of sample embedded in high-pressure devices were obtained. Therefore, it was confirmed that in situ high-pressure neutron diffraction was feasible with the engineering materials diffractometer "TAKUMI".

38000870
Investigation on new scintillators for subnanosecond time-resolved X-ray measurements
Haruki, Rie; Shibuya, Kengo*; Nishikido, Fumihiko*; Koshimizu, Masanori*; Yoda, Yoshitaka*; Kishimoto, Shunji*
Journal of Physics; Conference Series 217, p.012007_1-012007_4(2010) ; (JAEA-J 07513)

We investigated new X-ray detectors for nuclear resonant scattering measurements with high energy X-rays. The organic-inorganic perovskite scintillator of phenethylamine lead halide ((C₆H₅C₂H₄NH₃)₂PbX₄) (X:Br, I) was used. These compounds have fast light emission due to an exciton. They include heavy atoms, which make the detector to have high efficiency to high energy X-rays. The merit of these scintillators is that we can make a thick crystal compared to a Si wafer which is used in an avalanche photo-diode detector. We successfully measured 67.41 keV X-ray signals, the energy of ⁶¹Ni nuclear resonant scattering, with high detection efficiency of 42.5% by the scintillator.

38000871
Development of safety assessment code for decommissioning of nuclear facilities (DecDose)
Shimada, Taro; Oshima, Soichiro*; Sukegawa, Takenori
Journal of Power and Energy Systems (Internet) 4(1), p.40-53(2010) ; (JAEA-J 07514)

A safety assessment code, DecDose, for decommissioning of nuclear facilities has been developed, based on the experiences of the decommissioning project of Japan Power Demonstration Reactor (JPDR) at Japan Atomic Energy Research Institute DecDose evaluates the annual exposure dose of the public and workers according to the progress of decommissioning, and also evaluates the public dose at accidental situations including fire and explosion. As for the public, both the internal and the external doses are calculated by considering inhalation, ingestion, direct radiation from radioactive aerosols and radioactive depositions, and skyshine radiation from waste containers. For external dose for workers, the dose rate from contaminated components and structures to be dismantled is calculated. Internal dose for workers is calculated by considering dismantling conditions, e.g. cutting speed, cutting length of the components and exhaust velocity. DecDose was partially verified by comparison with the actual external dose of workers which were acquired during JPDR Decommissioning Project.

38000872
Application of magnetic Compton scattering for spin-specific magnetic hysteresis measurement
Agui, Akane; Sakurai, Hiroshi*; Tamura, Takuro*; Kurachi, Toshitaka*; Tanaka, Masahito*; Adachi, Hiromichi*; Kawata, Hiroshi*
Journal of Synchrotron Radiation 17(3), p.321-324(2010) ; (JAEA-J 07516)

An application of magnetic Compton scattering as a new tool to measure a spin-specific magnetic hysteresis loop was introduced and demonstrated its validity. The applied magnetic field dependence of the integrated intensity of magnetic Compton scattering spectra was interpreted as the spin-specific hysteresis in this study.

38000873
Low-temperature magnetic orderings and Fermi surface properties of LaCd₁₁, CeCd₁₁, and PrCd₁₁ with a caged crystal structure
Yoshiuchi, Shingo*; Takeuchi, Tetsuya*; Oya, Masahiro*; Katayama, Keisuke*; Matsushita, Masaki*; Yoshitani, Naohisa*; Nishimura, Naoto*; Ota, Hisashi*; Tateiwa, Naoyuki; Yamamoto, Etsuji; Haga, Yoshinori; Yamagami, Hiroshi*; Honda, Fuminori*; Settai, Rikio*; Onuki, Yoshichika
Journal of the Physical Society of Japan 79(4), p.044601_1-044601_11(2010) ; (JAEA-J 07517)

We succeeded in growing single crystals of cage-structure compounds RCd₁₁ (R: La, Ce, and Pr) and precisely studied their low-temperature magnetic and electronic properties. We found antiferromagnetic ordering at 0.44 and 0.39 K in CeCd₁₁ and PrCd₁₁, respectively, and clarified the magnetic phase diagrams of the compounds. From the dHvA experiment, we detected small dHvA branches ranging from 7×10⁵ to 2×10⁷ Oe, which correspond to small Fermi surfaces. This is mainly due to a small Brillouin zone based on a large unit cell. Moreover, the dHvA frequencies and cyclotron masses are approximately the same among RCd₁₁, revealing a localized character of 4f electrons in CeCd₁₁ and PrCd₁₁.

38000874
Anisotropic spin fluctuations in heavy-fermion superconductor NpPd₅Al₂
Chudo, Hiroyuki; Sakai, Hironori; Tokunaga, Yo; Kambe, Shinsaku; Aoki, Dai*; Homma, Yoshiya*; Haga, Yoshinori; Matsuda, Tatsuma; Onuki, Yoshichika; Yasuoka, Hiroshi
Journal of the Physical Society of Japan 79(5), p.053704_1-053704_4(2010) ; (JAEA-J 07518)

We present ²⁷Al NMR measurements of the Knight shift and nuclear spin-lattice relaxation rate 1/T₁ in the normal state for a single crystal of the heavy-fermion superconductor NpPd₅ Al₂ (T_c = 4.9 K). We report here that 1/T₁ shows a large anisotropy with a different temperature dependence for H || a and H || c. 1/T₁ for H || c shows a power-law temperature dependence ∼T^0.38, while 1/T₁ for H || a shows a T-linear dependence at low temperatures in fields well above H_c2. From the analysis of 1/T₁, XY-type anisotropy of AFM spin fluctuations is found to become prominent below 20 K.

38000875
NMR evidence for the 8.5 K phase transition in americium dioxide
Tokunaga, Yo; Nishi, Tsuyoshi; Kambe, Shinsaku; Nakada, Masami; Ito, Akinori; Homma, Yoshiya*; Sakai, Hironori; Chudo, Hiroyuki
Journal of the Physical Society of Japan 79(5), p.053705_1-053705_4(2010) ; (JAEA-J 07519)

We report here the first NMR study of americium dioxide (AmO₂). More than 30 years ago, a phase transition was suggested to occur in this compound at 8.5 K based on magnetic susceptibility data, while no evidence had been obtained from microscopic measurements. We have prepared a powder sample of ²⁴³AmO₂ containing 90 at.% ¹⁷O and have performed ¹⁷O NMR at temperatures ranging from 1.5 K to 200 K. After a sudden drop of the ¹⁷O NMR signal intensity below 8.5 K, at 1.5 K we have observed an extremely broad spectrum covering a range of ∼14 kOe in applied field. These data provide the first microscopic evidence for a phase transition as a bulk property in this system. In addition, the ¹⁷O NMR spectrum has been found to split into two peaks in the paramagnetic state, an effect which has not been reported for actinide dioxides studied up to now. We suggest that the splitting is induced by self-radiation damage from the alpha decay of ²⁴³Am.

38000876
Evidence for appearance of an internal field in the ordered state of CeRu₂Al₁₀ by μ⁺SR
Kambe, Shinsaku; Chudo, Hiroyuki; Tokunaga, Yo; Koyama, Takehide*; Sakai, Hironori; Ito, Takashi; Ninomiya, Kazuhiko; Higemoto, Wataru; Takesaka, Tomoaki*; Nishioka, Takashi*; Miyake, Yasuhiro*
Journal of the Physical Society of Japan 79(5), p.053708_1-053708_3(2010) ; (JAEA-J 07520)

We report zero-field μ⁺SR measurements made at J-PARC on CeRu₂Al₁₀. Below the phase transition temperature T₀∼27K, a clear modulation of μ⁺ polarization due to an internal field is observed, indicating that magnetic ordering takes place. Compared with the internal field expected from the effective magnetic moment in the disordered state, the observed internal field at the μ⁺ site is quite small. This indicates that the ordered Ce magnetic moment is small (∼10^-2μ_B) and/or the nearest pair of Ce magnetic moments are mutually anti-parallel. The T-dependence of the internal field is somewhat peculiar, suggesting that another ordering is taking place as well.

38000877
Brownian dynamics around the core of self-gravitating systems
Tashiro, Toru*; Tatekawa, Takayuki
Journal of the Physical Society of Japan 79(6), p.063001_1-063001_4(2010) ; (JAEA-J 07521)

We derive the non-Maxwellian distribution of self-gravitating N-body systems around the core by a model based on the random process with the additive and the multiplicative noise. The number density can be obtained through the steady state solution of the Fokker-Planck equation corresponding to the random process. We exhibit that the number density becomes equal to that of the King model around the core by adjusting the friction coefficient and the intensity of the multiplicative noise. We also show that our model can be applied in the system which has a heavier particle. Moreover, we confirm the validity of our model by comparing with our numerical simulation.

38000878
Soft-lithographic methods for the fabrication of dielectrophoretic devices using molds by proton beam writing
Shiine, Yasuharu*; Nishikawa, Hiroyuki*; Furuta, Yusuke*; kanamitsu, Kaoru*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro; Nakao, Ryota*; Uchida, Satoshi*
Microelectronic Engineering 87(5-8), p.835-838(2010) ; (JAEA-J 07522)

Proton Beam Writing (PBW) is a direct writing process using a MeV focused proton beam. The previous performance examinations of the dielectrophoretic (DEP) devices, the high-aspect-ratio micro-structures with the pillar arrays and the fluidic channels fabricated by PBW, showed that spatially modulated electric fields were effective for trapping Escherichia coli. The reproduction of the DEP device using PBW only is, however, unsuitable because it takes a lot of time to fabricate complicated and large area structures. In this study, the fabrication technique of the micro fluidic channel, combining a soft lithography and PBW techniques, was introduced to improve the productivity of the DEP devices. The prototypes of DEP deceives including SU-8 high-aspect-ratio pillar arrays in the micro fluidic channel were developed using the fabrication technique. Especially the pillar arrays in these devices were produced by 1.0 or 1.7 MeV proton beams focused around 1 μm in diameter. The observation of the DEP devices using an optical microscope image showed that the pillar arrays were successfully included in the micro fluidic channel. The prototyping capability of PBW combined with the soft lithography technique was highlighted by increasing the productivity of the DEP devices.

38000879
Intensely irradiated steel components; Plastic and fracture properties, and a new concept of structural design criteria for assuring the structural integrity
Suzuki, Kazuhiko; Jitsukawa, Shiro; Okubo, Nariaki; Takada, Fumiki
Nuclear Engineering and Design 240(6), p.1290-1305(2010) ; (JAEA-J 07523)

Review of mechanical properties of structural materials under intense neutron irradiation reveals several critical issues to be dealt with in developing a concept assuring the structural integrity of a component under such irradiation. Among these issues are possible reduction in ductility, significant change in mechanical properties, remarkable cyclic softening and other unique cyclic properties observed during a high-cycle fatigue testing, and the redundancy of the plastic collapse concept to bending. Therefore, a new concept for assuring structural integrity is required for application not only to components with high ductility but also components with reduced ductility. First, fracture ductility and the relation of true stress and true strain were formulated. Then, potential failure modes were identified, and a new and systematic concept is here proposed for preventing these modes of failure.

38000880
Nuclear transmutation as a phase 2 project
Oigawa, Hiroyuki
Nuclear Physics News 19(4), p.45-47(2009) ; (JAEA-J 07525)

Transmutation Experimental Facility (TEF) is planned as a Phase-2 project of J-PARC. The purpose of TEF is to study the nuclear transmutation technology aiming at the reduction of the burden caused by the disposal of the high-level radioactive wastes discharged by the nuclear power generation. The TEF consists of two buildings: the Transmutation Physics Experimental Facility (TEF-P) and the ADS Target Test Facility (TEF-T). TEF-P is a zero-power critical facility which can be operated with a low-power proton beam to investigate the reactor physics and the controllability of ADS. Moreover, nuclear fuel containing minor actinides can be used in TEF-P so as to carry out mock-up experiments for transmutation systems. TEF-T is a material irradiation facility which can accept a proton beam of 200 kW - 600 MeV into a spallation target of liquid lead-bismuth eutectic.

38000881
One-component description of magnetic excitations in the heavy-fermion compound CeIrIn₅
Kambe, Shinsaku; Tokunaga, Yo; Sakai, Hironori; Chudo, Hiroyuki; Haga, Yoshinori; Matsuda, Tatsuma; Walstedt, R. E.*
Physical Review B 81(14), p.140405_1-140405_4(2010) ; (JAEA-J 07526)

We report an ¹¹⁵In NMR study of a single-crystal sample of the heavy fermion compound CeIrIn₅. The observed non-linear variation of Knight shift with static susceptibility is consistent with the two-fluid model of Nakatsuji et al. However, our results can also be understood in terms of a T-dependent hyperfine coupling, which accounts for the spin-lattice relaxation data naturally on the basis of a one-component dynamical susceptibility. In addition, the observed T-dependence of the hyperfine coupling is scaled to a density of states given by dynamical mean field theory.

38000882
Photoneutron cross sections for ⁹⁶Zr; A Systematic experimental study of photoneutron and radiative neutron capture cross sections for zirconium isotopes
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Kondo, Takeo*; Ito, Osamu*; Kamata, Masaki*; Yamagata, Tamio*; Lui, Y.-W.*; Hilaire, S.*; Koning, A.*
Physical Review C 81(3), p.035801_1-035801_5(2010) ; (JAEA-J 07527)

This manuscript presents photoneutron cross sections for ⁹⁶Zr. Combining the present data with the previously published Zr data, we investigated the γ-ray strength function for zirconium isotopes systematically. We present a unified picture of the γ-ray strength function that consists of the HFB + QRPA model of E1 strength accompanied by an extra M1 strength attributable to giant M1 resonance. It is shown that the γ-ray strength function reproduces both (g,n) and (n,g) cross sections for Zr isotopes consistently.

38000883
Experimental study of the ²³⁸U(³⁶S, 3-5n)^269-271Hs reaction leading to the observation of ²⁷⁰Hs
Graeger, R.*; Ackermann, D.*; Chelnokov, M.*; Chepigin, V.*; Düllmann, C. E.*; Dvorak, J.*; Even, J.*; Gorshkov, A.*; Heßberger, F. P.*; Hild, D.*; Hübner, A.*; Jäger, E.*; Khuyagbaatar, J.*; Kindler, B.*; Kratz, J. V.*; Krier, J.*; Kuznetsov, A.*; Lommel, B.*; Nishio, Katsuhisa; Nitsche, H.*; Omtvedt, J. P.*; Petrushkin, O.*; Rudolph, D.*; Runke, J.*; Samadani, F.*; Schädel, M.*; Schausten, B.*; Türler, A.*; Yakushev, A.*; Zhi, Q.*
Physical Review C 81(6), p.061601_1-061601_5(2010) ; (JAEA-J 07528)

The deformed doubly-magic nucleus ²⁷⁰Hs so far has only been observed as the four-neutron (4n) evaporation residue of the reaction ²⁶Mg + ²⁴⁸Cm, where a maximum cross section of 3 pb was measured. Theoretical studies on the formation of ²⁷⁰Hs in the 4n evaporation channel of fusion reactions with different entrance channel asymmetry in the framework of a two-parameter Smoluchowski equation predict the reactions ⁴⁸Ca + ²²⁶Ra and ³⁶S + ²³⁸U to result in higher cross sections due to lower reaction Q-values. Here, we report on the first measurement of evaporation residues formed in the fusion reaction ³⁶S + ²³⁸U and the observation of ²⁷⁰Hs, produced in the 4n evaporation channel, with a measured cross section of 0.8 pb at 51 MeV excitation energy. The one event cross section limits for the 3n, 4n, and 5n evaporation channels at 39 MeV excitation energy are 2.9 pb, while the cross section limits of the 3n and 5n channel at 51 MeV are 1.5 pb. This is significantly lower than the 5n cross section of the ²⁶Mg + ²⁴⁸Cm reaction at a similar excitation energy.

38000884
Development of a lithium beam probe and measurement of density pedestal in JT-60U
Kojima, Atsushi; Kamiya, Kensaku; Fujita, Takaaki; Kubo, Hirotaka; Iguchi, Harukazu*; Oyama, Naoyuki; Suzuki, Takahiro; Kamada, Yutaka; JT-60 Team
Plasma and Fusion Research (Internet) 5, p.015_1-015_7(2010) ; (JAEA-J 07529)

A lithium beam probe (LiBP) has been developed for the measurement of electron density profiles with high spatial and temporal resolutions in JT-60U. Using an electron beam heating ion source with a capability of 10 mA extraction, a 5.5 mA beam has been injected to the plasmas. Using the LiBP, time evolutions of pedestal density profiles during type I and grassy edge localized modes (ELMs) have been obtained for the first time. After a type I ELM crash, the drop of the line-integrated density measured by an interferometer delays by 2 ms later than that of the pedestal density. Comparing the line-integrated density to the line integration of the edge density profile measured by the LiBP, it is found that the recovery from the type I ELM crash is correlated with the reduction of core plasma density. Compared with the type I ELM, grassy ELMs have smaller density crashes than that of type I ELMs, which is mainly derived from the narrower ELM affected area.

38000885
Electron parallel heat transport in the scrape-off layer using a particle-in-cell code
Froese, A.*; Takizuka, Tomonori; Yagi, Masatoshi
Plasma and Fusion Research (Internet) 5, p.S1017_1-S1017_4(2010) ; (JAEA-J 07530)

Electron heat transport parallel to the magnetic field in the scrape-off layer plasma is investigated with the use of the particle-in-cell code PARASOL. Coulomb collisions are simulated correctly by a binary collision model. The heat flux is lost by radiation cooling, in addition to convection/conduction to the divertor plates. It is confirmed for the collisional case that the conductive heat flux is given by the Spitzer-Harm expression. For the long mean free path case, the conductive heat flux is limited to a factor α of the free streaming value. It is found that α is small (∼0.1 of the sheath-limited value) for the low radiation condition, but becomes large (∼1.0) for the high radiation condition.

38000886
Evolution and nucleosynthesis in extremely metal-poor, asymptotic giant branch stars
Iwamoto, Nobuyuki
Publications of the Astronomical Society of Australia 26(3), p.145-152(2009) ; (JAEA-J 07531)

We evolve extremely metal-poor, thermally pulsing Asymptotic Giant Branch (AGB) models with the mass range of 1-8 M_☉. The ejected chemical yields are obtained by considering mass loss. We find that the 1- and 2-M_☉ AGB models are not affected by hot bottom burning (HBB). Nevertheless, they produce large amount of ⁷Li in an H-flash event. The occurrence of this event is associated with the ingestion of protons from the overlying H-rich envelope into the He convective shell driven by thermal pulse. The resulting ⁷Li abundances in the ejecta are higher than the primordial one predicted in Big-Bang nucleosynthesis. The efficient production of ⁷Li by the operation of HBB is also confirmed in the models of 4-8 M_☉. If these AGB stars have a low-mass companion, it is probable that mass loss from the primary AGB star brings the materials enriched in ⁷Li into the secondary star. This makes the surface composition of the secondary Li-rich.

38000887
Ion-exchange behavior of Zr and Hf as homologues of element 104, Rf, in H₂SO₄ and H₂SO₄ /HClO₄ mixed solutions
Li, Z.; Toyoshima, Atsushi; Tsukada, Kazuaki; Nagame, Yuichiro
Radiochimica Acta 98(1), p.7-12(2010) ; (JAEA-J 07532)

The ion-exchange behavior of Zr and Hf in H₂SO₄ and H₂SO₄/HClO₄ mixed solutions has been studied by a batch method using the carrier-free radiotracers ⁸⁸Zr and ¹⁷⁵Hf. It is found that the ion-exchange behavior of these elements is basically similar to each other, and that Zr and Hf are adsorbed on both cation- and anion-exchangers in H₂SO₄. M⁴⁺ and M(SO₄)₃^2- (M = Zr and Hf) are the predominant cationic and anionic species, respectively, adsorbed on the resins in 0.11-0.99 M H₂SO₄. The distribution coefficients of Zr and Hf on the cation-exchanger in H₂SO₄/HClO₄ at [H⁺]_eq = 1.0 M decrease with an increase of [HSO₄^-]_eq, indicating successive formation of sulfate complexes. The slope analysis demonstrates that Zr and Hf are coordinated by one SO₄^2- ion at 0.011 and 0.020 M [HSO₄^-]_eq, respectively, and by two SO₄^2- ions at 0.079 and 0.20 M [HSO₄^-]_eq, respectively.

38000888
Analyses of high power negative ion accelerators for ITER neutral beam injector
Kashiwagi, Mieko; Taniguchi, Masaki; Dairaku, Masayuki; Grisham, L.*; Hanada, Masaya; Mizuno, Takatoshi; Tobari, Hiroyuki; Umeda, Naotaka; Watanabe, Kazuhiro; Sakamoto, Keishi; Inoue, Takashi
Review of Scientific Instruments 81(2), p.02B113_1-02B113_5(2010) ; (JAEA-J 07533)

In JAEA, a multi aperture and multi grid accelerator has been tested for ITER NBI. In recent experiments, it was shown that the acceleration gaps (1st/2nd/3rd/4th/5th gap) have to be expanded from 104/94/87/78/72 in the original to all 100 mm to sustain 200 kV in each stage stably, and 1 MV in total. On the contrary, increases of beam divergence, stripping loss of negative ions and beamlet deflections due to space charge repulsion among beamlets could appear as issues due to the longer gaps. Beam divergence and stripping loss of ions have been examined in a 2D beam optics study utilizing BEAMORBT code and 3D gas flow code, respectively. Beamlet deflections have been examined in a 3D multi beamlet analysis utilizing OPERA-3d code. As results of these simulations, it was clarified that the gap length could be expanded up to 120 mm. This results were applied to design of the accelerator with the long gap of 120 mm.

38000889
Interesting experimental results in Japan Proton Accelerator Research Complex H^- ion source development
Ueno, Akira; Oguri, Hidetomo; Ikegami, Kiyoshi*; Namekawa, Yuya; Okoshi, Kiyonori
Review of Scientific Instruments 81(2), p.02A720_1-02A720_6(2010) ; (JAEA-J 07534)

In the development of J-PARC H^- ion source, the following interesting experimental results are observed; domination of surface production of H^- ion in cesium free source, a newly devised circuit system for high-power constant-current pulsed-arc-power-supply indispensable for a lanthanum hexaboride (LaB₆) filament, difference of cesium effect in the source with LaB₆-filament or tungsten (W) filament and so on. These experimental results are described in this paper.

38000890
High-voltage testing of a 500-kV dc photocathode electron gun
Nagai, Ryoji; Hajima, Ryoichi; Nishimori, Nobuyuki; Muto, Toshiya*; Yamamoto, Masahiro*; Honda, Yosuke*; Miyajima, Tsukasa*; Iijima, Hokuto*; Kuriki, Masao*; Kuwahara, Makoto*; Okumi, Shoji*; Nakanishi, Tsutomu*
Review of Scientific Instruments 81(3), p.033304_1-033304_5(2010) ; (JAEA-J 07535)

A high-voltage dc photocathode electron gun was successfully conditioned up to a voltage of 550 kV and a long-time holding test for 8 hours was demonstrated at an acceleration voltage of 500 kV. The dc photocathode electron gun is designed for future light sources based on energy-recovery linac and consists of a Cockcroft-Walton generator, a segmented cylindrical ceramic insulator, guard-ring electrodes, a support-rod electrode, a vacuum chamber and a pressurized insulating gas tank. The segmented cylindrical ceramic insulator and the guard-ring electrodes were utilized to prevent any damage to the insulator from electrons emitted by the support-rod electrode.

38000891
Advanced hydrometallurgical separation of actinides and rare metals in nuclear fuel cycle
Ozawa, Masaki; Suzuki, Shinichi; Takeshita, Kenji*
Solvent Extraction Research and Development, Japan 17, p.19-34(2010) ; (JAEA-J 07536)

A hydrometallurgical separation technologies by novel solvent extraction (SX), ion exchange chromatography (IXC) and electrolytic extraction techniques are reviewed as separation tools for light PGM (Ru, Rh, Pd), Tc and f-elements in high level liquid wastes of the nuclear fuel cycle. The SX process using N,N-dialkylamide can isolate U(VI) from fission products without Pu(IV) valence control, and extractants with soft-hard hybrid donors (PTA and PDA) and those containing six soft donors (TPEN) show good separation of actinides (III) from lanthanides (III). The catalytic electrolytic extraction (CEE) process utilizing Pd_adatom or Rh_adatom can effectively separate platinum group metals (PGM), Tc and Re by means of controlled under potential deposition (UPD). Some of the basic work on the hydrometallurgical separation of the elements of interest has been carried out through the strategic Advanced (Adv.-) ORIENT Cycle research in Japan.

38000892
Measurement of ionizing radiation (in Japanese)
Tanimura, Yoshihiko
Denki Hyoron 95(5), p.61-66(2010) ; (JAEA-J 07538)

There exist ionizing radiation from ground or galaxy around us. Recently, the usage of ionizing radiation is increasing in the industrial and medical fields as medical treatment, nondestructive inspection and so on. However, we cannot sense the radiation and many one have no idea to detect them around our surrounding. This article describes radiation measurement and calibration technique of radiation detectors.

38000893
How to utilize rare metals in spent nuclear fuel ? (in Japanese)
Ozawa, Masaki
Enerugi Rebyu 30(5), p.42-46(2010) ; (JAEA-J 07539)

Nuclear rare metals, as such platinum group metals and rare earths, etc, are reviewed. Quantity and radiochemical property are summarized. The state of the art of separation and utilization research are breify discussed, and the policy change on fuel cycle strategy is proposed.

38000894
What is IAEA's inspection performed? (in Japanese)
Kuno, Yusuke
Gaiko Foramu 22(8), p.67-69(2009) ; (JAEA-J 07540)

IAEA Safeguards to verify nuclear materials is one of the most effective tools among many nuclear non-proliferation measures. This paper describes how IAEA inspection is performed and how effectively it is functioned.

38000895
Zoning of rock facies and chemical composition in the Toki granitic body, Central Japan (in Japanese)
Yuguchi, Takashi; Tsuruta, Tadahiko; Nishiyama, Tadao*
Ganseki Kobutsu Kagaku 39(2), p.50-70(2010) ; (JAEA-J 07541)

The Toki granite (TKG), a single pluton, is located at the Cretaceous Sanyo belt in the Inner Zone of Southwest Japan. Samples collected from 19 borehole sites in TKG reveal the spatial variation of mineral assemblage, mode, bulk composition and mineral composition, representing a zoned pluton. Based on the petrography, TKG is divided into three rock facies: the muscovite-biotite granite (MBG), the hornblende-biotite granite (HBG), the biotite granite (BG) from the margin to the interior. ASI (mol. Al₂O₃/(CaO+Na₂O+K₂O)), Al₂O₃, K₂O and Na₂O change systematically from MBG through HBG to BG, corresponding to a systematic variation from S-type in the margin to I-type in the interior. Fe³⁺/Fe²⁺ become gradually higher from MBG through HBG to BG, corresponding to a systematic change from the ilmenite series in the margin to magnetite series in the interior. The sedimentary rocks of the Mino terrane is intruded and metamorphosed to hornfels by the Toki granitic magma. ASI, Na₂O/K₂O and Fe³⁺/Fe²⁺ of TKG become closer to those of the hornfels towards the margin of the body, indicating the assimilation of the crustal host rock by the Toki granitic magma. Both petrography and bulk chemistry suggest that (1) the chemical variation is not solely due to a fractional crystallization, and (2) assimilation has played a significant role in its margin.

38000896
Role of "Monju" in the international cooperation for the development of next generation FBR (in Japanese)
Nagura, Fuminori; Ichimiya, Masakazu; Sagayama, Yutaka
Genshiryoku eye 56(6), p.20-23(2010) ; (JAEA-J 07542)

As for Japan because it is energy security guaranty and the like, Japan continued the research and development of FBR ("Joyo", "Monju") and fuel cycle. In recent years, there are a growing interest in the long-term energy security and terrestrial environmental problem. And FBR cycle has again been observed, by the development of young country and the like. This year, reactor operation was reopened after about 14 years, "Monju" is the only prototype FBR reactor which it works as the Western Worlds, and the result of these research and developments is expected even worldwide. JAEA is carrying on international cooperation of "JAEA-CEA", "JAEA-DOE", GIF, IAEA, for the points of view "The efficient development", "Decrease of development risk", "Establishment of worldwide standard technology", "Monju" establishes to the position as base of international research and development, and JAEA makes the best endeavors to "Monju" carrying out worldwide contribution.

38000897
Primary functions of the first Japanese large-scale facility for exposing small animals to radon
Ishimori, Yu; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*; Tanaka, Hiroshi; Kataoka, Takahiro*; Sakoda, Akihiro*
Hoken Butsuri 45(1), p.65-71(2010) ; (JAEA-J 07543)

Japan atomic energy agency (JAEA) and Okayama University have carried out the experimental animal study and its related studies since 2007 in order to examine the physical effect of radon in detail. Thus, a radon test facility for small animals was developed in order to increase the statistical certainty of our animal tests. This paper illustrates the performance of the facility, the first large-scale facility in Japan. The facility has a potential of about 150 mouse-scale test at the same time. Different concentration at each animal chamber group is available. Controlling radon and avoiding thoron were theoretically and experimentally shown as the fundamental performance of the facility. The relative standard deviation of the radon concentration at the highest concentration group was about 5%, although the lower concentration groups seemed to be affected by variation of background.

38000898
The Radiation processing techniques expand the applications for Japanese paper (in Japanese)
Tamawaki, Hiroshi
Hoshasen To Sangyo (126), p.30-32(2010) ; (JAEA-J 07545)

38000899
Revision of AESJ Standard "The Code of Implementation of Periodic Safety Review of Nuclear Power Plants" (in Japanese)
Hirano, Masashi; Narumiya, Yoshiyuki*
Hozengaku 8(4), p.14-18(2010) ; (JAEA-J 07546)

The Periodic Safety Review (PSR) was launched in June 1992, when the Agency for Natural Resources and Energy issued a notification that required licensees to conduct comprehensive review on the safety of each existing nuclear power plant (NPP) once approximately every ten years based on the latest technical findings for the purpose of improving the safety of the NPP. In 2006, the Standard Committee of the Atomic Energy Society of Japan established the first version of "The Standard of Implementation for Periodic Safety Review of Nuclear Power Plants: 2006". Taking into account developments in safety regulation on PSR after the issuance of the first version, the Standard Committee has revised the Standard. This paper summarizes background on PSR, such developments and major contents of the Standard as well as the focal points of the revision.

38000900
Strategy for international cooperation activities on aging management (in Japanese)
Hirano, Masashi; Kanno, Masanori*; Koyama, Masakuni*
Hozengaku 9(1), p.23-25(2010) ; (JAEA-J 07547)

In March 2006, the Japan Nuclear Energy Safety Organization (JNES) formed the Committee on Coordination of Technical Information with three working groups (WGs), namely, the WG on Safety Research, that on Information Base and that on International Cooperation. In this report, the major activities of the WG on International Cooperation that are being done through the cooperation of the governmental organizations, industries, academia, and academic societies and associations are overviewed.

38000901
Effects of groundwater humic substances on sorption of Np(V) on sandy materials
Nagao, Seiya*; Sakamoto, Yoshiaki; Rao, R. R.*; Fujitake, Nobuhide*
Humic Substances Research 5-6(1), p.9-17(2009) ; (JAEA-J 07548)

Sorption behavior of Np(V) onto sandy materials (sand, tuffaceous sand and sandy rock) was studied in the absence and presence of humic substances (HS) using a batch method at pH 5-6 and ionic strength of 0.01M. The effects of shallow land groundwater HS on the Np(V) sorption depend on the mineralogical components of sandy materials. The distribution coefficient (Kd) of Np(V) increased in the presence of HS. The Kd values were in the order of sand<tuffaceous sand<sandy rock samples. The Np(V) sorption in the presence of HS with different origin for the sandy rock sample was divided into two groups. The Kd values were positively correlated with aliphatic carbon contents of the lake and the shallow groundwater HS, except for the deep saline groundwater HS. These results indicates that the characteristics of the sandy materials and groundwater HS are important factors determining the Np(V) sorption because of the presence of Np(V)-bound HS.

38000902
Electrostatic interactions between localized f-electrons and an interstitial charged particle in metal; μ⁺SR in an f-electron intermetallic compound PrPb₃ (in Japanese)
Ito, Takashi; Higemoto, Wataru
Kotai Butsuri 45(2), p.101-109(2010) ; (JAEA-J 07551)

38000903
New interplay of spin and heat (in Japanese)
Adachi, Hiroto; Maekawa, Sadamichi
Magune 5(6), p.256-263(2010) ; (JAEA-J 07552)

Recent progress in the field of thermoelectrics and thermo-spintronics is reviewed by focusing on the role of spins. Two topics are discussed, i.e., the manipulation of the spin degrees of freedom to enhance the thermoelectric effect, and the observation of the spin Seebeck effect. In the first part of the review, we introduce cobalt oxide as a superior thermoelectric material, and clarify why it has a large Seebeck effect. In the latter half, we discuss the recently observed spin Seebeck effect, and argue that a scenario based on thermal spin current mediated by spin-wave excitations can account for the observed phenomenon.

38000904
Muon spin relaxation in PrPb₃ with nonmagnetic crystalline-electric-field ground state (in Japanese)
Ito, Takashi
Meson (31), p.23-26(2010) ; (JAEA-J 07553)

38000905
Method for determining the number of samples in clearance verification by measurement and evaluation (in Japanese)
Ishigami, Tsutomu; Tachibana, Mitsuo; Yanagihara, Satoshi
Nippon Genshiryoku Gakkai Wabun Rombunshi 9(2), p.199-206(2010) ; (JAEA-J 07554)

To release some materials in considerably low radioactive concentration arising from decommissioning activities of nuclear installations, it is required to confirm that the sum of D/C is lower than the reference value by measurement and evaluation of radioactive concentration. When the radioactive concentration is evaluated by using a statistical method where samples are taken from the material, two points should be taken into account; (1) a conservative evaluation that prevents underestimation to be caused by statistical uncertainties, (2) an error that may lead to a wrong decision where the material is not released due to the conservative evaluation. This paper proposes a method to determine the number of samples required for clearance verification based on a statistical theory in a consistent manner, where uncertainties in the sum of D/C is taken into account.

38000906
Development of a fabrication method for oxide fuels containing metallic dopant materials (in Japanese)
Ishii, Tetsuya; Yoshimochi, Hiroshi; Tanaka, Kenya
Nippon Genshiryoku Gakkai Wabun Rombunshi 9(2), p.207-218(2010) ; (JAEA-J 07555)

In order to develop an innovative fuel fabrication method for americium containing oxide fuels, a feasibility study of metallic U and Mo-doped oxide fuel concept with extruding granulated oxide material was conducted using UO₂. In the concept, it is expected that doped U should reduce the effective oxygen potential and doped Mo should increase the thermal conductivity of the fuel. In this study, sintering tests of U and Mo-doped UO₂ powder were done and thermal conductivities of the sintered material were evaluated. From the results, it can be seen that the doped U and Mo would function as a oxygen potential reducer and thermal conductivity improver, respectively. And it can be seen that the U and Mo doped oxide fuel pellets would be fabricated successfully using hot pressing. Also, from the results of a sintering test of U and Mo-doped extruding granulated UO₂, it can be seen that the extruding granulated substances have a preferable sintering characteristic.

38000907
Characterization of 2D-C/C composite for application of very high temperature reactor (in Japanese)
Shibata, Taiju; Sumita, Junya; Makita, Taiyo*; Takagi, Takashi*; Kunimoto, Eiji*; Sawa, Kazuhiro; Kim, W. J.*; Jung, C. H.*; Park, J. Y.*
Nippon Kikai Gakkai Rombunshu, A 76(764), p.383-385(2010) ; (JAEA-J 07557)

38000908
Structure determination of drug target proteins by neutron crystallography (in Japanese)
Tamada, Taro; Adachi, Motoyasu
Radioisotopes 59(4), p.299-308(2010) ; (JAEA-J 07559)

Neutron diffraction data can provide information of the location of hydrogen atoms to the structural information determined by X-ray crystallography. Here, we show the recent results of the structural determination of drug-target proteins, porcine pancreatic elastase and human immuno-deficiency virus type-1 protease by both X-ray and neutron diffraction. The structure of porcine pancreatic elastase with its potent inhibitor was determined to 0.094 nm resolution by X-ray diffraction and 0.165 nm resolution by neutron diffraction. The structure of HIV-PR with its potent inhibitor was also determined to 0.093 nm resolution by X-ray diffraction and 0.19nm resolution by neutron diffraction. The ionization state and the location of hydrogen atoms of the catalytic residue in these enzymes were determined by neutron diffraction.

38000909
Rapid analysis method of ⁸⁹Sr and ⁹⁰Sr in effluent with a liquid scintillation counter (in Japanese)
Nakano, Masanao; Hiyama, Yoshinori; Watanabe, Hitoshi; Sumiya, Shuichi
Radioisotopes 59(5), p.319-328(2010) ; (JAEA-J 07560)

The rapid analysis method of ⁸⁹Sr and ⁹⁰Sr in effluent has been investigated by a liquid scintillation counter, which could distinguish the difference of beta energy. Analyzed the imitation effluent samples including interference radionuclides such as ⁵⁴Mn, ⁶⁰Co, ¹⁰⁶Ru, ¹³⁷Cs, the good accuracy, precision and chemical recovery were obtained in the analyses. It took only 3 or 4 days to analyze them by this method, though it took a few weeks by the conventional methods. These facts made it sure that this method was worth enough for the analysis of ⁸⁹Sr and ⁹⁰Sr in effluent.

38000910
Nanostructural analysis with atomic pair distribution function by neutron total scattering (in Japanese)
Shamoto, Shinichi
Radioisotopes 59(5), p.355-366(2010) ; (JAEA-J 07561)

It is possible to obtain a diffraction pattern with wide Q-range by using intense pulsed neutron beam, resulting in the accurate atomic pair distribution function (atomic correlation function) after Fourier transformation of the diffraction pattern. The atomic pair distribution function can be used for structural analyses of wide range of materials such as amorphous and disordered crystalline materials without periodicity, in addition to the in-between materials. The recent research examples are shown in conjunction with the relationship between the disordered structure and the physical property.

38000911
Probabilistic structural integrity assessment based on uncertainty of weld residual stress at the piping butt-welds of nuclear reactor components (in Japanese)
Katsuyama, Jinya; Ito, Hiroto; Tobita, Toru; Onizawa, Kunio
Yosetsu Gakkai Rombunshu (Internet) 28(2), p.193-202(2010) ; (JAEA-J 07562)

Weld residual stress near the welded joint of pipe is one of the most important factors to assess the structural integrity of piping because the tensile residual stress becomes a driving force of a stress corrosion cracking (SCC). In this study, a weld simulation method has been developed and verified. An effect of uncertainty of welding conditions, such as scatters of heat input and welding speed during welding, on weld residual stress at the piping butt-welds was evaluated using the simulation method by varying the welding conditions. Probabilistic fracture mechanics analysis using PASCAL-SP was also performed to evaluate the effect of uncertainty of weld residual stress on the break probability of piping. It was clarified that the break probability increased with increasing the uncertainties of residual stress.

38000912
Diffuse scattering of γ-PbF₂
Xianglian*; Sakuma, Takashi*; Basar, K.*; Takahashi, Haruyuki*; Igawa, Naoki
Journal of the Physical Society of Japan, Vol.79, Supplement A , p.29-32(2010) ; (JAEA-J 07564)

γ-PbF₂ belongs to cubic structure with disordered arrangements of F atoms and shows high ionic conductivity at high temperature. Neutron diffuse scattering intensity measurement has been performed at 773 K. Strong and oscillatory diffuse scattering intensity has been observed. The diffuse scattering can be explained by the correlation effects among thermal displacements of atoms and the short-range order in disordered arrangements of F atoms.

38000913
Superconducting twin quarter wave resonator for acceleration of low velocity heavy ions
Kabumoto, Hiroshi; Takeuchi, Suehiro; Matsuda, Makoto; Ishizaki, Nobuhiro; Otokawa, Yoshinori
Proceedings of 14th International Conference on RF Superconductivity (SRF 2009) (Internet) , p.849-853(2009) ; (JAEA-J 07565)

The JAEA-Tokai tandem accelerator was built for basic science researches with heavy ions. Its superconducting booster was developed for increasing the acceleration energy of ions. We have designed and fabricated a superconducting twin-quarter-wave resonator (Twin-QWR) made of niobium and copper for the acceleration of low velocity heavy ions from TRIAC facility. The resonator has two inner conductors and three acceleration gaps which give a resonant frequency of 129.8 MHz and an optimum beam velocity of 6% of the light velocity. Each inner conductor resonates like in a coaxial quarter-wave line resonator. The resonator was designed to have a separatable structure so that we could treat the inner conductors part fully made of high purity niobium apart from the outer conductor made of niobium and copper. We obtained an acceleration field gradient of 5.8 MV/m at an RF power input of 4 W.

38000914
Experimental test plan of air ingress for HTGR
Terada, Atsuhiko; Yan, X.; Hino, Ryutaro; Sato, Hiroyuki
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 5p.(2010) ; (JAEA-J 07566)

When a primary pipe of the HTGR ruptures, helium coolant gas in the reactor blows out into the reactor confinement structure and the reactor primary system depressurizes. Consequently, the core graphite structures may be oxidized by the air and the complicated natural convection of multi component gas mixtures with chemical reactions would take place inside the reactor. Hence, JAEA studies showed the air ingress phenomena in the depressurized reactor and proposed a new passive mechanism of sustained counter air diffusion (SCAD) that has been shown effective in preventing major air ingress through natural circulation in the reactor. In the present plan, JAEA will construct an experimental reactor mockup including reactor core, the SCAD system, pressure vessel, coaxial pipe and so on. The core is made of graphite or ceramics and heated by electric heaters to allow for test operation up to 1200°C. Present status of these activities will be presented.

38000915
Experimental study on fire-extinguishing of lithium
Furukawa, Tomohiro; Kato, Shoichi; Hirakawa, Yasushi; Kondo, Hiroo; Nakamura, Hiroo
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 6p.(2010) ; (JAEA-J 07567)

The EVEDA lithium test loop is constructed at the Oarai Research and Development Center, Japan Atomic Energy Agency. Since lithium is specified as a dangerous substance by a Japanese law, the countermeasure which assumed the lithium combustion incident is indispensable. In this experimental study, the fire-extinguishing behavior of four kinds of fire extinguishers - dryness sand, pearlite, Natrex-L and Natrex-M - to burning lithium was examined. In addition, the effect of depth of lithium pool on the fire-extinguishing performance of the candidate fire extinguisher was investigated to determine the amount of the fire extinguisher placed at the EVEDA lithium test loop.

38000916
Equilibrium partition coefficients of cesium and iodine between sodium pool and the inert cover gas
Miyahara, Shinya; Nishimura, Masahiro; Nakagiri, Toshio
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 6p.(2010) ; (JAEA-J 07568)

Equilibrium partition coefficients were experimentally measured using "Transpiration method" for volatile fission products of cesium and iodine between liquid sodium pool and the inert cover gas. The objectives of the experiments are to : (1) Obtain the equilibrium partition coefficients of cesium and iodine at high temperature between 600 and 850 °C and (2) Study the dependence of the partition coefficients upon the concentration in the sodium pool. The obtained empirical equations are consistent with Castleman's theoretical equations. The partition coefficients of cesium measured at five different points of mole concentration in the pool were almost consistent with the theoretical values. On the other hand, the measured partition coefficients of iodine increased with the increase in the concentration in the pool and this tendency was incompatible with the theoretical consideration. The reason of this discrepancy might be attributed to the formation of Na₂I₂ in the cover gas.

38000917
Direct observation and control of liquid sodium flow dynamics using VUV-LIF-PIV technique under ExB Lorentz force
Fukuda, Takeshi*; Takata, Takashi*; Horiike, Hiroshi*; Kimura, Nobuyuki; Kamide, Hideki
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 6p.(2010) ; (JAEA-J 07569)

It was successfully proven that Na is reasonably transparent to the VUV (vacuum ultraviolet) laser radiation, although the liquid Na surface is highly reflective, being like a mirror to human eyes. The impact of this result is that the velocity field information inside the liquid Na can be visualized by implementing the well developed PIV (particle image velocimetry) technique. A large eddy simulation (LES) code has also been developed for comparison with the experimental results. Furthermore, the newly developed Na loop is designed so as to enable the application of electric and magnetic field in the orthogonal direction to each other that vigorous dynamics of vortices inside the liquid Na are resolved in the phase space under the Lorentz force.

38000918
A Technical overview of the Japan's standards for risk-informed decision making
Narumiya, Yoshiyuki*; Hirano, Mitsumasa*; Hirano, Masashi
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 7p.(2010) ; (JAEA-J 07570)

Over the last thirty years, there have been many accomplishments throughout the world with regard to severe accident studies and the development and application of the PSA techniques. Based on the results and experience gained from these efforts, it is necessary to shift the emphasis toward risk-informed decision-making (RIDM) in Japan. In this context, the Atomic Energy Society of Japan (AESJ) has developed an implementation standard for RIDM. In this report, the content and background of the standard are summarized.

38000919
Development of superfine spherical silica grout as an alternative grouting material for the geological disposal of long-lived radioactive waste
Naito, Morimasa; Kishi, Hirokazu; Fukuoka, Naomi; Yamada, Tsutomu*; Ishida, Hideaki*
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 7p.(2010) ; (JAEA-J 07571)

As an alternative grouting material for the geological repository of long-lived radioactive waste, the "Superfine Spherical silica Grout" (SFSG) material is developed using a fine spherical silica and a fine calcium hydroxide. The developed SFSG material takes an advantage of its smaller particle size distribution (max. ∼1 micron or less) than those of the cementitious materials, and also provides a low alkaline environment so as to reduce unfavorable effects on the long-term performance of geological disposal system. The SFSG is a mixture of the super fine silica powder, the superfine calcium hydroxide and additives such as superplasticizer. Some preliminary laboratory experiments were carried out to characterize its fundamental properties from the viewpoint of practical use for geological disposal, which is required to be equivalent with the conventional cementitious materials in terms of penetrability, strength, pH performance and workability.

38000920
Numerical study on passive control of thermal striping phenomenon using Lorentz force in fast reactor
Takata, Takashi*; Fukuda, Takeshi*; Yamaguchi, Akira; Uchibori, Akihiro; Kimura, Nobuyuki; Kamide, Hideki
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 7p.(2010) ; (JAEA-J 07572)

Liquid sodium, used as a coolant of fast reactor (FR), is an electromagnetic fluid. When a magnetic field is embedded to liquid sodium flow, the Lorentz force will be induced and flow structure such as a turbulent mixing phenomenon will be influenced. In a FR piping system, thermal fatigue is one of key issues that may be occurred after a piping junction of different fluid temperature. In the present paper, a numerical study of sodium flow induced by the Lorentz force on a turbulent mixing after the junction has been carried out. The large eddy simulation (LES) coupled with the electromagnetic field analysis is used for this purpose. The numerical results showed that the temperature fluctuation due to turbulent mixing weakens after it runs through the magnetic field caused by the Lorentz force and thus the thermal fatigue will be suppressed. Accordingly, it is concluded that the passive control of the thermal fatigue will be possible by adding the magnetic field.

38000921
Model development of turbulent dispersion force for advanced two-fluid model in consideration of bubble-liquid phase interactions
Hosoi, Hideaki*; Yoshida, Hiroyuki
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 7p.(2010) ; (JAEA-J 07573)

At the advanced two-fluid model, an interface tracking method is combined with the two-fluid model to predict large interface structure behavior without any constitutive equations which depend on shapes of flow channels. However, constitutive equations to evaluate the effects of small bubbles or droplets on two-phase flow are required. In this study, we develop the new model for turbulent dispersion force term. In this model, effect of large bubbles and deformation of bubbles are neglected to fit the advanced two-fluid model. And the liquid phase turbulent kinetic energy and bubble-induced turbulent kinetic energy are considered as a driving force of dispersion of small bubbles. To verify the present model, the advanced two-fluid model and the model for turbulent dispersion term were incorporated to ACE-3D. And results of numerical simulation were compared with experimental results of air-water two-phase flow in 200 mm diameter vertical pipe.

38000922
Development of advanced two-fluid model for boiling two-phase flow in rod bundles
Yoshida, Hiroyuki; Hosoi, Hideaki*; Suzuki, Takayuki*; Takase, Kazuyuki
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 8p.(2010) ; (JAEA-J 07574)

Two-fluid model is useful for thermal hydraulic analysis in large-scale domain such as rod bundles. However, the two-fluid model includes a lot of constitutive equations. Then, applicability of these constitutive equations must be verified by use of experimental results. To solve these problems, we have been developing an advanced two-fluid model. In this model, an interface tracking method is combined with the two-fluid model to predict large interface structures behavior accurately. Interface structures larger than a computational cells, such as large droplets and bubbles, are calculated using the interface tracking method. And those smaller than cells are simulated by the two-fluid model. In this study, we modified this model to improve the stability of simulation and reduce the computational time. Moreover, the numerical simulation of two-phase flow in various flow channels including boiling two-phase flow were performed.

38000923
Prediction of radioactive corrosion product transfer in primary systems of Japanese prototype fast breeder reactor Monju
Matsuo, Yoichiro; Hasegawa, Masanori; Maegawa, Yoshiharu; Miyahara, Shinya
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 8p.(2010) ; (JAEA-J 07575)

Radioactive corrosion products are main cause of personal radiation exposure during maintenance with no breached fuel in FBR plants. CP is produced in the core region by activation of fuel cladding and sub-assembly wrappers, and they are transported to the primary circuit with sodium flow and deposited on the wall of the primary piping and components. In order to establish the techniques of radiation dose reduction for of personnel, program system for corrosion hazard evaluation code PSYCHE has been was developed. The PSYCHE code is based on the solution-precipitation model. The density of each deposited CP and dose rate of primary coolant system in Monju was estimated by using the PSYCHE and QAD-CG code.

38000924
Current status of conceptual design study toward the demonstration reactor of JSFR
Sakai, Takaaki; Kotake, Shoji; Aoto, Kazumi; Ito, Takaya*; Kamishima, Yoshio*; Oshima, Jun*
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 8p.(2010) ; (JAEA-J 07576)

JAEA is now conducting "Fast Reactor Cycle Technology Development (FaCT)" project for commercialization before 2050s. A demonstration reactor for Japan Sodium-cooled Fast Reactor (JSFR) is planned to start operation around 2025. In the FaCT project, conceptual design study on the demonstration reactor has been performed since FY2007 to determine referential reactor specifications for the next stage of design work of licensing and construction study. Plant performance as a demonstration reactor for the 1.5 GWe commercial reactor JSFR is being compared between 750 MWe and 500 MWe plant designs. In this paper, the current status of the conceptual design study for the demonstration reactor plant is summarized.

38000925
Current status of design and construction of IFMIF/EVEDA lithium test loop
Kondo, Hiroo; Furukawa, Tomohiro; Hirakawa, Yasushi; Matsushita, Izuru*; Ida, Mizuho; Horiike, Hiroshi*; Kanemura, Takuji; Sugiura, Hirokazu*; Yagi, Juro*; Suzuki, Akihiro*; Terai, Takayuki*; Fukada, Satoshi*; Nakamura, Hiroo*
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 9p.(2010) ; (JAEA-J 07577)

IFMIF is a neutron source aimed at producing an intense high energy neutron flux for testing candidate fusion reactor materials. Under Broader Approach activities, Engineering Validation and Engineering Design Activities (EVEDA) of IFMIF started on July 2007. Regarding to the lithium (Li) target facility, design and construction of EVEDA Li Test Loop is a major activity and is in progress. The detail design was started at the early 2009. Fabrication of the loop was started at middle of 2009, and completion is planned at the end of Feb. 2011.

38000926
Development of advanced loop-type fast reactor in Japan; Progress of design study based on preliminary assessment results
Sakamoto, Yoshihiko; Kotake, Shoji; Aoto, Kazumi; Toda, Mikio*
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 9p.(2010) ; (JAEA-J 07578)

JAEA is now performing a FaCT project. The first milestone is in 2010; decisions about whether or not to adopt innovative technologies in the JSFR design will be made in the year. Preliminary assessment is underway to produce recommendations for final discussion. This paper describes some important progress in the preliminary assessment. As for the reactor system design, structural integrity against both thermal stress and seismic force was investigated. Then, the specification of the reactor system was established. Also, investigation of design options to extend a design margin against seismic force has been suggested. Regarding thermal hydraulics issues, design measures have been introduced to restrain cover gas entrainment and vortex cavitations. Further investigation is now in progress for design optimization or improvement of preventive effect. Concerning the piping design of primary cooling circuit, the creep strength reduction by Type-IV damage was taken into account.

38000927
Detailed analyses of specific phenomena in core disruptive accidents of sodium-cooled fast reactors by the COMPASS code
Morita, Koji*; Zhang, S.*; Arima, Tatsumi*; Koshizuka, Seiichi*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Shirakawa, Noriyuki*; Inoue, Fusao*; Yugo, Hiroaki*; Naito, Masanori*; Okada, Hidetoshi*; Yamamoto, Yuichi*; Himi, Masashi*; Hirano, Etsujo*; Shimizu, Sensuke*; Oue, Masaya*
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 9p.(2010) ; (JAEA-J 07579)

A five-year research project has been initiated in 2005 to develop a code based on the MPS (Moving Particle Semi-implicit) method for detailed analysis of specific phenomena in core disruptive accidents (CDAs) of sodium-cooled fast reactors (SFRs). The code is named COMPASS (Computer Code with Moving Particle Semi-implicit for Reactor Safety Analysis). The specific phenomena include (1) fuel pin failure and disruption, (2) molten pool boiling, (3) melt freezing and blockage formation, (4) duct wall failure, (5) low-energy disruptive core motion, (6) debris-bed coolability, and (7) metal-fuel pin failure. Validation study of COMPASS is progressing for these key phenomena. In this paper, recent COMPASS results of detailed analyses for the several specific phenomena are summarized.

38000928
Pressure measurement test of single elbow simulating Na cooled fast reactor cold-leg piping
Ebara, Shinji*; Aoya, Yuta*; Sato, Tsukasa*; Hashizume, Hidetoshi*; Yuki, Kazuhisa*; Aizawa, Kosuke; Yamano, Hidemasa
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 9p.(2010) ; (JAEA-J 07580)

In this study, pressure measurement test is conducted to find out the FIV characteristic features related to the elbow turbulent flow, using 1/7 scale experimental loop simulating the JSFR cold leg piping. As the first step of multielbow piping, pressure measurement for single elbow was performed. The same measurement procedure was taken as a 1/15 scale experiment to assess the influence originated from the different scale flow at the same Reynolds number.

38000929
Unstructured adaptive mesh technique for gas-liquid two-phase flows
Ito, Kei; Kunugi, Tomoaki*; Ohshima, Hiroyuki
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 10p.(2010) ; (JAEA-J 07581)

In the design study of large-sized sodium-cooled fast reactors in Japan (JSFR), the suppression of gas entrainment (GE) phenomena at a free surface in the reactor vessel is very important to establish an economically superior design. In this study, the unstructured adaptive mesh technique is developed for the numerical simulations of gas-liquid two-phase flows. The redistribution methods of two-phase flow variables are newly developed to satisfy the conservations of the variables, i.e. the volumes of gas and liquid phases, the location of interfaces and the momentum of each phase. This improved unstructured adaptive mesh technique for gas-liquid two-phase flows is validated by solving the well-known slotted disk revolution and dam-break problems.

38000930
The Progress of R&Ds for JSFR innovative technologies
Kikuchi, Hirohiko*; Mochida, Haruo*; Ide, Akihiro*; Iitsuka, Toru*; Hayafune, Hiroki
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 10p.(2010) ; (JAEA-J 07582)

This paper shows R&Ds programs for innovative technology about main components of JSFR. JSFR is an advanced loop type Sodium-cooled Fast Reactor. Innovative technologies will be adopted in the JSFR for economic competitiveness, enhancing reliability, and safety. The concept of JSFR is to aim at reducing an amount of commodity, by reduction in the number of cooling loops, an adoption of high-chromium steel with low thermal expansion coefficient and high-temperature strength, and shortening a piping length by connection of outlet/inlet piping to an upper part of the reactor vessel, as well as the integration of a pump into IHX. Further, at secondary cooling system, higher reliable Steam Generator with double-walled straight tube using high chromium steel is adopted. In the FaCT project, a design for JSFR has been executed along design categories such as core design, reactor system, heat transport system, safety design, etc., with corresponding R&Ds.

38000931
Experimental analyses by SIMMER-III on debris-bed coolability and metallic fuel freezing behavior
Yamano, Hidemasa; Tobita, Yoshiharu
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 10p.(2010) ; (JAEA-J 07583)

This paper describes experimental analyses using the SIMMER-III computer code, which is a two-dimensional multi-component multi-phase Eulerian fluid-dynamics code. Two topics of key phenomena in core disruptive accidents were presented in this paper: debris-bed coolability and metallic fuel freezing behavior. To analyze the debris-bed coolability, the ACRR-D10 in-pile experiments were selected. SIMMER-III well simulated the heat transfer mechanisms including conduction, boiling and channeling observed in the experiment. Metallic fuel may freeze onto the stainless steel (cladding or wrapper tube) together with eutectic formation during core disruption in a metallic-fueled reactor. The CAFE-UT2 experiment carried out using pure Uranium melt to investigate such phenomena was selected for the experimental analysis. In spite of no eutectic formation model in the SIMMER-III code, the calculated fuel penetration behavior was in good agreement with the experimental data.

38000932
Safety evaluation of the HTTR-IS nuclear hydrogen production system
Sato, Hiroyuki; Ohashi, Hirofumi; Tazawa, Yujiro; Sakaba, Nariaki; Tachibana, Yukio
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 10p.(2010) ; (JAEA-J 07584)

In the present study, a practical safety evaluation method, which enables to design, construct and operate hydrogen production plants under conventional chemical plant standards, is proposed. An event identification for the HTTR-IS nuclear hydrogen production system is conducted in order to select abnormal events which would change the scenario and quantitative results of the evaluation items from the existing HTTR safety evaluation. In addition, a safety analysis is performed for the identified events. The results of safety analysis for the indentified five AOOs and three ACDs show that evaluation items such as a primary cooling system pressure, temperatures of heat transfer tubes at pressure boundary, etc., do not exceed the acceptance criteria during the scenario. In addition, the increase of peak fuel temperature is small in the most severe case, and therefore the reactor core was not damaged and cooled sufficiently.

38000933
Development of system based code, 1; Reliability target derivation of structures and components
Kurisaka, Kenichi; Nakai, Ryodai; Asayama, Tai; Takaya, Shigeru
Proceedings of 18th International Conference on Nuclear Engineering (ICONE-18) (CD-ROM) , 10p.(2010) ; (JAEA-J 07585)

The present paper describes a new method for determining the target value of structural reliability in the framework of the System Based Code by considering the safety point of view. In the new method, the reliability target is derived from the proposal to a quantitative safety goal that was published by the nuclear safety commission of Japan and the quantitative safety design requirements on the core damage frequency and the containment failure frequency that were determined in the Fast Reactor Cycle Technology Development Project by Japan Atomic Energy Agency, by utilizing analysis models of a probabilistic safety assessment (PSA). The present method was applied to determination of the reliability target of the structures and components which constitute the reactor cooling system in the Japanese sodium-cooled fast reactor. As a result, we confirmed that the present method combined with the PSA analysis model for internal initiating events is applicable to determination of the reliability target associated with a random failure of the structures and components, and that the method related to seismic initiating events can derive the target value of the occurrence frequency at which any of the important structures and components fails due to an earthquake.

38000934
In situ composition measurements of Bunsen reaction solution by radiation probes
Kubo, Shinji; Nagaya, Yasunobu
Proceedings of 18th World Hydrogen Energy Conference (WHEC 2010) (CD-ROM) , 8p.(2010) ; (JAEA-J 07586)

Measuring equipments are integral to chemical process controls. A stable hydrogen production by the Iodine-Sulfur thermochemical water-splitting process is relatively difficult because of lack of existing in situ composition measurement techniques for multiple components and corrosive solution. Composition regulations of Bunsen reaction solution is particularly important, since a closed cycle system provided with this process causes that the many streams with different composition return to this section. Accordingly Bunsen solution becomes changeable composition. Radiation probes have a potential for applications to determine this multiple component solution while the non-contact approach avoids the corrosive issues. Moreover the probes have features of the promptness, contact-less and sequential use. Laboratory scale experiments to evaluate these possibilities of the measurement were conducted with use of simulated Bunsen solution, HIx solution and H₂SO₄ solution, containing HI, I₂, H₂SO₄ and H₂O and sealed radiation sources. Radiations were counted, which were interacted with the solutions in various compositions around room temperature contained in vessels. For HIx solution, the obtained counting rates were correlated with hydrogen volume concentrations; moreover, the application of the Monte Carlo method suggests possibilities that the detector responses for HIx solution by the radiation probes are predictable. For H₂SO₄ solution, iodine atoms had significant influences on the relationship between output values of two gamma-ray density meters, cesium source as higher energy and barium source as lower energy. This results suggest that the neutron-ray probe, the gamma-ray probes of both lower energy and higher energy have possibilities to determine the composition of Bunsen solution of HIx and H₂SO₄ solutions.

38000935
Equations for estimating chest wall thickness in lung counting at JAEA-NCL
Kanai, Katsuta; Kurihara, Osamu
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM) , 3p.(2010) ; (JAEA-J 07588)

Chest wall thickness (CWT) of the subject is an important modifier to determine the lung burden of inhaled actinides such as Pu isotopes or ²⁴¹Am through lung counting. CWT prediction equations as a function of biometric indexes have been proposed by many authors based on chest wall measurements made with an ultrasound device. In the present study we derived such equations from CWT data of our subjects and then evaluated their applicability to monitoring with our currently used lung counter, mainly examining the accuracy of determinations of ²⁴¹Am, useful as a unique indicator that can be detected in most cases of internal contamination with Pu compounds. The error of the equations obtained was found to be within the range of - 8 mm to + 6 mm against actual CWT values of our subjects, complying with the bias performance criteria for direct measurements. However, further studies might be needed to clarify the effect of the difference in posture on the CWT caused by the modification of the counting geometry made for our lung counter.

38000936
The Investigation and consideration for introduction of surface contamination evaluation method based on JIS
Usui, Toshihide; Takashima, Hideki; Iwasa, Atsutoshi; Hamazaki, Masaaki
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM) , 3p.(2010) ; (JAEA-J 07589)

As to the evaluation method of surface contamination used in radiation control of ORDC, where an evaluation method of surface contamination provided by JIS (Z4329, Z4334, Z4504: 2008) is introduced, an influence on radiation control was investigated. As a result of the investigation, measurement conditions and radiation control method need to be changed where the evaluation method according to JIS (Z4329, 4334, 4504; 2008) is adopted. The operated radiation control may not be able to maintain because the detection limit is higher than current one. Therefore the procedure of surface contamination control of JIS (Z4329, 4334, 4504: 2008) should be adopted after reviewing details considering the reasonableness of radiation control.

38000937
Development of a hand-held fast neutron survey meter
Yoshida, Tadayoshi; Tsujimura, Norio; Yamano, Toshiya*
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM) , 3p.(2010) ; (JAEA-J 07590)

A neutron survey meter with a ZnS(Ag) scintillator to measure recoil protons was built. The detection probe weighs approx. 2 kg, therefore providing us with true portability. Performance tests exhibited satisfactory neutron dosimetry characteristics at unmoderated or lightly moderated fission neutron fields and in particular work environments at a MOX fuel facility. This new survey meter will augment a routine neutron monitoring inconveniently being carried out by moderator-based neutron survey meters.

38000938
Prediction analysis of dose equivalent responses of neutron dosemeters used at a MOX fuel facility
Tsujimura, Norio; Yoshida, Tadayoshi; Takada, Chie
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM) , 3p.(2010) ; (JAEA-J 07591)

To predict how accurately the neutron dosemeters can measure the neutron dose equivalent (rate) in MOX fuel fabrication facility work environments, the calculations of the dose equivalent responses of neutron dosemeters were performed by the spectral folding method. The dosemeters selected included two types of personal dosemeters (a thermoluminescent albedo neutron dosemeter and an electronic neutron dosemeter), three moderator-based neutron survey meters and one special instrument called an H_p(10) monitor. The calculations revealed the energy dependences of the responses expected within the entire range of neutron spectral variation observed in neutron fields at workplaces.

38000939
Monitoring network of atmospheric Radon-222 concentration in East Asia and backward trajectory analysis of Radon-222 concentration trend at a small solitary island on Pacific Ocean
Okura, Takehisa; Yamazawa, Hiromi*; Moriizumi, Jun*; Hirao, Shigekazu*; Guo, Q.*; Tojima, Yasunori*; Iida, Takao*
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM) , 3p.(2010) ; (JAEA-J 07592)

Monitoring network of ²²²Rn concentration in air which was measured in Beijing, Nagoya, Hegura-jima, Hachijo-jima and Hateruma-jima, as a tracer for long-range transport in East Asia was established. At inland sites, Beijing and Nagoya, high concentrations ²²²Rn were measured, at marine sites, Hachijo-jima and Hateruma-jima, ²²²Rn concentrations level was very low. Seasonal variations of the ²²²Rn concentration show that ²²²Rn concentration was the lowest in the summer and the highest in the winter. Diurnal variations were measured at inland sites. At marine sites several-day-cycle variations were measured. It was pointed out by this study that the several-day-cycle variations at Hachijo-jima were dependent on synoptic-scale atmospheric disturbance. Backward trajectory analysis of the relationship between atmospheric ²²²Rn concentrations at Hachijo-jima and transport pathway of air mass indicates that atmospheric ²²²Rn at Hachijo-jima has much to do with transport pathway of air.

38000940
Development of calculation code for estimating radiation dose for hypothetical accident of nuclear facility considering radioactive decay chain during atmospheric dispersion of released radionuclides
Takeyasu, Masanori; Nakano, Masanao; Sumiya, Shuichi; Nemoto, Hiromi*; Kanno, Mitsuhiro*; Kurosawa, Naohiro*
Proceedings of 3rd Asian and Oceanic Congress on Radiation Protection (AOCRP-3) (CD-ROM) , 4p.(2010) ; (JAEA-J 07593)

The dose to the public at hypothetical accident of nuclear facility is estimated on the basis of the method described in the Japanese meteorological guideline. However, the radioactive decay during atmospheric dispersion of released radionuclide is not considered in the calculation formula in the guideline. Therefore, when the radionuclide of the half life such as a few min is released, the dose may be excessively over-estimated. In this study, the calculation code was developed which could consider the radioactive decay of the released radionuclide and the generation of the product. The dose calculated on the basis of the developed code was compared with that on the basis of the guideline.

38000941
Status of advanced neutron multiplier development for DEMO in the Broader Approach activities in Japan
Nakamichi, Masaru; Yonehara, Kazuo; Nishitani, Takeo
Proceedings of 9th IEA International Workshop on Beryllium Technology (BeWS-9) , p.16-20(2009) ; (JAEA-J 07594)

Development of beryllium intermetallic compound (beryllide) as advanced neutron multiplier has been started as a part of the Broader Approach activities. The beryllium handling facility where fabrication of beryllide is planned will be installed in the DEMO R&D building at Rokkasho, Japan. The specifications of processing and testing devices were fixed, and the basic data of these devices was obtained for the licensing of the beryllium handling facility. The beryllide fabrication devices are the key components of the beryllium handling facility. Preliminary sintering test of TiAl intermetallic as an alternative material of beryllide was carried out using mixed with Ti and Al powders. The formations of TiAl and Ti₃Al intermetallics were identified using starting mixed powder of Ti and Al. From the result of this preliminary sintering test, it is assumed that beryllide could be directly synthesized by the plasma sintering method from mixed powder particles of Be and Ti.

38000942
Equivalent plastic solid materials of perforated plates based on effective stress ratio
Kasahara, Naoto*; Takasho, Hideki*; Kawasaki, Nobuchika; Ando, Masanori
Proceedings of International Symposium on Plasticity 2010 (CD-ROM) , p.34-36(2010) ; (JAEA-J 07597)

The method to determine equivalent solid materials of perforated plates was proposed. One of difficulties of plastic analysis is dependency of their solutions on constitutive equations. To overcome this problem, plastic behaviors of perforated plate were systematically investigated on various kinds of constitutive equations. These studies have found existence of the effective stress ratio (ESR) which is defined as the stress ratio between average stress of perforated plates and solid plates of base materials. The ESR is a function of geometrical parameters and is independent from constitutive equations. Therefore, the ESR can determine plastic solid materials of perforated plates from any kind of constitutive equations of base materials.

38000943
Current status of electrostatics accelerators at TIARA (in Japanese)
Chiba, Atsuya; Uno, Sadanori; Yamada, Keisuke; Yokoyama, Akihito; Agematsu, Takashi; Kitano, Toshihiko*; Takayama, Terumitsu*; Orimo, Takao*; Koka, Masashi*; Aoki, Yuki*; Yamada, Naoto*; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru
Dai-22-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu , p.104-106(2010) ; (JAEA-J 07598)

38000944
Emittance measurement using scintillator luminescence induced by MeV proton beams, 2 (in Japanese)
Yokoyama, Akihito; Ishii, Yasuyuki; Chiba, Atsuya; Uno, Sadanori; Agematsu, Takashi; Takayama, Terumitsu*; Koka, Masashi*
Dai-22-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu , p.136-139(2010) ; (JAEA-J 07599)

38000945
Measurement and analysis of Echizen pottery anagama; Toward a scientific elucidation of the firing process (in Japanese)
Terauchi, Makoto; Watanabe, Toshio; Sakakibara, Yasuhide; Tanaka, Teruhisa*; Masudaya, Kosei*
Shiseki "Suzu Tokigama Ato" Kuni Shitei Kinen Shimpojiumu Hokokusho , p.85-112(2010) ; (JAEA-J 07602)

JAEA has had many kinds of meetings for technology exchange willingly as an activity to widely make use of the accumulation of the results of research and development on the way to develop FBR "Monju" in general industry. In this report, one of the local traditional industries of Fukui Prefecture, "Echizen pottery" is featured to show an activity of technological exchange. JAEA established a "technological exchange group on Echizen pottery" to scientifically find out the process until firing ends by analyzing behaviors including temperature distribution and flow condition of the inside of anagama with an analyzing technology (thermal Hydraulics), one of our representative research results. This is a report to show the content which has been discussed and evaluated based on the results of firing experiments and their analysis in this group.

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