JAEA Abstracts

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

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

December 2007

35001663
Recent developments and benchmarking of the PHITS code
Sihver, L.*; Mancusi, D.*; Sato, Tatsuhiko; Niita, Koji*; Iwase, Hiroshi*; Iwamoto, Yosuke; Matsuda, Norihiro; Nakashima, Hiroshi; Sakamoto, Yukio
Advances in Space Research 40(9), p.1320-1331(2007) ; (JAEA-J 03227)

The General-Purpose Particle and Heavy-Ion Transport code System (PHITS) is based on NMTC and MCNP for nucleon/meson and neutron transport respectively; it includes the JAM hadron cascade model for high energy particle-induced reactions and JQMD for nucleus-nucleus collisions; the evaporation and/or fission stage of the reactions is handled by the GEM code. The experimental partial fragmentation cross sections appear to be systematically underestimated by a factor which is independent on the fragment species within the same data set. However, the simulated neutron energy spectra show generally a good agreement with measurements, and so do the attenuation and Bragg curves. These observations stimulate further benchmarking and give directions on possible improvements to be applied to the code in the near future.

35001664
Energetically deep defect centers in vapor-phase grown zinc oxide
Frank, T.*; Pensl, G.*; Tana-Zaera, R.*; Zúñiga-Pérez, J.*; Martínez-Tomás, C.*; Muñoz-Sanjosé, V.*; Oshima, Takeshi; Ito, Hisayoshi; Hofmann, D.*; Pfisterer, D.*; Sann, J.*; Meyer, B.*
Applied Physics A 88(1), p.141-145(2007) ; (JAEA-J 03228)

Deep Level Transient Spectroscopy (DLTS) measurements were carried out to investigate defects in vapor-phase grown ZnO crystals. The generation of defect center labeled E4 subsequent to annealing in different ambients was monitored. By conducting electron irradiations with energies, where either both the Zn- and O-sublattice are damaged or according to only the Zn-lattice, a chemical assignment to the defect centers E4 and E3 could be accomplished. DLTS investigations of ZnO samples under illumination give an evidence that E4 is a negative-U center.

35001665
Photochromism in yttrium hydride
Omura, Ayako*; Machida, Akihiko; Watanuki, Tetsu; Aoki, Katsutoshi; Nakano, Satoshi*; Takemura, Kenichi*
Applied Physics Letters 91(15), p.151904_1-151904_3(2007) ; (JAEA-J 03229)

Transparent orange yttrium hydride turns to black when illuminated by visible laser light at pressures of several gigapascals at room temperature. The marked reduction in optical transmittance extends over the infrared region, suggesting that illumination creates persistent free carriers. The opaque black sample returns to the transparent orange hydride during room-temperature annealing for a few hours. Photochromism is pronounced for the coexistent state of the metallic fcc-YH₂ and the insulating hexagonal-YH₃ state, but is depressed for the single phase of hexagonal-YH₃. The results indicate that light illumination can modify the optical and possibly electronic properties during a certain period of times.

35001666
Calixarene-assisted protein refolding via liquid-liquid extraction
Shimojo, Kojiro; Oshima, Tatsuya*; Naganawa, Hirochika; Goto, Masahiro*
Biomacromolecules 8(10), p.3061-3066(2007) ; (JAEA-J 03230)

We have found that a calix[6]arene acetic acid derivative forms a supramolecular complex with urea-denatured cytochrome c at the oil-water interface, which enables quantitative transfer of the protein from an 8 M urea aqueous solution into an organic phase through a proton-exchange mechanism. Denatured cytochrome c is completely separated from the denaturant, and is isolated from other denatured cytochrome c molecules to suppress the generation of aggregates due to protein-protein interactions. The recovery of cytochrome c from the organic phase is successfully achieved under acidic conditions using an appropriate amount of 1-butanol. UV-visible, CD, and fluorescence spectroscopic characterizations demonstrate that cytochrome c transferred into a denaturant-free aqueous solution regains its native structure. The reduction kinetics of refolded cytochrome c using ascorbic acid indicates that the protein provides approximately 72% of native activity as an electron-transfer protein.

35001667
Calculation of X-ray absorption near edge structure of CeO₂ using a model cluster
Suzuki, Chikashi; Tochio, Tatsunori*
Chemical Physics 340(1-3), p.203-210(2007) ; (JAEA-J 03231)

35001668
Linear comparison of gyrokinetic codes with trapped electrons
Rewoldt, G.*; Lin, Z.*; Idomura, Yasuhiro
Computer Physics Communications 177(10), p.775-780(2007) ; (JAEA-J 03232)

Three codes that solve the gyrokinetic equation in toroidal geometry are compared in the linear limit for the growth rates and real frequencies of the ion temperature gradient (ITG) mode and the trapped electron mode (TEM). The three codes are the gyrokinetic toroidal code (GTC) and GT3D, both of which are radially-global particle-in-cell initial value codes, and FULL, which is a radially-local continuum eigenvalue code. With the same standard input parameters on a reference magnetic surface, the three codes give good agreement for the linear eigenfrequencies, both without (i.e., with adiabatic electron response) and with trapped electrons, as the perpendicular wavenumber and the ion temperature gradient input parameters are varied.

35001669
Mutator alleles of yeast DNA polymerase ζ
Sakamoto, Ayako; Stone, J. E.*; Kissling, G. E.*; McCulloch, S. D.*; Pavlof, Y. I.*; Kunkel, T. A.*
DNA Repair 6(12), p.1829-1838(2007) ; (JAEA-J 03233)

35001670
Development of beam source and bushing for ITER NB system
Inoue, Takashi; Hanada, Masaya; Kashiwagi, Mieko; Taniguchi, Masaki; Tobari, Hiroyuki; Dairaku, Masayuki; Umeda, Naotaka; Watanabe, Kazuhiro; Sakamoto, Keishi; Ikeda, Yoshitaka
Fusion Engineering and Design 82(5-14), p.813-818(2007) ; (JAEA-J 03234)

35001671
The Plasma movie database system for JT-60
Sueoka, Michiharu; Kawamata, Yoichi; Kurihara, Kenichi; Seki, Akiyuki
Fusion Engineering and Design 82(5-14), p.1008-1014(2007) ; (JAEA-J 03235)

A plasma movie is generally expected as one of the most efficient methods to know what plasma discharge has been conducted in the experiment. On this motivation we have developed and operated a real-time plasma shape visualization system over ten years. The current plasma movie is composed of (1) video camera picture looking at a plasma, (2) computer graphic (CG) picture, and (3) magnetic probe signal as a sound channel. In order to use this movie efficiently, we have developed a new plasma movie database system, where a plasma movie is available (downloadable) for experiment data analyses at the Web-site. This new system and its future prospects will be discussed in detals from a technological point of view.

35001672
Engineering design of the ITER invessel neutron monitor using micro-fission chambers
Nishitani, Takeo; Yamauchi, Michinori; Izumi, Mikio*; Hayakawa, Atsuro*; Ebisawa, Katsuyuki*; Kondoh, Takashi; Kusama, Yoshinori
Fusion Engineering and Design 82(5-14), p.1192-1197(2007) ; (JAEA-J 03236)

35001673
Basic analysis of weldability and machinability of structural materials for ITER toroidal field coils
Onozuka, Masanori*; Shimizu, Katsusuke*; Urata, Kazuhiro*; Kimura, Masahiro*; Kadowaki, Hirokazu*; Okamoto, Mamoru*; Nakajima, Hideo; Hamada, Kazuya; Okuno, Kiyoshi
Fusion Engineering and Design 82(5-14), p.1431-1436(2007) ; (JAEA-J 03237)

35001674
Demonstration of full scale JJ1 and 316LN fabrication for ITER TF coil structure
Hamada, Kazuya; Nakajima, Hideo; Kawano, Katsumi; Takano, Katsutoshi; Tsutsumi, Fumiaki; Okuno, Kiyoshi
Fusion Engineering and Design 82(5-14), p.1481-1486(2007) ; (JAEA-J 03238)

35001675
Design of the superconducting coil system in JT-60SA
Tsuchiya, Katsuhiko; Kizu, Kaname; Ando, Toshinari*; Tamai, Hiroshi; Matsukawa, Makoto
Fusion Engineering and Design 82(5-14), p.1519-1525(2007) ; (JAEA-J 03239)

35001676
Structural design of ferritic steel tiles for ripple reduction of toroidal magnetic field in JT-60U
Shibama, Yusuke; Arai, Takashi; Miyo, Yasuhiko; Sawai, Tomotsugu; Sakurai, Shinji; Masaki, Kei; Suzuki, Yutaka; Jitsukawa, Shiro; Miya, Naoyuki
Fusion Engineering and Design 82(15-24), p.2462-2470(2007) ; (JAEA-J 03240)

The structural design of the tile as a ripple reduction for toroidal magnetic field in JT-60U was outlined. 8Cr-2W-0.2V ferritic steel plates were fabricated and mechanical and vacuum properties were evaluated to assess the design conditions. Tensile properties were uniform in yield and tensile strength at ambient temperature and sufficient strength as the structural integrity at operational temperature of 423 K and 573 K. Vacuum property was measured with the baking at 473 K and similar to the conventional stainless steel but not satisfy the JT-60 standard of the in-situ material of the vacuum vessel. The ferritic steel was judged as an installable because of that the JT-60 baking temperature is 573 K higher than this test temperature of 473 K, and of that residual out-gassing was hydrogen which was the fuel of the operational plasma.

35001677
Measurement of free surface of liquid metal lithium jet for IFMIF target
Kondo, Hiroo*; Kanemura, Takuji*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; Horiike, Hiroshi*
Fusion Engineering and Design 82(15-24), p.2483-2489(2007) ; (JAEA-J 03241)

Lithium flow experiments were conducted for International Fusion Materials Irradiation Facility (IFMIF) at Osaka University. In the experiment, Li plane jet of 10 mm in depth and 70 mm in width formed by a two contractions nozzle was tested in the velocity range of less than 15 m/s. In the present report, Li surface measurement by pattern projection method was tested. This is a three dimensional image measurement, where stripe patterns are projected onto the flow surface without touching it. The projected patterns were observed to be deformed according to the surface up- and- down. Three-dimensional surface shape could be obtained by analyzing the deformed patterns. By the method, shapes of wave pattern called surface wakes were successfully measured. The surface wakes were observed to be formed from the nozzle edge. It was found that the nozzle edge was damaged and became serrated after lithium flowing of 1,300 hours at this moment.

35001678
Estimation and control of beryllium-7 behavior in liquid lithium loop of IFMIF
Ida, Mizuho; Nakamura, Hiroo; Sugimoto, Masayoshi
Fusion Engineering and Design 82(15-24), p.2490-2496(2007) ; (JAEA-J 03242)

35001679
Investigation of free-surface fluctuations of liquid lithium flow for IFMIF lithium target by using an electro-contact probe
Kanemura, Takuji*; Kondo, Hiroo*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; Horiike, Hiroshi*
Fusion Engineering and Design 82(15-24), p.2550-2557(2007) ; (JAEA-J 03243)

For a study on characteristics of lithium target flow of International Fusion Materials Irradiation Facility (IFMIF), experiments were carried out by using a lithium loop at Osaka University. In the experiment, fluctuations of a free surface of the horizontal flow were directly measured by using an electro-contact probe acquiring condition of contact/non-contact of the probe with the flow surface as voltage data. Vertical location of the probe tip was set by 0.1 mm step. Horizontal location of the probe was 175 mm downstream from the nozzle exit, corresponding to the footprint of deuteron beam in the IFMIF case. It was found that the maximum amplitude of the surface wave, including rarely arising ones, was 2.2 mm at the center of the flow channel with width of 70 mm at the maximum flow velocity of 15 m/s. The average thickness of the flow was found to be 10.13 mm.

35001680
Design of a lip seal-replaceable backwall for IFMIF liquid lithium target
Nakamura, Hiroo; Ida, Mizuho; Chida, Teruo; Furuya, Kazuyuki*; Sugimoto, Masayoshi
Fusion Engineering and Design 82(15-24), p.2671-2676(2007) ; (JAEA-J 03244)

35001681
Impact of N-isotope composition control of ferritic steel on classification of radioactive materials from fusion reactor
Hayashi, Takao; Kasada, Ryuta*; Tobita, Kenji; Nishio, Satoshi; Sawai, Tomotsugu; Tanigawa, Hiroyasu; Jitsukawa, Shiro
Fusion Engineering and Design 82(15-24), p.2850-2855(2007) ; (JAEA-J 03245)

The impact of increasing the enrichment of ¹⁵N in low activation ferritic steel, F82H, of a fusion reactor has been investigated in order to increase the fraction of low level material (LLM), which can be disposed by shallow land burial. Carbon-14, mainly produced from nitrogen, is one of the most critical nuclei for qualifying as a LLM. The concentration of nitrogen in F82H is 200 ppm in the calculations. The enrichment of ¹⁵N was varied from natural abundance of 0.37% to 95%. The concentration of ¹⁴C at the outboard first wall decreased from 7.8 × 10⁴ to 3.2 × 10⁴ Bq/g by enriching ¹⁵N, which is lower than the ¹⁴C regulation (3.7 × 10⁴ Bq/g) for LLM in Japan. In the permanent blanket, the highest ¹⁴C concentration with 95% ¹⁵N enriched nitrogen was 1.0 × 10⁴ Bq/g. The ¹⁴C concentration on the inboard side was lower than the outboard side. Therefore, with regard to the ¹⁴C concentration, the F82H used in the inboard and outboard blankets can qualify as a LLM by enriching ¹⁵N.

35001682
Overview of recent Japanese activities and plans in fusion technology
Yamamoto, Ichiro*; Nishitani, Takeo; Sagara, Akio*
Fusion Science and Technology 52(3), p.347-356(2007) ; (JAEA-J 03246)

35001683
Simultaneous proton and X-ray imaging with femtosecond intense laser driven plasma source
Orimo, Satoshi; Nishiuchi, Mamiko; Daido, Hiroyuki; Yogo, Akifumi; Ogura, Koichi; Sagisaka, Akito; Li, Z.*; Pirozhkov, A. S.; Mori, Michiaki; Kiriyama, Hiromitsu; Kanazawa, Shuhei; Kondo, Shuji; Yamamoto, Yoichi*; Shimomura, Takuya*; Tanoue, Manabu*; Nakai, Yoshiki; Akutsu, Atsushi; Nakamura, Shu*; Shirai, Toshiyuki*; Iwashita, Yoshihisa*; Noda, Akira*; Oishi, Yuji*; Nemoto, Koshichi*; Choi, I. W.*; Yu, T. J.*; Sung, J. H.*; Jeong, T. M.*; Kim, H. T.*; Hong, K.-H.*; Noh, Y.-C.*; Ko, D.-K.*; Lee, J.*
Japanese Journal of Applied Physics, Part 1 46(9A), p.5853-5858(2007) ; (JAEA-J 03247)

A laser-driven proton beam with a maximum energy of a few MeV is stably obtained using an ultra-short and high-intensity Titanium Sapphire laser. At the same time, keV X-ray is also generated at almost the same place where protons are emitted. Here, we show the successful demonstration of simultaneous proton and X-ray projection images of a test sample placed close to the source with a resolution of ˜10μm, which is determined from the source sizes. Although the experimental configuration is very simple, the simultaneity is better than a few hundreds of ps. A CR-39 track detector and imaging plate, which are placed as close as possible to the CR-39, are used as detectors of protons and X-ray. The technique is applicable to the precise observation of microstructures.

35001684
Gasochromic properties of nanostructured tungsten oxide films prepared by sputtering deposition
Takano, Katsuyoshi; Inoue, Aichi; Yamamoto, Shunya; Sugimoto, Masaki; Yoshikawa, Masahito; Nagata, Shinji*
Japanese Journal of Applied Physics, Part 1 46(9B), p.6315-6318(2007) ; (JAEA-J 03248)

The amorphous, polycrystalline, and oriented films of the tungsten oxide were fabricated by sputtering deposition. It is found that each film has different roughness in the surface. The films with rough surface show fast coloration in 1% hydrogen. There is possibility that the gasochromic properties are improved effectively by the control of the surface morphology, and the films with large grains on the surface have better gasochromic coloration.

35001685
Hydration properties of magnesium and calcium ions from constrained first principles molecular dynamics
Ikeda, Takashi; Boero, M.*; Terakura, Kiyoyuki*
Journal of Chemical Physics 127(7), p.074503_1-074503_8(2007) ; (JAEA-J 03249)

We studied the solvation structures of the divalent metal cations Mg²⁺ and Ca²⁺ in ambient water by applying a Car-Parrinello-based constrained molecular dynamics method. By employing the metal-water oxygen coordination number as a reaction coordinate, we could identify distinct aqua complexes characterized by structural variations of the first coordination shell. In particular, our estimated free-energy profile clearly shows that the global minimum for Mg²⁺ is represented by a rather stable six-fold coordination in the octahedral arrangement, in agreement with experiments. Conversely, for Ca²⁺ the free-energy curve shows several shallow local minima, suggesting that the hydration structure of Ca²⁺ is highly variable. Implications for water exchange reactions are also discussed.

35001686
Distribution of plutonium isotopes and ¹³⁷Cs found in the surface soils of Nagasaki, Japan
Kokubu, Yoko; Yasuda, Kenichiro; Magara, Masaaki; Miyamoto, Yutaka; Sakurai, Satoshi; Usuda, Shigekazu; Yamazaki, Hideo*; Mitamura, Muneki*; Yoshikawa, Shusaku*
Journal of Geosciences, Osaka City University 50, p.7-13(2007) ; (JAEA-J 03250)

35001687
Design challenges for sodium cooled fast reactors
Konomura, Mamoru; Ichimiya, Masakazu
Journal of Nuclear Materials 371(1-3), p.250-269(2007) ; (JAEA-J 03251)

35001688
Development of 300°C heat resistant boron-loaded resin for neutron shielding
Morioka, Atsuhiko; Sakurai, Shinji; Okuno, Koichi*; Sato, Satoshi; Verzirov, Y. M.; Kaminaga, Atsushi; Nishitani, Takeo; Tamai, Hiroshi; Shibama, Yusuke; Yoshida, Shigeru*; Matsukawa, Makoto
Journal of Nuclear Materials 367-370(2), p.1085-1089(2007) ; (JAEA-J 03252)

A 300°C heat-resistant neutron shielding material is newly developed, which consists of phenol-based resin with 6 weight-% boron. The neutron shielding performance of the developed resin, examined by the ²⁵²Cf neutron source, is almost the same as that of the polyethylene. The neutron shielding characteristic was also estimated by 3D Monte Carlo Code MCNP-4C2 using the continuous energy cross section data sets based on the JENDL-3.2. The calculation result agrees well with the experimental result. To understand the kinds of the outgas from the developed resin in the high temperature region, the mass spectrum of the outgas was measured until ˜300°C by Thermal Desorption Specroscopy (TDS). The observed mass number was 2, 17, 18, 28, 32, and 44. The number corresponds to hydrogen (H₂), ammonia (NH₃), water (H₂O), carbon monoxide (CO), oxygen (O₂), carbon dioxide (CO₂), respectively. The main outgas component from the resin at 100˜150°C was NH ₃ and H₂O. The outgas of NH₃ and H₂O from the resin have been measured, however, the neutron shielding performance of the resin after 200°C baking was almost the same as that before baking. The quantitative analysis of the outgas from the resin in the high temperature region was done by the Temperature Programmed Desorption (TPD) / Gas Chromatography and Mass spectrometry (GC/MS). The 13 kinds of organic gases have been observed by the amount of μg/g at 300°C. The neutron shielding performance of the developed resin at 300°C was simulated by the 3D analysis. The resonance cross section of the nucleus is broad at the high temperature region by the Doppler effect. The calculation results using 327°C library and 20°C library are almost same.

35001689
Ferroelectric polarization and magnetic structure in Eu_0.595Y_0.405MnO₃
Kajimoto, Ryoichi; Yokoo, Tetsuya*; Kofu, Maiko*; Noda, Kohei*; Kuwahara, Hideki*
Journal of Physics and Chemistry of Solids 68(11), p.2087-2090(2007) ; (JAEA-J 03253)

Eu_0.595Y_0.405MnO₃ shows an antiferromagnetic transition below T_N = 47K. A spontaneous ferroelectric polarization P along c appears below T_C^c = 25K. The direction of P then switches to a below T_C^a = 23K. To investigate the relation between P and the magnetic structure (MS), we have performed a neutron diffraction study using EXCED diffractometer installed at KENS spallation neutron facility of KEK. Magnetic Bragg peaks with a wave vector (0,0.31,1) were observed. By comparing a magnetic Bragg peak whose scattering vector Q is almost parallel to b and that with Q almost parallel to c, we have succeeded in observing the change of the MS at the temperature (T) where P appears and at T where P changes its polarization direction. Our observations can be interpreted as formation of a spiral spin structure and change of its easy plane in response to the change of the dielectric properties.

35001690
Microscopic magnetic property of perpendicular magnetic films of Dy_xCo_100-x measured using soft X-ray magnetic circular dichroism
Agui, Akane; Mizumaki, Masaichiro*; Asahi, Toru*; Matsumoto, Koji*; Morikawa, Tsuyoshi*; Sayama, Junichi*; Osaka, Tetsuya*
Journal of Physics and Chemistry of Solids 68(11), p.2148-2152(2007) ; (JAEA-J 03254)

35001691
Instrumental design and expected performance of coupled-moderator near-backscattering spectrometer at J-PARC
Takahashi, Nobuaki; Shibata, Kaoru; Sato, Taku*; Tamura, Itaru; Kajimoto, Ryoichi; Harjo, S.; Oikawa, Kenichi; Arai, Masatoshi; Mezei, F.*
Journal of Physics and Chemistry of Solids 68(11), p.2199-2203(2007) ; (JAEA-J 03255)

A near-backscattering crystal-analyzer neutron inelastic spectrometer, DIANA has been proposed to construct at Materials and Life Science Facility (MLF) of Japan Proton Accelerator Research Complex (J-PARC). It has firstly been designed to see a decoupled non-poisoned moderator in order to obtain higher intensity and better energy resolution. In deed, the decoupled moderator has a narrower pulse width than a coupled moderator, and so it will give us a better energy resolution. However, the peak neutron flux of the decoupled moderator has only a half of the coupled moderator. In order to decide the best choice of this type of near-backscattering instruments, we have reconsidered instrumental parameters including the type of moderators. We have performed Monte-Carlo neutron ray-tracing simulations, using McStas and have compared these results in various viewpoints such as intensities, resolutions, shape of resolution functions, scan ranges and so on.

35001692
Self-assembly of synthetic cellulose during in-vitro enzymatic polymerization process as studied by a combined small-angle scattering method
Tanaka, Hirokazu*; Koizumi, Satoshi; Hashimoto, Takeji; Kurosaki, Kazuhiro*; Kobayashi, Shiro*
Macromolecules 40(17), p.6304-6315(2007) ; (JAEA-J 03256)

We have investigated the self-assembling process of cellulose artificially synthesized via enzymatic polymerization as one of general problems of non-equilibrium phenomenon and pattern formation. The chemical reaction and the self-assembling process were explored at real time and in-situ by a combined small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), ultra-SANS and ultra-SAXS method, together with wide-angle X-ray diffraction and field-emission scanning electron microscopy. The results revealed for the first time the following pieces of new evidence: (1) The enzymes (cellulase) as a catalyst aggregate themselves into associations; (2) Cellulose molecules created at each active site of enzymes associate themselves around the enzyme associations into cellulose aggregates having surface fractal dimensions Ds, increasing from 2 to 2.3 with reaction time. (3) The fractal structure formed at the end of the reaction extends over a surprisingly wide length scale ranging from 30 nm to 30 μm (3 orders of magnitude).

35001693
The Result of a wall failure in-pile experiment under the EAGLE project
Konishi, Kensuke; Toyooka, Junichi; Kamiyama, Kenji; Sato, Ikken; Kubo, Shigenobu*; Kotake, Shoji*; Koyama, Kazuya*; Vurim, A. D.*; Gaidaichuk, V. A.*; Pakhnits, A. V.*; Vassiliev, Y. S.*
Nuclear Engineering and Design 237(22), p.2165-2174(2007) ; (JAEA-J 03257)

The WF (Wall Failure) test of the EAGLE program, in which ˜2kg of uranium dioxide fuel-pins were melted by nuclear heating, was successfully conducted in the IGR of NNC/Kazakhstan. In this test, a 3mm-thick stainless steel (SS) wall structure was placed between fuel pins and a 10mm-thick sodium-filled channel (sodium gap). During the transient, fuel pins were heated, which led to the formation of a fuel-steel mixture pool. Under the transient nuclear heating condition, the SS wall was strongly heated by the molten pool, leading to wall failure. The time needed for fuel penetration into the sodium-filled gap was very short (less than 1 second after the pool formation). The result suggests that molten core materials formed in hypothetical LMFBR core disruptive accidents have a certain potential to destroy SS-wall boundaries early in the accident phase, thereby providing fuel escape paths from the core region. The early establishment of such fuel escape paths is regarded as a favorable characteristic in eliminating the possibility of severe re-criticality events.

35001694
Overview of JT-60U results for the development of a steady-state advanced tokamak scenario
Takenaga, Hidenobu; JT-60 Team
Nuclear Fusion 47(10), p.S563-S578(2007) ; (JAEA-J 03258)

Recent JT-60U experimental results towards development of a steady-state advanced tokamak scenario are presented. In order to reduce a toroidal magnetic field ripple, ferritic steel tiles (FSTs) are installed inside the vacuum vessel. The installation of FSTs decreases the fast ion loss and consequently enables to access high β regime in the large volume configuration close to the wall, which had so far suffered from the large toroidal filed ripple. High β_N (˜ 4.2) exceeding the no wall ideal limit is achieved by using wall stabilization effect. Small critical rotation velocity about 0.3% of Alfvén velocity is found for suppressing resistive wall mode, which is destabilized in the high β_N region above the no wall ideal limit. High β_N. HH_98(y,2) of 2.2 with β_N ˜ 2.3 and HH_98(y,2) ˜ 1 is sustained for 23.1 s significantly longer than the current diffusion time (˜ 12τ_R). The studies on understanding of self-regulating system with a high bootstrap current fraction of f_BS ˜ 0.7-1 and real time current profile control with Motional Stark Effect (MSE) diagnostics and Lower Hybrid wave Current Drive (LHCD) are also progressed.

35001695
Experimental progress on zonal flow physics in toroidal plasmas
Fujisawa, Akihide*; Ido, Takeshi*; Shimizu, Akihiro*; Okamura, Shoichi*; Matsuoka, Keisuke*; Iguchi, Harukazu*; Hamada, Yasuji*; Nakano, Haruhisa*; Oshima, Shinsuke*; Ito, Kimitaka*; Hoshino, Katsumichi; Shinohara, Koji; Miura, Yukitoshi; Nagashima, Yoshihiko*; Ito, Sanae*; Shats, M.*; Xia, H.*; Dong, J. Q.*; Yan, L. W.*; Zhao, K. J.*; Conway, G. D.*; Stroth, U.*; Melnikov, A. V.*; Eliseev, L. G.*; Lysenko, S. E.*; Perfilov, S. V.*; Hidalgo, C.*; Tynan, G. R.*; Holland, C.*; Diamond, P. H.*; Mckee, G. R.*; Fonck, R. J.*; Gupta, D. K.*; Schoch, P. M.*
Nuclear Fusion 47(10), p.S718-S726(2007) ; (JAEA-J 03259)

Present status of experiments on zonal flows is overviewed. Innovative use of modern diagnostics has revealed the existence of zonal flows, their spatio-temporal characteristics, their relationship with turbulence, and their effects on confinement. Particularly a number of observations have been accumulated on the oscillatory branch of the zonal flow, dubbed as geodesic acoustic modes suggesting necessity of theories to give their proper description. Several new methods have elucidated the zonal flow generation processes from the turbulence. Further investigation of relationship between the zonal flows and confinement is strongly encouraged as cross-device activity.

35001696
Reevaluation of experimental data and analysis on experimental fast reactor JOYO MK-I performance tests
Yokoyama, Kenji; Shono, Akira*; Ishikawa, Makoto
Nuclear Science and Engineering 157(3), p.249-263(2007) ; (JAEA-J 03260)

Experimental data acquired in the experimental fast reactor JOYO MK-I performance tests in the late 1970s have been revaluated and analyzed with a nuclear analysis system for fast reactors used in Japan Atomic Energy Agency (JAEA). For the purpose of improving the prediction accuracy of nuclear characteristics, nominal values and uncertainties of the experimental data were revaluated by using knowledge obtained after the MK-I performance test and calculation results based on the latest reactor physics analysis methods. All the nominal values were corrected by using a formulation of control rod interaction effects proposed in the present paper, and all the possible uncertainty factors were evaluated and quantified. The analysis results agreed well with measured values within the experimental and nuclear-induced uncertainties for all the nuclear characteristics of the criticality, control rod worth sodium void reactivity, fuel replacement reactivity and isothermal temperature coefficient.

35001697
Feasibility of designing the encapsulated nuclear heat source reactor with negative void reactivity feedback
Okawa, Tsuyoshi; Greenspan, E.*
Nuclear Technology 160(3), p.257-278(2007) ; (JAEA-J 03261)

Since all the ENHS (Encapsulated Nuclear Heat Source) cores designed so far have positive coolant void reactivity, the ENHS reactor core was investigated to have a negative coolant void reactivity feedback.

35001698
Development of a single-crystal X-ray diffraction system for hydrostatic-pressure and low-temperature structural measurement and its application to the phase study of quasicrystals
Watanuki, Tetsu; Machida, Akihiko; Ikeda, Tomohiro*; Omura, Ayako*; Kaneko, Hiroshi; Aoki, Katsutoshi; Sato, Taku*; Tsai, A. P.*
Philosophical Magazine 87(18-21), p.2905-2911(2007) ; (JAEA-J 03262)

We have constructed a single-crystal synchrotron X-ray diffraction system to precisely study the structure under hydrostatic pressure conditions at low temperatures and applied it to a study on the phase transition phenomena of a Cd-Yb periodic approximant and a Cd-Yb quasicrystal. Four phases were newly observed for the 1/1 approximant crystal in a P-T span up to 5.2 GPa and down to 10 K. The innermost part of the atomic clusters of Cd₄ tetrahedra exhibited various orientational ordering sensitively depending on pressure and temperature. High pressure diffraction measurements using a highly parallel synchrotron X-ray beam and a hydrostatically compressed single crystal enabled us to detect the weak diffractions due to the subtle structural changes.

35001699
Muon spin rotation measurements of the superfluid density in fresh and aged superconducting PuCoGa₅
Oishi, Kazuki; Heffner, R. H.; Morris, G. D.*; Bauer, E. D.*; Graf, M. J.*; Zhu, J.-X.*; Morales, L. A.*; Sarrao, J. L.*; Fluss, M. J.*; MacLaughlin, D. E.*; Shu, L.*; Higemoto, Wataru; Ito, Takashi
Physical Review B 76(6), p.064504_1-064504_10(2007) ; (JAEA-J 03263)

We have measured the temperature dependence and magnitude of the superfluid density ρ_s(T) via the magnetic field penetration depth λ(T) in PuCoGa₅ using the muon spin rotation technique in order to investigate the symmetry of the order parameter, and to study the effects of aging on the superconducting properties of a radioactive material. The same single crystals were measured after 25 days (T_c = 18.25 K) and 400 days (T_c = 15.0 K) of aging at room temperature. The temperature dependence of the superfluid density is well described in both materials by a model using d-wave gap symmetry. Within the context of a strong-coupling, dirty d-wave model, a zero-temperature gap value Δ₀ = 3.0k_BT_c0 is obtained in the fresh sample for a scattering rate Γ=0.005 π k_BT_c0, which is consistent with Abrikosov-Gor'kov (AG) pair-breaking theory. In the aged sample the same model yields Δ₀ = 2.4k_BT_c0 for Γ=0.010 π k_BT_c0. This value of Γ is much less than required by the AG pair-breaking formalism. Furthermore, the aged ρ_s(0) is reduced by at least 70% compared to the fresh sample, which is also incompatible with Δ T_c/T_c0 ˜ 20%, according to AG theory. We conclude that the data in aged PuCoGa₅ support the postulate that the scattering from radiation-induced defects is not in the limit of the AG theory of an order parameter which is spatially averaged over impurity sites, but rather in the limit of short-coherence-length superconductivity.

35001700
Structural relations between two ground states of NaV₂O₅ under high pressure; A Synchrotron X-ray diffraction study
Owada, Kenji; Fujii, Yasuhiko; Muraoka, Jiro*; Nakao, Hironori*; Murakami, Yoichi; Noda, Yukio*; Osumi, Hiroyuki*; Ikeda, Naoshi*; Shobu, Takahisa; Isobe, Masahiko*; Ueda, Yutaka*
Physical Review B 76(9), p.094113_1-094113_10(2007) ; (JAEA-J 03264)

Structural relations between two ground states of the ANNNI (Axial Next Nearest Neighbor Ising) compound NaV₂O₅, C_1/4- and C₀-phases below and above the transition pressure P_C = 1 GPa, were investigated by X-ray diffraction and scattering techniques. The structure of the C₀-phase is well explained by the A(A') pattern which is one of four layers (AAA'A') of the C_1/4-phase, however, the amount of the atomic shifts under the conditions 1.6 GPa and 6 K is 27 % that under ambient pressure. On the other hand, resonant X-ray scattering showed that the charges are disproportionated under high pressure. Based on these facts, it was concluded that charge disproportionation corresponds to the Ising variable in NaV₂O₅, where the atomic shifts are regarded as linearly coupled to the Ising spins. These results lead to the hypothesis that the competitive interactions between the Ising spins may result from the Ising spin-phonon coupling.

35001701
Intermittent transport associated with the geodesic acoustic mode near the critical gradient regime
Miki, Kazuhiro*; Kishimoto, Yasuaki; Miyato, Naoaki; Li, J. Q.*
Physical Review Letters 99(14), p.145003_1-145003_4(2007) ; (JAEA-J 03265)

Turbulent transport near critical gradient in toroidal plasmas is studied based on global Landau-fluid simulations and an extended predator-prey theoretical model of ion temperature gradient (ITG) turbulence. A new type of intermittent transport associated with the emission and propagation of geodesic acoustic mode (GAM) is found near critical gradient regime, which is referred to GAM intermittency. The intermittency is characterized by new time scales of trigger, damping, and recursion due to GAM damping. During the recursion of intermittent bursts, stationary zonal flow increases with a slow time scale due to the accumulation of undamped residues and eventually quenches the turbulence, suggesting that a nonlinear up-shift of critical gradient, i.e. Dimits shift, is established through such a dynamical process.

35001702
Uniformization of the transverse beam profile by means of nonlinear focusing method
Yuri, Yosuke; Miyawaki, Nobumasa; Kamiya, Tomihiro; Yokota, Wataru; Arakawa, Kazuo; Fukuda, Mitsuhiro*
Physical Review Special Topics; Accelerators and Beams 10(10), p.104001_1-104001_11(2007) ; (JAEA-J 03266)

Transformation of the transverse beam profile using nonlinear focusing forces produced by multipole magnets is studied theoretically. The strength of the nonlinear magnetic forces required for beam uniformization in a beam transport system is presented. The validity of the presented formulae is confirmed through particle-tracking simulations. It is also demonstrated that, at the Japan Atomic Energy Agency azimuthally-varying field cyclotron facility, the beam whose uniform region is 10 cm × 10 cm and uniformity is several percent can be established on a target in the beam transport system that includes a pair of octupole magnets.

35001703
Heat suppresses activation of an auxin-responsive promoter in cultured guard cell protoplasts of tree tobacco
Dong, M. A.*; Bufford, J. L.*; Ono, Yutaka; Church, K.*; Dau, M. Q.*; Michels, K.*; Haughton, M.*; Tallman, G.*
Plant Physiology 145(2), p.367-377(2007) ; (JAEA-J 03267)

Cultured guard cell protoplasts (GCP) of Nicotiana glauca, tree tobacco, comprise a novel system for investigating the cell signaling mechanisms that lead to acquired thermotolerance and thermoinhibition. At 32 °C in a medium containing an auxin and a cytokinin, GCP expand, regenerate cell walls, dedifferentiate, and divide. At 38 °C, GCP acquire thermotolerance, but their expansion is limited and they neither regenerate walls nor re-enter the cell cycle. Protoplasts were transformed with the fusion gene of BA auxin-responsive promoter and green fluorescent protein (GFP) gene. Heat suppressed auxin-mediated activation of BA. Heat-stressed cells accumulate reactive oxygen species, and H₂O₂ suppresses auxin-responsive promoter activation. H₂O₂ did not suppress BA activation at 32 °C, nor did superoxide and H₂O₂ scavengers prevent BA suppression at 38 °C.

35001704
Escaping ion measurement with high time resolution during bursting modes induced by neutral beam injection on CHS
Shinohara, Koji; Isobe, Mitsutaka*; Darrow, D. S.*; Shimizu, Akihiro*; Nagaoka, Kenichi*; Okamura, Shoichi*
Plasma and Fusion Research (Internet) 2, p.042_1-042_8(2007) ; (JAEA-J 03268)

A scintillator-based lost ion probe can measure the temporal evolution of both the gyro-radius and the pitch angle of energetic ions escaping a magnetically-confined plasma. On this system, the time resolution of the detailed two-dimensional (2D) measurement is determined by a framing rate of the video camera that records the luminous images produced by the ions striking the scintillator plate. By installing an image-intensified high-speed video camera system, the temporal resolution was improved from about 33 ms to 0.07 ms. We have successfully captured some new fast features caused by bursting modes, whose time scale is a few milli-second, induced by a neutral beam injection.

35001705
Numerical simulation of electron cyclotron current drive in magnetic islands of neo-classical tearing mode
Hamamatsu, Kiyotaka; Takizuka, Tomonori; Hayashi, Nobuhiko; Ozeki, Takahisa
Plasma Physics and Controlled Fusion 49(12), p.1955-1969(2007) ; (JAEA-J 03269)

35001706
Application of Inductively coupled plasma Mass Spectrometry to the determination of uranium isotope ratios in individual particles for nuclear safeguards
Zhang, X. Z.*; Esaka, Fumitaka; Esaka, Konomi; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Watanabe, Kazuo
Spectrochimica Acta, Part B 62(10), p.1130-1134(2007) ; (JAEA-J 03270)

The capability of inductively coupled plasma mass spectrometry (ICP-MS) for the determination of uranium isotope ratios in individual particles was determined. For this purpose, we developed an experimental procedure including single particle transfer with a manipulator, chemical dissolution and isotope ratio analysis. As the result, the ²³⁵U/²³⁸U isotope ratio for the particle with the diameter between 0.5 and 3.9 μm was successfully determined with the deviation from the certified ratio within 1.8%. The developed procedure was successfully applied to the analysis of a simulated environmental sample prepared from a mixture of indoor dust (NIST SRM 2583) and uranium particles (NBL CRM U050, U350 and U950a). From the results, the proposed procedure was found to be an alternative analytical tool for nuclear safeguards.

35001707
Structural analysis of Si(111)-√21×√21-(Ag,Au) surface by using reflection high-energy positron diffraction
Fukaya, Yuki; Kawasuso, Atsuo; Ichimiya, Ayahiko
Surface Science 601(22), p.5187-5191(2007) ; (JAEA-J 03271)

35001708
Surface structure of In/Si(111) studied by reflection high-energy positron diffraction
Hashimoto, Mie; Fukaya, Yuki; Kawasuso, Atsuo; Ichimiya, Ayahiko
Surface Science 601(22), p.5192-5194(2007) ; (JAEA-J 03272)

35001709
Preparation and properties of CMC gel
Takigami, Machiko*; Amada, Haruyo*; Nagasawa, Naotsugu; Yagi, Toshiaki; Kasahara, Takamitsu*; Takigami, Shoji*; Tamada, Masao
Transactions of the Materials Research Society of Japan 32(3), p.713-716(2007) ; (JAEA-J 03273)

Carboxymethylcellulose (CMC) gel was formed by addition of acid to CMC (CMC-acid gel). Gel fraction (weight of insoluble part/initial CMC weight) was calculated after removing uncrosslinked CMC by immersing the CMC-acid gel in water. It increased with acid concentration. Mechanism of CMC-acid gel formation was elucidated by aggregation of CMC molecules as the result of replacement of sodium in carboxyl group with hydrogen. Gels could be prepared by three different procedures; (1) mixing CMC and acid, (2) immersion of CMC or γ-irradiated CMC pastes in acid, and (3) γ-irradiation of CMC-acid gel. Gels with different elasticity and hardness were prepared changing degree of substitution of CMC, molar mass of CMC, species of acid, concentrations of acid and CMC, and application of γ-irradiation.

35001710
Current status and evolution of nuclear fusion development; Aiming at the achievement of the nuclear fusion energy (in Japanese)
Araki, Masanori; Kamada, Yutaka; Mori, Masahiro; Nishitani, Takeo
Denki Hyoron 92(10), p.38-44(2007) ; (JAEA-J 03274)

A general view of the current status and evolution of nuclear fusion research and development in JAEA is reviewed. Concretely, the outline is shown about the fruitful results of research that are obtaining mainly on an experimental device JT-60 concisely, and the international thermonuclear experimental reactor ITER project (design and technical R&D activities, and details for construction) as well as a Broader Approach Activities for aiming at the achievement of a DEMO reactor and of a nuclear fusion energy.

35001711
Real-time stress measurement in Ge/Si(111)-7×7 heteroepitaxial growth (in Japanese)
Asaoka, Hidehito; Yamazaki, Tatsuya; Shamoto, Shinichi; Arnoldo, A.*; Goto, Seiichi*; Suemitsu, Maki*
Hyomen Kagaku 28(9), p.500-503(2007) ; (JAEA-J 03275)

Stress evolution during initial stage of Ge nanodot formation on Si(111)-7×7 has been investigated by using simultaneous measurements of the substrate curvature and the surface morphology. In the beginning of the first bilayer growth of Ge on Si(111)-7×7, a strong compressive film stress is observed, indicating a formation of a two-dimensional wetting layer. When the layer thickness approaches the critical one for three-dimensional nanodot nucleation, a clear bend in the stress curve is observed, corresponding to a partial relaxation of the lattice planes on the surface of the nanodots. Moreover, a stress transition has been also found to exist in the very early stage of the nanodot formation, which is concurrent with the trench formation around the three-dimensional nanodots.

35001712
Altitude, area and time dependences of cosmic-ray dose rates in the atmosphere (in Japanese)
Sato, Tatsuhiko
Isotope News (641), p.9-13(2007) ; (JAEA-J 03276)

We analyzed the altitude, area and time dependences of cosmic-ray dose rates in the atmosphere, using our developed cosmic-ray spectrum calculation model PARMA. This report summarizes the results of the analysis.

35001713
Neutron irradiation effects on ¹¹B₄C and recovery by annealing (in Japanese)
Donomae, Takako; Tachi, Yoshiaki; Sekine, Manabu*; Morohashi, Yuko; Akasaka, Naoaki; Onose, Shoji
Journal of the Ceramic Society of Japan 115(1345), p.551-555(2007) ; (JAEA-J 03278)

Use of moderator materials in Fast Breeder Reactor (FBR) is effective for transmutation technology, and ¹¹B₄C is one of the candidates. Up to now, the behavior of ¹⁰B₄C as the Control rod material is well known, but that of ¹¹B₄C is hardly investigated. In this paper, the radiation effects of ¹¹B₄C pellets, neutron irradiated in the experimental fast reactor JOYO were studied. From the experimental results, it was observed that no macro-cracks were recognized in the irradiated ¹¹B₄C pellets. But, bubble nucleation was found in grain and along grain boundaries of ¹¹B₄C. And, it was shown that the conductivity of ¹¹B₄C was higher than that of ¹⁰B₄C. During the annealing from room temperature to 1400°C, three recovery stages were found on thermal conductivity. It was suggested that, the recovery of B₄C was related to the dispersion behavior of helium. Judging from these results, as ¹¹B₄C was mechanically more stable compared with ¹⁰B₄C under irradiation, it was shown that ¹¹B₄C had high applicability for a moderator.

35001714
Fast breeder reactor (in Japanese)
Sato, Koji
Karyoku Genshiryoku Hatsuden 58(10), p.1011-1028(2007) ; (JAEA-J 03280)

Details, current status and future plans for research and development of the fast breeder reactor (FBR) technology in Japan are introduced including a related fuel cycle and an international trend and the international cooperation on FBR cycle technology.

35001715
High-temperature gas-cooled reactors (in Japanese)
Ogawa, Masuro; Hino, Ryutaro; Kunitomi, Kazuhiko; Sato, Hiroyuki
Karyoku Genshiryoku Hatsuden 58(10), p.1029-1037(2007) ; (JAEA-J 03281)

High temperature gas reactors (HTGRs) are expected to expand the application field of the nuclear energy. This report describes the salient features of the HTGRs such as various heat utilization, excellent safety features, high efficiency, high burn-up, etc. Also, development status of the HTGRs in the world was described.

35001716
Nuclear fusion (in Japanese)
Ninomiya, Hiromasa
Karyoku Genshiryoku Hatsuden 58(10), p.1038-1046(2007) ; (JAEA-J 03282)

35001717
Holocene faulting on the Yugamine fault of the Atera fault zone, central Japan (in Japanese)
Hirouchi, Daisuke*; Yasue, Kenichi; Uchida, Chikara*; Hiramatsu, Takahiro*; Taniguchi, Kaoru*; Sugito, Nobuhiko*; Kaneda, Heitaro*
Katsudanso Kenkyu (27), p.201-209(2007) ; (JAEA-J 03283)

The Yugamine fault, 10 km in length, is in the north-central part of the Atera fault zone. We studied Holocene activity of the Yugamine fault through a trenching survey. Some humic layers and fluvial gravels are exposed on the trench walls. The Yugamine fault has cut through these layers to form a linear depression on its NE side. From the structural evidence along the fault plane and angular unconformity, we recognize at least four faulting events in this trench.

35001718
Present status of the development of radiation hardness SiC semiconductor devices (in Japanese)
Oshima, Takeshi
Kogyo Zairyo 55(10), p.60-64(2007) ; (JAEA-J 03284)

35001719
Development of sulfuric acid decomposer made of SiC ceramic with thermal and corrosion resistance (in Japanese)
Noguchi, Hiroki; Ota, Hiroyuki*; Terada, Atsuhiko; Hino, Ryutaro
Konsoryu 21(3), p.265-273(2007) ; (JAEA-J 03285)

The Japan Atomic Energy Agency has been conducting R&D on thermo-chemical Iodine-Sulfur (IS) process, which is one of the most attractive water-splitting hydrogen production methods using nuclear heat of a high-temperature gas-cooled reactor (HTGR). Since the sulfuric acid decomposer is exposed to severe corrosion condition, we proposed a new concept of a block type heat exchanger made of SiC ceramic which had excellent corrosion and mechanical strength performance. Through the fabrication and gastight tests of a mock-up model, fabricability and structural integrity were confirmed. Also, measured boiling heat transfer coefficient of sulfuric acid was predicted well with the Stephan-Korner correlation.

35001720
Anisotropic superconductivity in NpPd₅Al₂ in the vicinity of the heavy fermion formation (in Japanese)
Aoki, Dai*; Homma, Yoshiya*; Shiokawa, Yoshinobu*; Haga, Yoshinori; Matsuda, Tatsuma; Tateiwa, Naoyuki; Ikeda, Shugo; Sakai, Hironori; Yamamoto, Etsuji; Nakamura, Akio; Yasuoka, Hiroshi; Yamagami, Hiroshi*; Settai, Rikio*; Honda, Fuminori*; Onuki, Yoshichika
Kotai Butsuri 42(9), p.569-580(2007) ; (JAEA-J 03286)

The first neptunium superconductor was discovered in NpPd₅Al₂. Unconventional superconductivity of NpPd₅Al₂ is realized before onset of the heavy fermion state, which is compared with superconducting properties of CeCoIn₅ and PuRhGa₅ (PuCoGa₅).

35001721
Nuclear and thermal design for high temperature gas cooled reactor (GTHTR300C) using MOX fuel (in Japanese)
Mori, Tomoaki; Nishihara, Tetsuo; Kunitomi, Kazuhiko
Nippon Genshiryoku Gakkai Wabun Rombunshi 6(3), p.253-261(2007) ; (JAEA-J 03287)

Design studies of the hydrogen cogeneration high temperature gas cooled reactor (GTHTR300C), which can produce both electric power and hydrogen, have proceeded in Japan Atomic Energy Agency. In future, it will be obliged to operate using not enriched uranium but plutonium to coexist with fast reactors after the full deployment of fast reactor cycle. Therefore, a nuclear and thermal design has been performed to confirm the feasibility of the reactor core using Mixed-Oxide (MOX) fuel. The reactor core with operation period of 450 days and average burn-up of 123 GWd/ton for discharged fuel was designed. The reactor core met safety requirements of maximum fuel temperature of less than 1400 °C during normal operation, maximum power density of less than 13 W/cm³, shutdown margin of more than 1.0 %k/kk' and negative reactivity coefficient. The results proved that it is possible to operate the GTHTR300C using MOX fuels without consuming natural uranium resources.

35001722
Application effect of region temperature coefficients and improvement of heat transfer analysis model in HTGR (in Japanese)
Takamatsu, Kuniyoshi; Nakagawa, Shigeaki; Takeda, Tetsuaki
Nippon Genshiryoku Gakkai Wabun Rombunshi 6(3), p.262-275(2007) ; (JAEA-J 03288)

The HTTR, which has thermal output of 30 MW, coolant inlet temperature of 395 °C and coolant outlet temperature of 850 °C/950 °C, is a first high temperature gas-cooled reactor (HTGR) in Japan. The HTGR has a high inherent safety potential to accident. Safety demonstration tests using the HTTR are underway in order to demonstrate such excellent inherent safety features of HTGRs. The coolant flow reduction test demonstrates that rapid decrease of reactor power during tripping of the gas circulators is restrained by only the negative reactivity feedback effect without operation of the reactor power control system, and the temperature transient of the reactor is slow. A one-point core dynamics approximation with one fuel channel model could not simulate accurately the reactor power behavior. On the other hand, an original new method using a connection between some fuel channel models and whole core component model is adopted for calculating heat transfer in the core.

35001723
Solvent extraction and stripping of lanthanides into ionic liquids with a multidentate ligand
Shimojo, Kojiro; Naganawa, Hirochika; Kubota, Fukiko*; Goto, Masahiro*
Nippon Ion Kokan Gakkai-Shi 18(4), p.370-373(2007) ; (JAEA-J 03289)

The extraction behavior of lanthanides from aqueous solutions into ionic liquids (ILs) and the stripping test have been investigated with N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) as a ligand. TPEN in ILs shows the extremely high extraction performance for lanthanides compared to that in chloroform. The stripping of lanthanides from ILs into a receiving phase is successfully achieved under acidic conditions. Furthermore, the leaching of TPEN from ILs into the receiving phase is negligible small, although almost all TPEN molecules in chloroform readily leach.

35001724
Zirconium(IV) loaded bifunctional fiber containing both phosphonate and sulfonate as arsenate adsorbent
Awual, Md. Rabiul*; Jo, Akinori*; Tamada, Masao; Katakai, Akio
Nippon Ion Kokan Gakkai-Shi 18(4), p.422-427(2007) ; (JAEA-J 03290)

Fibrous arsenate adsorbent was prepared by loading Zr(IV) onto a bifunctional cation exchange fiber containing both phosphonate and sulfonate. This bifuctional cation exchange fiber was prepared by phosphorylation and sulfonation of the precursory fiber, which was obtained by co-graft polymerization of chloromethylstyrene and styrene onto polyethylene coated polypropylene fiber. Performances of the Zr(IV) loaded fiber as arsenate adsorbent was studied in columnar mode. The column packed with Zr(IV) loaded fiber removed arsenate from a weakly acidic pH solution containing 0.016 mM arsenate (1.2 mg of As dm^-3) even at a flow rate of 200 h^-1 in space velocity. Sodium salts of chloride, nitrate and sulfate did not interfere with uptake of arsenate but they slightly enhanced arsenate uptake. Adsorbed arsenate was quantitatively eluted with aqueous sodium hydroxide, and then the column was able to be regenerated by contact with dilute sulfuric acid for the next arsenate adsorption operation.

35001725
Critical rayleigh number of natural convection in an anisotropic horizontal porous layer with high porosity (in Japanese)
Shiina, Yasuaki; Hishida, Makoto*
Nippon Kikai Gakkai Rombunshu, B 73(733), p.1876-1883(2007) ; (JAEA-J 03291)

35001726
Lithology determination using 3D laser scanning; An Application of the method applied to the Mizunami Group at the Mizunami Underground Research Laboratory (in Japanese)
Mochida, Hiroyuki; Amano, Kenji; Tsuruta, Tadahiko
Oyo Chishitsu 48(3), p.126-131(2007) ; (JAEA-J 03292)

Various engineering tasks, such as geological mapping and taking photographs, are required for geological investigations in tunnels. Generally these tasks are performed during brief interruptions of construction activities under less than ideal conditions. For instance, the quality of photographic images may be adversely affected by inconsistent lighting conditions and the quality of geological mapping depends greatly on the skills of the geologist. 3D laser-scanning techniques provide consistent quality images that are unaffected by ambient lighting conditions. Comparison of digitally processed images with manually prepared maps of the shaft wall in the Mizunami Group (Miocene age) were preformed. The 3D laser-scanning technique shows promise in making geological investigations in tunnels more accurate and efficient.

35001727
Ultra-broadband optical parametric chirped-pulse amplification with a diverged pump beam (in Japanese)
Ogawa, Kanade; Akahane, Yutaka; Harimoto, Tetsuo*; Aoyama, Makoto; Tsuji, Koichi; Kawanaka, Junji*; Nishioka, Hajime*; Fujita, Masayuki*; Yamakawa, Koichi
Reza Kenkyu 35(9), p.596-598(2007) ; (JAEA-J 03295)

35001728
Corrosion resistant materials for hydrogen production plant by thermochemical IS process (in Japanese)
Tanaka, Nobuyuki; Noguchi, Hiroki; Iwatsuki, Jin; Kubo, Shinji; Terada, Atsuhiko; Onuki, Kaoru; Hino, Ryutaro
Ryusan To Kogyo 60(10), p.171-176(2007) ; (JAEA-J 03296)

35001729
Uncertainty theory in ultra microanalysis (in Japanese)
Osawa, Takahito
Tokei Joho 56(10), p.36-40(2007) ; (JAEA-J 03297)

Statistical work in ultramicro analysis is explained here as plainly as possible. The concept of "error" is denied recently, and the concept of "uncertainty" being used. In this paper, I account for how uncertainty propagate and measurements is obtained with no expression.

35001730
Residual stress in zirconia coating by EB-PVD method (in Japanese)
Suzuki, Kenji*; Wada, Kunihiko*; Matsubara, Hideaki*; Shobu, Takahisa; Kawamura, Masashi*; Tanaka, Keisuke*
Zairyo 56(7), p.588-593(2007) ; (JAEA-J 03298)

The Ni-based superalloy IN738LC was used as the substrate material, and CoNiCrAlY powder was pressureless plasma-sprayed on the substrate as the bond coating. Zirconia was coated as the top coating by the electron beam-physical vapor deposition (EV-PVD) method. In the EB-PVD process, the specimens were kept at 1223 K and rotated with 5 rpm, 10 rpm and 20 rpm. According to the microscopic observation and the result of the pole figures, the top coatings had a columnar structure, which was made by the piling up of (111) planes. The cross section of the column had a diamond shape, and its diagonal was parallel to the rotation axis. The residual stress on the surface of the top coatings was evaluated by the X-ray diffraction method. Each diffraction profile was separated into the 133 and the 331 peak, and the residual stress was measured by the sin² ψ method. The measured residual stresses were -76.6 MPa for 5 rpm, -63.0 MPa for 10 rpm and -25.1 MPa for 20 rpm.

35001731
Measurement of internal strain in materials using high energy synchrotron radiation white X-rays (in Japanese)
Shibano, Junichi*; Shobu, Takahisa; Suzuki, Kenji*; Hirata, Tomoyuki*; Kaneko, Hiroshi; Kobayashi, Michiaki*
Zairyo 56(10), p.985-992(2007) ; (JAEA-J 03299)

This paper presents a basic research on a measurement of strain in the bulk of materials by using high energy white X-rays from a synchrotron radiation source of SPring-8. WEL-TEN780E (JIS G3128 SHY685) whose grain size was 0.013 mm was used as a specimen. The specimen was loaded with four point bending. The white X-ray beam, which has a height of 0.05 mm and width of 0.03 mm, was incident in it. Bending strain at the surface of specimen was measured by a strain gauge. The internal strain of SHY685 of 5 mm thickness could be evaluated using white X-rays which range of energy from 60 keV to 150 keV. Furthermore, the measurement error of strain could be decreased by using the diffracted X-rays with high energy, high peak count and the profile which is close to Gaussian curve. The results showed that the high energy white X-ray is effective for internal strain measurements.

35001732
Control of current profile and instability by radiofrequency wave injection in JT-60U and its applicability in JT-60SA
Isayama, Akihiko; Suzuki, Takahiro; Hayashi, Nobuhiko; Ide, Shunsuke; Hamamatsu, Kiyotaka; Fujita, Takaaki; Hosoyama, Hiroki; Kamada, Yutaka; Nagasaki, Kazunobu*; Oyama, Naoyuki; Ozeki, Takahisa; Sakata, Shinya; Seki, Masami; Sueoka, Michiharu; Takechi, Manabu; Urano, Hajime; JT-60 Team
AIP Conference Proceedings 933 , p.229-236(2007) ; (JAEA-J 03300)

35001733
Application of a comprehensive sensitivity analysis method on the safety assessment of TRU waste disposal in Japan
Oi, Takao; Takase, Hiroyasu*; Inagaki, Manabu; Oyamada, Kiyoshi*; Sone, Tomoyuki; Mihara, Morihiro; Ebashi, Takeshi; Nakajima, Kunihiko*
Materials Research Society Symposium Proceedings, Vol.985 , p.129-134(2007) ; (JAEA-J 03301)

A comprehensive sensitivity analysis method has been developed with the aim of providing quantitative information in an efficient manner. This methodology is composed of the following two components: (1) a statistical method with random sampling of independent parameters, which identifies important parameters and extracts threshold values of parameters and/or combinations yielding a "successful condition" where maximum dose does not exceed a target value, (2) A nuclide migration model that as far as possible incorporates a comprehensive set of phenomena occurring within the repository. This approach was applied as part of a safety assessment of the geological disposal of TRU waste in Japan (TRU-2). It was shown that the concept of TRU waste disposal is robust from the point of view of safety.

35001734
Evaluation of fracturing process of soft rocks at great depth by AE measurement and DEM simulation
Mito, Yoshitada*; Chang, C. S.*; Aoki, Kenji*; Matsui, Hiroya; Niunoya, Sumio; Minami, Masayuki*
Proceedings of 11th Congress of the International Society for Rock Mechanics (ISRM 2007), Vol.1 , p.273-276(2007) ; (JAEA-J 03302)

In order to examine the relationship between AE, stress change and rock failure, the authors conducted the high stiffness triaxial compression tests including AE measurements, and its simulations by DEM (Distinct Element Method) using the bonded particle model. As the result, it is clarified that predominant AE frequency is a significant AE parameters to monitor the stress change in fracturing process of soft sedimentary rocks. After that, the DEM simulation of the triaxial compression test using the bonded particles model is conducted to visualize the fracturing process in the rock specimen. As the results, the relationship between AE, stress change and rock failure is clarified. Furthermore the three-dimensional DEM simulation under the in-situ stress condition provides a successful result to examine the borehole breakout observed in the actual deep borehole in the soft sedimentary rock, and the applicability of the simulation to the actual field is verified.

35001735
RELAP5 analysis of ROSA/LSTF vessel upper head break LOCA experiment
Takeda, Takeshi; Asaka, Hideaki; Suzuki, Mitsuhiro; Nakamura, Hideo
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12) (CD-ROM) , 3p.(2007) ; (JAEA-J 03303)

RELAP5 code analysis was performed to validate the code predictability by using ROSA/LSTF experiment data that simulated a PWR vessel upper head small break loss-of-coolant accident (SBLOCA) with a break equivalent to 1% cold leg break. The JAEA-modified RELAP5/MOD3.2.1.2 code was used by incorporating a break model that employs maximum bounding flow theory with a discharge coefficient (Cd) of 0.61 for two-phase break flow. In the experiment, liquid level in the upper head was found to control break flow rate as coolant in the upper plenum entered the upper head through control rod guide tubes (CRGTs) until the penetration holes at the CRGT bottom were exposed to steam in the upper plenum. The upper head noding and flow paths between the upper plenum and the CRGT were thus modeled to simulate well the liquid level and coolant flow around the upper portion of pressure vessel. The code, however, overpredicted the break flow rate due to the underprediction of break-upstream void fraction especially during two-phase flow discharge period. Cd for two-phase break flow was thus adjusted to be 0.58. Effects of break area on the core cooling were investigated further. The parameter analyses showed that peak cladding temperature (PCT) is the maximum at 1% break case, while the PCT would be lower than 1200 K in the larger break size cases because vapor condensation on injected accumulator coolant induces loop seal clearing and effectively enhances core cooling thereafter.

35001736
Numerical analysis of melting/solidification phenomena using the extended finite element method
Uchibori, Akihiro; Oshima, Hiroyuki
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12) (CD-ROM) , 12p.(2007) ; (JAEA-J 03304)

Melting/solidification is a key phenomenon in the several nuclear fuel cycle processes. In this paper, numerical analysis of the basic problems of melting/solidification using an extended finite element method is presented. The method is based on an enriched finite element interpolation to represent a discontinuous gradient of the temperature at a moving solid-liquid interface. This enables us to simulate movement of solid-liquid interface without the use of a moving mesh. The numerical solutions of the basic problems, a one-dimensional Stefan problem, a problem of solidification in a two-dimensional square corner and a problem of melting of a pure gallium, are compared to the exact solutions or the experimental data. Through these verifications, it is demonstrated that the extended finite element method can be applied to melting/solidification phenomena.

35001737
Application of LES with near wall model in nuclear plant thermal hydraulics
Takata, Takashi*; Yamaguchi, Akira*; Tanaka, Masaaki; Oshima, Hiroyuki
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12) (CD-ROM) , 12p.(2007) ; (JAEA-J 03305)

A Large Eddy Simulation (LES) with a simple Sub-Grid Scale (SGS) model and a Near Wall Model (NWM) is one of the simplest ways to overcome the heavy computational cost. In the present paper, two kinds of benchmark analyses have been carried out in order to investigate an applicability of the simple LES with NWM to an engineering problem concerning with a nuclear plant thermal hydraulics; one is the temperature mixing in the parallel triple-jets and the other is the isothermal turbulent flow under a rod bundle configuration. In the analyses, the standard Smagorinsky model is chosen as a SGS model using a second order central differential scheme. As the NWM, a wall function and a boundary layer approximation are implemented. As a result of the benchmark analyses, it is demonstrated that one can investigate a temperature fluctuation which causes a thermal striping phenomenon and a flow pulsation in a rod bundle configuration with the present LES with NWM.

35001738
Thermal influence on steam generator heat transfer tube during sodium-water reaction accident of sodium-cooled fast reactor
Yamaguchi, Akira*; Takata, Takashi*; Oshima, Hiroyuki; Kurihara, Akikazu
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12) (CD-ROM) , 12p.(2007) ; (JAEA-J 03306)

A breach of the heat transfer tube (HTT) in a steam generator (SG) of a Sodium Fast Reactor causes sodium-water reaction. The design and safety concern is a possibility of the secondary failure of nearby HTTs that could cause undesirable development of the accident. One needs to evaluate the temperature transients of the HTTs in the reaction region for safety evaluation. In the present study, a computational method is developed for this purpose. It solves the sodium thermal-hydraulics and the heat conduction in the adjacent HTTs. An experiment performed at JAEA is analyzed with the method developed in this study. It is found that analyzed temperatures are in good agreement with the experimental data. Based to the experimental and computational results, multi-phase multi-component flow characteristics are depicted. Furthermore, the heat transfer coefficient is evaluated using the numerical simulation result.

35001739
Core dynamics analysis on reactivity insertion and loss of coolant flow tests for HTGRs
Takamatsu, Kuniyoshi; Nakagawa, Shigeaki; Takeda, Tetsuaki
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12) (CD-ROM) , 13p.(2007) ; (JAEA-J 03307)

Safety demonstration tests using the HTTR are in progress to verify its inherent safety features and improve the safety technology and design methodology for High-Temperature Gas-cooled Reactors (HTGRs). The reactivity insertion test is one of the safety demonstration tests for the HTTR. This test simulates the rapid increase in the reactor power by withdrawing the control rod without operating the reactor power control system. In addition, the loss of coolant flow tests has been conducted to simulate the rapid decrease in the reactor power by tripping one, two or all out of three gas circulators. This paper describes the validation results for the newly developed code using the experimental results of the safety demonstration tests. Especially, the reactivity was clarified using an original mathematical expression which shows the relationship among region temperature coefficient, region temperature rise and power distribution.

35001740
Experimental study of gas entrainment phenomena; Developing process of surface vortex
Ezure, Toshiki; Kimura, Nobuyuki; Hayashi, Kenji; Kamide, Hideki
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12) (CD-ROM) , 13p.(2007) ; (JAEA-J 03308)

According to the compact sizing of reactor vessel, gas entrainment at the free surface of sodium coolant becomes one of the significant issues for the latest fast reactor design. It is required to clarify the criterion of gas entrainment at free surface and the tolerance of gas entrainment. In the present study, some visualization experiments were performed in the water-air system focusing on the gas entrainment due to a surface vortex. The gas entrainment occurs intermittently and the vortex develops and decays in time. Then developing process of the vortex is significant to estimate the gas entrainment phenomena. Multi plane PIV using a scanning mirror was adopted to investigate the temporal and spatial development of velocity around the vortex. The spatial propagation of downward velocity was clarified as the key factors of the vortex development.

35001741
Study on thermal striping phenomena in triple-parallel jet; Investigation on non-stationary heat transfer characteristics based on numerical simulation
Kimura, Nobuyuki; Kamide, Hideki; Emonot, P.*; Nagasawa, Kazuyoshi*
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12) (CD-ROM) , 14p.(2007) ; (JAEA-J 03309)

A quantitative evaluation on thermal striping, in which temperature fluctuation due to convective mixing between hot and cold fluids causes thermal fatigue in structural components, is of importance for reactor safety. In this study, a water experiment of parallel triple jets configuration was performed in order to evaluate temperature fluctuation characteristics in fluid, transfer characteristics of temperature fluctuation from fluid to structure. The power spectrum densities of temperature fluctuation, furthermore, were in good agreements between the experiment and calculation. The calculated results showed that the heat transfer coefficient obtained from the experiment was appropriate and proper. The decay due to the heat transfer at the wall surface was dominant for the decay of temperature fluctuation at the neighborhood of the wall.

35001742
Development of numerical method for simulation of gas entrainment phenomena
Ito, Kei; Yamamoto, Yoshinobu*; Kunugi, Tomoaki*
Proceedings of 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12) (CD-ROM) , 15p.(2007) ; (JAEA-J 03310)

For the purpose of direct numerical simulations of gas entrainment in fast breeder reactors, we are developing a high-precision seamless physical simulator based on computational scientific approaches. An unstructured mesh partitioning method was employed in this study and a high-precision calculation method for gas-liquid two-phase flow on the unstructured mesh was developed on the basis of the MARS formulated on a structured mesh. As the result of the verification, it was confirmed that the developed method has comparable or higher calculation accuracy compared to conventional methods. In addition, a correction method was introduced to the advection term of the volume fraction transport equation to improve volume conservation. The correction method led higher calculation accuracy on the unstructured mesh compared to the original method. Errors in a surface tension calculation were also estimated and the reconstructed distance function method showed the most accurate result.

35001743
System chemical decontamination technology by the IF₇ gas
Ema, Akira; Sugitsue, Noritake; Zaitsu, Tomohisa
Proceedings of 2007 ANS Topical Meeting on Decommissioning, Decontamination and Reutilization & Technology Expo (DD&R 2007) (CD-ROM) , 3p.(2007) ; (JAEA-J 03311)

When we decommission the equipments contaminated by the uranium, the dismantling process of the equipments and the disposal process of the radioactive waste will be carried out. However, costs of these processes will be very expensive. In order to minimize these costs, we have developed new decontamination technology to decontaminate below the clearance level without dismantling.

35001744
Activities of OECD/NEA expert group on assay data of spent nuclear fuel
Rugama, Y.*; Suyama, Kenya; Brady Raap, M.*
Proceedings of 2007 International Congress on Advances in Nuclear Power Plants (ICAPP 2007) (CD-ROM) , 4p.(2007) ; (JAEA-J 03312)

The importance of measured assay data from Post-Irradiation Examination (PIE) has long been understood by members of the OECD/NEA/NSC/WPNCS (Working Party on Nuclear Criticality Safety). These data are particularly important in criticality analyses related to any application of burnup credit as well as to evaluation of far-field criticality in geologic repositories and applications such as reprocessing where the fuel is not maintained intact. This report provide us the outline of the new expert group on assay data (PIE data) of spent nuclear fuel under OECD/NEA/NSC/WPNCS.

35001745
Separation of actinides(III) from lanthanides(III) by extraction chromatography using new N,N'-dialkyl-N,N'-diphenylpyridine-2,6-dicarboxyamides
Arisaka, Makoto; Watanabe, Masayuki; Kimura, Takaumi
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.111-113(2007) ; (JAEA-J 03313)

Four N,N'-dialkyl-N,N'-diphenylpyridine-2,6-dicarboxyamides (R-PDA; R = butyl, octyl, decyl, dodecyl) were newly synthesized and were applied to extraction chromatography as extractant to attain the separation of actinides(III) from high level radioactive waste containing lanthanides(III). R-PDA was successfully impregnated into XAD-4 resin. It was found that (i) the leakage of R-PDA from XAD-4 resin was suppressed with an increase of the length of the alkyl groups in R-PDA, while the leakage for each adsorbent resin was promoted with an increase of HNO₃ concentration in the aqueous phase and (ii) Oc-PDA or De-PDA/XAD-4 resin exhibits moderate separation ability of actinides(III) from lanthanides(III) at relatively high HNO₃ concentration.

35001746
Separation of Actinide(III) from Lanthanide(III) by thermosensitive gel copolymerized with TPEN derivatives
Takeshita, Kenji*; Fugate, G.*; Matsumura, Tatsuro; Nakano, Yoshio*; Mori, Atsunori*; Fukuoka, Sachio*
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.120-125(2007) ; (JAEA-J 03314)

Extraction separation of Am(III) and Eu(III) was examined by the thermal-swing extraction technique using a thermosensitive gel, poly-N-isopropylacrylamide (NIPA) copolymerized with a TPEN derivative, N,N,N',N'-tetrakis(4-propenyloxy-2-pyridylmethyl)ethylenediamine (TPPEN). The separation of Am(III) from Eu(III) was observed in the swollen state of gel (5°C) and the separation factor of Am(III) was evaluated as about 18 at pH5.2. More than 90% of Am(III) extracted into the gel was released by the volume phase transition of gel from the swollen state (5°C) to the shrunken one (40°C). The repetition test for the thermal swing extraction of a soft metal ion, Cd(II), which was used as a substitute of Am(III), was carried out and the extraction and release of Cd(II) were repeated three times stably under the thermal-swing operation between 5°C and 40°C. The radiation effect of gel on the extraction of Am and Eu was tested by the irradiation of γ-ray (10 kGy) and the long-term adsorption of α-emitter (²⁴⁴Cm). The TPPEN-NIPA gel sustained no damage by these radiation tests. These results suggest that the thermal-swing extraction technique is applicable to the MA partitioning process indispensable for the establishment of P&T technology.

35001747
Launch of fast reactor cycle technology development project in Japan
Sagayama, Yutaka
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.251-258(2007) ; (JAEA-J 03315)

JAEA launched a new FR Cycle Technology Development (FaCT) Project in cooperation with the Japanese electric utilities. The FaCT project is based on the conclusion of the Feasibility Study on Commercialized FR Cycle Systems (FS), which carried out in last seven years. In the FS, the combination of the sodium-cooled FR with oxide fuel, the advanced aqueous reprocessing and the simplified pelletizing fuel fabrication was selected as the main concept which should be developed principally. A conceptual design study of the main concept and R&D of innovative technologies are implemented toward an important milestone at 2015. The development targets, which were set up at the beginning stage of FS, were revised for the FaCT project based on the results of FS and change in Japanese society environment and in the world situation. International collaboration is promoted to pursue fast reactor cycle technology which deserves the global standard and its efficient development.

35001748
Conceptual study of measures against heat generation for TRU fuel fabrication system
Kawaguchi, Koichi; Namekawa, Takashi
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.290-295(2007) ; (JAEA-J 03316)

The JAEA has developed advanced FBR cycle system since 1999 as the Feasibility Study (FS). Several combination of fuel and reactor type, reprocessing method and fuel fabrication method were studied. As the result of FS, the combination of oxide fuel, sodium cooling reactor, advanced aqueous reprocessing system and simplified pelletizing fuel fabrication system is chosen as the most promissing fuel cycle system. In the Fast Reactor Cycle technology (FaCT), six development issues for simplified pelletising technology were selected. TRU fuel handling technology, which is heat removal from nuclear fuel material, is one of these issues. Accumulation of decay heat of MA which is contained in TRU fuel cause oxidation of fuel powder, fuel pellet and cladding tube. Authors designed concept of powder hoppper, O/M adjusting furnace and fuel assembling equipment with heat removal function, and evaluated temperature distribution using thermal hydraulics analysis technique. As a result, it is shown that it is possible to cool fuel materials with specific heat generation up to 20 W/kgHM enough, though more detailed study is required for comprehensive equipments.

35001749
Development of centrifugal contactor with high reliability
Okamura, Nobuo; Takeuchi, Masayuki; Ogino, Hideki; Kase, Takeshi; Koizumi, Tsutomu
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1070-1075(2007) ; (JAEA-J 03317)

35001750
Chemical separation of actinides from high level radioactive liquid waste using diglycolamide (DGA) compounds
Sasaki, Yuji; Kitatsuji, Yoshihiro; Sugo, Yumi; Asakura, Toshihide; Kimura, Takaumi
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1117-1120(2007) ; (JAEA-J 03318)

An innovative chemical separation process for the treatment of high level radioactive liquid waste (HLW) has been developed in our laboratory. There are two main stages in this process. The diglycolamide (DGA) compounds employed for TRU recovery have several advantages, (1) carbon, hydrogen, oxygen and nitrogen atoms in their structures and gasification by combustion, (2) easy synthesis, (3) neutral and tridentate ligands, and (4) strong extraction ability with An from HNO₃). DGA compounds with the different structures can be obtained by attachment of the different alkyl groups to amidic N atoms, i.e., tetraoctyl-diglycolamide (TODGA), tetradodecyl-diglycolamide (TDdDGA), tetrametyl-diglycolamide (TMDGA) and tetraetyl-diglycolamide (TEDGA). The utility of DGA compounds, which shows the different characters, is revealed and the flow-sheet based on the salt-free concept is exhibited in this paper.

35001751
Study on selective separation of uranium(VI) by new N,N-dialkyl carboxyamides
Suzuki, Shinichi; Yaita, Tsuyoshi; Sugo, Yumi; Kimura, Takaumi
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1137-1141(2007) ; (JAEA-J 03319)

35001752
An Effective loading method of americium targets in fast reactors
Oki, Shigeo; Sato, Isamu; Mizuno, Tomoyasu; Hayashi, Hideyuki; Tanaka, Kenya
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1280-1288(2007) ; (JAEA-J 03320)

Recently, the development of target fuel with high americium (Am) content has been launched for the reduction of the overall fuel fabrication cost of the minor-actinide (MA) recycling. In the framework of the development, this study proposes an effective loading method of Am targets in fast reactors. As a result of parametric survey calculations, we have found the ring-shaped target loading pattern between inner and outer core regions. This loading method is satisfactory both in core characteristics and in MA transmutation property. It should be noted that the Am targets can contribute to the suppression of the core power distribution change due to burnup. The major drawback of Am target is the production of helium gas. A target design modification by increasing the cladding thickness is found to be the most feasible measure to cope with the helium production.

35001753
Development of uranium crystallization system in "NEXT" reprocessing process
Oyama, Koichi; Nomura, Kazunori; Washiya, Tadahiro; Tayama, Toshimitsu; Yano, Kimihiko; Shibata, Atsuhiro; Komaki, Jun; Chikazawa, Takahiro*; Kikuchi, Toshiaki*
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1461-1466(2007) ; (JAEA-J 03321)

Japan Atomic Energy Agency (JAEA) has been developing the crystallization process technology in cooperation with Mitsubishi Materials Corporation, Saitama University and Waseda University. We have carried out experimental studies with uranium, MOX and spent fuel dissolved solution, and flowsheet analysis was researched. Crystal refinement study has been started to get more purified crystal. In association with these studies, an innovative continuous crystallizer and its system was developed to ensure high process performance. From the design study, an annular type continuous crystallizer was selected as the most promising design, and performance was confirmed by small-scale test and engineering scale demonstration at uranium crystallization conditions. In this paper, the research and development of crystallization process are described.

35001754
Development of advanced head-end systems in "NEXT" process
Washiya, Tadahiro; Komaki, Jun; Funasaka, Hideyuki
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1467-1473(2007) ; (JAEA-J 03322)

Japan Atomic Energy Agency (JAEA) has been developing the new aqueous reprocessing system named "NEXT" (New Extraction system for TRU recovery), which provides many advantages as waste volume reduction, cost savings by advanced components and simplification of process operation. Advanced head-end systems in the "NEXT" process consist of fuel disassembly system, fuel shearing system and continuous dissolver system. We developed reliable fuel disassembly system with innovative procedure, and short-length shearing system and continuous dissolver system can be provided highly concentrated dissolution to adapt to the uranium crystallization process. We have carried out experimental studies, and fabrication of engineering-scale test devices to confirm the systems performance. In this paper, research and development of advanced head-end systems are described.

35001755
Development of advanced reprocessing system based on use of pyrrolidone derivatives as novel precipitants with high selectivity and control ability, 1; Concept of advanced reprocessing system and precipitation behavior of U(VI)
Ikeda, Yasuhisa*; Takao, Koichiro*; Harada, Masayuki*; Morita, Yasuji; Nogami, Masanobu*; Nishimura, Kenji*
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1503-1507(2007) ; (JAEA-J 03323)

We have developed a reprocessing process for spent FBR fuels based on the precipitation method using pyrrolidone derivatives. In previous investigation, N-cyclohexyl-2-pyrrolidone (NCP) is used as a precipitant and a process consisting of selective U precipitation step and U-Pu co-precipitation step was developed. In the present study, in order to examine the applicability of precipitants with lower hydrophobicity than NCP to the selective U precipitation step, we have carried out precipitation experiments of U(VI) by N-butyl-2-pyrrolidone (NBP) and N-propyl-2-pyrrolidone (NProP) and measured decontamination factors of some fission products.

35001756
Development of an advanced reprocessing system based on use of pyrrolidone derivatives as novel precipitants with high selectivity and control ability; Precipitation behavior of plutonium
Morita, Yasuji; Kim, S.-Y.; Ikeda, Yasuhisa*; Nogami, Masanobu*; Nishimura, Kenji*
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.1508-1512(2007) ; (JAEA-J 03324)

We have been developing an advanced reprocessing system for spent FBR fuels based on precipitation method using pyrrolidone derivatives. In previous investigation, N-cyclohexyl-2-pyrrolidone (NCP) is used as a precipitant and a process consisting of selective U precipitation step and U-Pu co-precipitation step was developed. In order to make the process more effective and more economical, we are now studying precipitation of U and Pu with other pyrrolidone derivatives. In the present study, precipitation behavior of Pu was examined using N-butyl-2-pyrrolidone (NBP) and N-propyl-2-pyrrolidone (NProP), which have lower hydrophobicity than NCP. The experiments with Pu(IV) or Pu(VI) solutiona and U(VI)-Pu(IV) solutions showed that Pu is less precipitated with NBP or NProP than with NCP. From these results, it is expected that NBP and NProP can be used as precipitants for the selective U precipitation step and make the step more selective and effective.

35001757
High-energy colliding crystals; A Theoretical study
Wei, J.*; Okamoto, Hiromi*; Sugimoto, Hiroshi*; Yuri, Yosuke; Sessler, A. M.*
Proceedings of Workshop on Beam Cooling and Related Topics (COOL '07) , p.91-95(2007) ; (JAEA-J 03325)

Recent theoretical investigations of beam crystallization using computer modeling based on the method of molecular dynamics (MD) and analytical approach based on the phonon theory are motivated by the study of colliding crystalline beams. In order to investigate the stability of 1D crystals at high energies, we present a newly developed phonon theory in a time-dependent Hamiltonian system representing the actual alternating-gradient focusing ring. Using the theory, we explore ring lattices appropriate for beam crystallization at high energies. In comparison, we study both 1D and multi-dimensional high-energy crystals using the MD method. Both theoretical and numerical results show that it is possible to form 1D crystalline beams at high energies in rings that have high (γ_T>> ν_x) and imaginary (γ_T² < 0) transition energy. Finally, we present examples of ion-ion and electron-ion colliders with 1D ordered ions.

35001758
Cd-Yb alloy rich in order-disorder transitions; Clue to understanding of nature of quasicrystalline icosahedral lattice
Watanuki, Tetsu
SPring-8 Research Frontiers 2006 , p.58-59(2007) ; (JAEA-J 03326)

Unlike ordinary metals with translational periodic lattices, quasicrystals have icosahedral lattice components which pile up to form successively larger icosahedral units and eventually fill the three dimensional space without translational periodicity. The inner core clusters of Cd tetrahedrons in the Cd-Yb alloy, which is an approximant to its quasicrystal form, are randomly oriented at ambient pressure and temperature. The single-crystal X-ray diffraction measurements have revealed that the Cd-Yb alloy exhibits various types of ordering or disordering in the orientation of the Cd tetrahedron sensitively depending on pressure-temperature condition; eight phases appear at the range of 0-5 GPa and 5-300 K. The P-T sensitive transition behavior is attributed to the correlations between the neighboring Cd tetrahedra presumably through itinerant electrons: a new type of electron-lattice interaction.

35001759
Innovative oxide fuels doped with minor actinides for use in fast reactors
Osaka, Masahiko; Miwa, Shuhei; Tanaka, Kosuke; Sato, Isamu; Hirosawa, Takashi; Obayashi, Hiroshi; Mondo, Kenji; Akutsu, Yoko; Ishi, Yohei; Koyama, Shinichi; Yoshimochi, Hiroshi; Tanaka, Kenya
WIT Transactions on Ecology and the Environment, Vol.105 , p.357-366(2007) ; (JAEA-J 03327)

35001760
Study on filtration property of grouting materials; High-pressure filtration test (in Japanese)
Nobuto, Jun*; Mikake, Shinichiro; Sato, Toshinori; Nishigaki, Makoto*; Larry Pax, C.*
Doboku Gakkai Heisei-19-Nendo Zenkoku Taikai Dai-62-Kai Nenji Gakujutsu Koenkai Koen Rombunshu , p.269-270(2007) ; (JAEA-J 03328)

Authors are conducting research on method to achieve high-level water tightness in crystalline rock with suspension grout like cement slurry is studied. Grout should be infiltrated into very fine fractures to enhance the water tightness. For such fine fractures, the clogging phenomenon of grout material at the entrance of rock fractures tends to occur, and it results in insufficient infiltration of grout. Herein, laboratory experiment is conducted to investigate the clogging phenomenon using steel apparatus with fine slits simulating rock fracture. The results indicate clogging can be prevented to a significant level by increasing the injection pressure, although grout material accumulates over the slit.

35001761
Thermal stress evaluation of tubesheet structures for double-wall-tube steam generators of FBRs, 1; Study of stress inducement mechanism (in Japanese)
Kasahara, Naoto; Takasho, Hideki*; Ando, Masanori
Nippon Kikai Gakkai 2007-Nendo Nenji Taikai Koen Rombunshu, Vol.1 , p.683-684(2007) ; (JAEA-J 03329)

Tubesheet structures utilized in heat exchangers have complex perforated portions. For design analysis of these structures, axi-symmetric models with equivalent materials of perforated plate are conventionally adopted to simplify perforated portions. Double wall steam generators expected for commercial FBRs require new type of tubesheets, where conventional design methods are not applicable. Therefore, JAEA started research programs to develop a design by analysis method of these structures. This paper reports on the mechanism of thermal stress developments in new tubesheets with an associated paper.

35001762
Simplified evaluation guideline for thermal fatigue damage due to random fluctuation of fluid temperature (in Japanese)
Okajima, Satoshi*; Honda, Kei*; Sakai, Shinsuke*; Izumi, Satoshi*; Oishi, Kunio*; Kasahara, Naoto
Nippon Kikai Gakkai M&M 2007 Zairyo Rikigaku Kanfarensu Koen Rombunshu (CD-ROM) , p.262-263(2007) ; (JAEA-J 03331)

It is well known that fatigue damage accumulates around T-junctions of piping system where two kinds of fluid with different temperatures are mixed. Kasahara et al. have proposed the thermal fatigue evaluation method based on power spectrum density (PSD). However, this method is too complex to practical use in the design stage. In this paper, a simplified damage evaluation guideline is proposed based on the Kasahara et al. method. The damage evaluation procedure from stress PSD is simplified in this guideline.

35001763
Influence of crack initiation, propagation and coalescence on load in fatigue test at elevated temperature
Bubphachot, B.*; Watanabe, Osamu*; Kawasaki, Nobuchika; Kasahara, Naoto
Nippon Kikai Gakkai M&M 2007 Zairyo Rikigaku Kanfarensu Koen Rombunshu (CD-ROM) , p.346-347(2007) ; (JAEA-J 03332)

Crack initiation and propagation were observed on perforated plates at elevated temperature by the CCD video camera. The test specimens are made of SUS304 stainless steel, and temperature is kept to be 550°C, and the geometry of the perforated plate specimens are changed by diameter size of the hole. The photographs of all cycles were recorded to obtain number of cycle of crack initiation (N_c). The results were compared with predictions by the stress redistribution locus (SRL) method and the Neuber's rule's method.

35001764
Effective stress of triangular pattern perforated plates (in Japanese)
Kasahara, Naoto; Takasho, Hideki*
Nippon Kikai Gakkai M&M 2007 Zairyo Rikigaku Kanfarensu Koen Rombunshu (CD-ROM) , p.421-422(2007) ; (JAEA-J 03333)

For design analysis of perforated plates, axi-symmetric models with equivalent solid plates are conventionally adopted to simplify perforated geometries. ASME Sec.III Appendix A-8000 provides elastic constants for equivalent solid plates. However, no design codes give inelastic material properties of equivalent plates. This study reveals that perforated plates have their own effective stress ratio (ESR), which is a function of geometry and is independent from their materials. ESR enables the general determination method of non-linear equivalent material properties for perforated plates.

35001765
Applied geological evaluation of the relationship between the significant geological and structural features, and unconsolidated structures marked in granitic rocks; Geological and structural features of intrusive rocks (in Japanese)
Tsuruta, Tadahiko; Nakamata, Kiminori
Nippon Oyo Chishitsu Gakkai Heisei-19-Nendo Kenkyu Happyokai Koen Rombunshu , p.205-206(2007) ; (JAEA-J 03334)

35001766
Internal structures, deformation and alteration characteristics of an impermeable fault; A Case study of the Toki Granite in the Mizunami Underground Research Laboratory (in Japanese)
Nakamata, Kiminori; Tsuruta, Tadahiko; Amano, Kenji; Nishimoto, Shoji*; yoshida, hidekazu*
Nippon Oyo Chishitsu Gakkai Heisei-19-Nendo Kenkyu Happyokai Koen Rombunshu , p.207-208(2007) ; (JAEA-J 03335)

35001767
Use of a 3D laser scanner for prompt geological mapping of underground gallery; An Application to the Mizunami Underground Research Laboratory (in Japanese)
Hayano, Akira; Tsuruta, Tadahiko; Amano, Kenji
Nippon Oyo Chishitsu Gakkai Heisei-19-Nendo Kenkyu Happyokai Koen Rombunshu , p.211-212(2007) ; (JAEA-J 03336)

35001768
Geological structure survey using the vibration caused by the shafts excavation (in Japanese)
Hodotsuka, Yasuyuki; Matsuoka, Toshiyuki; Ishigaki, Koichi*
Nippon Oyo Chishitsu Gakkai Heisei-19-Nendo Kenkyu Happyokai Koen Rombunshu , p.213-214(2007) ; (JAEA-J 03337)

35001769
Application of multivariate analysis to rock mass classification (in Japanese)
Kikuchi, Teruyuki*; Amano, Kenji; Tsuruta, Tadahiko; Cheikhna, D.*
Nippon Oyo Chishitsu Gakkai Heisei-19-Nendo Kenkyu Happyokai Koen Rombunshu , p.223-224(2007) ; (JAEA-J 03338)

35001770
Seismic interferometry using long time measured microtremor (in Japanese)
Yamada, Nobuto*; Ishigaki, Koichi*; Yamaguchi, Shinji*; Narita, Norifumi*; Matsuoka, Toshiyuki; Hodotsuka, Yasuyuki; Matsuoka, Toshifumi*
Shadan Hojin Butsuri Tansa Gakkai Dai-117-Kai (Heisei-19-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu , p.146-148(2007) ; (JAEA-J 03339)

Seismic interferometry synthesizes the Green's function between two receivers by calculating cross-correlation of records measured at their locations. In Japan Atomic Energy Agency(JAEA), Seismic Interferometry using blasting vibration caused by the shafts excavation had been carried out to investigate the geologic structure in the surrounding area. The result was identical to the existing seismic reflection section. In this study, we applied this technique to long time measured microtremor. The result was also identical to the results of existing section and seismic interferometry using blasting vibration caused by the shafts excavation.

35001771
Progress in development of collective Thomson scattering diagnostic with high power CO₂ laser
Kondoh, Takashi; Kawano, Yasunori; Hatae, Takaki; Sugie, Tatsuo; Hayashi, Toshimitsu; Kusama, Yoshinori
NIFS-PROC-68 , p.126-129(2007) ; (JAEA-J 03340)

High power and high repetition CO₂ laser has been developed for collective Thomson scattering (CTS) diagnostic to establish a diagnostic method of confined α-particles in burning plasmas. Pulse energy of 17 J at a repetition rate of 15 Hz has been achieved in a single-mode operation. This result gives a prospect for the CTS diagnostic on International Thermonuclear Experimental Reactor (ITER), which requires energy of 20 J with repetition rate of 40 Hz. The laser injection test into the vacuum vessel of the JT-60U tokamak has been carried out to check the electric noise and stray signals of the receiver system using the new CO₂ laser without plasma. As a result, electrical noise has been decreased, however, stray signal due to multimode oscillation has been observed in about 30% of the pulses and a further improvement of the laser is needed.

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JAEA > JAEA Library > JOPSS > Papers Published in Journals [Back Issues] > December 2007