Papers Published in Journals
-Research results below have been sorted by order of journals name.
-Sorry, some research results below have no English abstract.

November 2007

35001574
Flow-assisted corrosion of carbon steel under neutral water conditions
Sato, Tomonori; Shao, Y.*; Cook, W. G.*; Lister, D. H.*; Uchida, Shunsuke
Corrosion 63(8), p.770-780(2007) ; (JAEA-J 03152)
 Flow-assisted corrosion (FAC) has often caused serious damage to carbon steel piping in nuclear power plants. As a first stage of experiments to determine the effects of water chemistry parameters on FAC, corrosion rates of carbon steel were measured in 140 degrees centigrade pure water with an on-line corrosion rate monitor based on electrical resistance measurement as [O2] and flow velocity were changed. The data were compiled as a function of electrochemical corrosion potential (ECP) and flow velocity. The conclusions are summarized as follows; (1) The FAC rate was below the detectable limit in highly oxygenated conditions, where [O2] was greater than 50 ppb and ECP was above than -0.2 V-SHE. (2) The effects of pre-oxidation treatment disappeared rapidly under deaerated conditions. (3) It is strongly recommended that the effects of flow on FAC rate should be evaluated from the viewpoint of Reynolds number as well as flow velocity.
35001575
Evaluation of operation scenario for fusion DEMO plant at JAEA; Constraint of neutral beam injection system
Sato, Masayasu; Nishio, Satoshi; Tobita, Kenji; Inoue, Takashi
Fusion Engineering and Design 81(23-24), p.2725-2731(2006) ; (JAEA-J 03154)
 
35001576
Single crystal growth, superconductivity and Fermi surface study of plutonium compounds
Haga, Yoshinori; Aoki, Dai*; Yamagami, Hiroshi*; Matsuda, Tatsuma; Nakajima, Kunihisa; Arai, Yasuo; Yamamoto, Etsuji; Nakamura, Akio; Homma, Yoshiya*; Shiokawa, Yoshinobu*; Onuki, Yoshichika*
Journal of Alloys and Compounds 444-445, p.114-118(2007) ; (JAEA-J 03155)
 We report the first dHvA study in plutonium compound PuIn3 with the cubic AuCu3 type structure, which can be regarded as a reference compound of PuCoGa5. The result of the angular dependence of the dHvA frequency, which corresponds to the extremal cross section of the Fermi surface perpendicular to the field direction, was analyzed by the band calculations. The experimental data agree well with the theory, indicating that the 5f electrons can be treated as itinerant ones. The experimental dHvA study for plutonium-based superconductors such as PuCoGa5 are also desired but more challenging because the superconducting mixed state extremely weaken the dHvA amplitude.
35001577
Multipoles in δ-Pu
Hotta, Takashi
Journal of Alloys and Compounds 444-445, p.162-167(2007) ; (JAEA-J 03156)
 In order to develop microscopic theories of magnetism and superconductivity in f-electron compounds, we have proposed the construction of an f-electron model on the basis of a j-j coupling scheme. Using this model, we have explained spin and orbital structure of UMGa5 and NpMGa5. Recently, octupole ordering in NpO2 has been also understood from the microscopic viewpoint. Encouraged by such successes of the j-j coupling model in actinide materials, we attempt to understand magnetism and superconductivity of Pu and PuMGa5. We focus on a key role of 5f orbital state for the appearance of superconductivity in PuMGa5 and the absence of magnetism in δ-Pu. We discuss multipoles as spin-orbital complex degrees of freedom.
35001578
The Oxidation rate of (U0.7Pu0.3)O2-x with two fcc phases
Suzuki, Kiichi; Kato, Masato; Tamura, Tetsuya*; Aono, Shigenori; Kashimura, Motoaki
Journal of Alloys and Compounds 444-445, p.590-593(2007) ; (JAEA-J 03157)
 It was reported that sintered MOX pellet of hypostoichiometric composition was oxidized at room temperature in an atmosphere of inert gas and air. The region of two fcc phases exist at room temperature in the (U,Pu)O2-X with Pu content of greater than 20%. In this study, the oxidation rate of (U0.7Pu0.3)O2-X with two fcc phases was investigated to contribute to understanding of the oxidation behavior using thermogravimetric technique. The sintered pellets of (U0.7Pu0.3)O2-X were prepared by mechanical blending method and were sliced into disc-like sample with about 1 mm thick and 85-93% theoretical density. The oxidation rate of the samples were measured at 60, 125 and 150°C in an atmosphere of Air, N2 and Air/N2 gas mixture containing moisture of 1 - 700ppm using thermal gravity and differential thermal analysis. The curve of the isothermal oxidation was analyzed by the model of diffusion in a system consisting of two phases. The diffusion model can represent the oxidation curve as a function of time and temperature. In the results of X-ray diffraction measurement, fcc phase with O/M ≈ 2.00 was observed to increase by oxidation of sample. These results indicate that the oxidation of the (U0.7Pu0.3)O2-X with two fcc phases proceeds by diffusion of the phase with O/M ≈ 2.00 which is formed on the sample surface.
35001579
Phase behavior of PuO2-x with addition of 9% Am
Miwa, Shuhei; Osaka, Masahiko; Yoshimochi, Hiroshi; Tanaka, Kenya; Kurosaki, Ken*; Uno, Masayoshi*; Yamanaka, Shinsuke*
Journal of Alloys and Compounds 444-445, p.610-613(2007) ; (JAEA-J 03158)
 
35001580
New conservative gyrokinetic full-f Vlasov code and its comparison to gyrokinetic δ f particle-in-cell code
Idomura, Yasuhiro; Ida, Masato; Tokuda, Shinji; Villard, L.*
Journal of Computational Physics 226(1), p.244-262(2007) ; (JAEA-J 03159)
 A new conservative gyrokinetic full-f Vlasov code is developed using a finite difference operator which conserves both the L1 and L2 norms. The growth of numerical oscillations is suppressed by conserving the L2 norm, and the code is numerically stable and robust in a long time simulation. In the slab ion temperature gradient driven (ITG) turbulence simulation, the energy conservation and the entropy balance relation are confirmed, and solutions are benchmarked against a conventional δ f particle-in-cell (PIC) code. The results show that the exact particle number conservation and the good energy conservation in the conservative Vlasov simulation are advantageous for a long time micro-turbulence simulation. In the comparison, physical and numerical effects of the v|| nonlinearity are clarified for the Vlasov and PIC simulations.
35001581
Understanding the SOL flow in L-mode plasma on divertor tokamaks, and its influence on the plasma transport
Asakura, Nobuyuki; ITPA SOL and Divertor Topical Group*
Journal of Nuclear Materials 363-365, p.41-51(2007) ; (JAEA-J 03160)
 SOL mass transport along the magnetic field lines (SOL flow) is of direct relevance to divertor pumping and impurity screening properties. In this review, recent progresses in the SOL flow measurements and modellings in tokamak plasmas, and understanding of the effects on plasma and impurity transport will be summarized.
35001582
Luminescence of Cr-doped alumina induced by charged particle irradiation
Inoue, Aichi; Nagata, Shinji*; To, Kentaro*; Tsuchiya, Bun*; Yamamoto, Shunya; Shikama, Tatsuo*
Journal of Nuclear Materials 367-370(2), p.1112-1116(2007) ; (JAEA-J 03161)
 The ion-induced luminescence behavior has been investigated for Cr-doped alumina (ruby, α-Al2O3: 0.5 wt% Cr) under MeV region H and He ion irradiation. The initial yield of the R- line luminescence (693 nm) increased proportionally to the projected range of the incident H ions, indicating that the ion- induced luminescence efficiency for an H ion was constant with independence of the electronic energy loss. However, the He induced luminescence yield was not directly related to either the projected range or the incident energy, corresponding that the efficiency decreased with increasing the electronic energy loss. The reduction of R-line yields by the ion irradiation was adequately explained by decreasing R-line luminescence centers.
35001583
New evaluation of neutron nuclear data for zinc isotopes
Iwamoto, Nobuyuki
Journal of Nuclear Science and Technology 44(9), p.1131-1141(2007) ; (JAEA-J 03162)
 New evaluation of neutron-induced nuclear data for five stable isotopes of zinc (mass numbers A=64, 66, 67, 68, and 70) is consistently carried out in the incident neutron energy range from 10-5 eV up to 20 MeV. In the low energy region up to about 100 keV resolved resonance parameters are evaluated by taking account of available measurements. In the fast energy region the comprehensive calculations with nuclear reaction models, in which compound, preequilibrium and direct processes are taken into account, are performed to estimate cross sections for various reactions and double differential cross sections of emitted neutrons and γ-rays. The comparisons of the evaluated cross sections with experimental data and existing evaluated nuclear data libraries are made and reveal a good reproducibility of measurements.
35001584
Toward innovative actinide separation processes; Sequential reduction scheme of uranium, neptunium, and plutonium in 3M HNO3 by external ultrasound irradiation
Toraishi, Takashi; Kimura, Takaumi; Arisaka, Makoto
Journal of Nuclear Science and Technology 44(9), p.1220-1226(2007) ; (JAEA-J 03163)
 An innovative remote valency control technique for actinide ions induced by external ultrasound irradiation was reported in the present study. It is known that ultrasound irradiation to water causes the oxidation and/or reduction of the solute by radicals. We very recently found that a noble metal catalyst drastically enhances the sonochemical effect, and even highly stable U(VI) is reduced to U(IV) by ultrasound irradiation. Employing this catalytic reaction, we are developing low-emission actinide ion separation schemes driven by external ultrasound irradiation. In the present work, U(VI), Np(VI) and Pu(VI) in 3 M HNO3 medium were chosen as target ions. Their valency was first adjusted to U(VI)/ Np(V)/ Pu(IV) by external ultrasound irradiation, and then further sonochemical reduction to U(IV)/ Np(IV)/ Pu(III) was carried out.
35001585
Evaluation of unintentionally doped impurities in silicon carbide substrates using neutron activation analysis
Oshima, Takeshi; Tokunaga, Okihiro*; Isshiki, Masahiko*; Sasajima, Fumio; Ito, Hisayoshi
Materials Science Forum 556-557, p.457-460(2007) ; (JAEA-J 03164)
 
35001586
Dynamical simulation of SiO2/4H-SiC(0001) interface oxidation process; From first-principles
Onuma, Toshiharu*; Miyashita, Atsumi; Iwasawa, Misako*; Yoshikawa, Masahito; Tsuchida, Hidekazu*
Materials Science Forum 556-557, p.615-620(2007) ; (JAEA-J 03165)
 We performed the dynamical simulation of the SiO2/4H-SiC(0001) interface oxidation process using first-principles molecular dynamics based on plane waves and the slab model supercells method. The heat-and-cool method is used to prepare the initial interface structure. In this structure, there is no transition oxide layer or dangling bond at the SiO2/SiC interface. As the trigger of the oxidation process, the carbon vacancy is introduced in the SiC layer near the interface. The oxygen molecules are added one by one to the empty sphere in the SiO2 layer near the interface in the oxidation process simulation. The molecular dynamics simulation is carried out at 2500 K. The oxygen molecule is dissociated and forms bonds with the Si atom in the SiO2 layer. The atoms of Si in the SiC layer at the SiO2/4H-SiC(0001) interface are oxidized. Carbon clusters are formed in the interface layer. Oxygen molecules react with the carbon clusters and formed CO molecules.
35001587
Microdosimetric study for secondary neutrons in phantom produced by a 290 MeV/nucleon carbon beam
Endo, Satoru*; Tanaka, Kenichi*; Takada, Masashi*; Onizuka, Yoshihiko*; Miyahara, Nobuyuki*; Sato, Tatsuhiko; Ishikawa, Masayoshi*; Maeda, Naoko*; Hayabuchi, Naofumi*; Shizuma, Kiyoshi*; Hoshi, Masaharu*
Medical Physics 34(9), p.3571-3578(2007) ; (JAEA-J 03166)
 Absorbed doses from main charged particle beams and charged-particle fragments have been measured with high accuracy for particle therapy but there is few report for doses from neutron components produced as fragments. This study describes measurements on neutron dose produced by carbon beam, microdosimetric distributions of secondary neutrons produced by 290 MeV/nucleon carbon beams have been measured by using a tissue equivalent proportional counter (TEPC) at the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). The ratios of neutrons to charged particle fragments dominated to be 11 to 89 % in the absorbed doses at the side and below the faces of the acrylic phantom (300 mm height × 300 mm width × 253 mm thickness).
35001588
Northern Hemisphere forcing of climatic cycles in Antarctica over the past 360,000 years
Kawamura, Kenji*; Parrenin, F.*; Lisiecki, L.*; Uemura, Ryu*; Vimeux, F.*; Severinghaus, J. P.*; Hutterli, M. A.*; Nakazawa, Takakiyo*; Aoki, Shuji*; Jouzel, J.*; Raymo, M. E.*; Matsumoto, Koji*; Nakata, Hisakazu; Motoyama, Hideaki*; Fujita, Shuji*; Azuma, Kumiko*; Fujii, Yoshiyuki*; Watanabe, Okitsugu*
Nature 448(7156), p.912-916(2007) ; (JAEA-J 03167)
 We present a new chronology of Antarctic climate change over the past 360,000 years that is based on the ratio of oxygen to nitrogen molecules in air trapped in the Dome Fuji and Vostok ice cores. This ratio is a proxy for local summer insolation, and thus allows the chronology to be constructed by orbital tuning without the need to assume a lag between a climate record and an orbital parameter. The accuracy of the chronology allows us to examine the phase relationships between climate records from the ice cores and changes in insolation. Our results indicate that orbital-scale Antarctic climate change lags Northern Hemisphere insolation by a few millennia, and that the increases in Antarctic temperature and atmospheric carbon dioxide concentration during the last four terminations occurred within the rising phase of Northern Hemisphere summer insolation. These results support the Milankovitch theory that Northern Hemisphere summer insolation triggered the last four deglaciations.
35001589
R&D progress at JAEA towards production of high power and large-area negative ion beams for ITER
Hanada, Masaya; Inoue, Takashi; Kashiwagi, Mieko; Taniguchi, Masaki; Tobari, Hiroyuki; Watanabe, Kazuhiro; Umeda, Naotaka; Dairaku, Masayuki; Ikeda, Yoshitaka; Sakamoto, Keishi
Nuclear Fusion 47(9), p.1142-1146(2007) ; (JAEA-J 03168)
 The paper reports the progress of R&D toward the ITER neutral beam (NB) system at Japan Atomic Energy Agency (JAEA). In the accelerator development, an H- ion beam of 146 A/m-2 was accelerated up to 836 keV in a vacuum insulated accelerator with five acceleration stages. This is the first production of a high power density beam at MeV range energy, which is more than twice higher than those of the existing NB systems for large experimental reactors such as JT-60U. Long pulse operations of the JT-60U negative ion sources with a large extraction area of 0.45 × 1.1 m2 are in progress. From two ion sources, D- ion beams of 21 A (90 A/m-2), 320 keV have been produced for 21 s. As the consequence, injection of 3.2 MW D0 beams was achieved. Thus the long pulse operation of negative ion based NB system has been demonstrated with multi-tens of ampere of D- ions extracted from the ion extraction area relevant to the ITER NB design (0.6 × 1.5 m2). For long pulse operation of such powerful beams, the negative ion uniformity over the wide extraction area is an essential issue to avoid excess power loading on the accelerator grids. By adopting a new magnetic configuration with so called tent shaped filter, the uniformity of the JAEA 10 ampere source (extraction area: 0.13 × 0.22 m2) was improved to be 8%, which fulfilled the ITER requirement.
35001590
Development of advanced tritium breeders and neutron multipliers for DEMO solid breeder blankets
Tsuchiya, Kunihiko; Hoshino, Tsuyoshi; Kawamura, Hiroshi; Mishima, Yoshinao*; Yoshida, Naoaki*; Terai, Takayuki*; Tanaka, Satoru*; Munakata, Kenzo*; Kato, Shigeru*; Uchida, Munenori*; Nakamichi, Masaru; Yamada, Hirokazu*; Yamaki, Daiju; Hayashi, Kimio
Nuclear Fusion 47(9), p.1300-1306(2007) ; (JAEA-J 03169)
 
35001591
Ion irradiation effects on amorphization and thermal crystallization in Zr-Al-Ni-Cu alloys
Nagata, Shinji*; Higashi, Seijiro*; Tsuchiya, Bun*; To, Kentaro*; Shikama, Tatsuo*; Takahiro, Katsumi*; Ozaki, Koichi*; Kawatsura, Kiyoshi*; Yamamoto, Shunya; Inoue, Aichi
Nuclear Instruments and Methods in Physics Research B 257(1-2), p.420-423(2007) ; (JAEA-J 03171)
 Structural modification and primary precipitates in the Zr55Al10Ni5Cu30 alloy films (50-100 μm thickness) caused by radiation with 300-500 keV H, Ag, Cu and Au ions has been studied. The results of XRD indicated that a metastable primary phase was formed in the alloy by the heat treatment after ion irradiation, but no difference was observed just after the ion irradiation at room temperature. Furthermore, higher incident Au ion fluence effectively suppressed thermal precipitation of the Zr2Ni type crystalline phase in the alloy. The deposited energy dependence of the precipitation behavior indicated an increase of the nucleation sites by the implanted metal atoms, simultaneously with a decrease of the growth rate by higher energy deposition density.
35001592
Ion beam effects on electrical characteristics of proton conductive polymer
Nagata, Shinji*; Konishi, Yoshitada*; Tsuchiya, Bun*; To, Kentaro*; Yamamoto, Shunya; Takahiro, Katsumi*; Shikama, Tatsuo*
Nuclear Instruments and Methods in Physics Research B 257(1-2), p.519-522(2007) ; (JAEA-J 03172)
 Effects of MeV ion irradiation on electrical characteristics of perfluorosulphonic polymer membrane have been studied. The DC electrical conductivity in dry condition increased of three orders of magnitude as a consequence of irradiation with MeV region H and He ion irradiation at a fluence of 2 × 1013 ions/cm2. The optical absorption in the ultra-violet region increased in the ion irradiated membrane due to the formation of fluorocarbon and peroxy radicals. The ion irradiation may form fluorocarbon and peroxy compounds and improve the transport property of protons in the membrane.
35001593
Strong pairing and microscopic inhomogeneity of lattice fermion systems
Yamada, Susumu; Machida, Masahiko; Ohashi, Yoji*; Matsumoto, Hideki*
Physica C 463-465, p.103-106(2007) ; (JAEA-J 03173)
 In order to study an interplay between electronic inhomogeneity and superconductivity as seen in High-Tc cuprates as well as to predict effects of optical lattice in atomic Fermi gases, we numerically examine attractive Hubbard model in the absence of the translation symmetry. For the purpose, we systematically calculate the particle density profile for both 1-D and 2-D attractive Hubbard models with harmonic potential wells using the exact diagonalization and the density-matrix renormalization group methods. The numerical results reveal that fine inhomogeneous zigzag patterns universally emerge in the 1-D model case and the zig-zag structure becomes checkerboard type in the 2-D one. Moreover, it is numerically and theoretically found that such inhomogeneities are caused by double occupation component, i.e., pairs tightly bound on a site. These calculation results are universal for many-body Fermi-particle systems on lattice. We predict that the behavior described above is widely observable from atomic Fermi gas to strong coupled superconductors including High-Tc superconductors.
35001594
Development of large current superconductors using high performance Nb3Sn strand for ITER
Koizumi, Norikiyo; Isono, Takaaki; Hamada, Kazuya; Nunoya, Yoshihiko; Matsui, Kunihiro; Nabara, Yoshihiro; Okuno, Kiyoshi
Physica C 463-465, p.1319-1326(2007) ; (JAEA-J 03174)
 Both mass production technique of strand having high critical current enough to recover the degradation observed in the model coil conductor and also trial fabrication of the ITER-TF cable and conduit section were successfully performed. Critical current degradation by spatially periodic transverse load was both experimentally and numerically studied. The simulation results show that the transverse resistance among the filaments significantly affect on degree of the degradation. The test results also showed that the developed strand has almost the same resistance against the transverse load as the TFMC strand. Therefore, the small degradation of the TF conductor, i.e., stable operation of the TF conductor is preliminarily anticipated.
35001595
Positron microscopic analysis of crack failure in stainless steels
Yu, R.; Maekawa, Masaki; Miwa, Yukio; Hirade, Tetsuya; Nishimura, Akihiko; Kawasuso, Atsuo
Physica Status Solidi (C) 4(10), p.3577-3580(2007) ; (JAEA-J 03175)
 Employing a positron beam with lateral resolution of about 30 micometer, we performed one and two dimensional scan of crack tips in mechanically fatigued as well as stress corrosion cracked (SCC) stainless steels. Results suggest the existence of quite different crack failure mechanisms in the two types of specimen. In agreement with normal crack propagation principal, creation of dislocations and vacancies close to a crack in the mechanically fatigued sample lead to an expected narrowing of the positron annihilation 511 keV Doppler broadening γ-ray peak (S(crack)/S(bulk)=1.01). Contrarily, widening of the Doppler broadening peak was observed for the SCC specimen (S(crack)/S(bulk)=0.97). Such phenomenon was ascribed to the micro-compositional and micro-structural differences between the studied samples.
35001596
Characterization of ion beam-induced SiC-OI structures by positron annihilation spectroscopy
Maekawa, Masaki; Yu, R.; Kawasuso, Atsuo
Physica Status Solidi (C) 4(10), p.3680-3683(2007) ; (JAEA-J 03176)
 
35001597
Design of a positron microprobe using magnetic lenses
Maekawa, Masaki; Yu, R.; Kawasuso, Atsuo
Physica Status Solidi (C) 4(10), p.4016-4019(2007) ; (JAEA-J 03177)
 
35001598
Long-period stacking structures in yttrium trihydride at high pressure
Machida, Akihiko; Omura, Ayako*; Watanuki, Tetsu; Aoki, Katsutoshi; Takemura, Kenichi*
Physical Review B 76(5), p.052101_1-052101_4(2007) ; (JAEA-J 03178)
 The pressure induced structural transition of yttrium tri-hydride YH3 has been investigated by X-ray diffraction experiments under hydrostatic pressure at room temperature. The hexagonal metal lattice transforms to a face-centered cubic (fcc) one through an intermediate state, which appears between 12-22 GPa. The diffraction patterns of the intermediate state are interpreted in terms of long-period rhombohedral polytypes with the periodic arrangements of hexagonal-type (ABA) and fcc-type (ABC) stacking layers of the yttrium metals. These polytypes gradually transforms toward the fcc metal lattice with a successive increase in the fcc-type component upon compression. The hydrogen-hydrogen repulsive interactions and hydrogen-metal bonding likely play a dominant role in the gradual hexagonal-fcc lattice conversion via the long-period polytypic structures.
35001599
Pressure dependence of the structure of liquid Sn up to 19.4 GPa
Narushima, Takashi*; Hattori, Takanori; Kinoshita, Tomohiro*; Hinzmann, A*; Tsuji, Kazuhiko*
Physical Review B 76(10), p.104204_1-104204_8(2007) ; (JAEA-J 03179)
 The structure of liquid Sn was investigated up to 19.4 GPa by synchrotron X-ray diffraction. Upon compression up to about 3-6 GPa, the structural features, which reflect the anisotropic local structure become less prominent; i.e., the hump on the high-Q side of the first peak in the structure factor S(Q) becomes smaller, the position of the second peak relative to that of the first peak in S(Q), Q2/Q1, decreases, and the coordination number, CN, increases. These features indicate that the liquid structure changes toward a simple liquid metal upon compression. However, at higher pressures, the structural parameters nearly unchanged. The parameters in this pressure range are still deviated from their respective values for simple liquid metals. These findings suggest that, contrary to previous expectations, the liquid does not monotonically approach a simple liquid metal, but takes a relatively stable intermediate form with an anisotropic local structure before approaching a simple liquid metal. The high-pressure behavior of liquid Sn is compared to those of liquid Si and liquid Ge and the systematics in liquid group 14 elements are discussed.
35001600
Neutron-induced reactions using a γ-ray detector in a 12C(α,γ)16O reaction study
Makii, Hiroyuki; Nagai, Yasuki*; Mishima, Kenji*; Segawa, Mariko; Shima, Tatsushi*; Igashira, Masayuki*
Physical Review C 76(2), p.022801_1-022801_5(2007) ; (JAEA-J 03180)
 Neutron-induced background events occurring within a γ-ray detector in the 12C(α,γ)16O reaction study are discussed by comparing a spectrum taken by a NaI(Tl) detector with a pulsed α-beam with that taken previously by a Ge detector using a continuous α-beam. Both spectra contain such background events induced by neutrons from the (α,n) reaction on 13C and/or 9Be contained in enriched 12C targets. These observations together with a calculated γ-ray spectrum of the neutron-induced reaction by Ge isotopes indicate the thus-produced background events, which would be hardly reduced by using shield materials, become significant background in the 12C(α,γ)16O reaction study at low α-beam energy.
35001601
Exotic superconducting properties in the electron-hole-compensated heavy-fermion "semimetal" URu2Si2
Kasahara, Yuichi*; Iwasawa, Takuya*; Shishido, Hiroaki*; Shibauchi, Takasada*; Behnia, K.*; Haga, Yoshinori; Matsuda, Tatsuma; Onuki, Yoshichika; Sigrist, M.*; Matsuda, Yuji*
Physical Review Letters 99(116), p.116402_1-116402_4(2007) ; (JAEA-J 03181)
 We show that the charge and thermal transport measurements on ultraclean crystals of URu2Si2 reveal a number of unprecedented superconducting properties. The uniqueness is best highlighted by the peculiar field dependence of thermal conductivity including the first order transition at Hc2 with a reduction of entropy flow. This is a consequence of multi-band superconductivity with compensated electronic structure in the hidden order state of this system. We provide strong evidence for a new type of unconventional superconductivity with two distinct gaps having different nodal topology.
35001602
Alteration of resistance to black Sigatoka (Mycosphaerella fijiensis Morelet) in banana by in vitro irradiation using carbon ion-beam
Reyes-Borja, W. O.*; Sotomayor, I.*; Garzón, I.*; Vera, D.*; Cedeño, M.*; Castillo, B.*; Tanaka, Atsushi; Hase, Yoshihiro; Sekozawa, Yoshihiko*; Sugaya, Sumiko*; Gemma, Hiroshi*
Plant Biotechnology 24(3), p.349-353(2007) ; (JAEA-J 03182)
 Carbon-ion beam was applied to explants of banana "Cavendish Enano" and "Williams" cultivars, in order to study the critical doses, genetic variability and response to black Sigatoka disease; doses employed were: 0, 0.5, 1, 2, 4, 8, 16, 32, 64 and 128 Gy. Biological effect of each dose on height (cm), weight (g), survival rate (%) was recorded. For black Sigatoka assessment on regenerated plants, the disease development period (DDP-days), infection index (II-%) and leaf disc necrotic area (LDNA-%) by juglone toxin were measured. As results, the mortality was increased in explants exposed to higher doses. Weight and height were reduced by doses of 16-128 Gy. Six plants of "Williams" (code number: "W16II74", "W128I67", "W1II148", "W8II13", "W1II19" and "W1II31") and two plants of "Cavendish Enano" (code numbers: "CE4II30" and "CE64I5") were selected as candidates by virtue of being less affected by the disease and by the toxin.
35001603
Biosynthesis and secretion of mugineic acid family phytosiderophores in zinc-deficient barley
Suzuki, Motofumi*; Takahashi, Michiko*; Tsukamoto, Takashi*; Watanabe, Satoshi; Matsuhashi, Shimpei; Yazaki, Junshi*; Kishimoto, Naoki*; kikuchi, Shoshi*; Nakanishi, Hiromi*; Mori, Satoshi*; Nishizawa, Naoko*
Plant Journal 48(1), p.85-97(2006) ; (JAEA-J 03183)
 Mugineic acid family phytosiderophores (MAs) are metal chelators that are produced in graminaceous plants in response to Fe deficiency, but current evidence regarding secretion of MAs during Zn deficiency is contradictory. HPLC analysis showed that Zn deficiency induces the synthesis and secretion of MAs in barley plants. Studies of the genes involved in the methionine cycle using microarray analysis showed that the transcripts of these genes were increased in both Zn-deficient and Fe-deficient barley roots. Analysis using the PETIS confirmed that more 62Zn(II)-MAs than 62Zn2+ were absorbed by the roots of Zn-deficient barley plants. These data suggest that the increased biosynthesis and secretion of MAs arising from a shortage of Zn are not due to an induced Fe deficiency, and that secreted MAs are effective in absorbing Zn from the soil.
35001604
Double crosslinked polyetheretherketone-based polymer electrolyte membranes prepared by radiation and thermal crosslinking techniques
Chen, J.; Maekawa, Yasunari; Asano, Masaharu; Yoshida, Masaru
Polymer 48(20), p.6002-6009(2007) ; (JAEA-J 03184)
 Novel one step preparation of polymer electrolyte membranes without a membrane casting process is achieved by radiation crosslinking of a polyetheretherketone (PEEK) film to prevent dissolution and deformation of the original film in sulfonating solutions. The films crosslinked with doses more than 33 MGy can be effectively sulfonated in a chlorosulfonic solution, resulting in a crosslinked sulfonated PEEK (sPEEK) electrolyte membrane with high proton conductivity comparable to Nafion. The thermal treatment was effective for further crosslinking of the membrane; as a result, the water uptake and methanol permeability of the double crosslinked sPEEK membranes drastically decreased, compensating for a slight decrease of proton conductivity.
35001605
Mutational reconstructed ferric chelate reductase confers enhanced tolerance in rice to iron deficiency in calcareous soil
Ishimaru, Yasuhiro*; Kim, S.*; Tsukamoto, Takashi*; Oki, Hiroyuki*; Kobayashi, Takanori*; Watanabe, Satoshi; Matsuhashi, Shimpei; Takahashi, Michiko*; Nakanishi, Hiromi*; Mori, Satoshi*; Nishizawa, Naoko*
Proceedings of the National Academy of Sciences of the United States of America 104(18), p.7373-7378(2007) ; (JAEA-J 03185)
 Fe deficiency is a worldwide agricultural problem on calcareous soils. Rice plants use a well documented phytosiderophore-based system to take up Fe from the soil. Rice plants are extremely susceptible to low-Fe supply, however, because of low phytosiderophore secretion and low Fe3+ reduction activity. A yeast Fe3+ chelate-reductase gene refre1/372, selected for better performance at high pH, was fused to the promoter of the Fe-regulated transporter, OsIRT1, and introduced into rice plants. The transgene was expressed in response to a low-Fe nutritional status in roots of transformants. Transgenic rice plants expressing the refre1/372 gene showed higher Fe3+ chelate-reductase activity and a higher Fe-uptake rate than vector controls under Fe-deficient conditions. Consequently, transgenic rice plants exhibited an enhanced tolerance to low-Fe availability and 7.9x the grain yield of nontransformed plants in calcareous soils.
35001606
52Mn translocation in barley monitored using a positron-emitting tracer imaging system
Tsukamoto, Takashi*; Nakanishi, Hiromi*; Kiyomiya, Shoichiro*; Watanabe, Satoshi; Matsuhashi, Shimpei; Nishizawa, Naoko*; Mori, Satoshi*
Soil Science and Plant Nutrition 52(6), p.717-725(2006) ; (JAEA-J 03186)
 Until now, the real-time uptake and movement of Mn, has not been documented in plants. In this study, the real-time translocation of Mn in barley was visualized using 52Mn and PETIS. In all cases, 52Mn first accumulated in the discrimination center (DC), suggesting that this region may play an important role in Mn distribution in graminaceous plants. Mn deficient barley showed greater translocation of 52Mn from roots to shoots than did Mn-sufficient barley. In contrast, the translocation of 52Mn from roots to shoots was suppressed in Mn-excess barley. In Mn-sufficient barley, the dark treatment did not suppress the translocation of 52Mn to the youngest leaf, suggesting that the translocation of Mn to the youngest leaf is independent of the transpiration stream. Our results show that the translocation of Mn from the roots to the DC depends passively on water flow, but actively on the Mn transporter(s).
35001607
Vibrationally-assisted dissociative adsorption of oxygen on Ru(0001)-p(2×1)-O
Takahashi, Shin*; Fujimoto, Yosuke*; Teraoka, Yuden; Yoshigoe, Akitaka; Okuyama, Hiroshi*; Aruga, Tetsuya*
Surface Science 601(18), p.3809-3812(2007) ; (JAEA-J 03187)
 Supersonic molecular beam techniques with 0.5-1.0eV and high resolution X-ray photoelectron spectroscopy using synchrotron radiation were applied to the dynamics study for oxygen dissociative adsorption on Ru(0001). Increase of adsorption probability and saturation coverage with increasing translational energy suggests a direct dissociation mechanism. We measured uptake curves with and without heating a molecular beam source to verify internal energy effects. We found drastic enhancement of dissociative adsorption. In comparison with rotational and translational cooling during beam expansion, vibrational populations are known to be almost unrelaxed. Then, we concluded that adsorption enhancement was mainly caused by vibrational excitation, indicating that dissociation barrier was located in the exit channel on the potential energy surface. Such vibrational effect was also found on oxygen pre-covered Ru(0001) surface with a 0.5 monolayer corresponding to a p(2×1) structure.
35001608
Single crystalline β-FeSi2 grown using high-purity FeSi2 source
Goto, Kohei*; Suzuki, Hirokazu*; Udono, Haruhiko*; Kikuma, Isao*; Esaka, Fumitaka; Uchikoshi, Masahito*; Isshiki, Minoru*
Thin Solid Films 515(22), p.8263-8267(2007) ; (JAEA-J 03188)
 We have investigated the effect of FeSi2 source purity on the electrical property of β-FeSi2 grown from solution. A high purity FeSi2 source avoided a contamination of Cu and W metals was synthesized by melting a high purity Fe (5N) and Si (5N-up) in a quartz ampoule. The β-FeSi2 crystals grown using the high purity FeSi2 and Zn solvent showed n-type conduction, whereas those grown using the arc-melted FeSi2 showed p-type. From the SIMS analysis of the grown crystals, we found that dominant impurity concentrations in the p-type crystals were higher than those in the n-type ones.
35001609
Paleogeography and geological evolution since the Late Pliocene in and around the Horonobe area, northern Hokkaido (in Japanese)
Niizato, Tadafumi; Funaki, Hironori; Yasue, Kenichi
Chishitsugaku Zasshi 113(Suppl.), p.119-135(2007) ; (JAEA-J 03189)
 The tectonic framework in the northern part of Hokkaido has been controlled by interrelationship between the Amurian Plate and Okhotsk Plate since the Late Pliocene. The developments of the geological structure of fold-and-thrust belt with westward vergence and migration of depositional axis from east to west have been progressed in the framework since Late Pliocene. On the basis of distribution of fossil-periglacial phenomena and its origin, northern part of Hokkaido was located in the southern margin of the continuous permafrost zone or the northern margin of the discontinuous zone during the Last Glacial Maximum. This field trip includes the minor deformation structures and sedimentary facies developed in the Tertiary to Quaternary sedimentary formations, aeolian deposits from MIS7 to MIS5e, periglacial deposits in the LGM. It also includes the periglacial landform distributed in the Horonobe area.
35001610
Recent progress in the technology development for the ITER superconducting coils (in Japanese)
Okuno, Kiyoshi
Chodendo Komyunikeshonzu 16(3), p.6-7(2007) ; (JAEA-J 03190)
 In the ITER, Cadarache was selected as ITER site by the six Participant Teams (PTs), namely, Japan, China, EU, Korea, Russia and US, and India was then accepted to be a new member. K. Ikeda was nominated to be the Director General for the ITER Organization. The build-up of the ITER Organization has been started and the construction of the ITER will soon be started. Japanese contribution to the construction of the ITER superconducting magnet system is to procure 25% of TF conductors, about half of TF coil winding packs, all of TF coil structures and all of CS conductors. JAEA has started extensive technology development for the preparation of these procurements, including trial fabrication of the superconductors at industry level and their performance demonstration, manufacturing studies on the TF coil winding pack and structures and full-scale trial fabrication of TF coil structures. Fruitful results have so far been obtained.
35001611
Effects of Abasic site and 8oxoG lesions on DNA molecule
Higuchi, Mariko; Pinak, M.; Saito, Kimiaki
Hoken Butsuri 42(2), p.166-173(2007) ; (JAEA-J 03191)
 The cluster damaged site on DNA consisting of 7,8-dihydro-8-oxoguanine (8oxoG) and apurinic/apyrimidinic (AP) site is one example of damage that inhibits enzymatic repair. The 2 nanosecond molecular dynamics simulation revealed that the effect of AP site was lager than it of 8oxoG in multiple damaged DNA. The multiple damaged DNA was bent mainly at AP site. Bending direction of multiple damaged DNA including AP site and 8oxoG was different from that at the lesion site of single 8oxoG damaged DNA. These changes may have an influence on the effectiveness of enzymatic repair.
35001612
Reliability of plant materials for nuclear fuel reprocessing process (in Japanese)
Yamamoto, Masahiro
Hyomen Gijutsu 58(9), p.500-505(2007) ; (JAEA-J 03192)
 The generation of mass-production and consumption had been ended and the generation of declining birth rate and aged society has been coming rapidly in Japan. The infrastructures which defend our security and safe have to keep these functions by maintenances. According to the research for cost of corrosion in Japan using economical data in 1997, the ratio of maintenance costs in total budget of electric power supply services has been reported to 10 times larger than that of 25 years before. In this report, the procedures to ensure the reliabilities of materials used in severe corrosive environment, nuclear reprocessing plant, has been shown and the future subjects are explained.
35001613
A Sensor for detecting temperature gradient (in Japanese)
Yoneda, Yasuhiro
Kemikaru Enjiniyaringu 52(9), p.665-670(2007) ; (JAEA-J 03193)
 The sensor that sensitively detected the temperature change by using the domain response of ferroelectric was developed. The barium titanate was used as a ferroelectric material. The thin film was made with the barium titanate to cause a proper domain response to the temperature change and it made it to the capacitor that became a sensor. As a result, the ferroelectric thin film was obstructed a free swing of the domain by the effect of the substrate, and became possible the control of the temperature change that had to be detected. The principle of operation of this sensor is clarified by the experiment on the topography done with SPring-8, and moreover, if the temperature change is not suppressed to mK-ordar for the barium titanate of the bulk, it is understood not to obtain a static domain composition, and is confirmed the effect of making it to the thin film.
35001614
Separation of rare earth elements by continuous stripping with DTPA from DIDPA solvent (in Japanese)
Fujiwara, Takeshi; Morita, Yasuji
Nippon Genshiryoku Gakkai Wabun Rombunshi 6(3), p.358-364(2007) ; (JAEA-J 03194)
 Continuous stripping of rare earth elements (REs) with diethylenetriaminepentaacetic acid (DTPA) solution from the diisodecylphosphoric acid (DIDPA) solvent was examined with lab-scale mixer-settlers, to develop a process for the separation of trivalent actinides (An(III)) from the mixture of An(III) and REs. DIDPA is an extractant applied in the 4-Group Partitioning Process developed in Japan Atomic Energy Research Institute (presently: Japan Atomic Energy Agency) to separate transuranic elements from high-level liquid waste. The experiment on continuous stripping with the DTPA solution of a little higher pH than an appropriate pH for selective stripping of An(III) showed that Nd could be selectively stripped from the DIDPA solvent containing La and Nd. The yield was higher than 99.8%, and 97.6% of La was left in the solvent. The pH of the DTPA solution decreased in the stages near the solvent feed, which was explained by the extraction of ammonium ion. These findings make it possible to predict quantitatively the behavior of An(III) and REs in the various conditions of the DIDPA-DTPA continuous stripping system.
35001615
Numerical evaluation of crack propagation of ITER first wall with an initial interfacial defect (in Japanese)
Suzuki, Satoshi; Enoeda, Mikio; Matsuda, Hirokazu*; Hiramatsu, Hideki*; Kuroda, Toshimasa*
Nippon Genshiryoku Gakkai Wabun Rombunshi 6(3), p.365-369(2007) ; (JAEA-J 03195)
 The first wall of ITER will be fabricated by means of HIP method for the bonding of cooling tubes and a copper alloy heat sink. A ultrasonic testing (UT) is adopted as a non-destructive inspection method for the bonding interface as one of acceptance tests of the first wall components. Therefore, clarification of defect size criteria is one of critical issues for the soundness of the first wall. Thermo-mechanical behavior of an initial defect at the bonded interface of the first wall was numerically analyzed. J-integral was calculated to evaluate the propagation behavior of the interfacial defects under thermal loading. As a result, it was found that the initial defect size of 10mm × 20mm in semi-elliptic shape was unlikely to propagate. This defect size is more than ten times larger than a detection limit of present UT techniques, and it can be resulted that the UT method presently available is sufficient to detect such harmful initial defects of the ITER first wall.
35001616
Observation of hydrogen in methane hydrate by neutron powder diffraction (in Japanese)
Hoshikawa, Akinori
Nippon Kessho Gakkai-Shi 49(4), p.219-224(2007) ; (JAEA-J 03196)
 
35001617
Atmospheric pressure dependence of the microwave rocket's performance powered by a high power gyrotron (in Japanese)
Oda, Yasuhisa*; Komurasaki, Kimiya*; Takahashi, Koji; Kasugai, Atsushi; Sakamoto, Keishi
Purazuma, Kaku Yugo Gakkai-Shi 83(3), p.296-299(2007) ; (JAEA-J 03197)
 
35001618
Plasma light sources with highly charged ions (in Japanese)
Tanuma, Hajime*; Sasaki, Akira
Purazuma, Kaku Yugo Gakkai-Shi 83(8), p.679-683(2007) ; (JAEA-J 03198)
 
35001619
Calculation of anisotropy factors for 241Am-Be neutron sources (in Japanese)
Tsujimura, Norio; Yoshida, Tadayoshi
Radioisotopes 56(9), p.497-508(2007) ; (JAEA-J 03199)
 The authors calculated anisotropy factors for 241Am-Be neutron sources. In this calculation, we created a calculation model composed of following three steps: (1) calculation of alpha-particle spectrum at the surface of spherical cluster of AmO2, (2) calculation of neutron yield in a thick beryllium target and of neutron spectrum produced by 9Be(alpha,n) reactions; and (3) calculation of angular fluence distribution of neutrons emerging from two different encapsulation types of 241Am-Be neutron sources. This computation was made by combining an in-house code using the 9Be(alpha,n) cross section data library (JENDL/AN-2005) and the Monte Carlo code MCNP-4C. As a result, anisotropy factors were evaluated to be 1.030 and 1.039 for 241Am-Be in a standard Amersham X3 capsule and X4 capsule, respectively. These values are in reasonable close agreement with the published experimental data.
35001620
Chemiluminescence ELISA for the detection of oxidative DNA base damage using anti-8-hydroxy-2'-deoxyguanosine antibody; Application to the detection of irradiated foods
Kikuchi, Masahiro; Gunawardane, C. R.; Alam, M. K.; Mohd Dzomir, A. Z.; Pitipanaarachchi, R. C.; Funayama, Tomoo; Hamada, Nobuyuki*; Sakashita, Tetsuya; Wada, Seiichi*; Sato, Katsuya; Narumi, Issei; Kobayashi, Yasuhiko
Radioisotopes 56(9), p.509-517(2007) ; (JAEA-J 03200)
 Since ionizing radiation is used for sterilizing or lowering the microbial content of foods, the development of versatile detection methods of irradiated foods is necessary for appropriate management. In an effort to distinguish between irradiated and non-irradiated food, a method based on the detection of oxidative DNA base damage using the chemiluminescence enzyme-linked immunosorbent assay (ELISA) with anti-8-hydroxy-2'-deoxyguanosine antibody was developed. It was shown that this chemiluminescence ELISA method could be applied to chicken, beef and pork that were irradiated with over 3 kGy. Twenty milligrams of a loaf of meat was sufficient to distinguish between irradiated and non-irradiated meat by this method.
35001621
A New method for parametiric imaging of photosynthesis with C-11 carbon dioxide and Positron Emitting Tracer Imaging System (PETIS)
Kawachi, Naoki; Fujimaki, Shu; Ishii, Satomi; Suzui, Nobuo; Ishioka, Noriko; Matsuhashi, Shimpei
Nuclear Science Symposium Conference Record, 2006 IEEE, Vol.3 (CD-ROM) , p.1519-1522(2006) ; (JAEA-J 03201)
 The positron emitting tracer imaging system (PETIS) and carbon-11-labeled carbon dioxide (11CO2) can image carbon movement during photosynthesis in a plant leaf, and 11C kinetics make it possible to estimate physiological function parameters in those photosynthesis processes. With an exposure 11CO2 gas to a leaf, PETIS experiments were performed iteratively under dark and light environments on a single leaf. In order to estimate the rate constants of photosynthetic parameters, time activity curves of 11CO2 gas input and leaf response were fitted to an appropriate compartmental tracer kinetic model, which applies influx and efflux for photo-assimilation and sucrose export rate constants respectively. Results obtained from the kinetic analysis are consistent with physiological knowledge and important to discuss photosynthesis in plant physiology and agriculture. In addition, the proposed method in this paper produce parametric images of photosynthetic functions on a pixel-by-pixel basis successfully, in other words, molecular imaging for plant study is demonstrated.
35001622
Storm surge simulation on hurricane Katrina in gulf of Mexico using air-wave-sea coupling model
Kim, K.*; Nagai, Haruyasu; Yamashita, Takao*
Proceedings of 4th International Conference on Asian and Pacific Coasts (APAC 2007) (CD-ROM) , p.567-578(2007) ; (JAEA-J 03202)
 In the numerical simulation system for environmental studies: SPEEDI-MP, the wind-wave-surge interaction modules has been developed for accurate storm surge simulation. An additional sea surface stress, the whitecap wave breaking stress, was introduced in this system to consider the processes of energy transfer from wind to current through whitecap breaking. The validity of the atmosphere-wave-ocean coupling system was confirmed in the storm surge simulation of the hurricane Katrina in 2005.
35001623
Current status and development plan on fuel cycle system of fast reactor cycle technology in Japan
Ito, Masanori; Funasaka, Hideyuki; Namekawa, Takashi
Proceedings of European Nuclear Conference 2007 (ENC 2007) (CD-ROM) , 7p.(2007) ; (JAEA-J 03203)
 The FaCT project in Japan is implemented purposing to decide the adoption of innovative technologies by 2010 and to judge the prospect of the applicability of innovative technologies to the commercialized fast reactor cycle system by 2015. Innovative technologies to be developed are identified as six development issues for advanced aqueous reprocessing system and six ones for simplified pelletizing method fuel fabrication system. As for reprocessing technology, uranium crystallization and extraction chromatography are important. Wide range of development work from chemical fundamental study to engineering-scale equipment operation are planned and practiced. As for fuel fabrication, conversion and granulation are important to get the source MOX powder with good flowability. Development of modular equipments with grater remote maintenance performance and repairing system in a hot cell is essential to put the low decontaminated TRU fuel fabrication into practical use.
35001624
Development of a new thermo-chemical and electrolytic hybrid hydrogen production process utilizing the heat from medium temperature heat source; Development of the 1NL/h hydrogen production experimental apparatus
Takai, Toshihide; Nakagiri, Toshio; Inagaki, Yoshiyuki
Proceedings of Hydrogen & Fuel Cells 2007; International Conference and Trade Show (CD-ROM) , p.233-242(2007) ; (JAEA-J 03204)
 A new experimental apparatus by the thermo-chemical and electrolytic Hybrid Hydrogen production in Lower Temperature range (HHLT) for 1NL/h (2.8×10-7Nm3/s) level hydrogen production have been developed. The HHLT process is based on sulfuric acid (H2SO4) synthesis and the decomposition processes developed earlier (Westinghouse process). Hydrogen production experiment to evaluate hydrogen production efficiency is undergoing, and the experimental results was reported in the presentation.
35001625
Progress in the R&D project on oxide dispersion strengthened and precipitation hardened ferritic steels for sodium cooled fast breeder reactor fuels
Kaito, Takeji; Otsuka, Satoshi; Inoue, Masaki
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.37-42(2007) ; (JAEA-J 03205)
 High burnup capability of sodium cooled fast breeder reactor (SFR) fuels depends significantly on irradiation performance of their component materials. Japan Atomic Energy Agency (JAEA) has been developing oxide dispersion strengthened (ODS) ferritic steels and a precipitation hardened (PH) ferritic steel as the most prospective candidate materials for fuel pin cladding and duct tubes, respectively. Technology for small-scale manufacturing is already established, and several hundreds of ODS steel cladding tubes and dozens of PH steel duct tubes were successfully produced. We will step forward to develop manufacturing technology for mass production to supply these steels for future commercialized SFRs. Mechanical properties of the products were examined by out-of-pile and in-pile tests including material irradiation tests in the experimental fast reactor JOYO and the Fast Flux Test Facility (FFTF). The material strength standards (MSSs) were tentatively compiled in 2005 for ODS steels and in 1993 for PH steel. In order to improve the MSSs and to demonstrate high burnup capability of the materials, we will perform a series of irradiation tests in BOR-60 and JOYO until 2015 and contribute to design study for a demonstration SFR of which operation is expected after 2025.
35001626
Current status and perspective of advanced loop type fast reactor in fast reactor cycle technology development project
Niwa, Hajime; Aoto, Kazumi; Morishita, Masaki
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.62-70(2007) ; (JAEA-J 03206)
 After selecting the combination of the sodium-cooled fast reactor (SFR) with oxide fuel, the advanced aqueous reprocessing and the simplified pelletizing fuel fabrication as the most promising concept of FR cycle system, Feasibility Study on Commercialized Fast Reactor Cycle Systems was finalized in 2006. Instead, a new project, Fast Reactor Cycle Technology Development Project (FaCT Project) was launched in Japan focusing on development of the selected concepts. This paper describes the current status and perspective of the advanced loop type SFR system in the FaCT Project, especially on the design requirements, current design as well as the related innovative technologies together with the development roadmap. Some considerations on advantages of the advanced loop type design are also described.
35001627
The Prospective role of JAEA Nuclear Fuel Cycle Engineering Laboratories
Ojima, Hisao; Dojiri, Shigeru; Tanaka, Kazuhiko; Takeda, Seiichiro; Nomura, Shigeo
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.273-282(2007) ; (JAEA-J 03207)
 The Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency (JAEA) was established to take over activities of the Tokai Works of Japan Nuclear Cycle Development Institute (JNC). From 1959, several kinds of technologies (such as uranium refining, centrifuge for uranium enrichment, LWR spent fuel reprocessing and MOX fuel fabrication) have been accomplished. And also, R&Ds on the treatment and disposal of high level waste and the FBR fuel reprocessing have been carried out. Through such activities, control of environmental release of radioactive material and radiation exposure and management of nuclear materials have been done appropriately. The Laboratories will contribute to establish the closed cycle with R&Ds of the reprocessing technology during the transition period from LWR era to FBR era, improved MOX fuel fabrication technology, advanced FBR fuel reprocessing technology and high level waste disposal technology.
35001628
Development of probabilistic design method for annular fuels
Ozawa, Takayuki
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.404-408(2007) ; (JAEA-J 03208)
 The probabilistic annular fuel design code "BORNFREE-CEPTAR" was developed for the reasonable design of annular fuels to be applied for fast reactors in future. In the probabilistic design method, the performance parameters, i.e. fuel center temperature, cladding temperature, cladding stress, etc., used to be evaluated with the Monte Carlo method under the irradiation behavior, and the quantitative design margin could be obtained. As the result of probabilistic evaluation with this code, the possibility of the improvement of reactor performance of the advanced fast reactor was quantitatively indicated.
35001629
Waste handling activities in glovebox dismantling facility
Kitamura, Akihiro; Okada, Takashi; Kashiro, Kashio; Yoshino, Masanori*; Hirano, Hiroshi*
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.531-536(2007) ; (JAEA-J 03209)
 We present our waste handling activities in glovebox dismantling facility, installed in Plutonium Fuel Production Facility, Nuclear Fuel Cycle Engineering Laboratories, JAEA. In this facility, we treat only one size gloveboxes (3m×3m×1m), but for the future waste treatment, we segregate waste into material categories. We analyzed the data collected for the future decommissioning, waste treatment and waste disposal. We also present the improvements which are already made and will be made in the near future.
35001630
Improvement on the prediction accuracy of transmutation properties for fast reactor core using the minor actinides irradiation test data on the JOYO MK-II core
Sugino, Kazuteru
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.653-661(2007) ; (JAEA-J 03210)
 For a validation of MAs nuclear data and improvement on the prediction accuracy of MAs transmutation properties in fast reactor cores, the MAs sample irradiation tests data of Joyo were utilized. Result of their analyses showed good agreement with experimental value, which indicates that the MAs cross sections in JENDL-3.3 are almost satisfactory for an application to fast reactor cores. Further, the present study clarified that the utilization of those data with cross section adjustment technique has the potential to reduce the uncertainty of MAs transmutation properties in fast reactor cores to less than half.
35001631
Conceptual design of the HTTR-IS hydrogen production system; Dynamic simulation code development for advanced process heat exchanger in the HTTR-IS system
Sato, Hiroyuki; Kubo, Shinji; Sakaba, Nariaki; Ohashi, Hirofumi; Sano, Naoki; Nishihara, Tetsuo; Kunitomi, Kazuhiko
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.812-819(2007) ; (JAEA-J 03211)
 The objective of this study is to confirm the availability of proposed mitigation methodology against thermal load increase events initiated by the thermochemical water splitting IS process hydrogen production system coupling with the HTTR. JAEA has been performing the development of dynamic simulation code which can evaluate complex phenomena in the HTTR-IS system all at one once to achieve the requirement. The notable feature of the developed code is the APHX module which enables to estimate the IS process thermal load variation considering phase change and chemical reaction behavior assumed in the APHX. In this paper, two cases of dynamic calculation for the thermal load increase events were performed using the newly developed APHX module. The results of the analytical studies clearly show the availability of the developed model for dynamic simulation of the HTTR-IS system and the thermal load increase mitigation methodology.
35001632
Study on characteristics of recycled MOX powder suitable for low density pellet fabrication
Murakami, Tatsutoshi; Suzuki, Kiichi; Aono, Shigenori
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.891-896(2007) ; (JAEA-J 03212)
 
35001633
Preparation of low oxygen-to-metal mixed oxide fuels for the advanced fast reactor
Kato, Masato; Nakamichi, Shinya; Takano, Tatsuo
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.916-920(2007) ; (JAEA-J 03213)
 
35001634
Attempts to improve radiolytic stability of amidic extractants
Sugo, Yumi; Sasaki, Yuji; Kimura, Takaumi; Sekine, Tsutomu*
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1870-1873(2007) ; (JAEA-J 03214)
 A tridentate diamide, N,N,N',N'-tetraoctyldiglycolamide (TODGA) is very useful for the recovery of actinide ions from spent nuclear fuel. Based on the mechanism of the radiolysis of TODGA in organic solution, an improvement of radiolytic stability of amidic extractants was attempted. The radiolytic degradation of TODGA was suppressed by the addition of appropriate compounds, due to reduction in the mole fraction of n-dodecane. In addition, by using the solvents having low ionization potentials, TODGA could be protected from radiation. Because the charge transfer reaction in the primary process was inhibited. It was also confirmed that aromatic substituents in the molecule effectively improved the radiolytic stability.
35001635
Simulation of long time averaged concentration under actual meteorological conditions
Hara, Tomohiro*; Oba, Ryoji*; Okabayashi, Kazuki*; Yoneda, Jiro*; Nagai, Haruyasu; Hayashi, Takashi*
Proceedings of International Workshop on Physical Modelling of Flow and Dispersion Phenomena (PHYSMOD 2007) , p.167-174(2007) ; (JAEA-J 03215)
 We simulated a meandering effect of wind direction fluctuation on horizontal gas diffusion over Mt. Tsukuba, using a rotating turntable in the wind tunnel experiment. Experimental results were validated with field data observed by Japan Atomic Energy Research Institute (JAERI), 1989 and 1990. We also simulated actual unsteady phenomena of airflow and gas diffusion over Mt. Tsukuba, and compared the calculated results with field data. Both data agreed well under neutral, stable and unstable atmospheric stabilities.
35001636
Preformed plasma characterization for high-intensity laser and plasma interactions
Sagisaka, Akito
Science and Technology Created by Ultra-Short, Ultra-High-Peak Power Lasers , p.43-53(2007) ; (JAEA-J 03216)
 
35001637
Optical injection for high-quality electron beam generation by using multiple laser pulses
Kotaki, Hideyuki
Science and Technology Created by Ultra-Short, Ultra-High-Peak Power Lasers , p.55-68(2007) ; (JAEA-J 03217)
 
35001638
Radiation protection for intense optical field science
Hayashi, Yukio
Science and Technology Created by Ultra-Short, Ultra-High-Peak Power Lasers , p.69-82(2007) ; (JAEA-J 03218)
 
35001639
Automatic tuning technology for a sparse eigensolver, application of LOBPCG to quantum many-body problems (in Japanese)
Imamura, Toshiyuki*; Yamada, Susumu; Machida, Masahiko
Joho Shori Gakkai Kenkyu Hokoku 2007-HPC-111 , p.167-172(2007) ; (JAEA-J 03220)
 
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