JAEA Abstracts

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

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

January 2010

38000018
Analytical methods using a positron microprobe
Oka, Toshitaka; Jinno, Satoshi*; Fujinami, Masanori*
Analytical Sciences 25(7), p.837-844(2009) ; (JAEA-J 06600)

Positrons have been used for material analysis not only because of their novel characteristics, such as an ability to detect open-volume type defects in materials, but also because interactions with solids differ from those of electrons in such processes as scattering and diffraction. Monoenergetic positron beams and microbeams were developed in the 1980s, and positron experiments have made progress in material analyses. In this article we review the fundamental technique of microbeam fabrication, especially using a magnetically-guided positron beam, its extension to various analytical methods, and expectations for future research.

38000019
First 3-D calculation of core disruptive accident in a large-scale sodium-cooled fast reactor
Yamano, Hidemasa; Tobita, Yoshiharu; Fujita, Satoshi; Maschek, W.*
Annals of Nuclear Energy 36(3), p.337-343(2009) ; (JAEA-J 06601)

The SIMMER-IV computer code is a three-dimensional fluid-dynamics code coupled with a fuel-pin model and a space- and energy-dependent neutron transport kinetics model. The present study attempted the first application of SIMMER-IV to a core disruptive accident in a large-scale sodium-cooled fast reactor. A main point of this study was to investigate reactivity effects with fuel relocation under three-dimensional core representation including control rods. The calculation has indicated that the fuel discharge from the core was disturbed by a significant flow resistance at the entrance nozzle in the current design. Additional static neutronic calculations have been performed to compare basic neutronic characteristics between different scale cores. The static neutronic calculations have clarified that the outward fuel compaction within the inner core increased the reactivity in the large-scale core unlike the small-scale core.

38000020
Multi-millijoule, nonlinear preamplifier for high intensity femtosecond Yb:YAG chirped-pulse amplification lasers at 1030 nm
Suzuki, Masayuki; Kiriyama, Hiromitsu; Daito, Izuru; Okada, Hajime; Nakai, Yoshiki; Orimo, Satoshi; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; Maeda, Junya*; Matsuoka, Shinichi*; Kan, Hirofumi*; Bolton, P.; Daido, Hiroyuki; Kawanishi, Shunichi
Applied Physics B 97(2), p.379-382(2009) ; (JAEA-J 06602)

We report the highest energy broadband laser pulses at a center wavelength of 1030 nm based on optical parametric chirped-pulse amplification (OPCPA). We have demonstrated amplification of 1030 nm femtosecond laser pulses from a broadband Yb oscillator to over 6.5 mJ with a total gain of greater than 10⁷ achieved in a single pass through only 56 mm of gain material at a 10 Hz repetition rate. The amplified spectral bandwidth of 10.8 nm affords recompression to a 230 fs pulse duration following amplification. As an alternative to the regenerative amplifier (RA) this system is one of the more promising candidates for realizing compact, high intensity, direct diode pumped, high repetition rate femtosecond Yb:YAG chirped-pulse amplification (CPA) in laser systems.

38000021
Local structure anomaly around Ge dopants in Mn₃Cu_0.7Ge_0.3N with negative thermal expansion
Matsuno, Jobu*; Takenaka, Koshi*; Takagi, Hidenori*; Matsumura, Daiju; Nishihata, Yasuo; Mizuki, Junichiro
Applied Physics Letters 94(18), p.181904_1-181904_3(2009) ; (JAEA-J 06603)

Local structure analysis of Cu and Ge atoms in the negative thermal expansion material Mn₃Cu_0.7Ge_0.3N was conducted using X-ray absorption fine structure measurements. The temperature dependence of the interatomic distance was found to reflect the macroscopic negative thermal expansion both for Cu-Mn and Ge-Mn shells, although the magnitude of the relative change was much larger for Ge-Mn than Cu-Mn. An enhanced anomaly of the Debye-Waller factor was observed for the Ge-Mn shell in the temperature region of the negative expansion, indicating the presence of static local disorder around Ge impurities. These local structure anomalies strongly suggest that the local and inhomogeneous strain around Ge is essential in broadening the discontinuous volume contraction.

38000022
Submicron ionography of nanostructures using a femtosecond- laser-driven-cluster-based source
Faenov, A. Y.; Pikuz, T. A.*; Fukuda, Yuji; Kando, Masaki; Kotaki, Hideyuki; Homma, Takayuki; Kawase, Keigo; Kameshima, Takashi*; Pirozhkov, A. S.; Yogo, Akifumi; Tampo, Motonobu; Mori, Michiaki; Sakaki, Hironao; Hayashi, Yukio; Nakamura, Tatsufumi; Pikuz, S. A.*; Skobelev, I. Yu.*; Gasilov, S. V.*; Giulietti, A.*; Cecchetti, C. A.*; Boldarev, A. S.*; Gasilov, V. A.*; Magunov, A.*; Kar, S.*; Borghesi, M.*; Bolton, P.; Daido, Hiroyuki; Tajima, Toshiki; Kato, Yoshiaki*; Bulanov, S. V.
Applied Physics Letters 95(10), p.101107_1-101107_3(2009) ; (JAEA-J 06604)

An intense isotropic source of multicharged carbon and oxygen ions with energy above 300 keV and high quantity per shot was obtained by femtosecond Ti:Sa laser irradiation of clusters, produced by expansion of the mixed He and CO₂ gases in a supersonic nozzle. The source was employed for high contrast ionography images with 600 nm spatial resolution. A difference in object thickness of 100 nm was well resolved for both Zr and polymer foils.

38000023
Performance measurement of the scintillator with optical fiber detector for boron neutron capture therapy
Komeda, Masao; Kumada, Hiroaki; Ishikawa, Masazumi*; Nakamura, Takemi; Yamamoto, Kazuyoshi; Matsumura, Akira*
Applied Radiation and Isotopes 67(7-8), p.S254-S257(2009) ; (JAEA-J 06605)

The thermal neutron flux can be easily measured in real time by using the SOF (Scintillator with Optical Fiber) detector. However the irradiation damage under high-intensity neutron flux causes the deterioration of the SOF detector due to the plastic scintillator in which ⁶LiF is blended. After irradiating the SOF detector for 4 hours (thermal neutron fluence approximately 2.0×10¹³ neutrons/cm²), the sensitivity of the SOF detector decreased by 3.0%. After irradiating the SOF detector for 2 months (thermal neutron fluence approximately 6.4×10¹⁴ neutrons/cm²), the sensitivity was reduced to 42%. Supposing that the thermal neutron fluence is 2×10¹² (neutrons/cm²) on the surface of a patient in a BNCT treatment, the sensitivity of the SOF detector is reduced by approximately 0.3%. This report presents investigations on the deterioration of the SOF detector in irradiation experiments.

38000024
Evaluation for the configurational and electronic state of SO₃ adsorbed on Pt surface
Suzuki, Chikashi; Yamada, Yoichi; Nakagiri, Toshio
Applied Surface Science 256(3), p.862-869(2009) ; (JAEA-J 06606)

38000025
X-ray absorption spectroscopy and magnetic circular dichroism in codeposited C₆₀-Co films with giant tunnel magnetoresistance
Matsumoto, Yoshihiro; Sakai, Seiji; Takagi, Yasumasa*; Nakagawa, Takeshi*; Yokoyama, Toshihiko*; Shimada, Toshihiro*; Mitani, Seiji*; Naramoto, Hiroshi*; Maeda, Yoshihito
Chemical Physics Letters 470(4-6), p.244-248(2009) ; (JAEA-J 06607)

Electronic and spin states of the codeposited C₆₀-Co films with large tunnel magnetoresistance (TMR) effect were investigated with the X-ray absorption and magnetic circular dichroism (MCD) spectroscopies. It is revealed that a C₆₀-Co compound generated in the C₆₀-Co films shows the clear MCD signal attributed to the spin-polarized Co 3d states hybridized with C₆₀ π orbitals. The magnetic response of these Co 3d-derived states agrees well with temperature dependence of the observed MR ratios of the granular C₆₀-Co films. This suggests the incorporation of the spin-polarized Co 3d-derived states of the C₆₀-Co compound into the observed TMR effect.

38000026
Sorption and oxidation of tetravalent plutonium on Mn oxide in the presence of citric acid
Tanaka, Kazuya; Suzuki, Yoshinori; Onuki, Toshihiko
Chemistry Letters 38(11), p.1032-1033(2009) ; (JAEA-J 06608)

Sorption experiments of Pu^IV on synthetic Mn oxide were made in 0.1 M NaCl + 0.1 mM sodium citrate solutions under acidic to alkaline pH conditions. As the results of the sorption experiments, Pu was efficiently removed from the solutions under neutral pH conditions, where Pu forms the stable 1:2 Pu^IV-citrate complex. Furthermore, it was demonstrated that Pu^IV was oxidized to Pu^V and Pu^VI on Mn oxide.

38000027
In situ observation of reductive deposition of uranium on an electrode/electrolyte interface by optical waveguide spectroscopy
Nankawa, Takuya; Suzuki, Yoshinori; Onuki, Toshihiko
Chemistry Letters 38(11), p.1090-1091(2009) ; (JAEA-J 06609)

We report the first in situ and real-time observation of UV-vis absorption spectra of uranium electrodeposited on indium-tin-oxide electrodes by slab optical waveguide spectroscopy. An absorption peak around 670 nm was distinguished after a 30-min holding period at -0.2 V (vs. Ag/AgCl). X-ray absorption near edge structure spectroscopy confirmed the presence of uranium(IV) in the uranium electrodeposited on the ITO electrode.

38000028
Complexation of Am with size-fractionated soil humic acids
Nagao, Seiya*; Aoyama, Masakazu*; Watanabe, Akira*; Tanaka, Tadao
Colloids and Surfaces A; Physicochemical and Engineering Aspects 347(1-3), p.239-244(2009) ; (JAEA-J 06610)

Humic substances play important role in geochemical behavior of trace elements such as actinides in aquatic environments. The association properties of Am with humic substances were studied on the basis of structural feature of humic substances. Humic acids prepared from three types of soils, and separated two humic acids with different structural features: fluorescence-poor and higher molecular size fraction, HA and fluorescence-rich and lower molecular size fraction, FL. The association experiments were carried out in a medium of 0.01M NaClO₄ solution at a humus concentration of 10 mg/l and pH 6-8. The dominant size fractions of Am in the presence of the HA were 450nm - 100k Daltons and 100k - 30k Daltons. On the other hand, Am was presented in the size of 30k - 10k Daltons in the FL. These results indicate that characteristics of size-fractionated humic acids are related association properties with Am.

38000029
Strong-gravity effect on twinned Y₁Ba₂Cu₃O_7-x single crystal
Bagun, R.*; Okayasu, Satoru; Iguchi, Yusuke*; Ono, Masao; Mashimo, Tsutomu
Defect and Diffusion Forum 289-292, p.517-521(2009) ; (JAEA-J 06611)

Ultracentrifuge experiments were performed on the twinned Y₁Ba₂Cu₃O_7-x (Y123) single crystal at much lower temperatures than the melting point. Two layers structure with slightly different compositions was observed in the sample ultracentrifuged at 250 °C (380,000 G), which might be due to the sedimentation of atoms. In the strong gravity layer, it was found that the Y123 phase disappeared, and unknown XRD peaks appeared. Decomposition occurred in the sample ultracentrifuged at 400 °C.

38000030
Prospect for extreme field science
Tajima, Toshiki
European Physical Journal D 55(2), p.519-529(2009) ; (JAEA-J 06612)

The kind of laser Extreme Light Infrastructure (ELI) provides will usher in a class of experiments we have only dreamed of for years. The characteristics that ELI brings in include: the highest intensity ever, large fluence, and relatively high repetition rate. A personal view of the author on the prospect of harnessing this unprecedented opportunity for advancing science of extreme fields is presented. The first characteristic of ELI, its intensity, will allow us to access, as many have stressed already, extreme fields that hover around the Schwinger field or at the very least the neighboring fields in which vacuum begins to behave as a nonlinear medium. In this sense, we are seriously probing the 'material' property of vacuum and thus the property that theory of relativity itself described and will entail. We will probe both special theory and general theory of relativity in regimes that have been never tested so far. We may see a glimpse into the reach of relativity or even its breakdown in some extreme regimes. We will learn Einstein and may even go beyond Einstein, if our journey is led. Laser-driven acceleration both by the laser field itself and by the wakefield that is triggered in a plasma is huge. Energies, if not luminosity, we can access, may be unprecedented going far beyond TeV.

38000031
Fuel safety limits; Experimental results and pending questions
Vitanza, C.*; Fuketa, Toyoshi
EUROSAFE Tribune (Internet) 16, p.13-17(2009) ; (JAEA-J 06613)

Considerable experimental effort has been made in the last decade to produce experimental data in support of the definition of fuel safety limits for a variety of fuel designs and considering the effect of burn-up. In particular, tests have been performed in specialized laboratories to address the fuel safety limits at conditions representative of design basis accidents, i.e. Reactivity Initiated Accident (RIA) and Loss-of-Coolant Accidents. In addition to assessing the effect of burn-up, the main focus of these tests has been on the safety performance of different cladding types, especially for PWR fuels. The main outcome of these efforts is discussed in this article.

38000032
Optimization of optical filters for ITER edge Thomson scattering diagnostics
Kajita, Shin; Hatae, Takaki; Naito, Osamu
Fusion Engineering and Design 84(12), p.2214-2220(2009) ; (JAEA-J 06614)

In ITER edge Thomson scattering measurement system, it is planned that polychromators by use of optical band-pass filters and avalanche photodiodes are used for the detection system. In this paper, the optimization of the filter transmission wavelength ranges is performed by minimizing the numerically calculated electron temperature error. The Thomson spectrum extends to considerably short wavelength range because high electron temperature measurement is required; therefore, it is important to eliminate the line emission from the plasma, such as D_α, in particular. It is shown that a filter, the transmission wavelength of which is shorter than D_α, becomes important to decrease the error in high temperature regime. Moreover, when the filter number is more than 7, it is found that a filter, the transmission wavelength of which is higher than the laser wavelength of 1064 nm, is useful to reduce the averaged error in wide temperature range.

38000033
Development of water-cooled solid breeder test blanket module in JAEA
Akiba, Masato; Enoeda, Mikio; Tsuru, Daigo; Tanigawa, Hisashi; Hirose, Takanori; Mori, Kensuke*; Seki, Yohji; Ezato, Koichiro; Suzuki, Satoshi; Nishi, Hiroshi; Mori, Seiji
Fusion Engineering and Design 84(2-6), p.329-332(2009) ; (JAEA-J 06615)

One of the most important missions of ITER is to provide a test bed for breeding blanket modules, which are called as Test Blanket Module (TBM). JAEA has been extensively developing a Water-Cooled Solid Breeder Test Blanket Module (WCSB TBM) for ITER. This paper describes results of recent R&D activities on WCSB TBM in JAEA. JAEA developed fabrication technology of F82H rectangular cooling tubes, and has successfully fabricated the near-full scale first wall mock-up of WCSB TBM by Hot Isostatic Press (HIP) technique, which is fully made of F82H. The mock-up has been high-heat flux tested in the DATS facility in JAEA, which is an ion beam test facility. The inlet temperature of the cooling water is about 280 °C with 15 MPa, which is almost the same as the WCSB TBM design conditions. The mock-up has endured a heat load of 0.5 MW/m², 30 s for 80 thermal cycles. Neither hot spots nor thermal degradation have been observed.

38000034
Progress of design and R&D of water cooled solid breeder test blanket module
Tsuru, Daigo; Enoeda, Mikio; Hirose, Takanori; Tanigawa, Hisashi; Ezato, Koichiro; Yokoyama, Kenji; Dairaku, Masayuki; Seki, Yohji; Suzuki, Satoshi; Mori, Kensuke*; Nishi, Hiroshi; Akiba, Masato
Fusion Science and Technology 56(2), p.875-882(2009) ; (JAEA-J 06616)

As the primary candidate of ITER Test Blanket Module (TBM) for the first day of ITER operation, development of Water Cooled Solid Breeder (WCSB) TBM has been performed toward the TBM milestones, which are necessary for acceptance of the TBM in ITER for testing from the first day of plasma operation. Milestones of ITER TBMs prior to the installation consist of milestones on safety assessment, module qualification and design integration in ITER. This paper overviews the recent achievements for preparation of the WCSB TBM for ITER day-1 operation, toward the TBM milestones.

38000035
Atomic modeling of the plasma EUV sources
Sasaki, Akira; Sunahara, Atsushi*; Furukawa, Hiroyuki*; Nishihara, Katsunobu*; Nishikawa, Takeshi*; Koike, Fumihiro*; Tanuma, Hajime*
High Energy Density Physics 5(3), p.147-151(2009) ; (JAEA-J 06617)

We study the radiative properties of the EUV source to address conditions to achieve an output power and efficiency required for its application to the next generation microlithography. An atomic model is developed based on the atomic data calculated by Hullac code, which is validated through detailed comparisons with experimental emission and a absorption spectra. The atomic model is improved with respect to the wavelength of the strong emission lines, and the number of satellite channels taken into account. As a result, the radiation hydrodynamics model is shown to successfully reproduce the experiments. We show Sn plasma is more efficient than Xe plasma because of the atomic number dependence of the emission wavelength, and the use of CO₂ lasers as a pumping source has an advantage to reduce satellite contribution and to have narrower emission spectrum to obtain higher conversion efficiency.

38000036
The Earth-moon system during the late heavy bombardment period; Geochemical support for impacts dominated by comets
Jorgrnsen, U.*; Appel, P. W. U,*; Hatsukawa, Yuichi; Frei, R.*; Oshima, Masumi; Toh, Yosuke; Kimura, Atsushi
Icarus 204(2), p.368-380(2009) ; (JAEA-J 06618)

The solid planets assembled 4.57 Gyr ago during a period of less than 100 Myr, but the bulk of the impact craters we see on the inner planets formed much later, in a narrow time interval between 3.8 and 3.9 Gyr ago, during the so-called Late Heavy Bombardment (LHB). It is not certain what caused the LHB, and it has not been well known whether the impactors were comets or asteroids, but our present study lend support to the idea that it was comets. During a field expedition to Isua, Greenland, we sampled three types of sedimentary river load from larger areas of surrounding land surface and of contemporaneous seawater. Our samples show evidence of the LHB impacts that took place on Earth, by an average of a seven times enrichment (150 ppt) in iridium compared to present day ocean crust (20 ppt).

38000037
Installation and test programme of the ITER poloidal field conductor insert (PFCI) in the ITER test facility at JAEA Naka
Nunoya, Yoshihiko; Takahashi, Yoshikazu; Hamada, Kazuya; Isono, Takaaki; Matsui, Kunihiro; Oshikiri, Masayuki; Nabara, Yoshihiro; Hemmi, Tsutomu; Nakajima, Hideo; Kawano, Katsumi; Tsutsumi, Fumiaki; Takano, Katsutoshi; Uno, Yasuhiro*; Koizumi, Norikiyo; Okuno, Kiyoshi; Baker, W.*; Salpietro, E.*; Rajainmaki, H.*; Sborchia, C.*; Mitchell, N.*
IEEE Transactions on Applied Superconductivity 19(3), p.1492-1495(2009) ; (JAEA-J 06619)

The ITER Poloidal Field Conductor Insert (PFCI) was constructed to characterize the performance of selected cable-in-conduit NbTi conductors for the ITER Poloidal Field (PF) under relevant operating conditions. The PFCI was installed and tested inside the bore of the ITER CS model coil, which provides the background magnetic field. The PFCI is a single-layer solenoid, wound from about 50 m of a full-size ITER cable-in-conduit conductor. The winding diameter and height are about 1.5 m and 1 m, respectively. The nominal design current of the conductor is 45 kA at 6 T and 5 K. The main items in the PFCI test programme are current sharing temperature (Tcs) measurements, critical current (Ic) measurements and AC loss measurement. The key technology of the installation, the test methods and procedures, and some preliminary results of the testing campaigns are described and discussed in this paper.

38000038
Trimethylamine-modified lignophenol for the recovery of precious metals
Parajuli, D.; Hirota, Koichi; Inoue, Katsutoshi*
Industrial & Engineering Chemistry Research 48(23), p.10163-10168(2009) ; (JAEA-J 06620)

A quaternary amine type sorbent has been prepared by the immobilization of trimethylamine group onto the crosslinked lignophenol matrix. The sorption behavior for a number of metal ions was studied in hydrochloric acid medium. From the batch test of individual metal ion as well as the mixture solution containing equal molar concentration of various metal ions, the sorbent was found to hold selectivity for Au(III), Pd(II), and Pt(IV) ions only with negligible sorption for other metal ions like Cu(II), Co(II), Fe(III), Ni(II), and Zn(II). The sorption kinetics was studied at 303, 323, and 338 K and elucidated the order of sorption of Au(III), Pd(II), and Pt(IV) and from the values of rate constants at different temperatures, the energy of activation has been evaluated. The sorption isotherm study revealed the Langmuir type sorption and from the Langmuir charts the maximum loading capacity of Au(III), Pd(II), and Pt(IV) has been evaluated.

38000039
Structural characterization and dielectric properties of hexagonal Lu(Fe,Ti)O₃
Matsuo, Yoji*; Hoshiyama, Takuya*; Mori, Shigeo*; Yoshii, Kenji; Michiue, Yuichi*; Kambe, Takashi*; Ikeda, Naoshi*; Brown, F.*; kimizuka, noboru*
Japanese Journal of Applied Physics 48(9), p.09KB04_1-09KB04_3(2009) ; (JAEA-J 06621)

We have investigated an average crystal structure and microstructures in LuFe_0.56Ti_0.44O₃ by the transmission electron microscopy (TEM), in combination with the dielectric measurements. In this work, high-qualitypolycrystalline samples of LuFe_0.56Ti_0.44O₃ were successfully synthesized in air by the conventional solid state reaction. The average crystal structure at room temperature is characterized by the hexagonal structure (space group: P6₃ cm). Dielectric measurements revealed that LuFe_0.56Ti_0.44O₃ shows broad dielectric dispersion around 570 K, which should originate from the formation of the polar domain structures on the nanometer scale.

38000040
TiCrV hydrogen storage alloy studied by positron annihilation spectroscopy
Kawasuso, Atsuo; Arashima, Hironobu*; Maekawa, Masaki; Ito, Hideaki*; Kabutomori, Toshiki*
Journal of Alloys and Compounds 486(1-2), p.278-283(2009) ; (JAEA-J 06622)

We have studied the degradation process of TiCrV hydrogen storage alloy alloy using positron annihilation spectroscopy. As the hydrogen storage capacity decreased with the number of pressure swing cycles, positron lifetime increased. The increase in positron lifetime is due to the volume expansion caused by hydride formation. After degassing at 500 °C, the hydrogen storage capacity recovered to the initial level. However, the positron lifetime was still longer than the initial level suggesting the survival of dislocations. The degradation of hydrogen storage capacity is probably caused by both hydride formation and the generation of dislocations.

38000041
Preparation and characterization of dicesium tetravalent plutonium hexanitrate
Nakahara, Masaumi; Nomura, Kazunori; Washiya, Tadahiro; Chikazawa, Takahiro*; Hirasawa, Izumi*
Journal of Alloys and Compounds 489(2), p.659-662(2010) ; (JAEA-J 06623)

Characterization of Cs and Pu(IV) nitrate complex was examined to separation from the UNH crystal. This complex is obtained as a precipitate by mixing dissolver solution of MOX fuel and CsNO₃ solution, which was identified to dicesium tetravalent plutonium hexanitrate, Cs₂Pu(NO₃)₆ by concentration analysis and XRD. The precipitate has a tendency to be generated at high HNO₃ condition. Thermal analysis shows that the precipitate is stable below 245 °C, and a weight loss of about 10.29% is observed at 245 °C. This result corresponds to the decomposition of Cs₂Pu(NO₃)₆ to Cs₂PuO₂(NO₃)₄. According to these properties, the UNH crystal can be melted at 60 °C to 100 °C, and separated from the Pu(IV) and Cs complex by a filtration. A new technology of crystal purification method aimed at higher decontamination of UNH crystal in the U crystallization process is proposed.

38000042
Validation of ¹³¹I ecological transfer models and thyroid dose assessments using Chernobyl fallout data from the Plavsk district, Russia
Zvonova, I.*; Krajewski, P.*; Berkovsky, V.*; Ammann, M.*; Duffa, C.*; Filistovic, V.*; Homma, Toshimitsu; Kanyár, B.*; Nedveckaite, T.*; Simon, S. L.*; Vlasov, O.*; Webbe-Wood, D.*
Journal of Environmental Radioactivity 101(1), p.8-15(2010) ; (JAEA-J 06624)

Within the project EMRAS organized by the IAEA in 2003 experimental data of ¹³¹I measurements following the Chernobyl accident in the Plavsk district of Tula region, Russia were used to validate the calculations of some radioecological transfer models. Ten participants were involved in the inter-comparison. Levels of ¹³⁷Cs soil contamination in all the settlements and ¹³¹I/¹³⁷Cs isotopic ratios in the depositions in some locations were used as the main input information. 370 measurements of ¹³¹I content in thyroid of people, and 90 measurements of ¹³¹I concentration in milk were used for validation of the model predictions. A remarkable improvement in model performance comparing with previous inter-comparison exercise was demonstrated. Predictions of the various models were within a factor of three relative to the observations, and discrepancies between the estimates of average doses to thyroid produced by most participants did not exceed a factor of ten.

38000043
Dynamic nuclear polarization study of UV-irradiated butanol for hyperpolarized liquid NMR
Kumada, Takayuki; Noda, Yohei; Hashimoto, Takeji; Koizumi, Satoshi
Journal of Magnetic Resonance 201(2), p.115-120(2009) ; (JAEA-J 06625)

We have carried out a dynamic nuclear polarization (DNP) study of proton spins of UV-irradiated solid butanol containing phenol. By the aid of butyl free radicals produced by the photolysis, the butanol sample was dynamically polarized up to the polarization of 1.4% at 1.5 K and 1.2 T. Unlike persistent free radicals such as nitroxy and trityl free radicals commonly used for DNP, the butyl free radicals immediately decay by melting. We propose that free radicals produced by UV-photolysis are applicable to the DNP-enhanced hyperpolarized liquid-state NMR.

38000044
Radiation-induced graft polymerization of styrene into a poly(ether ether ketone) film for preparation of polymer electrolyte membranes
Hasegawa, Shin; Sato, Ken*; Narita, Tadashi*; Suzuki, Yasuyuki; Takahashi, Shuichi; Morishita, Norio; Maekawa, Yasunari
Journal of Membrane Science 345(1-2), p.74-80(2009) ; (JAEA-J 06626)

Radiation-induced graft polymerization of styrene into poly(ether ether ketone) (PEEK) with 32% crystallinity was investigated with DSC, TGA, XRD, and ESR. Endothermic heats of melting of the original and styrene-grafted PEEK (grafted PEEK) films were similar, indicating the crystallinity was almost completely maintained up to a grafting degree of 51%. Lower glass transition temperature of the grafted PEEK film in the DSC, and the absence of an extra halo originating from amorphous polystyrene grafts in the XRD strongly indicate the grafting of styrene to crystalline PEEK films proceeded in the amorphous region of PEEK. This is probably because polystyrene grafts have hydrocarbon structures similar to a base PEEK polymer, resulting in compatibility to the amorphous phase of the PEEK films. The grafted PEEK films can be converted to PEEK-based electrolyte membranes by subsequent sulfonation, and had conductivity of more than 0.01 S/cm and exhibited higher water content above 100%.

38000045
Microstructure and elemental distribution of americium-containing uranium plutonium mixed oxide fuel under a short-term irradiation test in a fast reactor
Tanaka, Kosuke; Miwa, Shuhei; Sato, Isamu; Hirosawa, Takashi; Obayashi, Hiroshi; Koyama, Shinichi; Yoshimochi, Hiroshi; Tanaka, Kenya
Journal of Nuclear Materials 385(2), p.407-412(2009) ; (JAEA-J 06628)

In order to confirm the effect of americium addition on irradiation behavior of MOX fuel, the "Am-1" program is being conducted in Joyo. The Am-1 program consists of two short-term irradiation tests and a steady-state irradiation test. The short-term irradiation tests were successfully completed and the post irradiation examinations are in progress. This paper reports on the results of PIEs for Am-containing MOX fuel irradiated for 10 minutes. MOX fuel pellets containing 3% or 5% Am were fabricated in a shielded air-tight hot cell using a remote handling technique. The oxygen to metal ratio (O/M) of these fuel pellets was 1.98. They were irradiated at peak linear heating rate of about 43 kW/m. The ceramography results showed that structural changes such as lenticular voids and a central void occurred early, within the brief 10 minutes of irradiation. The results of EPMA revealed that Am migrated to the radial center of the fuel pellet up the temperature gradient.

38000046
Extensive study of the soft-rotator model Hamiltonian parameters for medium and heavy even-even nuclei
Kunieda, Satoshi; Chiba, Satoshi; Shibata, Keiichi; Ichihara, Akira; Iwamoto, Osamu; Iwamoto, Nobuyuki; Fukahori, Tokio; Sukhovitskij, E.*
Journal of Nuclear Science and Technology 46(9), p.914-924(2009) ; (JAEA-J 06629)

The soft-rotator model Hamiltonian parameters were deduced for 63 even-even nuclei in a mass range 56 ≤ A ≤ 238 by a combination of the low-lying level structure and the coupled-channels proton scattering analyses toward a systematic and accurate calculation of nuclear data. It was found that obtained effective quadrupole and octupole deformation parameters were consistent with those derived from experimental B(E2) and B(E3) data. Besides, the equilibrium ground-state quadrupole deformation parameters were also in reasonable accord with theoretical results for deformed heavy nuclei. The obtained parameters often varied with the neutron and/or proton numbers anomalously, showing mostly effects of the shell closure. On the other hand, some clear systematic trends were seen among the major Hamiltonian parameters.

38000047
Fuel pin behavior under slow-ramp-type transient-overpower conditions in the CABRI-FAST experiments
Fukano, Yoshitaka; Onoda, Yuichi; Sato, Ikken; Charpenel, J.*
Journal of Nuclear Science and Technology 46(11), p.1049-1058(2009) ; (JAEA-J 06630)

In the CABRI-FAST experimental program, four in-pile tests were performed with slow-power-ramptype transient-overpower conditions (called hereafter as "slow TOP") to study transient fuel pin behavior under inadvertent control-rod-withdrawal-type events in liquid-metal-cooled fast breeder reactors. The slow TOP test with a preirradiated solid-pellet fuel pin under a power ramp rate of approximately 3%Po/s was realized as a comparatory test against an existing test in the CABRI-2 program where approximately 1%Po/s was adopted with the same type of fuel pin. In spite of the different power ramp rates, the evaluated fuel thermal conditions at the observed failure time are quite similar. Three slow TOP tests with the preirradiated annular fuel resulted in no pin failure showing a high failure threshold. These CABRI-FAST slow TOP tests, in combination with the existing CABRI and TREAT tests, provided an extended slow TOP test database under various fuel and transient conditions.

38000048
Calculation of neutron cross sections on ^{90,91,92,94,96}Zr for JENDL-4
Ichihara, Akira; Kunieda, Satoshi; Shibata, Keiichi
Journal of Nuclear Science and Technology 46(11), p.1076-1084(2009) ; (JAEA-J 06631)

Neutron nuclear data of ^{90,91,92,94,96}Zr were calculated for the development of the 4-th version of the Japanese Evaluated Nuclear Data Library (JENDL-4) in the incident neutron energy range above the resolved resonance region to 20 MeV by using nuclear reaction models such as the spherical optical model, the distorted wave Born approximation, the Kalbach preequilibrium model, and the Hauser-Feshbach statistical model. Obtained cross sections were almost consistent with the experimental data for elastic, nonelastic and inelastic scattering, (n,γ), (n,2n), (n,p) and (n,α) reactions. The agreement with recent experiments is better than the evaluated data in JENDL-3.3 for the (n,γ) cross sections on ^90,92,94Zr.

38000049
Mockup experiments to investigate the leak rate correlation between mercury and helium for the mercury target system of J-PARC
Haga, Katsuhiro; Naoe, Takashi; Kogawa, Hiroyuki; Wakui, Takashi; Futakawa, Masatoshi
Journal of Nuclear Science and Technology 46(12), p.1145-1151(2009) ; (JAEA-J 06632)

Checking the seal performance of the mercury piping network is very important issue for the mercury target system operation of J-PARC and the helium leak test is preferable for this purpose because it can be carried out easily and precisely by measuring the pressure change and it is free from the risk of mercury contamination. Thus correlation between the helium leak rate and the mercury leak rate was investigated experimentally by carrying out the helium leak tests and the mercury leak tests for an identical chamber. The results showed that the mercury leak rates of the experimental data were lower than those of the estimated value by 64% in average. The contribution of the mercury surface tension force to the decrement of the mercury leak rate was estimated to be large. It was also found that the threshold of the helium leak rate at which good seal performance for mercury can be obtained exists in the vicinity of 10^-3 Pa.m³/s. The fact confirmed the enough safety margin of the mercury target system against the mercury leak, where 10^-6 Pa.m³/s is adopted as the seal performance criterion.

38000050
FEMAXI-6 code verification with MOX fuels irradiated in Halden reactor
Yamaji, Akifumi; Suzuki, Motoe; Okubo, Tsutomu
Journal of Nuclear Science and Technology 46(12), p.1152-1161(2009) ; (JAEA-J 06633)

The advanced reactor concept of Innovative Water Reactor for Flexible Fuel Cycle (FLWR) has been proposed and being studied to achieve effective and flexible utilization of the uranium and plutonium resources based on the well-developed light water reactor (LWR) technology. In order to design and evaluate the FLWR fuel rod behavior, the uncertainties in the FEMAXI-6 calculations and the key models and parameters for predicting LWR MOX fuel rod behavior need to be evaluated. In this study, the Test-Fuel-Data-Base (TFDB) obtained from the Halden reactor experiments (IFA-597.4 rod-10, rod-11, and IFA-514 rod-1) were used for the evaluations. The maximum discharge burnup was about 40 GWd/tMOX.

38000051
Development of local-scale high-resolution atmospheric dispersion model using Large-Eddy Simulation, 1; Turbulent flow and plume dispersion over a flat terrain
Nakayama, Hiromasa; Nagai, Haruyasu
Journal of Nuclear Science and Technology 46(12), p.1170-1177(2009) ; (JAEA-J 06634)

We have developed a local-scale atmospheric dispersion model using LES (Large-Eddy Simulation) to accurately predict the dispersion behavior of radioactive materials for the safety assessment of nuclear facilities and emergency responses against accidental release from nuclear facilities and intentional release by terrorist attack within a populated urban area. In this study, we validate its basic performance on the plume dispersion over the flat terrain in the atmospheric turbulent boundary layer as the first step. Comparing with the previous experimental data, it is found that we have successfully generated the spatially-developing turbulent boundary layer flow that has the characteristics corresponding to an atmospheric wind. Furthermore, dispersion characteristics obtained by LES such as mean concentrations, variances of concentration fluctuation, peak concentrations and concentration fluxes are similar to the previous experimental results.

38000052
Nucleobase lesions and strand breaks in dry DNA thin film selectively induced by monochromatic soft X-rays
Fujii, Kentaro; Shikazono, Naoya; Yokoya, Akinari
Journal of Physical Chemistry B 113(49), p.16007-16015(2009) ; (JAEA-J 06635)

In order to verify the possibility of selective damage induction in DNA, the yields of base lesions as well as strand breaks have been measured in dry plasmid DNA films irradiated with highly monochromatized soft X-rays in the energy region of 270-760 eV, which includes the carbon, nitrogen and oxygen K-edges. Our results strongly suggest that (1) the K-shell ionization of oxygen in both the nucleobases as well as in other parts of DNA and in the hydrating water molecules bound to DNA, but not the K-shell ionization of nitrogen in the nucleobases, most likely contributes to the induction of nucleobase lesions, and (2) migration of electrons and holes are involved differentially in the production of each type of DNA lesion. These results could potentially lead to new methods for selective induction of specific types of DNA damage through tuning the energy of soft X-rays.

38000053
Simulation and experiments of the laser induced breakdown of air for femtosecond to nanosecond order pulses
Koga, J. K.; Moribayashi, Kengo; Fukuda, Yuji; Bulanov, S. V.; Sagisaka, Akito; Ogura, Koichi; Daido, Hiroyuki; Yamagiwa, Mitsuru; Kimura, Toyoaki*; Fujikawa, Taketoshi*; Ebina, Masaki*; Akihama, Kazuhiro*
Journal of Physics D; Applied Physics 43(2), p.025204_1-025204_15(2010) ; (JAEA-J 06637)

Three dimensional simulations and experimental results for the laser induced breakdown of air are presented. The simulations include the laser propagation, multi-photon and impact ionization, and heating of the electrons using accurate atomic and molecular data. For laser pulses of duration from 100 femto-seconds to 1 nano-second mechanisms for the breakdown of air based on the pulse duration and intensity ranging from optical field ionization to electron impact ionization are found. The laser energies at which the breakdown occurs are found to be in good agreement with experimental results.

38000054
Dynamic neutron computer tomography technique for velocity measurement in liquid metal flow; Fundamental PTV experiment
Kureta, Masatoshi; Kumada, Hiroaki*; Kume, Etsuo; Someya, Satoshi*; Okamoto, Koji*
Journal of Physics; Conference Series 147, p.012087_1-012087_14(2009) ; (JAEA-J 06638)

The aim of this development is to visualize and measure the velocity distribution in liquid metal flow using the neutron beam with the high-speed imaging technique, computer tomography (CT) technique and particle tracking velocimetry (PTV). Final research purpose is to obtain the velocity distribution and flow profile data of liquid metal flow in a heated rod bundle for development of the FBR core. In this paper, visualization and measurement method using the JRR-4, spring model PTV method for this technique and results of the fundamental PTV experiment were reported. The fundamental experiment was conducted. As the result, cadmium tracers buried in the aluminum column with the speed of 1.5 revolving per second could be visualized as the 3D movie under 125Hz and 250Hz sampling conditions, the profile of the tracer could be traced, and fundamental velocity distribution measurement method could be conformed.

38000055
High pressure study on uranium heavy fermion compounds with antiferromagnetic ground state
Tateiwa, Naoyuki; Ikeda, Shugo*; Haga, Yoshinori; Matsuda, Tatsuma; Nakashima, Miho*; Aoki, Dai*; Settai, Rikio*; Onuki, Yoshichika
Journal of Physics; Conference Series 150, p.042206_1-042206_4(2009) ; (JAEA-J 06639)

We have studied the high pressure effect on the antiferromagnetic ground states of uranium heavy fermion compounds. In this paper we show our high pressure studies on U₂Zn₁₇ by the electrical resistivity measurements. In U₂Zn₁₇, the N&eacutte;el temperature T_N in U₂Zn₁₇ decreases slightly from 9.66 K at 1 bar to 9.33 K at 2.5 GPa, becomes almost pressure-independent up to 4.7 GPa, and starts to increase at the higher pressure region. We discuss the pressure dependences of the coefficient of T² term in the electrical resistivity A, an antiferromagnetic gap Δ and a characteristic temperature T_ρmax. It is found that the effect of pressure on the electronic states in U₂Zn₁₇ is weak compared with the other heavy fermion compounds.

38000056
Ferromagnetism and orbital order in the two-orbital Hubbard model
Kubo, Katsunori
Journal of Physics; Conference Series 150(4), p.042101_1-042101_4(2009) ; (JAEA-J 06640)

In order to understand magnetism in systems with an orbital degree of freedom, we investigate spin and orbital states of the two-orbital Hubbard model on a square lattice by using a variational Monte Carlo method. At quarter filling, i.e., the electron number per site is one, the ground state is the perfect ferromagnetic state with antiferro-orbital (AF-orbital) order in the strong Coulomb interaction limit. By decreasing the interaction, we find that the disordered state becomes the ground state.

38000057
XMCD spectroscopy on valence fluctuating and heavy fermion compounds in very high magnetic fields up to 40 T
Matsuda, Yasuhiro*; Her, J. L.*; Inami, Toshiya; Owada, Kenji; Ouyang, Z. W.*; Okada, Kyoko*; Nojiri, Hiroyuki*; Mitsuda, Akihiro*; Wada, Hirofumi*; Yoshimura, Kazuyoshi*; Amitsuka, Hiroshi*; Kawamura, Naomi*; Suzuki, Motohiro*; Kotani, Akira*
Journal of Physics; Conference Series 190, p.012019_1-012019_6(2009) ; (JAEA-J 06641)

L-edge X-ray magnetic circular dichroism (XMCD) and X-ray absorption spectra (XAS) in several rare-earth elements have been studied in pulsed high magnetic fields up to 40 T. XMCD spectrum of Eu in EuNi₂(Si_0.18Ge_0.82)₂ shows a characteristic two peak structure, reflecting the valence fluctuation. However, in YbInCu₄, it is found that the XMCD spectrum of Yb shows only a single peak. In contrast to XMCD, two absorption bands in XAS are observed in both compounds. The intensity ratio between the two absorption bands changes significantly with increasing magnetic field in these materials, suggesting the field-induced valence change. The high magnetic field XMCD and XAS measurements have also been conducted in an antiferromagnetic heavy fermion compound CeRh₂Si₂. The Ce valence is found to be nearly trivalent and insensitive to magnetic field. The XMCD at Ce L₂-edge increases rapidly around 26 T corresponding to the metamagnetic transition.

38000058
Dynamic structural change of Pd particles on LaFeO₃ under redox atmosphere and CO/NO catalytic reaction studied by dispersive XAFS
Matsumura, Daiju; Okajima, Yuka; Nishihata, Yasuo; Mizuki, Junichiro; Taniguchi, Masashi*; Uenishi, Mari*; Tanaka, Hirohisa*
Journal of Physics; Conference Series 190, p.012154_1-012154_6(2009) ; (JAEA-J 06642)

Pd/LaFeO₃ is known to keep the metal particle size small even after the long time redox processes because Pd atoms make complex oxide with LaFeO₃ perovskite-type crystal under the oxidative atmosphere. We observed the local structure of Pd atoms by dispersive optics from the viewpoint of dynamical structure change of Pd during metal-oxide change and CO-NO catalytic reaction. It was recognized that, under the reductive atmosphere, Pd atoms show similar speed of movement from oxide to metal state both on LaFeO₃ and Al₂O₃. However, under the oxidative atmosphere, Pd atoms on LaFeO₃ show faster movement from metal to oxide state with single reaction step than those on Al₂O₃ with two-step oxidation. In addition, many differences in structure and shape between Pd particles on LaFeO₃ and Al₂O₃ are observed.

38000059
Formation of continuous pore structures in Si-C-O fibers by adjusting the melt spinning condition of a polycarbosilane - polysiloxane polymer blend
Kita, Kenichiro; Narisawa, Masaki*; Mabuchi, Hiroshi*; Ito, Masayoshi*; Sugimoto, Masaki; Yoshikawa, Masahito
Journal of the American Ceramic Society 92(6), p.1192-1197(2009) ; (JAEA-J 06643)

The polymer blend including polycarbosilane (PCS) and 15 mass% of polyhydromethylsiloxane (H-oil) was prepared and properties of the polymer melt were investigated for clarifying the mechanisms of continuous pore formation. The fibers formed by the melt-spun of polymer blend at 578 K mainly possessed a single pore at the center of the fiber cross section. On the other hand, the fiber melt-spun at 543 K usually included multiple pores and the fibers melt-spun at 538 K included a number of tiny pores. It is proposed that the evolved hydrogen can be dissolved in the polymer melt and the desaturation process of the dissolved gas during the fiber spinning with sudden temperature reduction likely determined the size and location of pores in the fibers.

38000060
Various valence states of square-coordinated Mn in A-site-ordered perovskites
Long, Y.*; Saito, Takashi*; Mizumaki, Masaichiro*; Agui, Akane; Shimakawa, Yuichi*
Journal of the American Chemical Society 131(44), p.16244-16247(2009) ; (JAEA-J 06644)

A-site-ordered perovskites LaMn₃Cr₄O₁₂ and LaMn₃Ti₄O₁₂ were synthesized under high-pressure and high-temperature conditions. The charge formula of LaMn₃Cr₄O₁₂ was found to be LaMn₃Cr₄O₁₂ with Mn³⁺ at the square-coordinated A site. The valence of the A-site Mn ions in LaMnTi₄O₁₂ appeared to be less than +2, and the charge combination in this compound seemed to be LaMnTi₄O₁₂. Although the square-coordinated A site in A-site-ordered perovskites has been widely known to be occupied by Jahn-Teller active Mn³⁺, the present results show that the valence of Mn at the A site can vary from +3 to possible +1.67.

38000061
Production and decay properties of ²⁶³Hs
Kaji, Daiya*; Morimoto, Koji*; Sato, Nozomi*; Ichikawa, Takatoshi*; Ideguchi, Eiji*; Ozeki, Kazutaka*; Haba, Hiromitsu*; Koura, Hiroyuki; Kudo, Yuki*; Ozawa, Akira*; Sumita, Takayuki*; Yamaguchi, Takayuki*; Yoneda, Akira*; Yoshida, Atsushi*; Morita, Kosuke*
Journal of the Physical Society of Japan 78(3), p.035003_1-035003_2(2009) ; (JAEA-J 06645)

A new neutron deficient hassium (Z=108) isotope of ²⁶³Hs was identified via two different reactions of ²⁰⁶Pb(⁵⁸Fe,n) and ²⁰⁸Pb(⁵⁶Fe,n) by using a gas-filled recoil separator GARIS at June 2008. During the 25-h irradiation of ²⁰⁶Pb with the ⁵⁸Fe beam and 46-h irradiation of ²⁰⁸Pb with the ⁵⁶Fe beam, 8 decay chains and 1 decay chain, respectively, have been observed. The half-life of ²⁶³Hs is 0.60^+0.30_0.15 ms. In this experiment, the total beam doses of the Fe and ⁵⁶Fe was 4.1×10¹⁷ ions and 6.2×10¹⁷ ions, respectively. The production cross sections corresponding to the 8 decay chains and 1 decay chain have been deduced to be 21⁺¹⁰_-8 pb and 1.6^+3.7_-1.3 pb by assuming the transmission of the system to be 80%.

38000062
Intergrain Josephson currents in multigap superconductors; Microscopic origin of low intergrain critical current and its recovery potential in iron-pnictide materials
Ota, Yukihiro; Machida, Masahiko; Koyama, Tomio*
Journal of the Physical Society of Japan 78(10), p.103701_1-103701_4(2009) ; (JAEA-J 06646)

We microscopically examine the intergrain Josephson current in iron-pnictide superconductors in order to solve the puzzle of why the intergrain current is much lower than the intragrain one. The theory predicts that the intergrain Josephson current is significantly reduced by the ±s-wave symmetry when the incoherent tunneling becomes predominant and the density of states and the gap amplitude between two bands are identical. We find in such a situation that the temperature dependence of the intergrain Josephson current shows an anomalously flat curve over a wide temperature range. Finally, we suggest important points for increasing the intergrain current.

38000063
Production of an isomeric state of ⁹⁰Y by fast neutrons for nuclear diagnostics
Nagai, Yasuki; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kin, Tadahiro; Segawa, Mariko; Hatsukawa, Yuichi; Harada, Hideo
Journal of the Physical Society of Japan 78(11), p.113201_1-113201_4(2009) ; (JAEA-J 06647)

We have noted that the isomeric state of ⁹⁰Y with a half-life of 3.2 h as well as the ground state of ⁹⁰Y can be populated significantly by ⁹⁰Zr(n,p)⁹⁰Y and ⁹³Nb(n,α)⁹⁰Y at a neutron energy of 14 MeV. On the basis of the result, we have proposed a new method to use ⁹⁰Y radiopharmaceuticals containing the 682 keV isomeric state of ⁹⁰Y for diagnostics and the ground state for therapy, since the isomeric state decays to the ground state of ⁹⁰Y by emitting 480 and 203 keV γ-rays, appropriate energies for imaging. ⁹⁰Y radiopharmaceuticals containing ^90mY could solve long-standing problems associated with the use of ⁹⁰Y together with ¹¹¹In for imaging.

38000064
Combined SANS, SEC, NMR, and UV-Vis studies of simultaneous living anionic copolymerization process; Simultaneous elucidation of propagating living chains at three different length scales
Zhao, Y.; Tanaka, Hirokazu*; Miyamoto, Nobuyoshi*; Koizumi, Satoshi; Hashimoto, Takeji
Macromolecules 42(5), p.1739-1748(2009) ; (JAEA-J 06648)

The living anionic copolymerization of a mixture of isoprene (I) and styrene (S) monomers, in the dilute solution with deuterated benzene as a non-polar solvent and sec-butyllithium as an initiator, was investigated by a simultaneous measurement of time-resolved small-angle neutron scattering (SANS), size exclusion chromatography (SEC), nuclear magnetic resonance (NMR), and ultraviolet-visible (UV-Vis) spectroscopy. The combined time-resolved study on the same single batch reaction solution enabled us to investigate the structural change of the propagating living chains in three different length scales on a rigorously common time scale: the type of living chain ends, primary structure of single living chains, and the association of living chains. Although the living anionic copolymerization of S and I has been studied extensively, there is no study so far that uses such a combination of real-time methods as this study on the same single batch reaction solution.

38000065
Effect of heat treatment on TEM microstructures of Zirconium carbide coating layer in fuel particle for advanced high temperature gas cooled reactor
Aihara, Jun; Ueta, Shohei; Yasuda, Atsushi*; Takeuchi, Hitoshi*; Mozumi, Yasuhiro*; Sawa, Kazuhiro; Motohashi, Yoshinobu*
Materials Transactions 50(11), p.2631-2636(2009) ; (JAEA-J 06652)

The ZrC coating layer has been fabricated using the bromide process at JAEA. The coated particles with IPyC layers reported in a previous study were annealed at around 1800°C for 1h, under which compact sintering will be done in a practical process, in order to study effects of the heat treatment (annealing) on their microstructure evolution. Then the microstructures of the ZrC layers in the cases (batches) of C/Zr = 1.11 and 1.35 were characterized by means of TEM and STEM. Certain changes in the shape and size of voids or free carbons region caused by the heat treatment were found in the cases of both batches. After the heat treatment, the voids or free carbons region have shown a clod like feature with diameters of 50 to 100 nm. The grain growth of ZrC was also observed in both cases: In the ZrC layer with C/Zr = 1.11, the fibrous carbons grew as of to stand from the PyC to ZrC layers on some places in the IPyC/ZrC boundary.

38000066
Integrated simulation of ELM energy loss and cycle in improved H-mode plasmas
Hayashi, Nobuhiko; Takizuka, Tomonori; Aiba, Nobuyuki; Oyama, Naoyuki; Ozeki, Takahisa; Wiesen, S.*; Parail, V.*
Nuclear Fusion 49(9), p.095015_1-095015_8(2009) ; (JAEA-J 06653)

Energy loss due to an edge localized mode (ELM) crash and its cycle have been studied by using an integrated core transport code with a stability code for peeling-ballooning modes and a transport model of scrape-off-layer (SOL) and divertor plasmas. The integrated code reproduces a series of ELMs in which the ELM energy loss increases with decreasing collisionality and the ELM frequency increases linearly with the input power, as seen in experiments of type-I ELMs. A transport model with the neoclassical transport in the pedestal connected to the SOL parallel transport reproduces a lowered inter-ELM transport in the case of low collisionality so that the ELM loss power is enhanced as observed in experiments. The inter-ELM energy confinement time evaluated from simulation results agrees with the JT-60U scaling. The steep pressure gradient in the core just beyond the pedestal top, desirable for improved H-mode plasmas with the H_H factor above unity, is found to enhance the ELM energy loss and reduce the ELM frequency so that the ELM loss power remains constant. The steep pressure gradient in the core beyond the pedestal top broadens eigenfunction profiles of unstable modes and possibly induces subsequent instabilities. In the subsequent instabilities, when a large energy is transported to the vicinity of the separatrix by the instabilities, a subsequent instability arises near the separatrix and makes an additional loss.

38000067
Investigations of impurity seeding and radiation control for long-pulse and high-densi_ey H-mode plasmas in JT-60U
Asakura, Nobuyuki; Nakano, Tomohide; Oyama, Naoyuki; Sakamoto, Yoshiteru; Matsunaga, Go; Itami, Kiyoshi
Nuclear Fusion 49(11), p.115010_1-115010_8(2009) ; (JAEA-J 06654)

Impurity gas seeding is one of techniques to decrease peak heat flux to the divertor both in steady-state and transient phases. Power handling by large radiation power loss has been studied in the ELMy H-mode plasmas on JT-60U with argon (Ar) gas seeding since good confinement (H_H > 0.85) was obtained up to high density (n_e/n^GW = 0.8-0.9, n^GW is the Greenwald density). On the other hand, it was not clearly understood to sustain the good confinement plasma with the large radiation power under the wall saturated condition where particle recycling flux changes during the long discharge. In this paper, control of the large radiation in the good energy confinement plasma was, for the first time, investigated. Total radiation fraction of P_rad/P_abs = 0.7-0.95 was maintained for the cases of Ar gas puffing and combination of Ar and Ne puffing. Control of radiation power in the main plasma has been investigated using feedback control of gas puff rate during outgasing condition from the PFCs.

38000068
Tungsten accumulation in H-mode plasmas of JT-60U
Nakano, Tomohide; Asakura, Nobuyuki; Kubo, Hirotaka; Yanagibayashi, Jun*; Ueda, Yoshio*
Nuclear Fusion 49(11), p.115024_1-115024_10(2009) ; (JAEA-J 06655)

It has been observed that with increasing toroidal rotation velocity inside the q=1 layer in the direction opposite to the plasma current, sawtooth activity becomes moderate and tungsten accumulation becomes significant. The tungsten accumulation level is significantly reduced from this trend in the case that electron cyclotron wave or high energy neutral beam is injected into the plasma core. In contrast, the tungsten accumulation is kept high by the electron cyclotron wave injection into the peripheral region.

38000069
Design of hydrogen vent line for the cryogenic hydrogen system in J-PARC
Tatsumoto, Hideki; Aso, Tomokazu; Kato, Takashi; Otsu, Kiichi; Hasegawa, Shoichi; Maekawa, Fujio; Futakawa, Masatoshi
Nuclear Instruments and Methods in Physics Research A 600(1), p.269-271(2009) ; (JAEA-J 06656)

As one of the main experimental facilities in J-PARC, an intense spallation neutron source (JSNS) driven by a 1-MW proton beam selected supercritical hydrogen at the temperature of 20 K and the pressure of 1.5 MPa as a moderator material. A cryogenic hydrogen system plays a role in cooling the moderators. For safety reasons, we have designed a hydrogen relief system that can release hydrogen to the outside safely, even if some off-normal events occur. The design of the hydrogen vent line should be considered to prevent the cryogenic hydrogen from freezing purge nitrogen gas in the vent line and freezing moisture in the stack placed in an outdoor location, and to inhibit the piping temperature drop at the building wall penetration. In this work, the temperature change behaviors in the hydrogen vent line were analyzed by using a CFD code, STAR-CD. We determined the required sizes of the vent line based on the analytical results and its layout in the building.

38000070
Wavelength-shifting-fibre-based neutron image detector with a fibre-optic taper to increase the spatial resolution
Nakamura, Tatsuya; Katagiri, Masaki; To, Kentaro; Sakasai, Kaoru; Ebine, Masumi; Birumachi, Atsushi; Soyama, Kazuhiko
Nuclear Instruments and Methods in Physics Research A 604(1-2), p.158-160(2009) ; (JAEA-J 06657)

The effective pixel size of a two-dimensional wavelength-shifting-fibre (WLS-fibre)-based neutron image detector was improved from 0.5 to 0.16 mm by including a fibre-optic taper (FOT) between the scintillator screen and the WLS fibre. The WLS-fibre-based detector consisted of a thin ZnS/⁶LiF screen, a FOT and WLS ribbons crossed in the x and y directions. The demonstrator detector had 16 fibre channels in each direction, and the light signals in each fibre were read out individually. The FOT was constructed from fine glass fibres with a taper ratio of 3.1, and served as an image magnifier. The prototype detector equipped with the FOT exhibited a spatial resolution of 0.3 mm, compared to the spatial resolution of 0.8 mm for the original detector without the FOT.

38000071
Development of an ultra-high-speed scanning neutron tomography system for high-quality and four-dimensional visualizations
Kureta, Masatoshi; Iikura, Hiroshi
Nuclear Instruments and Methods in Physics Research A 605(1-2), p.81-84(2009) ; (JAEA-J 06658)

A new neutron tomography imaging system was developed in order to realize a high-quality three-dimensional (3D) and four-dimensional (4D) visualizations by fusing the high-frame-rate neutron radiography and computed tomography (CT) techniques. Fundamental idea is that the object is revolved with high rotating speed and the neutron radiography images are recorded with a high-speed video camera and an image intensifier, and then the consecutive images are processed by 3D CT technique. The 4D dynamic images of the sand flow in the sandglasses could be visualized clearly. This new technique has also an advantage to reduce radio activation of the object materials remarkably.

38000072
A Combined method of small-angle neutron scattering and neutron radiography to visualize water in an operating fuel cell over a wide length scale from nano to millimeter
Iwase, Hiroki; Koizumi, Satoshi; Iikura, Hiroshi; Matsubayashi, Masahito; Yamaguchi, Daisuke; Maekawa, Yasunari; Hashimoto, Takeji
Nuclear Instruments and Methods in Physics Research A 605(1-2), p.95-98(2009) ; (JAEA-J 06659)

We constructed an in-situ and simultaneous observation method as a result of combination between ultra-small-angle neutron scattering and neutron imaging (radiography). With this novel technique, we are able to visualize water distribution or transportation, occurring from micro to macro length scales in a polymer electrolyte fuel cell (PEFC). At a sample position of SANS-J-II at JRR-3, we installed a neutron imaging camera in order to construct an in-situ and simultaneous observation method by USANS and neutron imaging with monochromatized cold neutrons. In addition, in order to selectively observe MEA in a running PEFC by using the in-situ and simultaneous observation method, we need to replace carbon separators which cause strong small-angle scattering as a noise. To reduce this strong background, we replaced the carbon separators with the aluminium ones. As a result, the background scattering was minimized (1/10) as compared to before.

38000073
MeV- and sub-MeV-photon sources based on Compton backscattering at SPring-8 and KPSI-JAEA
Kawase, Keigo; Kando, Masaki; Hayakawa, Takehito; Daito, Izuru; Kondo, Shuji; Homma, Takayuki; Kameshima, Takashi; Kotaki, Hideyuki; Chen, L.*; Fukuda, Yuji; Faenov, A. Y.; Shizuma, Toshiyuki; Bulanov, S. V.; Kimura, Toyoaki*; Tajima, Toshiki; Shoji, Masazumi*; Suzuki, Shinsuke*; Tamura, Kazuhiro*; Okuma, Haruo*; Arimoto, Yasushi*; Yorita, Tetsuhiko*; Fujiwara, Mamoru; Okajima, Shigeki*
Nuclear Physics Review 26(Suppl.), p.94-99(2009) ; (JAEA-J 06660)

We constructed MeV- and sub-MeV-photon sources by means of Compton backscattering with a laser light and an electron beam at SPring-8 and KPSI-JAEA. MeV-photon source consists of a continuous-wave optically-pumped far infrared laser and an 8-GeV stored electron beam. Sub-MeV-photon source consists of a Nd:YAG pulse-laser and an 150-MeV electron beam accelerated by a microtron. Both source have been succeeded backscattered photon generation. In this talk, I will present characteristics and future prospects of these photon sources.

38000074
Measurement of angular dependent neutron production from thick target bombarded with 140-MeV protons
Iwamoto, Yosuke; Satoh, Daiki; Hagiwara, Masayuki*; Iwase, Hiroshi*; Kirihara, Yoichi*; Yashima, Hiroshi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Nakamura, Takashi*; Tamii, Atsushi*; Hatanaka, Kichiji*
Nuclear Technology 168(2), p.340-344(2009) ; (JAEA-J 06661)

It is important to calculate neutron production from thick targets at forward angle near 0 degree and backward angle near 180 degree for the shielding design of proton accelerator facilities, and the accuracy should be determined by experimental data. There are, however, few experimental data near 0 degree, and no data near 180 degree in the energy region above 100 MeV. Neutron energy spectra at 0, 90 and 180 degrees produced from thick graphite and iron targets by 140 MeV protons were measured. It was found that the calculation with JENDL-HE was more suitable for the shielding design of proton accelerator facilities in the forward direction.

38000075
Monte Carlo calculations for the shielding design of beam injection and extraction areas at the 3-GeV synchrotron in J-PARC
Nakane, Yoshihiro; Abe, Teruo*; Nakashima, Hiroshi
Nuclear Technology 168(2), p.519-523(2009) ; (JAEA-J 06662)

For the shielding design of 3-GeV synchrotron in J-PARC, radiation shielding calculations were performed around beam injection and beam extraction areas. It is difficult to apply the simplified methods for these areas that the geometries are complicated and the larger beam losses are assumed. Therefore, Monte Carlo code, PHITS, were applied to particle transport calculations for the shielding designs around those areas. The shielding designs were performed with the condition that the maximum dose rates at the boundary of radiation controlled areas are in less than both the design criterion defined in J-PARC and the limit defined in regulation of Japan. Calculation methods and conditions used for the shielding design and the calculation results are presented in this work.

38000076
Generation and application of bremsstrahlung production data calculated by EGS4 code
Sakamoto, Yukio; Hirayama, Hideo*; Sato, Osamu*; Shimizu, Akinao*
Nuclear Technology 168(3), p.585-590(2009) ; (JAEA-J 06663)

A Bremsstrahlung production data is needed in the calculation of buildup factors included by the contribution of Bremsstrahlung as secondary photons by IE method. In this work, the emission of Bremsstrahlung is treated as possible as exactly by the introduction of EGS4 results. The Bremsstrahlung production data by pair-created electrons and Compton scattered electrons is evaluated for 26 elements and 4 compound and mixtures. The error estimation of Bremsstrahlung contribution to buildup factors by IE method coupled with this Bremsstrahlung data is coincident with fully transported results by EGS4 code within about 5%. By the introduction of this Bremsstrahlung production data into IE methods, we can calculate buildup factors included by the contribution of Bremsstrahlung with good accuracy up to deep penetration.

38000077
Accelerator experiments on source term and radiation shielding performed by Japan Atomic Energy Agency
Sakamoto, Yukio; Iwamoto, Yosuke; Nakashima, Hiroshi
Nuclear Technology 168(3), p.654-658(2009) ; (JAEA-J 06664)

We review some accelerator benchmark experiments on source term and radiation shielding conducted by JAEA to validate the accuracy of the radiation behavior simulation code such as PHITS code. (1) Neutron spectra measurement from thin beryllium target bombarded with about 10 MeV protons for accelerator boron neutron capture therapy. (2) Forward direction neutron spectra measurements and shielding experiments from beryllium target bombarded with 140, 250 and 350 MeV protons. (3) Neutron spectra measurement from tungsten target bombarded with about 400 MeV protons for the establishment of irradiation field for semiconductor tests. (4) Shielding experiments at Pbar target station and NuMI target station of Fermi Lab.

38000078
Estimation of radioactivity produced in cooling water at high-intensity proton accelerator facility
Masukawa, Fumihiro; Nakane, Yoshihiro; Iwamoto, Yosuke; Nakashima, Hiroshi
Nuclear Technology 168(3), p.680-684(2009) ; (JAEA-J 06665)

The radioactivity produced in the accelerator cooling water was estimated to draw up the maintenance scenario of the J-PARC accelerators. Activation cross section sets from Nitrogen and Oxygen were evaluated from the available experimental data and theoretically calculated data by INC/GEM and LAHET for high-energy proton and neutron. The PHITS and MCNPX codes were used to calculate the proton and neutron fluxes in the water-cooled accelerator components. The radioactivity from the corrosion product was also estimated by scaling of the measurements at KEK-PS and LAMPF. Tritium are estimated 5.7×10⁷ [Bq] in LINAC and 2.5×10⁹ [Bq] in 3-GeV Synchrotron by annual operation. Dose in machinery rooms by short-lived nuclides are reasonably low at LINAC, whereas ∼10³ times higher at 3-GeV Synchrotron. The estimation of tritium is acceptable level for the disposal to the environment, while short-lived nuclides at 3-GeV Synchrotron may make the facility maintenance difficult.

38000079
A Generalized conformational energy function of DNA derived from molecular dynamics simulations
Yamasaki, Satoshi*; Terada, Toru*; Shimizu, Kentaro*; Kono, Hidetoshi; Sarai, Akinori*
Nucleic Acids Research 37(20), p.e135_1-e135_9(2009) ; (JAEA-J 06666)

Proteins recognize DNA sequences by two different mechanisms. The first is direct readout, in which recognition is mediated by direct interactions between the protein and the DNA bases. The second is indirect readout, which is caused by the dependence of conformation and the deformability of the DNA structure on the sequence. Various energy functions have been proposed to evaluate the contribution of indirect readout to the free-energy changes in complex formations. We developed a new generalized energy function to estimate the dependence of the deformability of DNA on the sequence. This function was derived from molecular dynamics (MD) simulations previously conducted on B-DNA dodecamers, each of which had one possible tetramer sequence embedded at its center. By taking the logarithm of the probability distribution function (PDF) for the base-step parameters of the central base-pair step of the tetramer, its ability to distinguish the native sequence from random ones was superior to that with the previous method that approximated the energy function in harmonic form. From a comparison of the energy profiles calculated with these two methods, we found that the harmonic approximation caused significant errors in the conformational energies of the tetramers that adopted multiple stable conformations.

38000080
A Beam divergence correction mirror for neutron resonance spin echo
Maruyama, Ryuji; Hino, Masahiro*; Hayashida, Hirotoshi; Kitaguchi, Masaaki*; Achiwa, Norio*; Yamazaki, Dai; Ebisawa, Toru*; Soyama, Kazuhiko
Physica B; Condensed Matter 404(17), p.2594-2599(2009) ; (JAEA-J 06667)

Neutron resonance spin echo (NRSE) is one of the most useful techniques for quasi-elastic scattering with high energy resolution. The path length variation due to the beam divergence has to be corrected in high resolution NRSE measurement because it gives the limit in the energy resolution. A neutron focusing technique using neutron supermirrors is effective to overcome this problem. When a cylindrical shaped neutron supermirror placed in the center of the flight path with a pair of RSFs has the object and the image plane corresponding to the each coil plane of the first and the second RSF, the path length difference can be corrected for the neutron beam with large divergent angle, which leads to the realization of high intensity as well as high resolution in NRSE measurement. In this study, the correction method of the beam divergence with a cylindrical shaped supermirror and its experimental results are discussed.

38000081
μSR study of an layered organic superconductor κ-(BEDT-TTF)₄Hg_2.89Br₈
Sato, Kazuhiko*; Fujita, Hidemi*; Katayama, Kazuhiro*; Taniguchi, Hiromi*; Ito, Takashi; Oishi, Kazuki*; Higemoto, Wataru
Physica B; Condensed Matter 404(5-7), p.597-599(2009) ; (JAEA-J 06668)

Zero-field muon spin relaxation and high-field transverse muon spin rotation have been measured for an organic superconductor κ-(BEDT-TTF)₄Hg_2.89Br₈. No anomaly is found in zero-field relaxation spectrum at the superconducting transition temperature, 4.2 K. The muon Knight shift determined by transverse muon spin rotation at 6 T exhibits Curie-Weiss like behavior down to 2 K, whereas static magnetic susceptibility shows a peak around 30 K. The muon Knight shift does not scale with the magnetic susceptibility at low temperatures.

38000082
μSR study of organic antiferromagnet β'-(BEDT-TTF)₂ICl₂ under high pressure
Sato, Kazuhiko*; Sato, Koichi*; Yoshida, Tetsushige*; Taniguchi, Hiromi*; Goko, Tatsuro*; Ito, Takashi; Oishi, Kazuki*; Higemoto, Wataru
Physica B; Condensed Matter 404(5-7), p.600-602(2009) ; (JAEA-J 06669)

Zero-field muon spin relaxation was measured for organic antiferromagnet β'-(BEDT-TTF)₂ICl₂ under high pressure of up to 1.37 GPa. Neel temperature, which is 22 K at ambient pressure, increases with increasing pressure and becomes approximately 48 K at 1.37 GPa. Muon precession frequency at 1.37 GPa, becomes about 5 times larger than that at ambient pressure.

38000083
Novel features in filled skutterudites containing rare-earth elements with a plural number of 4f-electrons
Sato, Hideyuki*; Aoki, Yuji*; Kikuchi, Daisuke*; Sugawara, Hitoshi*; Higemoto, Wataru; Oishi, Kazuki; Ito, Takashi; Heffner, R. H.; Saha, S. R.*; Koda, Akihiro*; Sato, Koki*; Nishiyama, Kusuo; Kadono, Ryosuke*; Nishida, Nobuhiko*; Shu, L.*; MacLaughlin, D. E.*
Physica B; Condensed Matter 404(5-7), p.749-753(2009) ; (JAEA-J 06670)

Wide varieties of strongly correlated electron phenomena are performed on the stage of a filled skutterudite structure. Especially when one of the players contains a plural number of 4f electrons, the orbital degrees of freedom play a major role as a new type of nonmagnetic and/or weak-magnetic phenomena. Several examples found in Pr- and Sm-based filled skutterudites are introduced in relation to muon spin relaxation experiments.

38000084
Weak ferromagnetic ordering in the anomalous field-insensitive heavy-fermion state in SmOs₄Sb₁₂
Aoki, Yuji*; Higemoto, Wataru; Tsunashima, Yoshino*; Yonezawa, Yuki*; Sato, Koki*; Koda, Akihiro*; Ito, Takashi; Oishi, Kazuki; Heffner, R. H.; Kikuchi, Daisuke*; Sato, Hideyuki*
Physica B; Condensed Matter 404(5-7), p.757-760(2009) ; (JAEA-J 06671)

Zero field (ZF) and transverse field (TF) muon spin relaxation and rotation (μSR) study has been carried out in filled-skutterudite SmOs₄Sb₁₂ in order to investigate the magnetically robust heavy-fermion (HF) state and the weak ferromagnetic anomaly. A large-amplitude oscillating signal appears in the ZF-μSR spectra at low temperatures, confirming that the weak ferromagnetic anomaly is an intrinsic bulk property. Analysis reveals that the weak ferromagnetic moment is carried by itinerant heavy quasiparticles.

38000085
Birth of an intense pulsed muon source, J-PARC MUSE
Miyake, Yasuhiro*; Shimomura, Koichiro*; Kawamura, Naritoshi*; Strasser, P.*; Makimura, Shunsuke*; Koda, Akihiro*; Fujimori, Hiroshi*; Nakahara, Kazutaka*; Kadono, Ryosuke*; Kato, Mineo*; Takeshita, Soshi*; Nishiyama, Kusuo; Higemoto, Wataru; Ishida, Katsuhiko*; Matsuzaki, Teiichiro*; Matsuda, Yasuyuki*; Nagamine, Kanetada*
Physica B; Condensed Matter 404(5-7), p.957-961(2009) ; (JAEA-J 06672)

The muon science facility (MUSE) is one of the experimental areas of the J-PARC. The MUSE facility is located in the Materials and Life Science Facility (MLF), which is a building integrated to include both neutron and muon science programs. Construction of the MLF building was started at the beginning of 2004, and was recently completed at the end of the 2006 fiscal year. We have been working on the installation of the beamline components, expecting the first muon beam in the autumn of 2008.

38000086
Spectroscopy of ²⁵⁷Rf
Qian, J.*; Heinz, A.*; Khoo, T. L.*; Janssens, R. V. F.*; Peterson, D.*; Seweryniak, D.*; Ahmad, I.*; Asai, Masato; Back, B. B.*; Carpenter, M. P.*; Garnsworthy, A. B.*; Greene, J. P.*; Hecht, A. A.*; Jiang, C. L.*; Kondev, F. G.*; Lauritsen, T.*; Lister, C. J.*; Robinson, A.*; Savard, G.*; Scott, R.*; Vondrasek, R.*; Wang, X.*; Winkler, R.*; Zhu, S.*
Physical Review C 79(6), p.064319_1-064319_13(2009) ; (JAEA-J 06673)

α-, γ-, and conversion electron spectroscopy experiments for ²⁵⁷Rf have been performed using Fragment Mass Analyzer at Argonne National Laboratory. A new isomer with a half-life of 160 μs has been discovered in ²⁵⁷Rf, and it is interpreted as a three-quasiparticle high-K isomer. Neutron configurations of one-quasiparticle states in ²⁵³No, the α-decay daughter of ²⁵⁷Rf, have been assigned on the basis of α-decay hindrance factors. Excitation energies of the 1/2⁺[620] states in N=151 isotones indicate that the deformed shell gap at N=152 increases with the atomic number.

38000087
Hot hadron-quark mixed phase including hyperons
Yasutake, Nobutoshi*; Maruyama, Toshiki; Tatsumi, Toshitaka*
Physical Review D 80(12), p.123009_1-123009_8(2009) ; (JAEA-J 06674)

We study the hadron-quark phase transition with the finite size effects at finite temperature. The properties of the mixed phase are clarified by considering the finite size effects under the Gibbs conditions. We find that the equation of state becomes softer than that at zero-temperature for some density region. We also find that the equation of state gets closer to that given by the Maxwell construction. Moreover, the number of hyperons is suppressed by the presence of quarks. These are characteristic features of the hadron-quark mixed phase, and should be important for many astrophysical phenomena such as mergers of binary neutron stars.

38000088
Dual nature of a Ni dopant in the hole-type La_2-xSr_xCuO₄ cuprate superconductor
Hiraka, Haruhiro*; Matsumura, Daiju; Nishihata, Yasuo; Mizuki, Junichiro; Yamada, Kazuyoshi*
Physical Review Letters 102(3), p.037002_1-037002_4(2009) ; (JAEA-J 06675)

Local distortions around a Ni dopant in the hole-type La_2-xSr_xCuO₄ superconductor system were studied by X-ray-absorption fine structure (XAFS) using single crystals over a wide hole-doping range. Two distinct interatomic distances between Ni and in-plane oxygen appear in the Ni K-edge extended XAFS. Combined with previous results on hole-localization effects by Ni doping, two types of charge states are strongly indicated for Ni. This duality disqualifies a magnetic-impurity picture for Ni dopant in the superconducting phase of cuprates.

38000089
Boosted high-harmonics pulse from a double-sided relativistic mirror
Esirkepov, T. Z.; Bulanov, S. V.; Kando, Masaki; Pirozhkov, A. S.; Zhidkov, A.*
Physical Review Letters 103(2), p.025002_1-025002_4(2009) ; (JAEA-J 06676)

An ultra-bright high-power X- and γ-radiation source is proposed. A high-density thin plasma slab, accelerating in the radiation pressure dominant regime by an ultra-intense electromagnetic wave, reflects a counter-propagating relativistically strong electromagnetic wave, producing extremely time-compressed and intensified radiation. The reflected light contains relativistic harmonics generated at the plasma slab, all upshifted with the same factor as the fundamental mode of the incident light. The theory of an arbitrarily moving thin plasma slab reflectivity is presented.

38000090
Rotation drive and momentum transport with electron cyclotron heating in tokamak plasmas
Yoshida, Maiko; Sakamoto, Yoshiteru; Takenaga, Hidenobu; Ide, Shunsuke; Oyama, Naoyuki; Kobayashi, Takayuki; Kamada, Yutaka; JT-60 Team
Physical Review Letters 103(6), p.065003_1-065003_4(2009) ; (JAEA-J 06677)

The role of electron cyclotron range of frequency (ECRF) wave on the toroidal rotation velocity profile has been investigated in JT-60U plasmas by separating the effects of the momentum transport, the intrinsic rotation by pressure gradient and the intrinsic rotation by ECRF. It is found that ECRF increases the toroidal momentum diffusivity and the convection velocity. ECRF drives the CO-intrinsic rotation inside the EC deposition and drives the CTR-intrinsic rotation outside the EC deposition. This CTR-rotation starts from the EC deposition radius and propagates to the edge region.

38000091
Generation of stable and low-divergence 10-MeV quasimonoenergetic electron bunch using argon gas jet
Mori, Michiaki; Kondo, Kiminori; Mizuta, Yoshio*; Kando, Masaki; Kotaki, Hideyuki; Nishiuchi, Mamiko; Kado, Masataka; Pirozhkov, A. S.; Ogura, Koichi; Sugiyama, Hironori*; Bulanov, S. V.; Tanaka, Kazuo*; Nishimura, Hiroaki*; Daido, Hiroyuki
Physical Review Special Topics; Accelerators and Beams 12(8), p.082801_1-082801_5(2009) ; (JAEA-J 06678)

The pointing stability and divergence of a quasimonoenergetic electron bunch generated in a self-injected laser-plasma acceleration regime using 4 TW laser is studied. A pointing stability of 2.4 mrad root-mean-square (RMS) and a beam divergence of 10.6 mrad (RMS) were obtained using an argon gas-jet target for 50 sequential shots, while these values were degraded by a factor of three at the optimum condition using helium. The peak electron energies were 8.5±0.7 MeV and 24.8±3.6 MeV using argon and helium, respectively. The experimental results indicate that the different propagation condition could be generated with the different material, although it is performed with the same irradiation condition.

38000092
Rotational stabilization of resistive wall mode on JT-60U
Matsunaga, Go; Takechi, Manabu; Aiba, Nobuyuki; Kurita, Genichi; Sakamoto, Yoshiteru; Koide, Yoshihiko; Isayama, Akihiko; Suzuki, Takahiro; Fujita, Takaaki; Oyama, Naoyuki; Ozeki, Takahisa; Kamada, Yutaka; JT-60 Team
Plasma and Fusion Research (Internet) 4, p.051_1-051_7(2009) ; (JAEA-J 06679)

38000093
Neutron diffraction studies on strain evaluation of rebar in reinforced concrete
Suzuki, Hiroshi; Kanematsu, Manabu*; Kusunoki, Koichi*
Powder Diffraction 24(Suppl.1), p.S68-S71(2009) ; (JAEA-J 06680)

It is typical method to measure the strains on a rebar in a reinforced concrete using strain gauges glued on the rebar. The waterproof treatment and wiring of the strain gauges, however, would affect the accuracy of the strain evaluation of the rebar in the reinforced concrete. In this study, neutron diffraction technique, which is nondestructive and noncontact technique, was applied to the strain evaluation of the rebar in reinforced concrete in order to solve above problems. It was confirmed that the absorption coefficient of concrete is smaller than that of steels, and that the effect of absorption of concrete on the accuracy of strain measurement is low. We measured strain distribution of the rebar in reinforced concrete, and the size of anchorage zone was evaluated. It was confirmed that the size of anchorage zone evaluated using neutron diffraction was smaller than that evaluated using strain gauges.

38000094
Application of clear polymethylmethacrylate dosimeter Radix W to a few MeV electron in radiation processing
Seito, Hajime; Ichikawa, Tatsuya*; Hanaya, Hiroaki; Sato, Yoshishige*; Kaneko, Hirohisa; Haruyama, Yasuyuki; Watanabe, Hiroshi*; Kojima, Takuji
Radiation Physics and Chemistry 78(11), p.961-965(2009) ; (JAEA-J 06682)

38000095
Spectral change in X-ray absorption near edge structure of DNA thin films irradiated with monochromatic soft X-rays
Fujii, Kentaro; Yokoya, Akinari
Radiation Physics and Chemistry 78(11), p.1188-1191(2009) ; (JAEA-J 06683)

To reveal the chemical changes induced in DNA by irradiation with ionizing radiation, we have investigated the spectral change in the X-ray absorption near edge structure (XANES) of DNA resulting from exposure to monochromatic soft X-rays. We used a thin film of calf thymus DNA as a sample and observed nitrogen K-shell and oxygen K-shell XANES spectra. The energies correspond to those just below or just above the nitrogen and oxygen K-shell ionization energy, respectively. The obtained XANES spectra show significant changes by irradiation. Particularly a new π* resonance peak in oxygen XANES spectra is evidently appeared by the irradiation above oxygen K-shell ionization potential. These results suggest that carbonyl groups, presumably a propenal group (O=C-C=C), may be produced in the sample by oxygen ionization. Thus characteristic damage induced by induction in the DNA molecule would be predicted following exposure to monochromatized synchrotron soft X-rays.

38000096
Metal adsorption of carboxymethyl cellulose/carboxymethyl chitosan blend hydrogels prepared by γ irradiation
Hiroki, Akihiro; Tran, H. T. *; Nagasawa, Naotsugu; Yagi, Toshiaki*; Tamada, Masao
Radiation Physics and Chemistry 78(12), p.1076-1080(2009) ; (JAEA-J 06684)

To investigate an adsorption of Pb and Au ions, blend hydrogels based on the carboxymethyl cellulose (CMC) and carboxymethyl chitosan (CMCts) were prepared by γ-irradiation of a high concentrated CMC/CMCts aqueous solution. The blend hydrogels showed a degree of swelling in the range of 30 to about 550 g -water/g -dried gel. The gel fraction of the blend hydrogels increased sharply up to 30 kGy and reached a constant value in the range of 100-200 kGy. The gel fraction of the blend hydrogel decreased with increasing the ratio of CMCts. Nitrogen content in the hydrogels was determined by means of elemental analysis. The nitrogen content in the obtained hydrogels was proportional to the ratio of CMCts in the mixture, which was almost equal with theoretical ones. This is indicated that the obtained hydrogels were constructed at the initial ratio of CMC/CMCts. The rate of the metal ions adsorbed to the blend hydrogels increased with increasing the composition of CMCts. In the case of Pb, the CMC/CMCts blend gels showed the enhancement of the adsorption rate in the range of 55% to 80%. Although the adsorption rate of Au ions was only 10% at CMC/CMCts 100/0, it reached at 60% at 75/25, and then increased up to about 90% at 0/100. The obtained blend hydrogels had high adsorption performance which was controlled by adjusting the composition of CMC/CMCts.

38000097
Enhanced radiation-induced cell killing by Herbimycin A pre-treatment
Noguchi, Miho; Hirayama, Ryoichi*; Druzhinin, S.*; Okayasu, Ryuichi*
Radiation Physics and Chemistry 78(12), p.1184-1187(2009) ; (JAEA-J 06685)

Herbimycin A (HA), as in Geldanamycin, binds to conserved pockets of heat shock protein 90 (Hsp90) and inhibits its chaperone functions. Hsp90 plays an integral role in cancer cell growth and survival, because it maintains the stability of several key proteins by its chaperone's activity. It is known that some of the proteins associated with radiation responses are functionally stabilized by Hsp90. In this study, we investigated the effect of HA on radiosensitivity in human cancer cells and the mechanism related to the sensitization. In order to gain a mechanistic insight of this sensitization, we examined repair of DNA double strand breaks (DSBs) in irradiated human cancer cells pre-treated with HA, as unrepaired DSBs are thought to be the main cause of radiation-induced cell death. Cellular radiosensitivity was determined by clonogenic assay, and the DSB rejoining kinetics was examined by constant field gel electrophoresis. SQ-5, a lung squamous carcinoma cell line, showed synergistic increase in radiosensitivity when cells were pre-treated with HA. In addition, HA significantly inhibited repair of radiation induced DSBs. These results suggest that the combination of HA and ionizing radiation may be a useful therapeutic strategy for treating certain cancer cells.

38000098
Operational radiation protection issues specific to high-intensity beams
Nakashima, Hiroshi
Radiation Protection Dosimetry 137(1-2), p.35-50(2009) ; (JAEA-J 06686)

Recently, accelerator technology is progressing with brilliant innovations, and the intensity of high-energy accelerators is gradually increasing. Their applications are widening into many fields such as medical services and physics. Many high-energy accelerators are under operation and many projects are planned all over the world. In these accelerator facilities, it is important to consider the radiological safety during construction and operation. Therefore, safety characteristics, radiological safety design, and safety management systems of high-intensity accelerators are summarized in this paper with taking the Japan Proton Accelerator Research Complex (J-PARC) as a reference.

38000099
Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution
Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko*; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Ichikawa, Shinichi; Yasuda, Kenichiro; Miyamoto, Yutaka; Hashimoto, Kazuyuki; Nagame, Yuichiro; Goto, Shinichi*; Kudo, Hisaaki*; Sato, Wataru*; Shinohara, Atsushi*; Oura, Yasuji*; Sueki, Keisuke*; Kikunaga, Hidetoshi*; Kinoshita, Norikazu*; Yokoyama, Akihiko*; Schädel, M.*; Brüchle, W.*; Kratz, J. V.*
Radiochimica Acta 97(2), p.83-89(2009) ; (JAEA-J 06687)

Anion-exchange chromatography of element 105, dubnium (Db), produced in the ²⁴⁸Cm(¹⁹F, 5n)²⁶²Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K_d) of Db on an anion-exchange resin is successfully determined by running cycles of the 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta ≈ Nb > Db ≥ Pa.

38000100
Synergistic extraction of Am(III) and Eu(III) by tris(2-pyridylmethyl)amine with various anions in 1,2-dichloroethane
Ishimori, Kenichiro; Watanabe, Masayuki; Yaita, Tsuyoshi; Kimura, Takaumi; Yamada, Takashi*; Shinoda, Satoshi*; Tsukube, Hiroshi*
Solvent Extraction and Ion Exchange 27(4), p.489-500(2009) ; (JAEA-J 06688)

The remarkable enhancements of the extraction efficiency of Am(III) and Eu(III) and the separation efficiency between Am(III) and Eu(III) were achieved through changes in counter anions and/or organic solvents, in the solvent extraction of Am(III) and Eu(III) with a tripodal ligand, tris(2-pryidylmethyl)amine (tpa). The separation factor (Am/Eu), which is defined as the ratio between the distribution ratios of Am(III) and Eu(III), ranged from 10 to 50 using various combinations of counter anions and organic solvents. The extraction equilibria of Am(III) and Eu(III) with tpa in 1,2-dichloroethane were determined in detail through slope analyses in order to elucidate the mechanism of separation and identify the extracted species.

38000101
Effects of CMC molar mass on mechanical properties of CMC-acid gel
Takigami, Machiko*; Hiroki, Akihiro; Nagasawa, Naotsugu; Kasahara, Takamitsu*; Takigami, Shoji*; Tamada, Masao
Transactions of the Materials Research Society of Japan 34(3), p.391-394(2009) ; (JAEA-J 06689)

Carboxymethyl cellulose (CMC) with different molar mass was prepared by acid hydrolysis at 121°C. CMC thus prepared was mixed with citric acid aqueous solution to form CMC-acid gel. By replacing sodium existing as counter ion in carboxymethyl group with hydrogen, CMC molecules coagulate and hydrogen bonds are formed among CMC molecules. The CMC-acid gel prepared in that way was subjected to evaluation of gel fraction, water absorption and mechanical properties. Gel fraction was higher in CMC with higher molar mass than that in CMC with lower molar mass at short incubation time. However, there was no difference in gel fraction attributable to molar mass of CMC after long time incubation. CMC with higher molar mass crosslinked more easily than CMC with lower molar mass. The gel made of CMC with lower molar mass was softer and absorbed more amount of water than that with higher molar mass. All the results were elucidated by number of hydrogen bonds in CMC molecule. The gel made of higher molar mass CMC becomes stiff and brittle after long time incubation, however, the gel made of lower molar mass CMC keeps softness and strength longer.

38000102
Influence of magnetic fields on turbo-molucular pumps
Ogiwara, Norio; Kanazawa, Kenichiro; Inohara, Takashi*; Wada, Kaoru*
Vacuum 84(5), p.718-722(2009) ; (JAEA-J 06690)

Recently turbo-molecular pumps (TMPs) have been widely used in nuclear fusion devices and sometimes in particle accelerators. Therefore, in order to use them in a quasi-static magnetic field the influence of the fields on TMPs has been exactly investigated. First of all, the influence for the two special magnetic fields has been examined: one is due to the vertical magnetic field, and the other due to the parallel component. The parallel magnetic field has no influence of the operation of the TMP. On the contrary, the driving power and the rotor temperature were largely affected by the vertical magnetic field. The eddy current loss in the vertical field increases rapidly with the field strength. It is proportional to the square of the field strength. The eddy current loss also increases as the revolution frequency, however, it has quite different dependence from the magnetic field strength. These dependences are well explained by the skin depth, which referred to the region where a localized magnetic field and current flow exists. Then we have successfully evaluated the influence of the magnetic field with an arbitrary direction by means of adding the contributions from the two magnetic components. Furthermore, from the demonstration experiment, it is generally found that the magnetic field with the symmetry around the rotor axis does not affect the operation of the TMP.

38000103
Vacuum system of the 3-GeV RCS in J-PARC
Ogiwara, Norio; Kinsho, Michikazu; Kamiya, Junichiro; Yamamoto, Kazami; Yoshimoto, Masahiro; Hikichi, Yusuke; Kanazawa, Kenichiro; Mio, Keigo; Takiyama, Yoichi; Suganuma, Kazuaki; Saito, Yoshio*
Vacuum 84(5), p.723-728(2009) ; (JAEA-J 06691)

To minimize the radiation exposure during maintenance, it is necessary to compose the 3-GeV RCS vacuum system with reliable components which have long life time in such a high level of radiation. In addition, it is necessary to keep the operating pressure with beam in ultra high vacuum for suppressing the pressure instability. Thus we should think of not only the outgassing mainly due to ion desorption but also the pumping efficiency. From the above, the vacuum system was designed. The ring is divided by the isolation valves into 6 sections, which can be pumped down independently. For avoiding any eddy current loss ceramic ducts are used in the bending and focusing magnets. These ducts are connected to the Ti ducts, putting the Ti bellows between. Here, we adopt pure Ti as a material for the ducts and bellows because of its small residual radioactivity. The ring is evacuated with 20 ion pumps (0.7 m³/s) and 24 turbomolecular pumps (TMPs) (1.3 m³/s), which are attached to the Ti ducts. The TMPs are used for not only rough pumping but also evacuation during the beam operation. Especially a collimator system for localizing beam losses in a restricted area is evacuated with the TMPs, because the outgassing from this region will be probably the largest. On the other hand, each arc section is pumped by 4 ion pumps and 2 TMPs. To realize the above system, we have developed some components such as large aperture ceramic ducts and TMPs with high radioactive-resistance, as well as several kinds of heat treatment to reduce the outgassing. Finally, we have realized the UHV without baking in the RCS and the beam operation has been succeeded until now.

38000104
Non-destructive profiling by quantum beams (in Japanese)
Yamamoto, Hiroyuki; Esaka, Fumitaka; Matsue, Hideaki; Sasase, Masato*
Bunseki 2009(11), p.612-618(2009) ; (JAEA-J 06692)

Present status and future prospects are discssed on the analysis of profiling by quantum beams.

38000105
Proposal of efficient pre-excavation grouting concept for deep underground rock excavation (in Japanese)
Nobuto, Jun*; Mikake, Shinichiro; Nishigaki, Makoto*
Doboku Gakkai Rombunshu, C 65(4), p.806-821(2009) ; (JAEA-J 06693)

This paper describes a study on efficient pre-excavation grouting concept using cement grout for reducing water-inflow during excavation of crystalline rock in deep underground. Although thick grout mix is favorable for the efficiency of pre-excavation grouting, clogging phenomenon at the entrance of rock fractures in grout hole is concerned for thick grout mix. The influence of water-cement ratio on basic grout characteristics and clogging phenomenon is studied by laboratory experiment using cement grout with water-cement ratio of from 0.5 to 10.0. Finally, the efficient pre-excavation concept for the excavation of deep underground is proposed.

38000106
The Rules of the professional engineers responsible for radiation protection (in Japanese)
Yamasoto, Kotaro
Genshiryoku eye 55(12), p.56-57(2009) ; (JAEA-J 06695)

Professional engineers have an obligation to develop own technical capability and high degree of a sense of ethics. This report describes authors recognition on the rules of professional engineer responsible for radiation protection. In order to fulfill the sake of radiation control, follows are taken into account; (1) how we should solve about a dilemma between compliance and sense of ethics which is encountered in daily activities, (2) the rules of professional engineers for developing new technology, and (3) transmission of technology to be done as a professional engineer.

38000107
Development of neutron visual sensing techniques (in Japanese)
Kureta, Masatoshi
Hamon 19(4), p.218-223(2009) ; (JAEA-J 06696)

Neutron visual sensing technique is one of the nondestructive visualization and image-sensing techniques. In this article, some advanced neutron visual sensing techniques are introduced. The most up-to-date high-speed neutron radiography, neutron 3D CT, high-speed scanning neutron 3D/4D CT and multi-beam neutron 4D CT techniques are included with some fundamental application results. Oil flow in a car engine was visualized by high-speed neutron radiography technique to make clear the unknown phenomena. 4D visualization of painted sand in the sand glass was reported as the demonstration of the high-speed scanning neutron 4D CT technique. The purposes of the development of these techniques are to make clear the unknown phenomena and to measure the void fraction, velocity etc. with high-speed or 3D/4D for many industrial applications.

38000108
Food irradiation; Exposing food to ionizing radiation for the purpose of prevention of sprouting; control of insects, parasites, pathogenic and spoilage bacteria, moulds and yeasts; and sterilization (in Japanese)
Kobayashi, Yasuhiko; Kikuchi, Masahiro
Hoshasen Kagaku (88), p.18-27(2009) ; (JAEA-J 06697)

Food irradiation can have a number of beneficial effects, including prevention of sprouting; control of insects, parasites, pathogenic and spoilage bacteria, moulds and yeasts; and sterilization, which enables commodities to be stored for long periods. It is most unlikely that all these potential applications will prove commercially acceptable; the extent to which such acceptance is eventually achieved will be determined by practical and economic considerations. A review of the available scientific literature indicates that food irradiation is a thoroughly tested food technology. Safety studies have so far shown no deleterious effects. Irradiation will help to ensure a safer and more plentiful food supply by extending shelf-life and by inactivating pests and pathogens. As long as requirements for good manufacturing practice are implemented, food irradiation is safe and effective. Possible risks of food irradiation are not basically different from those resulting from misuse of other processing methods, such as canning, freezing and pasteurization.

38000109
Ion beam as a radiation for life (in Japanese)
Tanaka, Atsushi
Hoshasen To Sangyo (122), p.35-39(2009) ; (JAEA-J 06699)

As ion beam is the most effective radiation to living things, new biotechnologies for ion-beam application have been progressed. The collimating heavy-ion microbeam system at JAEA-Takasaki has provided target irradiation of heavy charged particles to biological material at atmospheric pressure using a minimum beam size 5 mm in diameter. The ion beam breeding technique, which was first developed in JAEA as a new mutation induction technology, has been applied for many varieties of plants and microorganisms such as flower, crop, vegetable, yeast, alga and fungus. No-invasive imaging methods are powerful tools for biology and medical diagnosis. The Positron Emitting Tracer Imaging System (PETIS) is one of such methods and it visualizes the distribution of positron-emitting radioisotope in intact plants like a video camera in order to understand plant nutrition. The in-air micro-PIXE system has also been used for investigation of elemental analysis in a cell for medical diagnosis such as Asbestos. A new radionuclide for medicine such as Cu-64 and Br-76, was produced by using AVF cyclotron and studied for the diagnosis of cancer by positron emission tomography, PET.

38000110
Development of highly durable polymer electrolyte membranes for residential fuel cell system (in Japanese)
Maekawa, Yasunari; Chen, J.; Asano, Masaharu
Hoshasen To Sangyo (123), p.4-9(2009) ; (JAEA-J 06700)

The polymer electrolyte membranes (PEM) consisting of a poly(ether ether ketone) film, which is mechanically and thermally stable aromatic hydrocarbon polymers, so-called "super engineering plastics" are successfully prepared by thermal/radiation induced two step graft polymerization. The developed PEM exhibited 1.5 times higher conductivity and 2.3 times higher mechanical strength, compared with conventional fluorinated PEM. The single fuel cell device maintained stable operation over 1000 hours under the operation at 95°C. This durability test is estimated to be the stable operation over 40,000 hours at 80°C.

38000111
Activities in Monju to improve public relations and a risk communication booklet (in Japanese)
Yanagisawa, Tsutomu; Tabata, Hiroaki; Mori, Masaomi
Hozengaku 8(3), p.17-22(2009) ; (JAEA-J 06701)

Monju, the Japanese prototype of fast breeder reactor, has engaged in various activities to restore the public trust since the sodium leak accident occurred in 1995. Among the activities is the publication of a risk communication booklet Response to the Possible Accident and Trouble in Monju which is compiled according to the operational progress of Monju. This booklet is intended for promoting the public understanding toward the restart. The supplement of the booklet illustrates the outline and characteristics of Monju, the recent troubles at not only Monju, but also home and abroad, and the assumed troubles during the Core Confirmation Test which is implemented when the System Start-Up Test is commenced. These efforts for the restart are also explained.

38000112
Development of novel adsorbents for rare metals from hot spring water (in Japanese)
Seko, Noriaki
Jidosha Gijutsu 63(11), p.102-105(2009) ; (JAEA-J 06702)

Our objective focuses on the development of fibrous adsorbent for rare metals such as scandium and vanadium by means of radiation-induced graft polymerization and their adoption to recovery from hot spring water in Kusatsu-spa.

38000113
Source fault of the Iwate-Miyagi Nairiku Earthquake in 2008 estimated by distribution of heights of fluvial terraces (in Japanese)
Tajikara, Masayoshi; Ikeda, Yasutaka*; Nohara, Tsuyoshi
Jishin 62(1), p.1-11(2009) ; (JAEA-J 06703)

We estimated distribution of uplift rates during the last 150 kyrs around the focal region of the Iwate-Miyagi Nairiku Earthquake in 2008 (occurred at June 14, 2008; Mj 7.2, Mw 6.9), based on relative heights of fluvial/marine terraces. Active fault has not been mapped around this area, because clear fault scarp with large displacement does not exist. We showed that the uplift rates vary around the focal region and that the variation of uplift rates is related to the activities of the source fault of the Iwate-Miyagi Nairiku Earthquake in 2008. We estimated the vertical displacement rate of this fault as 0.4-0.5 mm/yr, based on difference of uplift rates on the both side of the source fault. We considered that the existence of (blind) active fault can be estimated even in the area with no clear fault scarp, by clarifying the distribution of uplift rates based on heights of fluvial/marine terraces.

38000114
A Novel technique for monitoring the reproducibility of laser tape-target interactions using an X-ray pinhole camera
Ogura, Koichi; Fukumi, Atsushi*; Li, Z.*; Orimo, Satoshi; Sagisaka, Akito; Nishiuchi, Mamiko; Kado, Masataka; Mori, Michiaki; Yogo, Akifumi; Hayashi, Yukio; Daido, Hiroyuki; Bulanov, S. V.; Oishi, Yuji*; Nayuki, Takuya*; Fujii, Takashi*; Nemoto, Koshichi*; Nakamura, Shu*; Iwashita, Yoshihisa*; Noda, Akira*
Journal of the Vacuum Society of Japan 52(10), p.570-574(2009) ; (JAEA-J 06704)

For accurate control of relativistic laser-plasma interaction under the repetitive operation, we have to measure and control the laser irradiation conditions such as laser parameters, the target shooting accuracy and so on as well as measuring proton parameter on each laser shot. The displacement of the laser shooting position on a tape target, that are used in the high energy proton generation using an ultra-short Ti:sapphire laser system, is measured by observing an X-ray image from laser plasma with an X-ray pinhole camera for each laser shot. The displacement of the shooting position on the target is about 20micron and the accuracy of the target positioning is within 20micron which is small enough for present laser focusing optics with an F number of 3.6 (f=179mm). The technique contributes to accurate control of a repetitive laser driven proton accelerators.

38000115
Current status of metal adsorbent for recover from seawater and the prospect of coexistence with fishing industry (in Japanese)
Seko, Noriaki
Nippon Kaisui Gakkai-Shi 63(4), p.221-225(2009) ; (JAEA-J 06706)

Braid adsorbent having functional group of amidoxime is a promising material for the recovery of uranium dissolved in the seawater. This long braid adsorbent was made by polyethylene multi-fibers in which amidoxime groups were introduced by radiation-induced graft polymerization and subsequent chemical treatment. The braid adsorbent obtained was moored at the offing of Okinawa Island. The average U adsorption of the adsorbent became 1.5 g-U/kg-adsorbent for 30 d soaking. The mooring system for braid adsorbent has possibility which reduced the cost for the recovery of uranium from seawater. Annual product of 1200 tons of uranium needs 134 km² of mooring area. In addition, there is 6000 km² and more of suitable sea area for the collection of the uranium in the regions from Okinawa Islands to Tosa Bay in Japan.

38000116
Laser-driven plasma-wave electron accelerators (in Japanese)
Kondo, Kiminori
Pariti 24(11), p.21-31(2009) ; (JAEA-J 06707)

The article written by Wim Leemans and Eric Esarey of Lawrence Berkeley laboratory in Physics Today is translated in Japanese. Dr. Leemans has succeeded in generating 1 GeV quasi-mono energetic electrons by the laser wakefield acceleration scheme proposed by Tajima and Dawson. In this article, the review and the future prospective for plasma accelerator are described including his study.

38000117
Anodic polarization behavior and film breakdown potential of pure copper in the simulated geological environment containing carbonate (in Japanese)
Kawasaki, Manabu; Taniguchi, Naoki; Naito, Morimasa
Zairyo To Kankyo 58(11), p.386-394(2009) ; (JAEA-J 06709)

In order to clarify the influence of environmental factors on the corrosion behavior of copper overpacks in oxidizing environment, potentiodynamic and potentiostatic anodic polarization tests were performed in carbonate aqueous solutions at 80 °C. As the results, the passivation was promoted and film breakdown was suppressed in higher carbonate concentrations, in lower chloride ion concentrations, and in higher pH conditions. The sulfate ion tended to promote the film breakdown of copper. The effects of the composition of the test solutions on the anodic polarization curve of copper in bentonite/sand mixture were quite smaller than those in simple aqueous solution. By comparison with previous data for lower temperature condition, it was clarified that passivation of copper was promoted in higher temperature condition, but breakdown potential, Eb was independent of temperature. The Eb, was expressed as a function of the ratio of aggressive ion and inhibiting ion such as [Cl^-]/[HCO₃^-] and [SO₄^2-]/[HCO₃^-], and it was confirmed that the Eb was lowered with increasing the ratio. When the ratio exceeds a certain value, the Eb was no longer able to be determined since the anodic poralization curve becomes active dissolution type. The lower limit of Eb in passive type region was estimated to be about -200mV vs. SCE. The results of potentiostatic tests showed that pitting corrosion or non-uniform corrosion was observed at the potentials over Eb or second current peak potentials in anodic polarization curve.

38000118
Shell evolution in the sd-pf shell studied by the shell model
Utsuno, Yutaka; Otsuka, Takaharu*; Brown, B. A.*; Homma, Michio*; Mizusaki, Takahiro*
AIP Conference Proceedings 1120 (Internet) , p.81-86(2009) ; (JAEA-J 06711)

38000119
General relativistic compact stars with exotic matter
Yasutake, Nobutoshi*; Maruyama, Toshiki; Tatsumi, Toshitaka*; Kiuchi, Kenta*; Kotake, Kei*
AIP Conference Proceedings 1120 (Internet) , p.146-150(2009) ; (JAEA-J 06712)

We study the structure of magnetized hybrid stars in general relativistic formalism and calculate possible evolutionary paths of formation of hybrid stars due to spin-down of magnetized rotating neutron stars. Our study is based on axisymetric and stationary formalism including purely toroidal magnetic field. For hybrid stars, we find characteristic distribution of magnetic field, which is confined in the stellar core of mixed phase. The released energy by QCD phase transition is very large, ∼10⁵² ergs. The liberated energy might become a new energy source for a delayed explosion of supernova. Moreover, we find and estimate the spin-up by the transition. This spin-up accompanies the energy release, hence it will be candidates such astrophysical phenomena. We also study the finite size effects of quark-hadron mixed phase on the structures of magnetars.

38000120
Structure of multi-antikaonic nuclei
Muto, Takumi*; Maruyama, Toshiki; Tatsumi, Toshitaka*
AIP Conference Proceedings 1120 (Internet) , p.270-274(2009) ; (JAEA-J 06713)

We investigate multi-antikaonic nuclei (MKN), where several K^- mesons are bound in the nucleus. We base our study on the relativistic mean-field theory, coupled with kaon-nucleon and kaon-kaon interactions which respect chiral symmetry. We discuss the effects of the nonlinear K - K interaction, which is inherent in the chiral model, and on the properties of the MKN. We obtain density profiles for nucleons and K^- mesons, the single particle energy of the K^- mesons, and binding energy of the MKN by systematically changing |S| (the number of the embedded K^-). We discuss the nonlinear K - K repulsive effect, which makes the K^- field saturate above a certain value of |S| in nuclei. We also discuss a possible observation of the MKN in experiments.

38000121
Plasma physics found in JT-60 tokamak over the last 20 years
Kikuchi, Mitsuru; JT-60 Team
AIP Conference Proceedings 1150 , p.161-167(2009) ; (JAEA-J 06714)

JT-60 is a large tokamak to achieve equivalent break-even condition, started its operation in April 1985 and completed its operation in August 2008. JT-60 achieved world record ion temperature Ti of 45keV as recorded in Guiness Book in 1996 and record electron temperature Te of 20 keV. It also achieved world record of equivalent energy gain Q^eq = 1.25. In parallel with research to achieve missions of JT-60, concept development to overcome pulsed nature of tokamak system has been made, so-called Steady-State Tokamak Reactor (SSTR) based on the maximum utilization of the bootstrap current. This concept development led to dramatic change in research direction from low q and high β_T regime to high q and high β_p regime, sometimes called advanced tokamak research. This talk addresses physics of the steady-state tokamak disclosed mainly in JT-60.

38000122
Multi-code ab intio calcualtion of ionization distributions and radiation losses for tungsten for tokamak plasmas
Ralchenko, Y.*; Abdallah, J. Jr.*; Bar-Shalom, A.*; Bauche, J.*; Bauche-Arnoult, C.*; Bowen, C.*; Busquet, M.*; Chung, H.-K.*; Colgan, J.*; Faussurier, G.*; Fontes, C. J.*; Foster, M.*; de Gaufridy de Dortan, F.*; Golovkin, I.*; Hansen, S. B.*; Klapisch, M.*; Lee, R. W.*; Novikov, V.*; Oreg, J.*; Peyrusse, O.*; Poirier, M.*; Sasaki, Akira; Scott, H.*; Zhang, H. L.*
AIP Conference Proceedings 1161 , p.242-250(2009) ; (JAEA-J 06715)

We present calculations of ionization balance and radioactive power losses for tungsten in magnetic fusion plasmas. The simulation were performed within the framework of non-LTE code comparison workshops utilizing independent collisional-radioactive models. The calculations generally agree with each other, however, a clear disagreement with experimental ionization distributions at low temperatures, 2 keV < T_e < 3 keV.

38000123
Toroidal rotation profiles under the influence of fast-ion losses due to toroidal field ripple
Honda, Mitsuru; Takizuka, Tomonori; Fukuyama, Atsushi*; Yoshida, Maiko; Ozeki, Takahisa
Journal of Plasma and Fusion Research SERIES, Vol.8 , p.316-320(2009) ; (JAEA-J 06717)

Characteristics of toroidal rotation profiles in tokamak plasmas are studied under the influence of fast-ion losses due to a toroidal field (TF) ripple by using a one-dimensional multi-fluid transport code, TASK/TX. When a neutral beam (NB) is injected into a plasma, a part of fast ions is lost due to the effect of the TF ripple. The radial current then flows inward in the bulk plasma to keep quasi-neutrality and it exerts a torque on the plasma in the direction opposite to the plasma current. A parametric survey of the toroidal rotation driven by this torque is conducted to quantify the sensitivity to various externally-controllable sources such as a co-tangential NBI power. In the case of a larger ripple amplitude, it is observed that the counter-toroidal rotation develops near the periphery of the plasma as an increase in the co-NBI input power while the co-toroidal rotation velocity on the magnetic axis reaches a maximum value at a certain NBI power. This torque can be mitigated by increasing a gas puff rate. An increase in the plasma current also leads to the reduction in the counter rotation induced by ripple.

38000124
Numerical modelling of high energy ion transport in tokamak plasmas
Hamamatsu, Kiyotaka
Journal of Plasma and Fusion Research SERIES, Vol.8 , p.1134-1137(2009) ; (JAEA-J 06718)

38000125
A Systematic approach to evaluate the importance of concerns affecting the geological disposal of radioactive wastes
Oi, Takao; Inagaki, Manabu; Kawamura, Makoto; Ebashi, Takeshi
Materials Research Society Symposium Proceedings, Vol.1124 , p.407-412(2009) ; (JAEA-J 06720)

In the safety assessment of geological disposal system of radioactive waste, diverse apprehensions have been extracted from the viewpoint of the impact on the safety and the researches relating to those have been carried out strenuously. However, systematical investigation for presenting the relative importance of those has so far scarcely been conducted. The demonstration of the importance is critical issue to contribute the improvement of reliability of safety assessment. In this study, the following investigations were carried out with the goal of developing the systematic approach which can present the relative importance of the apprehensions: (1) Establishment of Total Assessment Work Frame [TAWF], (2) Establishment of the organaization procedure for evaluating the relative importance.

38000126
Sorption and diffusion of Cs in Horonobe-URL's sedimentary rock; Comparison and model prediction of retardation parameters from sorption and diffusion experiments
Tachi, Yukio; Seida, Yoshimi; Doi, Reisuke; Xia, X.*; Yui, Mikazu
Materials Research Society Symposium Proceedings, Vol.1124 , p.573-579(2009) ; (JAEA-J 06721)

Diffusion and sorption of Cs in the sedimentary rock of Horonobe generic URL site were studied in the present study. The retardation parameters, De and Kd, of rock for Cs were measured by both batch sorption and intact diffusion experiments with the comparison of obtained retardation parameters each other. The tracer depletion, breakthrough and inner concentration data in the through diffusion experiment were simulated simultaneously by the conventional transport model with one set of the retardation parameters. The Kd values obtained from the data fitting were consistent with those obtained by the batch sorption experiment with crushed rock. The obtained sorption parameters were also simulated based on geochemical model calculation to interpret the sorption behavior theoretically under the assumption of dominant sorption minerals and their sorption mechanism.

38000127
Nano-particle materials prepared from a synthetic antigenic sequence of plasmodium falciparum enolase
Oku, Hiroyuki*; Yamada, Keiichi*; Kobayashi, Kyoko*; Katakai, Ryoichi*; Ashfaq. M*; Hanaoka, Hirofumi*; Iida, Yasuhiko*; Endo, Keigo*; Hasegawa, Shin; Maekawa, Yasunari; Yano, Kazuhiko*; Kano, Shigeyuki*; Suzuki, Mamoru*
Peptide Science 2008 , p.439-442(2009) ; (JAEA-J 06722)

Malaria is the major cause of mortality and morbidity in the tropical and subtropical regions in the world. Our previous studies have shown that a series of partial peptides of a Plasmodium falciparum enolase have antigenic reactivity against patients' sera. In this paper, we wish to report nano-encapsulation of a synthetic antigen into bioabsorbable polymer particles and their releasing studies in vitro and in vivo.

38000128
Present status of operation and maintenance of JRR-3
Ichimura, Toshiyuki; Suwa, Masayuki; Fukushima, Manabu; Oba, Toshinobu; Nemoto, Yoshinori; Terakado, Yoshibumi
Proceedings of 12th International Group on Research Reactors (12th IGORR) (USB Flash Drive) , 8p.(2009) ; (JAEA-J 06724)

The JRR-3 (Japan Research Reactor No. 3) was constructed as the first domestic reactor in 1962. The large-scale modification such as removal and re-installation of the core was carried out from 1985 to 1990. It reached integrated output of 59.9 GWd in July, 2009. JRR-3 has continued the stable operation with several maintenance. Three topics are picked up as major maintenances; modification of fuel elements from aluminide to silicide, replacement of a process control computer system, replacement of a helium compressor of the helium gas system which is part of the heavy water cooling system.

38000129
Validation for multi-physics simulation of core disruptive accidents in sodium-cooled fast reactors by COMPASS code
Koshizuka, Seiichi*; Morita, Koji*; Arima, Tatsumi*; Zhang, S.*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Naito, Masanori*; Shirakawa, Noriyuki*; Okada, Hidetoshi*; Uehara, Yasushi*; Nagamine, Yasuo*; Yamamoto, Yuichi*; Himi, Masashi*; Hirano, Etsujo*; Shimizu, Sensuke*; Oue, Masaya*
Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) (CD-ROM) , 11p.(2009) ; (JAEA-J 06725)

Dispersion and freezing of molten core material was calculated by the COMPASS code to compare with the experimental data of GEYSER. Molten core material flowed up with freezing on the pipe inner surface. As a molten pool behavior, CABRI-TPA2 experiment was analyzed, where a sphere of solid steel was surrounded by solid fuel. Power was injected to cause melting and boiling of the steel sphere. SCARABEE-BE+3 test was analyzed by COMPASS as a validation of failure of duct walls.

38000130
Fuel pin behavior under slow ramp-type transient-overpower conditions in the CABRI-FAST experiments
Fukano, Yoshitaka; Onoda, Yuichi; Sato, Ikken; Charpenel, J.*
Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) (CD-ROM) , 13p.(2009) ; (JAEA-J 06726)

In the CABRI-FAST experimental program, four in-pile tests were performed with slow power-ramp-type transient-overpower conditions to study transient fuel pin behavior under inadvertent control rod withdrawal events in liquid metal cooled fast breeder reactors. Annular-pellet fuel pins were used in three tests, while a solid-pellet fuel pin was used in the other test. All of these pins were pre-irradiated in Phenix. The slow TOP test with a solid-pellet fuel pin was realized as a comparatory test against an existing test (E12) in the CABRI-2 program. In the CABRI-FAST test (BCF1), a power ramp rate of 3%Po/s was applied, while in the CABRI-2 test, 1%Po/s was adopted. In spite of the different power ramp rates, evaluated fuel thermal conditions at the observed failure time are quite similar. The continued overpower condition in the BCF1 test resulted in gradual degradation of the pin structure providing information effective for evaluation of various accident scenarios. Three slow TOP tests with the annular fuel in the CABRI-FAST program resulted in no pin failure showing high failure threshold. These CABRI FAST slow TOP tests, in combination with the existing CABRI and TREAT tests, provided an extended slow TOP test database with various fuel and transient conditions.

38000131
CABRI-RAFT TP2 and TP-A1 tests simulating the unprotected loss-of-flow accident in sodium-cooled fast reactors
Onoda, Yuichi; Fukano, Yoshitaka; Sato, Ikken; Marquie, C.*; Duc, B.*
Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) (CD-ROM) , 15p.(2009) ; (JAEA-J 06727)

TP2 and TP-A1 tests were conducted in the framework of the CABRI-RAFT program to study post-failure material-relocation during the Unprotected Loss-of-Flow (ULOF) accident in sodium-cooled fast reactors. In these tests, a three-pin-cluster geometry was adopted to supply complementary information to the existing CABRI-single-pin tests. Two different levels of energy injection into the fuel pins were realized to clarify the effect of fuel enthalpy on axial fuel relocation. Starting from a steady-state condition, Loss of Flow (LOF) was applied and then Transient Over Power (TOP) was triggered 13.4 s and 9.1 s after the coolant boiling in the TP2 and TP-A1 tests, respectively. Through a close look at these test results, it is concluded that the fuel relocation is dominated by accumulated fuel enthalpy and is not depending on three-pin-cluster or single pin conditions.

38000132
Criteria for occurrence of self-leveling in the debris bed
Zhang, B.*; Harada, Tetsushi*; Hirahara, Daisuke*; Matsumoto, Tatsuya*; Morita, Koji*; Fukuda, Kenji*; Yamano, Hidemasa; Suzuki, Toru; Tobita, Yoshiharu
Proceedings of 13th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-13) (CD-ROM) , 15p.(2009) ; (JAEA-J 06728)

Although the decay heat from fuel debris drives the coolant boiling in fast reactor accident conditions, the present experiments were conducted by employing depressurization boiling of water to simulate axially increasing void distribution in a debris bed instead of conventional heating or gas injection from the debris bottom. Good agreements on self-leveling occurrence were obtained between model predictions and experimental results. Extrapolation of the present model was also discussed against reactor conditions.

38000133
Application of radiation probes to in situ composition measurements of Bunsen reaction solution
Kubo, Shinji; Nagaya, Yasunobu
Proceedings of 2009 AIChE Annual Meeting (CD-ROM) , 5p.(2009) ; (JAEA-J 06729)

Concerning stable plant operations of the Iodine-Sulfur thermochemical water-splitting process, composition measurements of Bunsen reaction solution is one of key techniques. Radiation probes have a potential for applications to determine this multiple component solution while the non-contact approach avoids the corrosive issues. Laboratory scale experiments to examine its applicability were conducted with use of simulated HI-I₂-H₂O solution by a neutron moisture meter with a sealed radiation source. The obtained counting rates were correlated with hydrogen volume concentrations; this fact suggests that the neutron ray is a candidate probe to determine the composition of HI-I₂-H₂O solution.

38000134
Computational simulations on melting process of fine metal powders with laser irradiation welding
Takase, Kazuyuki; Muramatsu, Toshiharu; Shobu, Takahisa; Tsukimori, Kazuyuki
Proceedings of 2009 ASME International Mechanical Engineering Congress & Exposition (IMECE 2009) (CD-ROM) , 2p.(2009) ; (JAEA-J 06730)

38000135
Numerical simulations on turbulent heat transfer characteristics of supercritical pressure fluids
Nakatsuka, Toru; Takase, Kazuyuki; Yoshida, Hiroyuki; Misawa, Takeharu
Proceedings of 2009 ASME International Mechanical Engineering Congress & Exposition (IMECE 2009) (CD-ROM) , 8p.(2009) ; (JAEA-J 06731)

As one of next generation nuclear reactors, development of a supercritical pressure water reactor (SCWR) has been performed. In order to design the SCWR, it is necessary to investigate thermal-hydraulic characteristics in the SCWR core precisely. As for those characteristics, many experimental studies have been conducted from the former in each country using circular tubes, annular channels and the simulated fuel bundles. An objective of this study is to clarify the prediction accuracy of the turbulent heat transfer characteristics in the supercritical pressure fluids for the SCWR design. From the experimental results of the supercritical pressure fluids flowing upward in a vertical circular tube, it was confirmed that the turbulent heat transfer coefficient suddenly decreases under the high heat flux condition. Although many numerical studies have been done in order to confirm the deterioration of turbulent heat transfer in supercritical pressure fluids, it is important to choose a suitable turbulence model to obtain high prediction accuracy. Then, the prediction accuracy on the deteriorated turbulent heat transfer was investigated numerically using four kinds of turbulence models, SKE, MKE, RSM and LES. The predicted result of each turbulence model was compared with the experimental results of the concentric smooth annulus and vertical circular tube. >From the results of the present study, it was found that LES is the most effective to simulate the deterioration of the turbulent heat transfer at the supercritical pressure fluids.

38000136
COMPASS code development and validation; A Multi-physics analysis of core disruptive accidents in sodium-cooled fast reactors using particle method
Koshizuka, Seiichi*; Liu, J.*; Morita, Koji*; Arima, Tatsumi*; Zhang, S.*; Tobita, Yoshiharu; Yamano, Hidemasa; Ito, Takahiro*; Naito, Masanori*; Shirakawa, Noriyuki*; Hosoda, Seigo*; Uehara, Yasushi*; Yamamoto, Yuichi*; Kozakai, Hiroshi*; Himi, Masashi*; Hirano, Etsujo*; Shimizu, Sensuke*; Oue, Masaya*
Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM) , 1p.(2009) ; (JAEA-J 06732)

A computer code, named COMPASS, is developed for multi-physics analysis of core disruptive accidents of sodium-cooled fast reactors (SFRs). A meshless method, called MPS method, is employed since complex thermal-hydraulics and structural problems with various phase change processes have to be analyzed. Verification for separeted basic processes and validation for practical phenomena are carried out. COMPASS is also expected to investigate molten fuel discharge to avoid re-criticality in large size SFR cores. Both MOX and metal fuels are considered. Eutectic reactions between the metal fuel and the cladding material are investigated by phase diagram calculation, classical and first-principles molecular dynamics. Basic studies relevant to the numerical methods support the code development of COMPASS. Parallel processing is implemented by OpenMP to treat large-scale problems. A visualization tool is also prepared by using AVS.

38000137
A Dispersive, lane-consistent coupled-channel optical model based on soft-rotator theory for accurate calculation of nuclear reaction data
Chiba, Satoshi; Soukhovitski, E. Sh.*; Capote, R.*; Quesada, J.*
Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM) , p.9172_1-9172_7(2009) ; (JAEA-J 06733)

Coupled-channels optical model code OPTMAN is widely applied to analyze experimental nucleon-nucleus interaction data. Sophisticated dispersive optical potential forms had been included in the code along with the possibility to calculate direct excitations of isobar analog states in (p,n) reactions. The latter along with accounting of the proton "effective" energy decrease due to Coulomb repulsion by nuclei, leads to full Lane-consistent optical potential. Such approach had been successfully applied to nucleon-nucleus interaction reaction analyses of experimental data for several nuclei up to 200 MeV incident energies.

38000138
JAEA study on assurance of supply of nuclear fuel
Naoi, Yosuke; Kobayashi, Naoki; Tazaki, Makiko
Proceedings of American Nuclear Society 2009 Annual Meeting (CD-ROM) , p.163-164(2009) ; (JAEA-J 06737)

Assurance of supply (AOS) of nuclear fuel is a special arrangement in case of supply disruptions caused by political reasons other than nonproliferation. It aims to support the stable supply of nuclear fuel while avoiding the spread of sensitive technology of enrichment. Current discussion on the AOS has been initiated by the IAEA DG's article followed by the experts' group report. Since then, various proposals on the AOS have been presented on the discussion table. To facilitate the international discussion of AOS System (the System), authors have been conducted studies of AOS. We focused and based our study on Japanese proposal, "IAEA Standby Arrangement System", setting up the IAEA managed registration system to which supplier states' voluntarily register their supply capacity. Member states are encouraged to register voluntarily the following information to the IAEA, based on the Japanese proposal. (1) Approximate amount of supply of nuclear materials/services, (2) Form and composition of nuclear materials, (3) Approximate lead time for the supply. We redefined the supply assurance steps as "Mode 1 to 3"; compared with "Three Levels" of the "Possible Framework" of the IAEA Director General's Report.

38000139
Compatibility of zirconium alloy with high temperature sodium
Furukawa, Tomohiro; Kato, Shoichi; Maeda, Shigetaka
Proceedings of European Corrosion Congress (EUROCORR 2009) (CD-ROM) , 8p.(2009) ; (JAEA-J 06738)

Application of zirconium alloy as a neutron reflector around the driver fuel region of the Japanese experimental fast reactor JOYO has been planned for a further increase of core average burn-up. In this study, corrosion tests on the zirconium alloy bar were performed for 1000 h at 650 °C and 500 °C in stagnant sodium whose initial dissolved oxygen was 1 ppm. Weight gain caused by high temperature oxidation in sodium was slightly observed on the specimens. The microstructure of the specimens was the same as that of as-received specimen. No dissolution of alloy elements such as Zr, Sn, Cr and Fe into sodium was observed. Ultimate tensile strength of the exposed specimens was the same as that of as-received specimen. In fact, no effect of sodium exposure on mechanical strength was observed.

38000140
Current understanding on radiation chemistry of high temperature and supercritical water
Lin, M.; Katsumura, Yosuke; Muroya, Yusa*; Yamashita, Shinichi
Proceedings of Symposium on Water Chemistry and Corrosion in Nuclear Power Plants in Asia 2009 (CD-ROM) , p.66-70(2009) ; (JAEA-J 06740)

Supercritical water cooled reactor (SCWR) is expected to be one of the most promised next generation reactors (GenIV). Proper water chemistry control, in particular, the injection of H₂ into the coolant to convert O₂ and H₂O₂ into H₂O by radiolytic processes, may represent the key to keep the integrity of the reactors. In recent years, studies on the radiolytic yields and rate constants up to supercritical conditions were performed. The experimental results show that the radiolytic yields at temperatures above 300°C do not follow linear relationship with temperature and there is a very significant density effects under supercritical conditions, especially around t_c. The rate constants of many reactions do not follow linear Arrhenius relationship and there is also strong density dependence under supercritical conditions.

38000141
Rotamer libraries for molecular modeling and design of proteins
Kono, Hidetoshi
Protein Engineering and Design , p.281-292(2009) ; (JAEA-J 06741)

Although the 3D structures of more than 50,000 proteins have been determined and recorded in the Protein Data Bank (PDB) to date (Berman et al. 2000), accurate structural modeling of unknown proteins remains one of the most challenging problems in molecular biology. Modeling the protein structure, which involves determining the optimum side-chain conformations as well as backbone geometry, is important to understand molecular function because the activity of a protein often depends critically on its structure. For example, to understand enzymatic catalysis at a molecular level, one must first understand the structural aspects of the active site, including the elaborate tertiary arrangement of side chain and backbone atoms.

38000142
A Fluorescent micro capsule manufacture of magnetic particle testing for advanced inspection technique of heat exchanger tubes (in Japanese)
Ito, Fuyumi; Nishimura, Akihiko
Nippon Hozen Gakkai Dai-6-Kai Gakujutsu Koenkai Yoshishu , p.551-553(2009) ; (JAEA-J 06743)

Fine magnetic particles having UV fluorescence are commonly used in magnetic crack detection technique. Stress corrosion cracking sometimes happens in nuclear power plants. To apply this technique to maintain the heat exchanger tubes, it is desired that these particles has performance to be collected with ease. To collect these fine magnetic particles from millimeter size crack depth, a chemosynthesis technique to produce the micro capsules successfully produced hundreds micron sized capsules containing the fine magnetic particles. The synthesized micro capsules indicated the collective sensitivity for lines of magnetic force.

38000143
Preliminary investigation on material welding simulation by laser irradiation (in Japanese)
Takase, Kazuyuki; Muramatsu, Toshiharu; Seki, Akiyuki; Kitamura, Tatsuaki*; Machida, Hiromu*
Nippon Kikai Gakkai Netsu Kogaku Konfarensu 2009 Koen Rombunshu , p.217-218(2009) ; (JAEA-J 06744)

38000144
Preliminary assessment of flow stability of once-through steam generator by TRAC-BF1 (in Japanese)
Nakatsuka, Toru; Liu, W.; Yoshida, Hiroyuki; Takase, Kazuyuki
Nippon Kikai Gakkai Netsu Kogaku Konfarensu 2009 Koen Rombunshu , p.269-270(2009) ; (JAEA-J 06745)

To assess the stability of components which comprises parallel channels like steam generators in fast breeder reactors, Japan Atomic Energy Agency has been developing a prediction method for thermal-hydraulic instability based on system analysis code TRAC-BF1. In the present paper, TRAC-BF1 code was modified to simulate both primary and secondary coolant flow with VESSEL component. The calculation model was established and tested with preliminary simulations in which the primary sodium was replaced by high pressure water.

38000145
Characteristics of high angle fractures distributed in granite of MIU (Mizunami Underground Research Laboratory) (in Japanese)
Tagami, Masahiko; Ishida, Hideaki; Tsuruta, Tadahiko
Nippon Oyo Chishitsu Gakkai Heisei-21-Nendo Kenkyu Happyokai Koen Rombunshu , p.175-176(2009) ; (JAEA-J 06746)

Fractures in crystalline rocks have exerted a big influence on the underground water stream. It is necessary to understand the fracture shape and distribution from the viewpoint of the material transfer and the safety construction in designing the geological disposal facilities of the high-level nuclear waste. In this report, we examined the fracture characteristics along the horizontal tunnel which was named -300m Access/Research gallery in Mizunami Underground Research Laboratory. Spring water that exceeded 1000 liters per minute was confirmed in the horizontal boring investigation along the tunnel before gallery excavation. We considered the fracture formation process and the function as the passage of water.

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