JAEA Abstracts

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

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

January 2008

36000017
Extraction behavior and separation of lanthanides with a diglycol amic acid derivative and a nitrogen-donor ligand
Shimojo, Kojiro; Naganawa, Hirochika; Noro, Junji*; Kubota, Fukiko*; Goto, Masahiro*
Analytical Sciences 23(12), p.1427-1430(2007) ; (JAEA-J 03342)

The extraction and separation of lanthanides have been investigated using CHON type extractants, which are composed of only C, H, O, and N atoms. N, N-dioctyldiglycol amic acid (DODGAA) shows the high extraction and separation performances for heavier lanthanides compared with typical CHON type extractants. On the other hand, N, N, N', N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) provides the unprecedentedly high selectivity for lighter lanthanides. Furthermore, it was found that the combination of DODGAA and TPEN under suitable conditions enables the mutual separation of light, middle, and heavy lanthanides.

36000018
Highly selective extraction of TcO₄^-, ReO₄^- and MoO₄^2- by the new ligand, 2,2'-(Methylimino)bis(N,N-Dioctylacetamide) (MIDOA)
Sasaki, Yuji; Kitatsuji, Yoshihiro; Kimura, Takaumi
Chemistry Letters 36(11), p.1394-1395(2007) ; (JAEA-J 03344)

Highly selective extraction of oxonium anions can be achieved by the new ligand, N,N,N,N-tetraoctyl-3-methyliminodiglycolamide (TOMIDGA). TOMIDGA has a high solubility in n-dodecane, any types of diluents can be employed for the solvent extraction. The extraction using TOMIDGA was performed under the condition, HNO₃ and n-dodecane, considering the chemical process of high-level radioactive liquid waste. It was obvious that the oxonium anions, like TcO₄^-, ReO₄^-, Cr₂O₇^2-, MoO₄^2-, and WO₄^2-, are extracted, and the distribution ratios (D) decrease with increase of HNO₃ concentration.

36000019
Magnetically induced ferroelectricity in multiferroic compounds of RMn₂O₅
Kimura, Hiroyuki*; Kobayashi, Satoru*; Wakimoto, Shuichi; Noda, Yukio*; Kon, Keiichiro*
Ferroelectrics 354, p.77-85(2007) ; (JAEA-J 03345)

A review is given on the studies of magnetic properties and dielectric properties as functions of temperature and magnetic field for various multiferroic RMn₂O₅ (R = rare-earth) compounds. We have observed successive dielectric and magnetic phase transitions which concomitantly take place and a so-called multiferroics is realized. In this system, the ferroelectricity is magnetically induced and the commensurate magnetism is indispensable to produce a spontaneous electric polarization. The microscopic origin of the magnetically induced ferroelectricity and the role of the rare-earth magnetic moment for a colossal magnetoelectric effect in RMn₂O₅ will be discussed in the viewpoint of the magnetic structure.

36000020
Design study of a new antenna system for steering microwave beam in electron cyclotron heating/current drive system
Moriyama, Shinichi; Seki, Masami; Fujii, Tsuneyuki
Fusion Engineering and Design 82(5-14), p.785-790(2007) ; (JAEA-J 03346)

A power measurement method for an electron cyclotron heating (ECH) system using a ceramic disk was studied and tested. A model calculation showed that the disk edge temperature of the diamond vacuum window was sufficient to estimate the transmission power at 1 MW and 110 GHz with a response time of 0.2 s. The initial high power test with very thin thermocouple demonstrated successful power measurement with response time of < 1.0 s. The concept of the linear motion ECH antenna suitable for reactor (like) environment is newly introduced and studied. A typical design would involve a mm-wave beam reflected at a flat mirror and a concave mirror. In the second reflection, the reflection angle can be changed by varying the point of reflection. The point of reflection is easily controlled by the linear movement of either the flat mirror or the concave mirror. It is notable that mirror rotation, which may require regular maintenance, is not required and backlash can be eliminated.

36000021
Technical design of NBI system for JT-60SA
Ikeda, Yoshitaka; Akino, Noboru; Ebisawa, Noboru; Hanada, Masaya; Inoue, Takashi; Honda, Atsushi; Kamada, Masaki; Kawai, Mikito; Kazawa, Minoru; Kikuchi, Katsumi; Kikuchi, Mitsuru; Komata, Masao; Matsukawa, Makoto; Mogaki, Kazuhiko; Noto, Katsuya; Okano, Fuminori; Oga, Tokumichi*; Oshima, Katsumi; Takenouchi, Tadashi; Tamai, Hiroshi; Tanai, Yutaka; Umeda, Naotaka; Usui, Katsutomi; Watanabe, Kazuhiro; Yamazaki, Haruyuki
Fusion Engineering and Design 82(5-14), p.791-797(2007) ; (JAEA-J 03347)

Modification of JT-60U to a superconducting device (so called JT-60SA) has been planned to contribute to ITER and DEMO. The NBI system is required to inject 34 MW for 100 s. The upgraded NBI system consists of twelve positive ion based NBI (P-NBI) units and one negative ion based NBI (N-NBI) unit. The injection power of the P-NBI units are 2 MW each at 85 keV, and the N-NBI unit will be 10 MW at 500 keV, respectively. On JT-60U, the long pulse operation of 30 s at 2 MW (85 keV) and 20 s at 3.2 MW (320 keV) have been achieved on P-NBI and N-NBI units, respectively. Since the temperature increase of the cooling water in both ion sources is saturated within 20 s, further pulse extension up to 100 s is expected to mainly modify the power supply systems in additioin to modification of the N-NBI ion source for high acceleration voltage.The detailed technical design of the NBI system for JT-60SA will be presented.

36000022
Development of optimum manufacturing technologies of radial plates for the ITER toroidal field coils
Nakajima, Hideo; Hamada, Kazuya; Okuno, Kiyoshi; Abe, Kanako*; Shimizu, Tatsuya; Kakui, Hideo*; Yamaoka, Hiroto*; Maruyama, Naoyuki*; Takayanagi, Tadatoshi*
Fusion Engineering and Design 82(5-14), p.1473-1480(2007) ; (JAEA-J 03348)

36000023
Superconducting tokamak JT-60SA project for ITER and DEMO researches
Hosogane, Nobuyuki; JT-60SA Design Team; Japan-Europe Satellite Tokamak Working Group
Fusion Science and Technology 52(3), p.375-382(2007) ; (JAEA-J 03349)

JT-60SA is a superconducting tokamak with wide flexibility in plasma shape and single/double null divertors, capable of confining break-even class high temperature plasma for 100 s with intensive heating power of 41 MW. The design of JT-60SA is based on the National Centralized Tokamak NCT, and has been proposed as an ITER satellite tokamak in the 10 years Broader Approach (BA) program between Japan and Europe. The JT-60SA project is a combination of the BA project and the NCT project. The former mission is to support ITER by developing an understanding of physics issues, optimizing operation scenarios etc.. The latter mission is mainly to explore steady state, high beta DEMO relevant scenarios. The construction period is 7 years and 3 years will be devoted to experimental studies with a possibility of extension. The detail design of JT-60SA is progressing under their collaboration. Overview of the project and machine design will be presented.

36000024
Recent activities on tritium technologies for ITER and fusion reactors at JAEA
Hayashi, Takumi; Isobe, Kanetsugu; Kobayashi, Kazuhiro; Iwai, Yasunori; Kawamura, Yoshinori; Nakamura, Hirofumi; Shu, Wataru; Arita, Tadaaki; Hoshi, Shuichi; Suzuki, Takumi; Yamada, Masayuki; Yamanishi, Toshihiko
Fusion Science and Technology 52(3), p.651-658(2007) ; (JAEA-J 03350)

The design studies of Air Detirtiation System have been carried out in JAEA as a contribution of Japan to ITER. For the tritium processing technologies, our efforts have been focused on the R&D of the tritium recovery system of ITER test blanket, using mainly molecular sieve and/or electro-chemical pumping system. A series of fundamental studies on tritium safety technologies, such as tritium behavior in a confinement and its barrier materials, monitoring, accountancy, detritiation and decontamination etc., has been carried out as a major activity in JAEA for ITER and fusion demo reactors. In this paper, the above recent activities on tritium technologies at Tritium Process Lab. in JAEA are summarized for ITER and future fusion reactor.

36000025
Tritium behavior on the water-metal boundary for the permeation into cooling water through metal piping
Hayashi, Takumi; Nakamura, Hirofumi; Isobe, Kanetsugu; Kobayashi, Kazuhiro; Yamanishi, Toshihiko; Okuno, Kenji*
Fusion Science and Technology 52(3), p.687-691(2007) ; (JAEA-J 03351)

How to confine tritium within high temperature breeding blanket is the key issue for safety and fuel economy of the fusion reactor. Specially, tritium permeation into cooling water is very important, however, there is little report of the systematic experiment comparing with that into gaseous coolant. Therefore, a series of tritium transportation experiments into water was performed through pure iron piping samples, which contained more than 1 kPa of pure tritium gas and fixed inside the water jacket under controlled temperature and pressure. Chemical species of tritium in water were measured during the experiment until reaching enough stable permeation, and tritium distribution/situation on the metal surface layer was also measured using autoradiography etc. after the experiment. In this paper, the results of tritium transportation experiments were summarized and tritium behavior on the boundary surface between metal piping and cooling water was discussed.

36000026
Fundamental study on purity control of the liquid metal blanket using solid electrolyte cell
Yamamoto, Yoshihiko*; Yamanishi, Toshihiko; Kawamura, Yoshinori; Isobe, Kanetsugu; Yamamoto, Yasushi*; Konishi, Satoshi*
Fusion Science and Technology 52(3), p.692-695(2007) ; (JAEA-J 03352)

A solid electrolyte (ionic conductor) cell has been developed for measurement and control of hydrogen and oxygen density in liquid metal blanket with LiPb. The ceramic tubes of the SrCe_0.95Yb_0.05O_3-x (proton conductor) and Yttria Stabilized Zirconia (oxygen ion conductor) that can be used at operating temperature of LiPb blanket have been utilized for electrolytes of the devices, which enable the continuous measurement of respectively hydrogen and oxygen in liquid LiPb. Fundamental electrochemical data such as EMF for a partial pressure and ion conductivity were measured, and the results were used to evaluate the feasibility of these devices.

36000027
Study for the behavior of tritiated water vapor on organic materials
Kobayashi, Kazuhiro; Hayashi, Takumi; Nakamura, Hirofumi; Yamanishi, Toshihiko; Oya, Yasuhisa*; Okuno, Kenji*
Fusion Science and Technology 52(3), p.696-700(2007) ; (JAEA-J 03353)

In a fusion reactor of high safety and acceptability, safe confinement of tritium is one of key issues for the fusion reactor. Tritium should be well-controlled and not excessively released to the environment and to prevent workers from excess exposure. Especially, the hot cell and tritium facilities of ITER will use various construction materials. For tritium decontamination processes, so-called soaking effect is important. This effect is based on sorption of tritiated water vapor on the materials and subsequent desorption from them. Therefore, in order to develop for the optimal decontamination technique, the decontamination experiment was carried out as a function of water vapor concentration in the purging gas for epoxy paint, acrylic resin and butyl rubber. As the result, about 70% of the adsorbed tritium on the epoxy paint was removed by adding water vapor in purging gas for 12 hrs. The effect of adding water vapor was found on the decontamination for epoxy paint.

36000028
Self-decomposition behavior of high concentration tritiated water
Ito, Takeshi*; Hayashi, Takumi; Isobe, Kanetsugu; Kobayashi, Kazuhiro; Yamanishi, Toshihiko
Fusion Science and Technology 52(3), p.701-705(2007) ; (JAEA-J 03354)

In a fusion reactor, how to handle high concentration tritiated water (HTO) is one of the key issues for the safety control. High concentration HTO decomposes by itself, and generates hydrogen and oxygen in the gas phase and hydrogen peroxide in the liquid phase, as the final products. There are many report of the G values for water decomposition by γ-ray irradiation experiments, however, those for self-decomposition of HTO are limited because of the difficulty of the safety handling of HTO. In the Tritium Process Lab. of Japan Atomic Energy Agency, the characteristics of a wide rage of HTO up to about 2 EBq/m³ has been investigated for more than 10 years. The effective G values of hydrogen and hydrogen peroxide under self-decomposition of HTO were evaluated from their concentration increase in the leak tight vessel stored HTO, as a function of time. In this paper, the above effective G values are summarized, and the dependences of HTO concentration and temperature are discussed.

36000029
Isotope effect of hydrogen rapidly supplied from the metal storage bed
Hayashi, Takumi; Suzuki, Takumi; Shu, Wataru; Yamanishi, Toshihiko
Fusion Science and Technology 52(3), p.706-710(2007) ; (JAEA-J 03355)

In the tritium Storage and Delivery System (SDS) of ITER, how to control the isotope balance of DT fuel is one of the key issues for the stable and optimum operation. Basically, the equilibrium pressure of hydrogen-metal system has large isotope effect such as PH₂ < PD₂ < PT₂, however, there is only a limited data of the isotope composition of hydrogen mixture, which is supplied rapidly from the storage bed by a vacuum pump under ITER/SDS conditions. Therefore, in order to investigate the isotope composition of supplied hydrogen gases, a series of rapid supply experiments was performed using a 1/10 ITER scale ZrCo bed with a scroll pump as functions of bed temperature (573 K ˜ 623 K) and isotope composition of hydrogen mixture stored initially (H:D = 1:9 ˜ 9:1). The isotope composition was measured by in-line mass spectrometer during continuous hydrogen supply. In this paper, the above results are summarized and the isotope effect is discussed. The effective way to control the isotope balance of DT fuel is also discussed with more moderate SDS design conditions.

36000030
Oxidation performance test of detritiation system under existence of SF₆
Kobayashi, Kazuhiro; Miura, Hidenori*; Hayashi, Takumi; Hoshi, Shuichi; Yamanishi, Toshihiko
Fusion Science and Technology 52(3), p.711-715(2007) ; (JAEA-J 03356)

The tritium released in the building is removed by Atmosphere Detritiation System (ADS), where the tritium is oxidized by catalysts and is removed as water. Special gas of SF₆ is used as an electric insulation gas in ITER, and is expected to be released in an accident such as fire. Although SF₆ has the potential as a catalyst poison, the performance of ADS with the existence of SF₆ has not been confirmed yet. Therefore, to study the effect of SF₆, the performance tests of ADS was carried out with air containing ˜1% of hydrogen, ˜1% of methane and ˜1% of SF₆. The SF₆ gas was notably decomposed in the case of the catalyst temperature higher than 673 K. In addition, a part of the water produced by the 473 K catalyst was reduced to hydrogen due to the reaction with the decomposed gas in SF₆. Consequently, the detritiation factor of ADS was decreased to less than 50 from > 1000 of its initial value.

36000031
Activation analysis for sequential reactions of a fusion Demo-reactor
Yamauchi, Michinori; Nishitani, Takeo; Nishio, Satoshi; Hori, Junichi*; Kawasaki, Hiromitsu*
Fusion Science and Technology 52(4), p.781-785(2007) ; (JAEA-J 03357)

Low activation material is one of the important factors for constructing high power fusion reactors in future. Unexpected activation, however, may be produced through sequential reactions due to charged particles created by primary neutron reactions. In the present work, the effect of the sequential activation reaction was studied for candidate low activation materials of a fusion demo-reactor. The calculations were conducted by the ACT4 code developed in JAEA for the activation analysis of fusion reactor designs and revised for dealing with the sequential activation reactions. The results say that the real dose rate around vanadium alloy which may be used as structural material becomes larger after the cooling for 3 years by considering the reaction. Although metal hydrate is regarded as an excellent low activation shield material, the reactions due to recoil protons are influential and the dose rate around vanadium hydrate is several orders of magnitude larger than the value calculated without the sequential process after 2 weeks cooling. In case of liquid breeders, the effect of sequential reactions is popularly observed and it affects the shield design of circulation loop.

36000032
Progress in neutronics studies for the water cooled pebble bed blanket
Nishitani, Takeo; Sato, Satoshi; Ochiai, Kentaro; Kutsukake, Chuzo; Tanaka, Shigeru; Abe, Yuichi; Konno, Chikara
Fusion Science and Technology 52(4), p.791-795(2007) ; (JAEA-J 03358)

36000033
Recent progress in solid breeder blanket development at JAEA
Nishitani, Takeo; Enoeda, Mikio; Akiba, Masato; Yamanishi, Toshihiko; Hayashi, Kimio; Tanigawa, Hiroyasu
Fusion Science and Technology 52(4), p.971-978(2007) ; (JAEA-J 03359)

36000034
Tritium release behavior from steels irradiated by high energy protons
Nakamura, Hirofumi; Kobayashi, Kazuhiro; Yamanishi, Toshihiko; Yokoyama, Sumi; Saito, Shigeru; Kikuchi, Kenji
Fusion Science and Technology 52(4), p.1012-1016(2007) ; (JAEA-J 03360)

36000035
Electron cyclotron heating applied to the JT-60U tokamak
Hoshino, Katsumichi; Suzuki, Takahiro; Isayama, Akihiko; Ide, Shunsuke; Takenaga, Hidenobu; Kubo, Hirotaka; Fujita, Takaaki; Kamada, Yutaka; Fujii, Tsuneyuki; Tsuda, Takashi; JT-60 Team; Ida, Katsumi*; Inagaki, Shigeru*
Fusion Science and Technology 53(1), p.114-129(2008) ; (JAEA-J 03361)

We report on the applications of the ECH to the JT-60U tokamak. The ECH contributes to the advanced tokamak study in JT-60U in such respects as (1)NTM suppression, (2)Study on the internal transport barrier, (3)Impurity exhaust, (4)Tokamak start-up without center solenoid, (5)Current hole study, (6)Confinement and transport study, and (7)Start-up and shut-down assist. These contributions comes from the good local coupling of the ECH to the tokamak plasma.

36000036
Difference between local and average structures of La₃Ga₅SiO₁₄ crystal
Yoneda, Yasuhiro; Takeda, Hiroaki*; Shiosaki, Tadashi*; Mizuki, Junichiro
Japanese Journal of Applied Physics, Part 1 46(10B), p.7163-7166(2007) ; (JAEA-J 03362)

The langasite (La₃Ga₅SiO₁₄, LGS) crystal grown by the Czochralski technique was investigated by X-ray diffraction measurements. The X-ray diffraction profiles of the LGS were consisted with sharp Bragg peaks and large amount of diffuse scatterings. The diffuse scattering inducated the existence of the local structure which is different from the average structure. The local structure was analyzed by the pair-distrivution function method. The local structure fluctuated by the chemical ordering of Ga and Si, and the local disordering feature of La.

36000037
Magnetic and dielectric properties of Tb_0.5Ca_0.5MnO₃
Hiramitsu, Yusuke*; Yoshii, Kenji; Yoneda, Yasuhiro; Mizuki, Junichiro; Nakamura, Akio; Shimojo, Yutaka; Ishii, Yoshinobu*; Morii, Yukio; Ikeda, Naoshi*
Japanese Journal of Applied Physics, Part 1 46(10B), p.7171-7174(2007) ; (JAEA-J 03363)

Magnetic and dielectric properties of a perivskite manganite Tb_0.5Ca_0.5MnO₃ were investigated. Magnetic measurements showed three characteristic temperatures, originating from charge ordering (300 K), antiferromagnetic ordering (120 K) and a transition to a glassy state (50 K). The coexistence of the charge and antiferromagnetic ordering was consistent with the result of powder neutron diffraction. AC dielectric measurements showed large dielectric constants of about 5000 at around room temperature. A temperature dependence of the dielectric constant changed just below the charge-ordering temperature. From the analysis of tanδ;, the activation energy for a domain-boundary motion was calculated to be about 0.09 eV. These results strongly suggest that the dielectric properties of this material are governed by the ordering and transfer of the Mn-3d charges.

36000038
Variable-frequency nuclear monochromator using single-line pure nuclear bragg reflection of oscillating ⁵⁷FeBO₃ single crystal
Mitsui, Takaya; Seto, Makoto; Masuda, Ryo
Japanese Journal of Applied Physics, Part 2 46(38), p.L930-L932(2007) ; (JAEA-J 03364)

A variable-frequency ⁵⁷Fe nuclear monochromator has been developed using a pure nuclear Bragg reflection from an oscillating ⁵⁷FeBO₃ single crystal at the Néel temperature. The Doppler-shifted single-line ⁵⁷Fe M"ossbauer radiation at a fixed beam position was successfully filtered using the third-generation synchrotron radiation (SR) of SPring-8. We describe the principle of the variable-frequency Mossbauer filtering technique, the study on the beam characteristics, and some demonstrative experiments on energy-domain SR M"ossbauer spectroscopy.

36000039
X-ray spectroscopic diagnostics of ultrashort laser-cluster interaction at the stage of the nonadiabatic scattering of clusters
Faenov, A. Y.; Magunov, A. I.*; Pikuz, T. A.*; Skobelev, I. Y.*; Giulietti, D.*; Betti, S.*; Galimberti, M.*; Gamucci, A.*; Giulietti, A.*; Gizzi, L. A.*; Labate, L.*; Levato, T.*; Tomassini, P.*; Marques, J. R.*; Bourgeois, N.*; Dobosz-Dufrenoy, S.*; Ceccotti, T.*; Monot, P.*; Reau, F.*; Popescu, H.*; D'Oliveira, P.*; Martin, P.*; Fukuda, Yuji; Boldarev, A. S.*; Gasilov, S. V.*; Gasilov, V. A.*
JETP Letters 86(3), p.178-183(2007) ; (JAEA-J 03365)

X-ray spectroscopy diagnostics of laser-cluster interactions at a stage of non-adiabatical cluster expansion and formation of the spatially homogeneous plasma channel is carried out for the first time. It is shown, that X-ray line emission spectra of light elements, allows to determine parameters of the plasma formed at the time moment 10 ps from the beginning of femtosecond laser with relatively high plasma temperature Te 100 eV iand electron density Ne about 10¹⁹ - 10²⁰ cm^-3.

36000040
Magnetic structure study of antiferromagnet NpPtGa₅ by neutron diffraction
Jonen, Shintaro; Metoki, Naoto; Yamamoto, Etsuji; Homma, Yoshiya*; Aoki, Dai*; Shiokawa, Yoshinobu*; Onuki, Yoshichika
Journal of Alloys and Compounds 448(1-2), p.84-88(2008) ; (JAEA-J 03366)

The magnetic structure of NpPtGa₅ was investigated by neutron diffraction. NpPtGa₅ exhibits an A-type antiferromagnetic structure with propagation vector q = (0 0 1/2) below T_N = 26 K. The estimated Np magnetic moment is 0.38(5) μ_B, and it is oriented parallel to the <100> direction. This small moment would be consistent with the large γ = 123 mJ/(K²·mol), indicative of the heavy fermion nature. The field-induced anomaly in the magnetic susceptibility is clarified to be a signature for an antiferromagnetic domain change between multi-domains to single-domain states.

36000041
Hydrogen incorporation and gasochromic coloration of tungsten oxide films
Nagata, Shinji*; Inoue, Aichi; Yamamoto, Shunya; Tsuchiya, Bun*; Takano, Katsuyoshi; To, Kentaro*; Shikama, Tatsuo*
Journal of Alloys and Compounds 446-447, p.558-561(2007) ; (JAEA-J 03367)

The effect of the composition of non-stoichiometric WO₃ films on the gasochromic coloration are investigated. The films are prepared by a reactive RF magnetron sputtering with varying oxygen partial pressure. To determine the quantitative composition of deposited films, Rutherford backscattering spectroscopy (RBS) and Elastic recoil detection (ERD) are employed. Gasochromic coloration of the films coated with Pd catalyst is examined by optical transmission in hydrogen gas. O/W atomic ratio of the films increases from 0.25 to 3.0 with increasing the oxygen partial pressure in the sputtering gas. H/W ratio increases up to 0.7 with increasing the O/W ration. As regards gasochromic coloration, the film with O/W atomic ratio of 3.0 shows superior coloration performance comparing with that of less than 3.0. Therefore, it is assumed that the good gasochromic coloration of tungsten oxide films is realized by near-stoichiometric WO₃. In addition, gasochromic coloration state, increasing of hydrogen concentration in WO₃ films is observed. It indicates that gasochromic coloration of WO₃ is relate to formation of HWO₃ structure.

36000042
Pressure-induced structural change from hexagonal to fcc metal lattice in scandium trihydride
Omura, Ayako; Machida, Akihiko; Watanuki, Tetsu; Aoki, Katsutoshi; Nakano, Satoshi*; Takemura, Kenichi*
Journal of Alloys and Compounds 446-447, p.598-602(2007) ; (JAEA-J 03368)

Pressure-induced structural change from hcp to fcc-like metal lattice was investigated for scandium hydride, ScHx, by X-ray diffraction measurement up to 60 GPa at room temperature. Hydride was prepared in a diamond anvil cell (DAC) by compressing the metal foil with fluid hydrogen. The metal foil reacted with fluid hydrogen to form ScH₂ with an fcc metal lattice at about 4 GPa. Up to 5 GPa, fcc ScH₂ changed for the most part to ScH₃ with a hexagonal metal lattice, which persisted to about 25 GPa together with unreacted ScH₂. On further compression, the hcp lattice began to transform towards an fcc-like lattice. The transition completed at about 46 GPa. The successive change in diffraction pattern during the transition was quite similar to that observed for YHx, the transient state was not explained by the coexistence phase of ScH₂ and ScH₃ but able to be interpreted in terms of the gradual change in the sequential stacking of the metal layers.

36000043
Structural development of dynamically asymmetric polymer blends under uniaxial stretching
Takeno, Hiroyuki*; Uehara, Hiroki*; Murakami, Shozo*; Takenaka, Mikihito*; Kim, M.*; Nagasawa, Naotsugu; Sasaki, Sono*
Journal of Applied Crystallography 40(s1), p.s656-s661(2007) ; (JAEA-J 03369)

36000044
Extracting ion emission lines from femtosecond-laser plasma X-ray spectra heavily contaminated by spikes
Gasilov, S. V.*; Faenov, A. Y.; Pikuz, T. A.*; Villoresi, P.*; Poletto, L.*; Stagira, S.*; Calegari, F.*; Vozzi, C.*; Nisoli, M.*
Journal of Applied Physics 102(6), p.063303_1-063303_7(2007) ; (JAEA-J 03370)

Charged-coupled device (CCD) detectors are widely used nowadays for the registration of X-ray spectra of multicharged ions, generated in a plasma during interaction of ultrashort, ultraintenselaser pulses with solid targets. In this work we propose "mean to median" algorithm for the removal of noise from the X-ray spectra of femtosecondlaser plasma. Series of spectra is necessary for the identification of corrupted data points by the developed method. The algorithm was tested with model spectra and was used for extracting information about spectral lines of Ne like ions of Fe XVII and He like Al ions which allowed to calculate plasma parameters. It is demonstrated that M2M method is able to clean spectra with more then 0.1 of corrupted pixels. The method is also valid if variations in spectral lines induced by fluctuations in laser beam intensity are present.

36000045
Convergence acceleration of parallel CG-FEM with controlled domain decomposition for singularity problems
Kushida, Noriyuki; Okuda, Hiroshi*
Journal of Computational Science and Technology (Internet) 1(1), p.2-13(2007) ; (JAEA-J 03371)

Stress singularity is usually observed in practical stress analysis, and it may lead to the deterioration of the convergence rate of the preconditioned conjugate gradient method(PCG). Until now, parallel PCG has been used without considering the practical issues; therefore, the deterioration was induced in the problem in which stress singularity was observed. The convergence acceleration method was developed in parallel PCG based on controlled domain decomposition. The acceleration method can be achieved by considering the spatial locality of stress singularity and preconditioning of conjugate gradient method. The convergence acceleration method reduces the 15 % of iteration of PCG as a maximum, where the singular area is included in one domain.

36000046
Sequential variation of atmospheric mercury in Tokai-mura, seaside area of eastern central Japan
Osawa, Takahito; Ueno, Takashi; Fu, F.*
Journal of Geophysical Research 112(D19), p.D19107_1-D19107_9(2007) ; (JAEA-J 03372)

Concentrations of gaseous elemental mercury (GEM) were continuously measured from Oct. 2005 to Aug. 2006 in Tokai-mura, a small city on the Pacific side of central Japan. The concentration of atmospheric mercury in summer and autumn is higher than in winter and spring, and an 11-month average of one-hour measurements is 3.78 ng/m³ (n=7551). Our results showed that changes in the GEM level in Tokai-mura are largely determined by temperature and relative humidity, but are independent of wind speed and direction. Two contrary patterns were observed in the daily-cycle of GEM concentrations: the most frequent pattern of lower concentrations at noon and a pattern of higher concentrations at noon, which was only observed in November. Our results showed that two nearby potential anthropogenic sources of mercury, a coal-fired power plant and incineration facility, have only little effect on the gaseous elemental mercury (GEM) in Tokai-mura based on only GEM measurements.

36000047
Effect of truncation of electron velocity distribution on release of dust particle from plasma-facing wall
Tomita, Yukihiro*; Smirnov, R.*; Nakamura, Hiroaki*; Zhu, S.*; Takizuka, Tomonori; Tskhakaya, D.*
Journal of Nuclear Materials 363-365, p.264-269(2007) ; (JAEA-J 03373)

In the study of dust behavior in plasma it is usually assumed that plasma particles are Maxwell distributed. If the dust is located on the conducting wall, the surrounding particle distribution can significantly differ from the Maxwellian. In this work we study the effect of truncation of electron velocity distribution on release conditions of a spherical dust particle from a plasma-facing wall. The truncation effect enlarges the electric field at the wall compared compared to the Maxwellian. The stronger electric field at the wall makes the released region smaller when the gravitational force is directed from the wall.

36000048
Effect of heat treatments on tensile properties of F82H steel irradiated by neutrons
Wakai, Eiichi; Ando, Masami; Sawai, Tomotsugu; Tanigawa, Hiroyasu; Taguchi, Tomitsugu; Stroller, R. E.*; Yamamoto, Toshio; Kato, Yoshiaki; Takada, Fumiki
Journal of Nuclear Materials 367-370(1), p.74-80(2007) ; (JAEA-J 03374)

36000049
Effect of solute elements in Ni alloys on blistering under He⁺ D⁺ ion irradiation
Wakai, Eiichi; Ezawa, Tadashi*; Takenaka, Tsuyoshi*; Imamura, Junko*; Tanabe, Tetsuo*; Oshima, Ryuichiro*
Journal of Nuclear Materials 367-370(1), p.478-482(2007) ; (JAEA-J 03375)

36000050
Critical power characteristics in 37-rod tight lattice bundles under transient conditions
Liu, W.; Kureta, Masatoshi; Tamai, Hidesada; Onuki, Akira; Akimoto, Hajime
Journal of Nuclear Science and Technology 44(9), p.1172-1181(2007) ; (JAEA-J 03376)

Critical power characteristics in the postulated abnormal transient processes that may be possibly met in the normal operation of Innovative Water Reactor for Flexible Fuel Cycle (FLWR), were investigated for the design of the FLWR core. Transient Boiling Transition (BT) tests were carried out using two sets of 37-rod tight lattice rod bundles (rod diameter: 13 mm; rod clearance: 1.3 mm or 1.0 mm) at Japan Atomic Energy Agency (JAEA) under the conditions covering the FLWR operating condition (Pex = 7.2 MPa, Tin = 556 K) for mass velocity G = 400 - 800 kg/(m²s). For the postulated power increase and flow decrease transients, no obvious change of the critical power against the steady one was observed. The traditional quasi-steady characteristic was confirmed working for the postulated power increase and flow decrease transients in the design of the FLWR core. The experiments were analyzed with TRAC-BF1 code, where JAEA newest critical power correlation was implemented for the BT judgment. The TRAC-BF1 code showed good prediction for the occurrence or the non occurrence of the BT and for the exact BT starting time. The traditional quasi-steady state prediction of the BT in transient process was confirmed being applicable for the postulated abnormal transient processes in the tight lattice rod bundles.

36000051
Electrochemical studies on uranium in the presence of organic acids
Suzuki, Yoshinori; Nankawa, Takuya; Ozaki, Takuo; Onuki, Toshihiko; Francis, A. J.*; Enokida, Yoichi*; Yamamoto, Ichiro*
Journal of Nuclear Science and Technology 44(9), p.1227-1232(2007) ; (JAEA-J 03377)

We examined electrochemical redox reactions of UO₂²⁺ in organic acid (oxalic, malonic, succinic, adipic, L-malic, and L-tartaric acids) solutions using cyclic voltammetry. A redox reaction of UO₂²⁺/UO₂⁺ and an oxidation reaction of U(IV) were observed. The peak potentials of the UO₂²⁺ reduction showed a good linear relationship with the log of the stability constants of 1:1 UO₂²⁺-organic complexes. We also revealed the redox reactions of UO₂²⁺ in the presence of malonic or oxalic acids between pH 1 and 6.

36000052
REIDAC; A Software package for retrospective dose assessment in internal contamination of radionuclides
Kurihara, Osamu; Hato, Shinji; Kanai, Katsuta; Takada, Chie; Takasaki, Koji; Ito, Kimio; Ikeda, Hiroshi*; Oeda, Mikihiro*; Kurosawa, Naohiro*; Fukutsu, Kumiko*; Yamada, Yuji*; Akashi, Makoto*; Momose, Takumaro
Journal of Nuclear Science and Technology 44(10), p.1337-1346(2007) ; (JAEA-J 03378)

In the case of internal contamination of radionuclides, it is necessary to perform internal dose assessment for radiation protection. For this purpose, the ICRP has given the dose coefficients and the retention and excretion rates for various radionuclides. However, these dosimetric quantities are calculated only in typical conditions, therefore, are not necessarily covered enough in the case of dose assessment in which specific information on the incident or/and individual biokinetic characteristics should be taken into account retrospectively. This paper describes a developed PC-based package of software REIDAC to meet the needs in retrospective dose assessment. REIDAC was verified by comparisons with dosimetric quantities given on the ICRP publications and several examples of practical use were also shown.

36000053
Development of three-dimensional numerical model for ²²²Rn and its decay products coupled with a mesoscale meteorological model, 1; Model description and validation
Nishizawa, Masato; Nagai, Haruyasu; Chino, Masamichi; Moriizumi, Jun*; Yoshioka, Katsuhiro*; Okura, Takehisa; Yamazawa, Hiromi*; Iida, Takao*; Mukai, Hitoshi*; Tojima, Yasunori*; Oda, Nobukazu*; Shimano, Fujio*
Journal of Nuclear Science and Technology 44(11), p.1458-1466(2007) ; (JAEA-J 03379)

A three-dimensional Eulerian numerical model for ²²²Rn and its decay products coupled with a mesoscale meteorological model has been developed and applied to the reproduction of the daily and monthly variations of ²²²Rn concentration, the monthly variation of ²¹⁰Pb deposition in Japan and the temporal variation of γ dose rate after the cold front passage in the coastal area of the Japan Sea for the verification of model capability. The results are as follows: (1) The model reproduced the monthly variation of surface ²²²Rn concentration in remote islands, but underestimated inland concentration due to coarse vertical resolution near the surface of the model. (2) The model reproduced the seasonal variation of the observed and the long-term yearly averaged ²¹⁰Pb depositions as long as precipitations are predicted precisely. (3) The model reproduced the rise of γ dose rate in precipitation accompanied with the cold front passage. In particular, ²²²Rn decay products in melted snow and graupel contributed the rise of γ dose rate.

36000054
Unravelling the role of steps in Cu₂O formation via hyperthermal O₂ adsorption at Cu(410)
Okada, Michio*; Vattuone, L.*; Gerbi, A.*; Savio, L.*; Rocca, M.*; Moritani, Kosuke*; Teraoka, Yuden; Kasai, Toshio*
Journal of Physical Chemistry C 111(46), p.17340-17345(2007) ; (JAEA-J 03380)

We report a study on the oxidation process of Cu(410) using high-resolution electron energy loss spectroscopy and X-ray photoemission spectroscopy using synchrotron radiation. We demonstrate that a hyperthermal O₂ molecular beam (HOMB) is an efficient tool to fabricate Cu₂O thin film also at room temperature. The efficiency of the Cu₂O formation in the initial stages depends on the angle of incidence of HOMB. Step roughening, acting as a source of mobile precursor Cu adatoms and opening channels for bulk diffusion of the O atoms, is a key feature in determining the Cu₂O formation rate.

36000055
Pressure and temperature dependence of cuprous oxide nucleation on Cu(410)
Okada, Michio*; Vattuone, L.*; Moritani, Kosuke*; Savio, L.*; Teraoka, Yuden; Kasai, Toshio*; Rocca, M.*
Journal of Physics; Condensed Matter 19(30), p.305022_1-305022_7(2007) ; (JAEA-J 03381)

We studied the oxidation of Cu(410) for thermal O₂ exposure and using High-resolution Electron Energy-loss Spectroscopy. Cu₂O is identified by loss peaks at 19 meV and 79 meV. By monitoring the intensity of the latter, we find that Cu₂O formation depends strongly on surface temperature and on O₂ pressure and is kinetically limited by the impinging O₂ flux. Thermally activated step roughening, leading to detachment of Cu adatoms from the step edge, acts as a source of mobile Cu atoms allowing for subsequent nucleation of Cu₂O patches.

36000056
Development of a neutron radiography three-dimensional computed tomography system for void fraction measurement of boiling flow in tight lattice rod bundles
Kureta, Masatoshi
Journal of Power and Energy Systems (Internet) 1(3), p.211-224(2007) ; (JAEA-J 03382)

Neutron radiography 3D computed tomography (NR3DCT) technique has been developed comprehensibly in order to measure and visualize the 3D void fraction distribution of boiling flow in tight lattice heated-rod bundles. In this paper, NR3DCT system, data processing and error estimation methods were mainly described. Many kinds of practical data correction and processing methods were investigated to improve the reliability of the experimental data. Void fraction distributions from the incipient of boiling to high void fraction condition in tight-lattice 14-rod bundle was measured systematically. Effects of various data processing methods on experimental results were also discussed using the obtained data. As the result of the development, detailed vapor distribution of boiling flow in a heated bundle was made clear, and new void fraction database for verification of advanced numerical analysis codes could be provided.

36000057
Magnetic and magnetotransport properties in nanogranular Co/C₆₀-Co film with high magnetoresistance
Sakai, Seiji; Yakushiji, Kei*; Mitani, Seiji*; Sugai, Isamu; Takanashi, Koki*; Naramoto, Hiroshi*; Avramov, P.; Lavrentiev, V.*; Narumi, Kazumasa; Maeda, Yoshihito
Materials Transactions 48(4), p.754-758(2007) ; (JAEA-J 03383)

Magnetic properties were investigated for the alternately deposited film of C₆₀ and Co which has found to exhibit tunnel magnetoresistance (MR) of 10-80 %. Magnetic field and temperature dependences of magnetization showed typical superparamagnetic behaviors with the blocking temperature of 40 K. The magnetization curve at 300 K was well fitted by the Langevin function with the size distribution of Co particles, and the mean diameter and size distribution were evaluated to be 3.1 nm and 1 nm, respectively. Based on the magnetic properties, the detailed structure and magnetotransport properties are discussed.

36000058
Effect of helium and hydrogen production on irradiation hardening of F82H steel irradiated by ion beams
Wakai, Eiichi; Ando, Masami; Sawai, Tomotsugu; Onuki, Somei*
Materials Transactions 48(6), p.1427-1430(2007) ; (JAEA-J 03384)

Effects of helium and hydrogen production on irradiation hardening of martensitic steel F82H (Fe-8Cr-2W-0.2V-0.04Ta-0.1C) were examined by dual or triple beam experiments. The effects of tempering and cold working were also examined. The irradiations were performed at about 500°C to 50 dpa under simultaneous dual beams of 10.5 MeV-Fe and 1.05 MeV-He or triple beams of those and 380keV-H ions. The value of appm-He/dpa for the dual ion beams was about 15, and the values of appm-He/dpa and appm-H/dpa for the triple ion beams were 15 and 15 (or 150), respectively. The hardness of the irradiated specimens measured at room temperature using a micro indentation after the irradiations. Irradiation softening and hardening was observed in F82H-std, F82H+CW and a non-tempered F82H steels irradiated at about 500°C to 18 and 50 dpa, respectively, by dual ion beams. The hardness of the specimens irradiated at about 500°C to 18 dpa under triple ion beams was harder than that under dual ion beams.

36000059
Inter-subassembly heat transfer of sodium cooled fast reactors; Validation of the NETFLOW code
Mochizuki, Hiroyasu
Nuclear Engineering and Design 237(19), p.2040-2053(2007) ; (JAEA-J 03385)

This paper describes an applicability of the NETFLOW code for prediction of temperature at the exit of subassemblies of a sodium cooled fast reactor. So far, this code has been validated using data obtained at facilities and reactors of which coolants are water or sodium. A natural circulation test was conducted in the "Joyo" reactor with a 100 MW irradiation core, and a turbine trip test at "Monju". These tests were chosen to validate a model to calculate inter-subassembly heat transfer. Through a calculation for the natural circulation of "Joyo", a model to calculate heat transfer in radial direction of the inter-subassemblies gave the reasonable sodium temperatures at the exit of subassemblies. Good agreements were also obtained in prediction of temperatures of "Monju". It was shown that the NETFLOW could evaluate temperatures at the exit of the subassemblies with the inter-subassembly heat transfer model without heat transfer by inter-wrapper flow.

36000060
Confinement degradation and transport of energetic ions due to Alfvén eigenmodes in JT-60U weak shear plasmas
Ishikawa, Masao; Takechi, Manabu; Shinohara, Koji; Cheng, C. Z.*; Matsunaga, Go; Kusama, Yoshinori; Fukuyama, Atsushi*; Nishitani, Takeo; Morioka, Atsuhiko; Sasao, Mamiko*; Baba, Mamoru*; JT-60 Team
Nuclear Fusion 47(8), p.849-855(2007) ; (JAEA-J 03386)

Confinement degradation of energetic ions due to Alfvén Eigenmodes (AEs) induced by negative-ion-based neutral beam injection for the classical confinement is quantitatively evaluated for the first time. AEs, whose frequency largely sweep and then saturate as the minimum value of the safety factor decrease, have been observed in JT-60U. These mode behavior can be explained by RSAEs and the transition from RSAEs to TAEs. Measured total neutron emission rate in the presence of these AEs is compared with that predicted by a classical theory. As a result, confinement degradation of energetic ions is confirmed. Line-integrated neutron emission profile is also compared with that predicted when assuming that the confinement is classical. The result indicates energetic ions are transported from core region of the plasma due to these AEs.

36000061
ITER activities and fusion technology
Seki, Masahiro
Nuclear Fusion 47(10), p.S489-S500(2007) ; (JAEA-J 03387)

In the 21st IAEA Fusion Energy Conference, 68 and 67 papers were presented in the categories of ITER activities and the fusion technology, respectively. ITER performance prediction, results of technology R&D and the construction preparation provide good confidence of ITER realization. Superconducting tokamak EAST achieved the first plasma just before the conference. Constructions of other new experimental machines have also shown steady progress. Future reactor studies stress the importance of down sizing and steady state approach. Reactor technology in the field of blanket including the ITER TBM program and materials for demonstration power plant showed sound progress in both R&D and design activities.

36000062
Extended steady-state and high-beta regimes of net-current free heliotron plasmas in the Large Helical Device
Motojima, Osamu*; Yamada, Hiroshi*; Komori, Akio*; Oyabu, Nobuyoshi*; Muto, Takashi*; Kaneko, Osamu*; Kawahata, Kazuo*; Mito, Toshiyuki*; Ida, Katsumi*; Imagawa, Shinsaku*; Nagayama, Yoshio*; Shimozuma, Takashi*; Watanabe, Kiyomasa*; Masuzaki, Suguru*; Miyazawa, Junichi*; Morisaki, Tomohiro*; Morita, Shigeru*; Odachi, Satoshi*; Ono, Noriyasu*; Saito, Kenji*; Sakakibara, Satoru*; Takeiri, Yasuhiko*; Tamura, Naoki*; Toi, Kazuo*; Tokitani, Masayuki*; Yokoyama, Masayuki*; Yoshinuma, Mikiro*; Ikeda, Katsunori*; Isayama, Akihiko; Ishii, Kameo*; Kubo, Shin*; Murakami, Sadayoshi*; Nagasaki, Kazunobu*; Seki, Tetsuo*; Takahata, Kazuya*; Takenaga, Hidenobu; LHD Experimental Group*
Nuclear Fusion 47(10), p.S668-S676(2007) ; (JAEA-J 03388)

The performance of net-current free heliotron plasmas has been developed by findings of innovative operational scenarios in conjunction with an upgrade of the heating power and the pumping/fuelling capability in the Large Helical Device (LHD). Consequently, the operational regime has been extended, in particular, with regard to high density, long pulse length and high beta. Diversified studies in LHD have elucidated the advantages of net-current free heliotron plasmas. In particular, an internal diffusion barrier (IDB) by a combination of efficient pumping of the local island divertor function and core fuelling by pellet injection has realized a super dense core as high as 5×10²⁰ m^-3, which stimulates an attractive super dense core reactor. Achievements of a volume averaged beta of 4.5% and a discharge duration of 54 min with a total input energy of 1.6 GJ (490 kW on average) are also highlighted. The progress of LHD experiments in these two years is overviewed by highlighting IDB, high-beta and long pulse.

36000063
Studies on impact of electron cyclotron wave injection on the internal transport barriers in JT-60U weak shear plasmas
Ide, Shunsuke; Takenaga, Hidenobu; Isayama, Akihiko; Sakamoto, Yoshiteru; Yoshida, Maiko; Gormezano, C.*
Nuclear Fusion 47(11), p.1499-1505(2007) ; (JAEA-J 03389)

Impact of the electron cyclotron range of frequency wave (ECRF) on the internal transport barriers (ITBs) in a weak shear (WS) plasma has been investigated in JT-60U. It is observed that the ion temperature (T_i) ITB in a WS plasma can be degraded by ECRF. It is clarified for the first time that the degradation depends increasingly on the EC power (P_EC) but decreasingly on the plasma current (I_p). Moreover it is confirmed that ECRF affects the toroidal rotation (V_t) indirectly and results in flattening of V_t(ρ) profiles regardless of the direction of the target V_t(ρ). Furthermore, it is newly found that T_i and V_t in the whole ITB region are affected with almost no delay from the EC onset even with off-axis EC deposition. These results indicate that the EC injection unveiled a semi-global structure that characterizes T_i ITB in a WS plasma.

36000064
Controllability of large bootstrap current fraction plasmas in JT-60U
Sakamoto, Yoshiteru; Takenaga, Hidenobu; Fujita, Takaaki; Ide, Shunsuke; Suzuki, Takahiro; Takechi, Manabu; Kamada, Yutaka; Oyama, Naoyuki; Isayama, Akihiko; Koide, Yoshihiko; JT-60 Team
Nuclear Fusion 47(11), p.1506-1511(2007) ; (JAEA-J 03390)

36000065
Design optimization for plasma performance and assessment of operation regimes in JT-60SA
Fujita, Takaaki; Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Bialek, J.*; Aiba, Nobuyuki; Tsuchiya, Katsuhiko; Sakurai, Shinji; Suzuki, Yutaka; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Oyama, Naoyuki; Suzuki, Takahiro; Navratil, G. A.*; Kamada, Yutaka; Miura, Yukitoshi; Takase, Yuichi*; Campbell, D.*; Pamera, J.*; Romanelli, F.*; Kikuchi, Mitsuru
Nuclear Fusion 47(11), p.1512-1523(2007) ; (JAEA-J 03391)

Design of modification of JT-60U, JT-60SA, has been optimized in viewpoint of plasma control, and operation regimes have been evaluated. Upper and lower divertors with different geometry are prepared for flexibility of plasma shape control. The beam lines of negative-ion NBI are shifted downward for off-axis current drive, in order to obtain a weak/reversed shear plasma. The feedback control coils along the port hole in the stabilizing plate are found effective to suppress the resistive wall mode (RWM) and sustain high β_N close to the ideal wall limit. The regime of full current drive operation has been extended with upgraded heating and current drive power. Full current drive operation for 100 s with reactor-relevant high values of normalized beta and bootstrap current fraction (I_p = 2.4 MA, β_N = 4.4, f_BS = 0.70, n_e/n_GW = 0.86, H_H98y2 = 1.3) is expected in a highly-shaped low-aspect-ratio configuration (A = 2.65). High β_N, high-density ELMy H-mode is also expected.

36000066
Hydrogen retention and carbon deposition in plasma facing components and the shadowed area of JT-60U
Masaki, Kei; Tanabe, Tetsuo*; Hirohata, Yuko*; Oya, Yasuhisa*; Shibahara, Takahiro*; Hayashi, Takao; Sugiyama, Kazuyoshi*; Arai, Takashi; Okuno, Kenji*; Miya, Naoyuki
Nuclear Fusion 47(11), p.1577-1582(2007) ; (JAEA-J 03392)

In JT-60U, erosion/deposition analyses for the plasma facing wall have shown that deposition was dominant at the inner-middle first wall and the inner divertor, whereas erosion dominant at the upper first wall and the outer divertor. Assuming toroidal symmetry in the erosion and deposition patterns, the net carbon erosion and deposition in the divertor area were estimated to be 0.34 kg and 0.55 kg, respectively. In a whole, the increment of carbon in the divertor region was 0.21 kg, which should be originated from the first wall. The hydrogen concentration in the thick deposition layer of the inner divertor was 0.02 in (H+D)/C. In the plasma-shadowed area underneath the divertor region at around 420 K, re-deposited layers of 2 μm-thick were found with high hydrogen concentration of 0.8 in (H+D)/C. The carbon deposition rate in the plasma-shadowed area, however, was 8×10¹⁹ atoms/s, which was one order smaller than that (6×10²⁰ atoms/s) on the wall surface.

36000067
Reevaluation of secondary neutron spectra from thick targets upon heavy-ion bombardment
Sato, Daiki; Kurosawa, Tadahiro*; Sato, Tatsuhiko; Endo, Akira; Takada, Masashi*; Iwase, Hiroshi*; Nakamura, Takashi; Niita, Koji*
Nuclear Instruments and Methods in Physics Research A 583(2-3), p.507-515(2007) ; (JAEA-J 03393)

Previously-published data of secondary neutron spectra from thick targets of C, Al, Cu and Pb bombarded with heavy ions from He to Xe are revised by using a new set of neutron-detection efficiency values for a liquid organic scintillator calculated with SCINFUL-QMD. Additional data have been measured for bombardment of C target by 400-MeV/nucleon C ions and 800 MeV/nucleon Si-ions. The set of spectra are compared with the calculation results using a Monte-Carlo heavy-ion transport code, PHITS. It was found that PHITS is able to reproduce the secondary neutron spectra in a wide neutron-energy regime.

36000068
PHITS; Benchmark of partial charge-changing cross sections for intermediate-mass systems
Mancusi, D.*; Sihver, L.*; Gustafsson, K.*; La Tessa, C.*; Guetersloh, S.*; Zeitlin, C.*; Miller, J.*; Heilbronn, L.*; Niita, Koji*; Sato, Tatsuhiko; Nakashima, Hiroshi; Murakami, Takeshi*; Iwata, Yoshiyuki*
Nuclear Instruments and Methods in Physics Research B 254(1), p.30-38(2007) ; (JAEA-J 03394)

The PHITS code is a three-dimensional Monte Carlo code that is able to simulate the transport of nuclei and other particles in complicated geometries. As a part of a comprehensive benchmarking program, we have investigated the possibility of using PHITS to calculate partial charge-changing cross sections and we have compared the results with measurements. The results suggest that the current reaction-cross-section models might be inadequate for use in space radiation protection: We therefore claim the need for a thorough benchmarking of the models and for new reaction-cross-section measurements and experimental techniques.

36000069
Syntheses of amine-type adsorbents with emulsion graft polymerization of glycidyl methacrylate
Seko, Noriaki; Bang, L. T.*; Tamada, Masao
Nuclear Instruments and Methods in Physics Research B 265(1), p.146-149(2007) ; (JAEA-J 03395)

Radiation-induced graft polymerization is attractive technique for preparing metal-ion adsorbents. The reactive monomer of glycidyl methacrylate (GMA) has been widely used for the syntheses of metal-ion adsorbents. This is because the GMA contains an epoxy group which can react easily with amine derivatives. Therefore, GMA-grafted polymer can be converted to various kinds of metal-ions adsorbents. Generally, GMA can be grafted by using organic solvent such as methanol and dimethyl sulfoxide. We found that the emulsion of GMA was available for effective grafting. The GMA was grafted onto polyethylene fiber (PE fiber) in the emulsion system. Polyoxyethylene sorbitan monolaurate (Tween 20) was used as a surfactant to prepare the micelles of GMA in water. The degree of grafting reached 300% after the 1h grafting on 30 kGy irradiated PE fiber in the GMA emulsion obtained by mixture of 5% GMA, 0.5% Tween 20, and 94.5% water. Then, the GMA grafted PE fiber was chemically modified by using diethylene-triamine and triethylenetetramine and the amine-type adsorbents were obtained.

36000070
Radiation effects on hydroxypropyl methylcellulose phthalate in aqueous system
Xu, L.*; Yue, Z.*; Wang, M.*; Zhai, M.*; Yoshii, Fumio; Seko, Noriaki; Peng, J.*; Wei, G.*; Li, J.*
Nuclear Instruments and Methods in Physics Research B 265(1), p.394-398(2007) ; (JAEA-J 03396)

A water insoluble cellulose derivative, hydroxypropyl methylcellulose phthalate (HPMCP) hydrogels, was converted to Na type to form hydrogel in paste-like status by radiation crosslinking. Mechanism for radiation crosslinking of cellulose-derivatives in paste-like status was discussed. Crosslinkers, i.e., methyl N,N-bis-acrylamide (MBA) or ethyleneglycol dimethacrylate (EGDMA) has been used to decrease gelation dose (Dg) of synthesis HPMCP hydrogels and improve its mechanical properties. MBA was found to be more effective for accelerating the crosslinking of HPMCP than EGDMA. Swelling degree of HPMCP hydrogel in many kinds ofsalt solutions followed Hofmeister series, which is ubiquitous in polyelectrolyte hydrogel. Specific reswelling was observed in concentrated KF solution, implying a very strong F^- binding ability of benzyl group. The comprehensive results obtained in this study will be utilized on the design of HPMCP-based controlled release system.

36000071
Sequence-dependent DNA deformability studied using molecular dynamics simulations
Fujii, Satoshi*; Kono, Hidetoshi; Takenaka, Shigeori*; Go, Nobuhiro; Sarai, Akinori*
Nucleic Acids Research 35(18), p.6063-6074(2007) ; (JAEA-J 03397)

Proteins recognize specific DNA sequences not only through direct contact between amino acids and bases, but also indirectly based on the sequence-dependent conformation and deformability of the DNA (indirect readout). We used molecular dynamics simulations to analyze the sequence-dependent DNA conformations of all 136 possible tetrameric sequences sandwiched between CGCG sequences. The deformability of dimeric steps obtained by the simulations is consistent with that by the crystal structures. The simulation results further showed that the conformation and deformability of the tetramers can highly depend on the flanking base-pairs. The conformations of xATx tetramers show the most rigidity and are not affected by the flanking base-pairs and the xYRx show by contrast the greatest flexibility and change their conformations depending on the base-pairs at both ends, suggesting tetramers with the same central dimer can show different deformabilities. These results suggest that analysis of dimeric steps alone may overlook some conformational features of DNA and provide insight into the mechanism of indirect readout during protein-DNA recognition. Moreover, the sequence dependence of DNA conformation and deformability may be used to estimate the contribution of indirect readout to the specificity of protein-DNA recognition as well as nucleosome positioning and large-scale behavior of nucleic acids.

36000072
Spectral phase measurement of attosecond pulses using the quantum beat between the P_1/2 and P_3/2 levels of alkali-metal atoms
Itakura, Ryuji
Physical Review A 76(3), p.033810_1-033810_8(2007) ; (JAEA-J 03398)

We propose a method for measuring the spectral phase of attosecond pulses by means of angle-resolved photoelectron spectroscopy of alkali atoms in the ²P state. A coherent superposition of ²P_1/2 and ²P_3/2 allows us to observe the quantum beat, whose phase offset is measured as a function of photoelectron energy. The formulation derived in this study elucidates that the phase offset is straightforwardly utilized for measuring the spectral phase of attosecond pulses. This method is applicable not only to near transform-limited attosecond pulses, but also to significantly chirped pulses with the same spectrum. Numerical simulation for Cs atoms demonstrates the feasibility in the experiment and the simplicity in the analysis.

36000073
Multiply inner-shell excited states produced through multiple X-ray absorption relevant to X-ray pulses
Moribayashi, Kengo
Physical Review A 76(4), p.042705_1-042705_6(2007) ; (JAEA-J 03399)

We study fluorescence X-rays emitted from multiply inner-shell excited states produced by high-brightness X-ray absorption. The pulses of the fluorescence X-rays from the multiply inner-shell excited states are shorter than that of the original X-ray source. As the pulse of X-ray sources becomes shorter, hollow atoms are produced more efficiently.

36000074
Pressure-induced structural change of liquid InAs and the systematics of liquid III-V compounds
Hattori, Takanori; Tsuji, Kazuhiko*; Miyata, Yasuhisa*; Sugawara, Takayuki*; Shimojo, Fuyuki*
Physical Review B 76(14), p.144206_1-144206_10(2007) ; (JAEA-J 03400)

To understand the pressure-induced structural changes of liquid III-V compounds systematically, the pressure dependence of liquid InAs was investigated using the synchrotron X-ray diffraction and an ab initio molecular dynamics simulation (AIMD). The X-ray diffraction experiments revealed that the liquid changes its compression behavior from a nearly uniform type to a nonuniform one around 9 GPa. Corresponding to this change, the coordination number CN, which is maintained up to 9 GPa, markedly increases from 6.0 to 7.5. The AIMD simulation revealed that this change is related to the change in the pressure dependence of all three pair correlations. In particular, a marked change is observed in the As-As correlation; in the low pressure region the position of the first peak in g_AsAs(r), r_AsAs, increases with maintaining the CN_AsAs, but in the high pressure region the r_AsAs stops increasing and the CN_AsAs begins to increase. The results for InAs are compared with those for GaSb and InSb and the systematics of the pressure-induced structural change of liquid III-V compounds are dicussed.

36000075
Role of multiparticle-multihole states in ^18,19O in thermal neutron capture of ¹⁸O
Nagai, Yasuki*; Segawa, Mariko; Osaki, Toshiro*; Matsue, Hideaki; Muto, Kazuo*
Physical Review C 76(5), p.051301_1-051301_6(2007) ; (JAEA-J 03401)

The primary E1 γ-ray transition strength from the thermal neutron capture of ¹⁸O to the 3/2^- state, 18 keV below the neutron threshold of ¹⁹O, was found to be about two hundred thousand times stronger than that to the 1/2^- excited state, 729 keV below the threshold. In addition, the E1 strength from the 3/2^- state leading to the 3/2⁺ state with three (d_5/2)³ neutrons was six times stronger than that to the 5/2⁺ ground state with a single (d_5/2) neutron. These anomalous γ-ray decay patterns give the first clear experimental evidence for the predicted property of the 3/2^- state as mainly having a one-hole-four-particle configuration. Unique features of the ¹⁸O ground state with a two-hole-four-particle configuration and of the 3/2⁺ state combined with a discrete prompt γ-ray spectroscopy following the thermal neutron capture of ¹⁸O enabled us to exclusively identify the configuration of the 3/2^- state.

36000076
Suppression of cavitation inception by gas bubble injection; A Numerical study focusing on bubble-bubble interaction
Ida, Masato; Naoe, Takashi; Futakawa, Masatoshi
Physical Review E 76(4), p.046309_1-046309_10(2007) ; (JAEA-J 03402)

The dynamic behavior of cavitation and gas bubbles under negative pressure has been studied numerically to evaluate the effect of gas bubble injection on the suppression of cavitation inception. In our previous studies it has been demonstrated by direct observation that cavitation occurs in liquid mercury when mechanical impacts are imposed and it will cause cavitation damage in spallation neutron sources. In the present paper, we have performed numerical investigations on the dynamics of cavitation bubbles in liquid mercury using a multibubble model that takes into account the interaction of a cavitation bubble with preexisting gas bubbles through the bubble-radiated pressure waves. The numerical results suggest that cavitation inception is suppressed by the positive pressure wave radiated by the injected large gas bubbles which decreases the magnitude of the negative pressure in the mercury.

36000077
Genetic characterization of mutants resistant to the antiauxin p-chlorophenoxyisobutyric acid reveals that AAR3, a gene encoding a DCN1-like protein, regulates responses to the synthetic auxin 2,4-dichlorophenoxyacetic acid in Arabidopsis roots
Biswas, K. K.*; Oura, Chiharu*; Higuchi, Kanako*; Miyazaki, Yuji*; Nguyen, V. V.*; Rahman, A.*; Uchimiya, Hirofumi*; Kiyosue, Tomohiro*; Koshiba, Tomokazu*; Tanaka, Atsushi; Narumi, Issei; Ono, Yutaka
Plant Physiology 145(3), p.773-785(2007) ; (JAEA-J 03403)

We screened mutants for root growth resistance to a putative antiauxin, PCIB, which inhibits auxin action by interfering the upstream auxin signaling events. Eleven PCIB-resistant mutants were obtained. Genetic mapping indicates that the mutations are located in at least 5 independent loci including two known auxin-related loci, TIR1 and AtCUL1. antiauxin-resistant mutants aars) aar3-1, aar4 and aar5 were also resistant to 2,4-D as shown by a root growth assay. Positional cloning of aar3-1 revealed that the AAR3 gene encodes a protein with a domain of unknown function (DUF298), which has not previously been implicated in auxin signaling. The protein has a putative nuclear localization signal and shares homology with the DCN-1 protein through the DUF298 domain. The results also indicate that PCIB can facilitate the identification of factors involved in auxin or auxin-related signaling.

36000078
AtREV1, a Y-family DNA polymerase in Arabidopsis, has deoxynucleotidyl transferase activity in vitro
Takahashi, Shinya*; Sakamoto, Ayako; Tanaka, Atsushi; Shimizu, Kikuo*
Plant Physiology 145(3), p.1052-1060(2007) ; (JAEA-J 03404)

To clarify the functions of AtREV1 protein, we expressed it in E. coli and purified it. The deoxynucleotidyl transferase activity of the recombinant AtREV1 was examined in a primer extension assay in vitro. The recombinant AtREV1 transferred one or two nucleotides to the primer end. Especially, it efficiently inserted dCMP regardless of the opposite base. AtREV1 also inserted a dCMP opposite the apurinic/apyrimidinic (AP) sites, which are physiologically generated or induced by various DNA-damaging agents. However, AtREV1 had no insertion activities against UV-inducible DNA lesions. Although the substrate specificity of AtREV1 was rather narrow in the presence of magnesium ion, it widened in the presence of manganese ion. These results suggest that AtREV1 serves as a deoxycytidyl transferase in plant cells.

36000079
Advanced fabrication method of planar components for plasma diagnostics
Ito, Naoki*; Mase, Atsushi*; Kogi, Yuichiro*; Seko, Noriaki; Tamada, Masao; Shen, Z.*; Yang, L.*; Domier, C. W.*; Luhmann, N. C. Jr.*; Sakata, Eiji*
Plasma and Fusion Research (Internet) 2, p.S1042_1-S1042_4(2007) ; (JAEA-J 03405)

As the importance of plasma imaging diagnostics increases, the fabrication of high performance millimeter-wave planar components becomes essential. This paper describes the development of high performance millimeter-wave planar components such as antennas and filters using low-loss fluorine substrate. The problems to be solved are low degree of adhesion between copper foil and fluorine substrate and shape of antenna pattern. In order to solve the problems, surface treatment of fluorine films and a fabrication method using Electro Fine Forming (EF2) are utilized.

36000080
Development of real-time measurement system of charge exchange recombination spectroscopy and its application to feedback control of ion temperature gradient in JT-60U
Kobayashi, Shinji*; Yoshida, Maiko; Takenaga, Hidenobu; Sakata, Shinya; Kamada, Yutaka; Sakamoto, Yoshiteru; Koide, Yoshihiko; JT-60 Team
Plasma and Fusion Research (Internet) 2, p.S1049_1-S1049_4(2007) ; (JAEA-J 03406)

Real-time measurement system of the ion temperature profile has been developed for the feedback (FB) control of the ion temperature gradient (grad-T_i) with the filter charge exchange recombination spectroscopy (CXRS) system in JT-60U. The rapid analytical scheme without non-linear least square fitting enables us to calculate the ion temperature with four spatial points every 10 ms using a real-time processor system. The FB control experiment of grad-T_i has been demonstrated in ELMy H-mode plasmas by use of the neutral beam injectors having different deposition profiles as actuators. Grad-T_i was controlled to the reference value in the ramp-down phase, however, it did not recovered in the ramp-up phase because the internal transport barrier or transport was affected by the ramp-down of grad-T_i. From the transient response analysis of grad-Ti, the increase in the central T_i using the additional heating was required to recover the deteriorated grad-T_i.

36000081
Development of impurity influx monitor (Divertor) for ITER
Ogawa, Hiroaki; Sugie, Tatsuo; Kasai, Satoshi; Katsunuma, Atsushi*; Hara, Hirotsugu*; Kusama, Yoshinori
Plasma and Fusion Research (Internet) 2, p.S1054_1-S1054_4(2007) ; (JAEA-J 03407)

36000082
Development of ITER diagnostic upper port plug
Sato, Kazuyoshi; Omori, Junji; Ebisawa, Katsuyuki*; Kusama, Yoshinori; Neyatani, Yuzuru
Plasma and Fusion Research (Internet) 2, p.S1088_1-S1088_4(2007) ; (JAEA-J 03408)

A part of diagnostic device in vacuum vessel is planned to install in the port plug to make sure the line of sight of diagnostics. Only basic concept is shown for the port plug since design of diagnostic devices has not been substantiated yet. The integration design of the port plug has been performed and the structure concept for electro-magnetic and neutron load has been investigated as for the No.11 upper port plug to confirm reliability of the proposed design. Three diagnostics will be installed in the No.11 upper port plug, the edge Thomson scattering system, the visible-IR TV divertor viewing system and the neutron activation system. To integrate theses diagnostic systems in the port plug, it was designed the arrangement of the labyrinth of optical path, the driving mechanism and cooling systems for shutters and mirrors, the maintenance space. The part just behind the blanket shield module (BSM) was changed to secure a space for maintenance and for associated diagnostic first mirror and shutter, whereas this place is assigned for neutron shielding in the present design. The BSM support, which is main component to apply the electro-magnetic load, was arranged with optical path inside BSM.

36000083
Sensitivity study for the optimization of the viewing chord arrangement of the ITER poloidal polarimeter
Yamaguchi, Taiki; Kawano, Yasunori; Kusama, Yoshinori
Plasma and Fusion Research (Internet) 2, p.S1112_1-S1112_4(2007) ; (JAEA-J 03409)

36000084
Biodegradability of poly(3-hydroxybutyrate) film grafted with vinyl acetate; Effect of grafting and saponification
Wada, Yuki; Seko, Noriaki; Nagasawa, Naotsugu; Tamada, Masao; Kasuya, Kenichi*; Mitomo, Hiroshi*
Radiation Physics and Chemistry 76(6), p.1075-1083(2007) ; (JAEA-J 03410)

Radiation-induced graft polymerization of vinyl acetate (VAc) onto poly(3-hydroxybutyrate) (PHB) film was carried out. At a degree of grafting higher than 5%, the grafted films (PHB-g-VAc) completely lost the enzymatic degradability that is characteristic of PHB due to the grafted VAc covering the surface of the PHB film. However, the biodegradability of the PHB-g-VAc films was recovered when the films were saponified in alkali solution under optimum conditions. Graft chains of the PHB-g-VAc film reacted selectively to become biodegradable polyvinyl alcohol (PVA). The biodegradability of the saponified PHB-g-VAc film increased rapidly with time.

36000085
Circulation in the northern Japan Sea studied chiefly with radiocarbon
Aramaki, Takafumi*; Senju, Tomoharu*; Togawa, Orihiko; Otosaka, Shigeyoshi; Suzuki, Takashi; Kitamura, Toshikatsu; Amano, Hikaru; Volkov, Y. N.*
Radiocarbon 49(2), p.915-924(2007) ; (JAEA-J 03411)

36000086
Space environmental effects on MoS₂ and diamond-like carbon lubricating films; Atomic oxygen-induced erosion and its effect on tribological properties
Tagawa, Masahito*; Yokota, Kumiko*; Matsumoto, Koji*; Suzuki, Mineo*; Teraoka, Yuden; Kitamura, Akira*; Belin, M.*; Fontaine, J.*; Martin, J. M.*
Surface & Coatings Technology 202(4-7), p.1003-1010(2007) ; (JAEA-J 03412)

Effects of 5 eV atomic oxygen beam on MoS₂ and diamond-like carbon (DLC) lubrication films are evaluated relevance to space environmental effects in the low Earth orbit. X-ray photoelectron spectra indicate that the loss of S atoms and Mo oxidation at the atomic oxygen irradiated MoS₂ is significant. Depth profiles of S and Mo indicate that the oxidation is restricted within 3 nm from the surface. This is due to the fact that Mo oxide plays as a protective layer against further oxidation. The surface oxidation affects the friction coefficient. However, due to the delamination of oxide layer, wear-life of the film is reduced in some conditions. In contrast, no sever oxidation states of C atoms are detected at DLC surface. However, the loss of DLC itself is measured by Rutherford backscattering spectroscopy. It is concluded that the protection of DLC film is mandatory for the use of DLC in the LEO space applications.

36000087
R&D of lifetime extension for primary materials by active chemistry control for coolant helium; Corrosion tests of heat resistant alloy
Takeda, Yoichi*; Hamamoto, Shimpei; Sakaba, Nariaki
Transactions of the American Nuclear Society 97, p.677(2007) ; (JAEA-J 03413)

Ni-base heat-resistant alloys are used for the structural components in gas cooled reactors and exposed to high-temperature helium gas environment. The degradation issues of the material like oxidation and creep are primary concern for the plant operation and further development of the alloys to be used in Very High-Temperature Reactor (VHTR) and Gas-Cooled Fast Reactor (GFR). In this investigation, corrosion testing facility was fabricated in order to investigate oxidation behavior of heat resistant alloys in high-temperature helium environments.

36000088
Measurement of thermal conductivity of (U_0.68Pu_0.3Am_0.02)O_2-x in high temperature region
Komeno, Akira; Morimoto, Kyoichi; Kato, Masato; Kashimura, Motoaki; Ogasawara, Masahiro*; Sunaoshi, Takeo*
Transactions of the American Nuclear Society 97, p.616-617(2007) ; (JAEA-J 03414)

36000089
Evaluation of thermal conductivity of (U, Pu, Am)O_2-x
Morimoto, Kyoichi; Kato, Masato; Komeno, Akira; Kashimura, Motoaki
Transactions of the American Nuclear Society 97, p.618-619(2007) ; (JAEA-J 03415)

Plutonium and uranium mixed oxide (MOX) fuel with high Pu-content has been developed as a fuel for fast reactors (FRs). Thermal conductivity of the oxide fuel is among the most important properties for design and performance analyses of fuel rods. Among recent reports, there have been none examining of thermal conductivity of MOX fuel containing Am except our studies. In this study, the thermal conductivities of MOX fuel with 30% Pu-content, as obtained by our group, were evaluated as functions of temperature, oxygen-to-metal (O/M) ratio and Am-content.

36000090
Three-dimensional X-ray CT image of irradiated FBR fuel assembly
Katsuyama, Kozo; Nagamine, Tsuyoshi; Nakamura, Yasuo; Asaga, Takeo; Furuya, Hirotaka
Transactions of the American Nuclear Society 97, p.620-621(2007) ; (JAEA-J 03416)

36000091
R&D of lifetime extension for primary materials by active chemistry control for coolant helium; A Study of chemical equilibrium in the HTGR core
Sakaba, Nariaki; Hamamoto, Shimpei; Takeda, Yoichi*
Transactions of the American Nuclear Society 97, p.678-680(2007) ; (JAEA-J 03417)

Inherent safety advantages of the helium gas cooled reactors over other types of reactors depend importantly on the chemical stability of the actual helium coolant gas itself. Although helium being an inert gas does not react with fuel and components, chemical impurities which exist in the actual helium coolant can react with the surface of high-temperature materials such as the heat transfer tubes of the intermediate heat exchanger. The chemical effect of the impurities strongly influences to shorten the lifetime of the high-temperature materials. The dominant chemical reactions occurring in the core have not previously identified due to the complicated effects of not only high temperatures but also radioactivity during power operation of the helium gas cooled reactors. As such the methodology to control the high-temperature material lifetime has not been established because of the lack of knowledge and active control of the carbon activity and partial pressure of the oxygen which determine the creep fatigue of the high-temperature materials. The present study of the chemical equilibriums in the HTGR core is an initial effort to establish the lifetime extension methodology. The study examines the effects of high temperature and irradiation on the chemical equilibriums in the core by using an analytical code and basing on the chemical impurity data obtained in the HTTR operations.

36000092
Development of sheet-type hydrogen sensors
Takano, Katsuyoshi; Inoue, Aichi; Yamamoto, Shunya; Sugimoto, Masaki; Sugiyama, Akira; Yoshikawa, Masahito
Transactions of the Materials Research Society of Japan 32(3), p.673-676(2007) ; (JAEA-J 03418)

The deposition of tungsten oxide on the sheet of polyethylene terephthalate or polyvinylindene chloride was performed by sputtering method. It was found that the color of the sheets changes within few minuets to expose 0.1 vol.% diluted hydrogen, so as to be able to confirm the change by viewing. The sheets can be produced with low cost, and are useful as convenient sheet-type hydrogen sensors for the utilization of hydrogen in fuel cell as a clean energy source.

36000093
Scrapping work of gloveboxes in plutonium fuel research facility (in Japanese)
Iwai, Takashi; Kikuchi, Hironobu; Arai, Yasuo
Dekomisshoningu Giho (36), p.54-63(2007) ; (JAEA-J 03419)

Both gloveboxes No.121-D and No.122-D used for metallography were installed about thirty years ago in the room No.101 of Plutonium Fuel Research Facility in Oarai Research Esbtablishment of former Japan Atomic Energy Research Institute (JAERI). It was planned to scrap the old gloveboxes and build new ones for starting new research on advanced fuel. This report summarized the scrapping work of the gloveboxes from the technical viewpoints.

36000094
Visualization of physiological functions of plant using positron imaging technique (in Japanese)
Matsuhashi, Shimpei
Denki Hyoron 92(10), p.63-67(2007) ; (JAEA-J 03420)

36000095
Alteration type and thermoluminescence ages of altered rocks in the Mutsu-Hiuchidake volcanic field, Shimokita peninsula, NE Japan (in Japanese)
Tomiyama, Shingo*; Umeda, Koji; Hanamuro, Takahiro; Takashima, Isao*; Hayashi, Shintaro*; Negishi, Yoshimitsu*; Masudome, Yukiko*
Ganseki Kobutsu Kagaku 36(4), p.111-121(2007) ; (JAEA-J 03421)

To clarify a progress history of the alteration accompanied by Mutsu-Hiuchidake volcanic activities, the study on distribution and characteristics of alteration zones and alteration dating at the Mutsu-Hiuchidake Volcano. The results of alteration zoning and alteration dating suggest that alteration zones generated by hydrothermal activities accompanied by Mutsu-Hiuchidake volcanic activities are distributed along the fracture zones and enlarged by fractures or highly permeable zones in the body of volcano and basement. The result of measurement of homogeneous temperatures of fluid inclusion suggests that the highest temperature of these hydrothermal alterations is about 200 to 250°C.

36000096
Epidemiological studies on indoor radon risk; A Review and current issues (in Japanese)
Yonehara, Hidenori*; Ishimori, Yu; Akiba, Suminori*; Iida, Takao*; Iimoto, Takeshi*; Kai, Michiaki*; Shimo, Michikuni*; Tokonami, Shinji*; Yamada, Yuji*; Yoshinaga, Shinji*; Yonezawa, Rika
Hoken Butsuri 42(3), p.201-213(2007) ; (JAEA-J 03422)

The pooled analysis recently carried out in European countries and North American countries showed the excess relative risk of lung cancer increased by 10-20% per 100 Bqm^-3 increase in indoor radon concentration. The Scientific Committee on Indoor Radon Risk and Response to the Issue established by the Japan Health Physic Society reviewed the scientific evidence on the indoor radon risk obtained so far and evaluated the pooled analysis results from the viewpoint of estimating the risk coefficient in Japan. The committee concludes that the risk shown by the pooled analysis results has the consistency from miners risk analysis, and that it is probably not low in the reliability and validity, although the value may include the uncertainties caused from the correction of radon concentration measured, from the effect of thoron on measurement results, from the differences of environmental parameters in exposure, and so on.

36000097
Transport processes of radionuclides in the Japan Sea obtained by JAEA's expeditions
Togawa, Orihiko; Ito, Toshimichi; Otosaka, Shigeyoshi
Hoken Butsuri 42(3), p.234-246(2007) ; (JAEA-J 03423)

The Japan Atomic Energy Agency (JAEA) has carried out expeditions in the Japanese and Russian exclusive economic zones (EEZ) of the Japan Sea for 10 years to clarify seawater circulation and transport processes of radionuclides in the sea. The Japan Sea expeditions by JAEA started with its participation in the Japanese-Korean-Russian joint expeditions of 1994 and 1995. Through 18 expeditions, JAEA succeeded in covering almost all areas of the Japan Sea that can be observed at present. As a result, for the first time, JAEA has made distribution maps of anthropogenic radionuclides in the Japan Sea and outlined the transport processes of radionuclides in the sea. Furthermore, we also obtained the results on water circulation and oceanographic features of the Japan Sea. This review summarizes representative and important results obtained in the Japan Sea expeditions by JAEA. The dataset on the distribution of anthropogenic radionuclides established by this study provides background data in assessing the radiological consequences in cases of radioactive waste disposal in the sea or nuclear emergency response to accidental releases of radionuclides in or near the Japan Sea.

36000098
Traceability on radon measurements at the JAEA Ningyo-toge
Ishimori, Yu
Hoken Butsuri 42(3), p.247-254(2007) ; (JAEA-J 03424)

The study on the establishment and maintenance of the traceability on radon measurements at the Ningyo-toge Environmental Engineering Center of the Japan Atomic Energy Agency (JAEA Ningyo-toge) is illustrated in this paper. A primary standard is a radium solution provided by the National Bureau of Standard (present the National Institute of Standards and Technology) in the U.S.A., a secondary standard is the method with gas-filled ionization chambers calibrated with the solution. The radon test chamber is utilized to provide reference atmospheres in calibration experiments for other monitors. Through the intercomparison experiments among the international reference institutes, it was confirmed that the reliability and consistency of the secondary standard of the JAEA Ningyo-toge has been retained since 1984. It shows that the calibration and measurement techniques associated with the traceability system constructed were maintained well at the JAEA Ningyo-toge. Since there is no reference field as a national standard and no method regulated by the Japanese Industrial Standard, this paper provides not only reliability and accuracy of the radon measurements at the JAEA Ningyo-toge, but also useful information for the standardization of radon measurements in Japan.

36000099
Lightning caused by energetic radiation (in Japanese)
Torii, Tatsuo
Hoshasen Bogo Iryo (3), p.10-13(2007) ; (JAEA-J 03425)

36000100
Roles of JAEA as a designated public corporation to nuclear disaster caused by armed attack (in Japanese)
Fukumoto, Masahiro
Hoshasen Bogo Iryo (3), p.22-24(2007) ; (JAEA-J 03426)

JAEA is a public corporation designated by the Armed Attack Situation Law and set the plan for protection of the civilian population in armed attack situations which describes basic countermeasures for protection of the civilian population in armed attack situations. The exercise for protection of the civilian population to the nuclear disaster caused by the armed attack in Ibaraki prefecture (2006) is refered and JAEA's roles in the nuclear disaster defined by the Law concerning the Measures for Protection of the Civilian Population in Armed Attack Situations. Differences between the two kinds of Nuclear Disaster are to consider the sheltering and evacuation concerning armed attack and so on. It is important for us to improve the effectiveness of the Countermeasures by the exercises. And JAEA is needed to announce the relevant information from the research on Japanese and foreign countries' cases and keep on improving the technological support ability.

36000101
Nuclear tests in China and environmental radiation monitoring (in Japanese)
Watanabe, Hitoshi
Hoshasen Bogo Iryo (3), p.28-30(2007) ; (JAEA-J 03427)

36000102
The Future target by environment purification and conservation with radiation processing (in Japanese)
Seko, Noriaki
Hoshasen Kagaku (84), p.37-43(2007) ; (JAEA-J 03428)

Environment functional materials can contribute the environmental conservation such as removal reagents of toxic metal and security of metal resources. These functions were introduced into the artificially and naturally occurring polymers by radiation graft polymerization. Graft polymerization can change the conventional polymer to metal adsorbents which realize rapid adsorption and easy handling. The synthesized fibrous adsorbents were applied for the collection of uranium from seawater or scandium from hot spring water and the removal of toxic metal ions form scallop waste.

36000103
A Novel non-intrusive resistance thermometer for sodium in fast breeder reactor (in Japanese)
Yamasaki, Hiro*; Honda, Satoshi*; Ueda, Masashi; Endo, Akira*; Fueki, Manabu*
Keisoku Jido Seigyo Gakkai Rombunshu 43(9), p.756-761(2007) ; (JAEA-J 03430)

A non-intrusive temperature sensing system is proposed. It is developed for temperature measurement of liquid sodium coolant in fast breeder reactor. Liquid sodium is used as coolant due to high heat flux density in the reactor core. In this paper, the results of our feasibility study by 2-dimensional numerical simulation, small size experimental test done by Japan Atomic Energy Agency Oarai Institute, and theoretical analysis are described. The basic principle of temperature measurement is resistant thermometry of liquid sodium. The resistivity of liquid sodium is quite lower than that of the stainless steel (SUS304), which is used in the pipe wall. The resistivity temperature coefficient of liquid sodium(0.337%/deg) is higher than that of stainless steel(0.0865%/deg). If we feed electric current perpendicular to the axis of flow pipe, the current penetrates the pipe wall and flow across the liquid. The current concentrates the liquid sodium, only small portion of the current flows along the pipe wall. The electric potential distribution is almost dominated by resistivity of sodium. The potential distribution can be measured along the out side of the pipe wall. The potential difference between two fixed points on the pipe wall indicates the resistivity of sodium So the sodium temperature can be measured by potential difference. Measurement accuracy of ±5°C is obtained in experimental tests. Better estimation data are obtained by theoretical analysis using three dimensional model.

36000104
Preparation of polylactic acid nonwoven fabric-based metal adsorbent by radiation-induced graft polymerization
Ueki, Yuji; Seko, Noriaki; Hoshina, Hiroyuki; Tamada, Masao
Nippon Ion Kokan Gakkai-Shi 18(4), p.214-219(2007) ; (JAEA-J 03431)

Fibrous metal adsorbent was prepared by radiation-induced graft polymerization of glycidyl methacrylate onto a polylactic acid (PLA) nonwoven fabric and its subsequent modification based on ring opening of epoxides with disodium iminodiacetate (IDA-Na). The degree of grafting of PLA fabric can be controlled in the range of up to 225% by optimizing the grafting conditions such as reaction time, preirradiation dose, monomer concentration and reaction temperature. The optimal IDA group density of the prepared adsorbent was 500 μmol/g-adsorbent, and its selectivity for metal ions was Cu²⁺ > Pb²⁺ > Ni²⁺ > Zn²⁺ > Cd²⁺ > Co²⁺ > Ca²⁺ > Mg²⁺.

36000105
Preparation of graft adsorbent having amine groups and its Au(III) adsorption performance
Seko, Noriaki; Ueki, Yuji; Hoshina, Hiroyuki; Tamada, Masao
Nippon Ion Kokan Gakkai-Shi 18(4), p.232-235(2007) ; (JAEA-J 03432)

Metal adsorbent was prepared by co-graft polymerization of allylamine and methacrylic acid (or N-vinylacetamide) onto nonwoven fabrics made of polyethylene-coated polypropylene fiber using radiation induced graft polymerization method. Behavior of the resulting adsorbents in uptake of Au(III) was evaluated by both batch and columnar methods. In the column test, the breakthrough of Au(III) was evaluated with three different flow rates of 260, 520 and 1040 h^-1 in space velocity (SV) by pumping 1 mM Au(III) solution into the column at pH 3. Breakthrough points of three flow rates were 163, 150 and 144 bed volumes (BV), respectively. Furthermore, the breakthrough of Au(III) was evaluated at pH range from 1 to 7 by pumping 100 ppb Au(III) solution into the column in the SV of 4680 h^-1. The breakthrough point was 175 BV at the pH 1 and 2, and went up to 179 BV at pH 3.

36000106
Synthesis of graft adsorbent with N-methyl-D-glucamine for boron adsorption
Hoshina, Hiroyuki; Seko, Noriaki; Ueki, Yuji; Tamada, Masao
Nippon Ion Kokan Gakkai-Shi 18(4), p.236-239(2007) ; (JAEA-J 03433)

It is well known that adsorbents having N-methyl-D-glucamine (NMDG) preferentially adsorb boron. The boron adsorbent developed in this study has promising properties of rapid boron adsorption from the natural water. The adsorbent was prepared by radiation induced graft polymerization of glycidyl methacrylate (GMA) onto non-woven polyethylene fabrics in aqueous medium, and following chemical modification with NMDG. The resulting adsorbent was evaluated by column-mode adsorption of boron at various flow rates. Comparison between graft adsorbent and granular resin, graft adsorbent has 4 times higher bed volume (BV) at breakthrough point at space velocity (SV) 50 h^-1. The BV at breakthrough point of graft adsorbent at SV 100 h^-1 gave the same one with granular resin at SV 10 h^-1.

36000107
Solvent extraction of various metals including actinides by bidentate and tridentate diamides
Sasaki, Yuji; Kimura, Takaumi; Oguma, Koichi*
Nippon Ion Kokan Gakkai-Shi 18(4), p.354-359(2007) ; (JAEA-J 03434)

Many diamide-type extractants were synthesized and tested for the extraction of actinides (III), (IV), (V) and (VI). The diglycolamides (DGA) with two amidic oxygen and one ether oxygen, which show the tridentate feature, have the high extractability of actinides (An). In order to increase the lipophilic property, the diglycolamides with the different functional groups attached to N atoms were synthesized and examined for their extractability. It was found that tetraoctyl-diglycolamide (TODGA) and tetradecyl-diglycolamide (TDDGA) exhibit the satisfactory dissolution into dodecane with less solubility in H₂O. The results of various metal extractions using TODGA revealed that the divalent, trivalent and tetravalent metals with ionic radius of 90-120 pm gave notably high D values. After elucidation of the effect on substitution of the functional group, the chemical form of DGA to have high performance on An extraction was proposed.

36000108
Irradiation creep behavior of reduced activation ferritic/martensitic steel irradiated in HFIR (in Japanese)
Ando, Masami; Tanigawa, Hiroyasu; Shiba, Kiyoyuki; Jitsukawa, Shiro; Kono, Yutaka*; Koyama, Akira*; Li, M.*; Stoller, R. E.*
Nippon Kinzoku Gakkai-Shi 71(7), p.559-562(2007) ; (JAEA-J 03435)

36000109
Modification of elastic poly(lactic acid) by radiation-induced crosslinking (in Japanese)
Nagasawa, Naotsugu; Tamada, Masao; Kanazawa, Shinichi*; Hayasaki, Toshikatsu*
Purasuchikkusu 58(11), p.45-48(2007) ; (JAEA-J 03436)

Poly(lactic acid), PLA was irradiated using electron beams in the presence of triallyl isocyanurate at 5 phr concentration as crosslinking agent. The crosslinked PLA, of which heat resistance was improved, is applied on flexible and elastic materials by addition of plasticizer or immersion in plasticizer. The elastic PLA material has several advantages such as high holding plasticizer, heat resistance at 80 °C and transparency. It is therefore proven that crosslinking technology is beneficial to expanding application of soften PLA.

36000110
Radiation hydrodynamic simulation of extreme ultra-violet emission from laser-produced tin plasmas (in Japanese)
Sunahara, Atsushi*; Sasaki, Akira; Tanuma, Hajime*; Nishihara, Katsunobu*; Nishikawa, Takeshi*; Koike, Fumihiro*; Fujioka, Shinsuke*; Aota, Tatsuya*; Yamaura, Michiteru*; Shimada, Yoshinori*; Nishimura, Hiroaki*; Izawa, Yasukazu*; Miyanaga, Noriaki*; Mima, Kunioki*
Purazuma, Kaku Yugo Gakkai-Shi 83(11), p.920-926(2007) ; (JAEA-J 03438)

We study the EUV emission from laser produced Sn plasmas using the 1D and 2D radiation hydrodynamics simulation, for the development of EUV source for the next generation semiconductor lithography. The opacity and emissivity of the plasma used in the simulation are calculated by a detailed atomic model, with the accurate wavelength of emission lines obtained from the detailed spectroscopic measurements. Calculation is shown to reproduce the experimental spectrum and conversion efficiency reasonably, including the effect of photo pumping which modifies the EUV emission spectrum in the case with a long scale length of the plasmas.

36000111
Phantom development for radiation dose estimation, 2; Development of tissue equivalent materials (in Japanese)
Kinase, Sakae
Radioisotopes 56(10), p.625-628(2007) ; (JAEA-J 03439)

36000112
Application of neutron imaging to inspection of art objects and ancient artifacts (in Japanese)
Matsubayashi, Masahito; Masuzawa, Fumitake*
Radioisotopes 56(11), p.763-775(2007) ; (JAEA-J 03440)

36000113
New type of shotcrete containing much pozzolanic additives (in Japanese)
Miura, Norihiko*; Konishi, Kazuhiro*; Iriya, Keishiro*; Nakayama, Masashi; Matsui, Hiroya
Semento, Konkurito (728), p.63-67(2007) ; (JAEA-J 03441)

High level radioactive waste(HLW) repository is to be constructed at depth of over 300m below the surface. Shotcrete and lining will be used for safety under construction and operational period. Concrete is a kind of composite material which is constituted by aggregate, cement and additives. Low alkaline cement has been developed from the viewpoint of long term stability of the barrier systems which would be influenced by high alkaline arising from cement material. Japan Atomic Energy Agency(JAEA) has been developed HFSC(Highly Fly-ash contained Silica-fume Cement) which is one of a low alkaline cement contained silica-fume and fly-ash. JAEA is now implementing the construction of the underground research laboratory(URL) at Horonobe for the purpose of research in deep geological science and repository engineering technology. This report shows the properties of HFSC using as shotcrete.

36000114
Single-cell/single-particle irradiation using heavy-ion microbeams (in Japanese)
Kobayashi, Yasuhiko
Shinku 50(9), p.564-568(2007) ; (JAEA-J 03442)

36000115
Spallation neutron source at J-PARC and its cryogenic hydrogen system (in Japanese)
Kato, Takashi; Aso, Tomokazu; Tatsumoto, Hideki; Hasegawa, Shoichi; Otsu, Kiichi
Teion Kogaku 42(8), p.244-254(2007) ; (JAEA-J 03443)

The JAEA and the KEK are collaborating in the construction of the Japan Proton Accelerator Research Complex (J-PARC). The J-PARC has four science experimental facilities, a materials and life science experimental facility, a nuclear and particle experimental facility, a neutrino experimental facility, and a nuclear transmutation facility (planned for the future). At the materials and life science experimental facility, a spallation neutron source has been constructed to provide experiment users with neutron beams that have the world's highest pulse intensity. Neutrons produced using spallation reaction should possess a high energy of MeV order, but neutrons used for experiments should have energy of a low meV order. Therefore, an effective material that is capable of moderating neutron energy is required. That material is supercritical hydrogen; and the spallation neutron source should therefore be equipped with a cryogenic hydrogen system that provides supercritical hydrogen to the neutron energy moderating system. This paper discusses the spallation neutron source and the cryogenic hydrogen system.

36000116
Safety design of the cryogenic hydrogen system at J-PARC (in Japanese)
Kato, Takashi; Aso, Tomokazu; Tatsumoto, Hideki; Hasegawa, Shoichi; Otsu, Kiichi
Teion Kogaku 42(8), p.255-264(2007) ; (JAEA-J 03444)

JAEA has been constructing the J-PRAC in collaboration with the KEK. The materials and life science experimental facility (MLF) has been constructed as one of the experimental science facilities at J-PARC. A spallation neutron source that produces neutrons through nuclear spallation reaction using high-energy proton beam injection and provides neutron beams for experimental users has been installed at the MLF. Hydrogen nuclei are used as a neutron moderating material (moderator) to reduce the neutron energy from MeV to meV order. Therefore, a cryogenic hydrogen system should be installed at the spallation neutron source to provide supercritical hydrogen to moderators. This paper describes the safety design of the cryogenic hydrogen system. Especially, the system is subject to high-pressure gas safety laws, and refrigeration safety regulations are applied to the system for the first time. We also discuss the technical contents that were argued through this application.

36000117
Evaluation of thermal strain caused by Nb₃Sn reaction heat treatment for the ITER cable-in-conduit conductors (in Japanese)
Matsui, Kunihiro; Koizumi, Norikiyo; Nabara, Yoshihiro; Isono, Takaaki; Takahashi, Yoshikazu; Okuno, Kiyoshi
Teion Kogaku 42(9), p.311-316(2007) ; (JAEA-J 03445)

Cable-in-conduit (CIC) conductor using Nb₃Sn strand will be used in ITER Toroidal Field (TF) coil. The thermal strain is generated in the CIC conductor by heat treatment because of the difference of the thermal expansion between the Nb₃Sn strands and stainless steal jacket. The fabrication method of the TF coil winding and design of conductor joint should be determined by taking into account the elongation/shrinkage and the residual force of CIC conductor caused by the thermal strain. To evaluate them, the authors developed a new apparatus and those of the TF conductors were measured. The maximum elongation/shrinkage of the conductors was 0.03%, and the maximum residual force was 35 kN. The winding method of TF coil is proposed based on these results.

36000118
Development of new treatment process for low level liquid waste at Tokai reprocessing plant
Saito, Yasuo; Takano, Masato; Tanaka, Kenji; Kobayashi, Kentaro; Otani, Yoshikuni
Proceeding of International Symposium on Radiation Safety Management 2007 (ISRSM 2007) , p.275-280(2007) ; (JAEA-J 03446)

The Low-radioactive Waste Treatment Facility (LWTF), which aims to provide the safe, efficient and economic treatment and disposal of Low-level Liquid Waste (LLW) generated from LWR spent fuel reprocessing, was constructed at the Tokai Reprocessing Plant (TRP), and a cold test is now being carried out. New treatment processes such as a removal process for radio-nuclides and the ROBE (BORSAURE EINENGUNG ANLAGE) solidification process are being implemented in the LWTF. In order to treat the large amount of sodium nitrate contained in the concentrated LLW with higher safety and economy, R&D work on nitrate-ion decomposition technology using a catalytic reduction method and on the solidification process by cementation is being undertaken. The results of this R&D will be adopted in the LWTF in the near future. This report describes an outline of liquid waste treatment in the LWTF and new treatment technologies for LLW to achieve safe, efficient and economic treatment and disposal.

36000119
Flow sheet evaluations for the thermochemical water-splitting Iodine-Sulfur process, 2
Kubo, Shinji; Imai, Yoshiyuki; Ohashi, Hirofumi; Kasahara, Seiji; Tanaka, Nobuyuki; Okuda, Hiroyuki; Onuki, Kaoru
Proceedings of 2007 AIChE Annual Meeting (CD-ROM) , 5p.(2007) ; (JAEA-J 03447)

36000120
Control techniques for Bunsen reaction solution to regulate process condition
Kubo, Shinji; Nakajima, Hayato; Imai, Yoshiyuki; Kasahara, Seiji; Onuki, Kaoru
Proceedings of 2007 AIChE Annual Meeting (CD-ROM) , 5p.(2007) ; (JAEA-J 03448)

36000121
Flow sheet evaluations for the thermochemical water-splitting Iodine-Sulfur process, 1
Kubo, Shinji; Ijichi, Masanori*; Hodotsuka, Masatoshi; Yoshida, Mitsunori*; Kasahara, Seiji; Isaka, Kazuyoshi; Tanaka, Nobuyuki; Imai, Yoshiyuki; Onuki, Kaoru
Proceedings of 2007 AIChE Annual Meeting (CD-ROM) , 7p.(2007) ; (JAEA-J 03449)

36000122
Strategic recycling of fission products in nuclear fuel cycle as for hydrogen production catalyst
Ozawa, Masaki; Fujita, Reiko*; Koyama, Shinichi; Suzuki, Tatsuya*; Fujii, Yasuhiko*
Proceedings of 9th OECD/NEA Information Exchange Meeting on Actinide and Fission Product Partitioning and Transmutation , p.315-324(2007) ; (JAEA-J 03450)

Catalytic Electrolytic extraction method has been studied as a separation tool for rare metal fission products, RMFP in the spent nuclear fuel. In an employed CEE process, Pd²⁺ cation itself would not only be easily deposited from various nitric acid solutions, but enhance also the deposition of co-existing RuNO³⁺, ReO₄^- and ⁹⁹TcO₄^- by acting as a catalyst. The quaternary-, Pd-Ru-Rh-Re, deposit Pt or Ti electrode, fabricated by CEE, suggested the highest cathodic current corresponding to the hydrogen generation reaction in both alkaline solution and sea water. Advanced ORIENT Cycle, where ion exchange chromatography using tertiary pyridine resin and the CEE employ as mainstay separation technology, will enhance separation and utilization of actinide and fission product, and thus be expected to realize ultimate reducing radioactive wastes.

36000123
Vitrification experience and new technology development in Tokai vitrification facility
Aoshima, Atsushi; Ueno, Tsutomu; Shiotsuki, Masao
Proceedings of European Nuclear Conference 2007 (ENC 2007) (CD-ROM) , 5p.(2007) ; (JAEA-J 03451)

Tokai Vitrification Facility (TVF) started hot operation in 1996 and produced 241 canisters as of June 2007. Through TVF operation, JAEA had much experience and accumulated much technical know-how which indicated that management for noble metal accumulation in a melter was key technology for smooth plant operation. JAEA should continue service operation based on a vitrification contract with the Japanese utilities because there remains about two third of High Active Liquid Waste (HALW) produced in the reprocessing service operation of Tokai Reprocessing Plant (TRP). TVF melter is designed in condition of five years life time because of very corrosive characteristic of melted glass. Five years design life time is equivalent to 500 canisters production in TVF. Because estimated number of canisters which will be produced in the future is over 500 canisters, exchange of the present melter is necessary. From these situations, JAEA decided basic strategy to increase stability of the existing melter operation and develop an advanced new melter for replacement in future which has largely prolonged life time and high noble metal drain ability. To attain these targets, JAEA extracted necessary key technologies to assemble into a ten years road map and started development. This development has been progressing on schedule.

36000124
Use of WWR-K reactor for long-term trials of lithium ceramic Li₂TiO₃ for fusion reactor blanket
Tazhibayeva, I. L.*; Kenzhin, E. A.*; Chachrov, P. V.*; Arinkin, F. M.*; Gasatulin, Sh. Kh.*; Bekamukhabetov, E. S.*; Shestakov, V. P.*; Chikhray, E. V.*; Kulsartov, T. V.*; Kuykabaeva, A. A.*; Kawamura, Hiroshi; Tsuchiya, Kunihiko
Questions of Atomic Science and Technology; Series the Thermonuclear Fusion, 2 , p.3-10(2007) ; (JAEA-J 03452)

36000125
Advanced ORIENT cycle, toward realizing intensified transmutation and utilization of radioactive wastes
Ozawa, Masaki; Koyama, Shinichi; Suzuki, Tatsuya*; Fujita, Reiko*; Mimura, Hitoshi*; Fujii, Yasuhiko*
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM) , p.451-457(2007) ; (JAEA-J 03453)

To minimize the ecological burden originating in nuclear fuel recycling, a new R&D strategy, Adv.-ORIENT (Advanced Optimization by Recycling Instructive ElemeNTs) cycle, was set forth. A key separation tool is ion exchange chromatography (IXC) by a tertiary pyridine resin having soft donor nitrogen atoms. This method has provided individual recovery of pure Am and Cm products with a Pu/U/Np fraction from irradiated fuel in just a 3-step separation. A catalytic electrolytic extraction (CEE) method by Pd_adatom has been employed to separate, purify and fabricate RMFP catalysts. High separation efficiency of RMFP proved hydrochloric acid as a suitable media for their recovery. Different functioned ion exchangers, e.g., ammonium molybdophosphate (AMP), have been investigated for the separation of Cs⁺. Theoretical and laboratory studies on the isotope separation of LLFPs were begun for ⁷⁹Se, ¹²⁶Sn and ¹³⁵Cs.

36000126
Some advanced technologies for low-level radioactive waste treatment in JAEA
Meguro, Yoshihiro; Tomioka, Osamu; Yamaguchi, Hiromi; Takahashi, Kuniaki
Proceedings of International Symposium on EcoTopia Science 2007 (ISETS '07) (CD-ROM) , p.1043-1046(2007) ; (JAEA-J 03454)

In order to lower the cost of the disposal of low-level radioactive waste, several waste treatment technologies, such as reduction of radioactive concentration in the waste, reduction in amount of the waste, and removal of harmful materials for the disposal, are essential. The authors have developed four waste treatment technologies; these are a supercritical CO₂ fluid decontamination method, a calcination method, a chemical reductive denitration method, and a steam reforming method in JAEA. It was demonstrated that these methods showed promise for the waste treatment.

36000127
Uranium crystallization study with irradiated MOX fuel
Nomura, Kazunori; Nakahara, Masaumi; Yano, Kimihiko; Sano, Yuichi; Shibata, Atsuhiro; Washiya, Tadahiro
Proceedings of International Symposium on EcoTopia Science 2007 (ISETS '07) (CD-ROM) , p.1058-1061(2007) ; (JAEA-J 03455)

The uranium crystallization study has been carried out with various solutions. Several tens % of uranium was recovered from the simulated dissolver solution. As the results of the tests, pre-adjustment of the plutonium valence to (+4) was necessary to prevent plutonium co-crystallizing with uranium. Among the fission products, cesium behavior in some trials with the actual dissolver solution was different from that with the simulated dissolver solution. Decontamination factor of cesium to uranium crystals was about 100 in the simulated dissolver solution tests. From the other trials, however, it was suggested that the cesium was precipitated, and accompanied with uranium crystals. This cesium behavior is under investigation while the modification of the process conditions of the uranium crystallization and a new technology of crystal purification has been studying.

36000128
Corrosion study on cold crucible for pyrochemical reprocessing of spent nuclear fuel
Takeuchi, Masayuki; Arai, Yoichi; Kase, Takeshi; Koizumi, Tsutomu
Proceedings of International Symposium on EcoTopia Science 2007 (ISETS '07) (CD-ROM) , p.1084-1088(2007) ; (JAEA-J 03456)

Pyrochemical reprocessing methods using molten salt for spent nuclear fuel have been studied in the world, because of advantage over the nuclear weapons proliferation and cost benefit. However, electrowinning process, which is one of the processes in pyrochemical reprocessing method, includes severe corrosion environment. In this study, the efficacy of cold crucible in electrowinning process was experimentally discussed. We carried out the corrosion test of several metals in molten 2CsCl-NaCl with corrosive gases at 923 K to investigate the relationship between material temperature controlled by air cool and corrosion rate. As results, the corrosion rate of hastelloy alloy was less than 0.1 mm/y by cooling the material surface at 473 K and corresponds to 1/1000 of that at 923 K. In such way, the cold crucible gives the extreme improvement of corrosion, and this result gave promising prospect to solve the corrosion problem in electrowinning process.

36000129
Thermal fatigue evaluation method considering fluid-structure interaction against fluid temperature fluctuation
Kasahara, Naoto; Kawasaki, Nobuchika; Kamide, Hideki; Sakai, Shinsuke*; Okajima, Satoshi*
Proceedings of International Symposium on Research for Aging Management of Light Water Reactors and Its Future Trend , p.23-1-23-16(2007) ; (JAEA-J 03457)

Fluid temperature fluctuates at an incomplete mixing area of high and low temperature fluids in nuclear components. It induces random variations of local temperature gradients in structural walls, which lead to cyclic thermal stresses. When thermal stresses and cycle numbers are large, there are possibilities of fatigue crack initiations and propagations. It is recognized that there are attenuation factors depending on fluctuation frequency in the transfer process from fluid temperature to thermal stresses. Considering above fluid-structure interaction against fluid temperature fluctuation, authors has proposed a fatigue evaluation method related to frequencies. JAEA has the plan to develop thermal load modeling guidelines, which has consistency with JSME guidelines for light water reactors.

36000130
Variation of volume transport of the Tsugaru Warm Current in the period from 2000 to 2002
Ito, Toshimichi; Kawamura, Hideyuki; Nakayama, Tomoharu*; Shima, Shigeki*; Onishi, Mitsuyo*; Isoda, Yutaka*
Proceedings of International Workshop on Monitoring and Forecasting of the Rapid Change in Ocean-Atmosphere Environment in the East Asia , p.13-14(2007) ; (JAEA-J 03458)

The volume transport of the Tsugaru Warn Current (TgWC) from April 2000 to June 2002, which was estimated based on the ferry-borne ADCP observation was examined in this study. The estimated transport varied from about 0.6 Sv to 2.5 Sv (=10⁶ m³s^-1), and the mean value was estimated to be about 1.3 Sv with ± 0.3 Sv showing the similar level as that in the preliminary result. The temporal variation with a period of about 20-30 days seemed to be remarkable in the anterior half of this observation period rather than seasonal variation. By contrast, the seasonal variation was dominant in the posterior half in which the minimum and maximum values appear in the spring and autumn, respectively. The temporal change of the transport showed good correlation with the sea level differences around the strait as expected. In addition, the present result suggests that the change of local wind around the strait also lead in part of the change of the transport.

36000131
Status of ERL development at JAEA, 2007 (in Japanese)
Nagai, Ryoji; Hajima, Ryoichi; Sawamura, Masaru; Nishimori, Nobuyuki; Kikuzawa, Nobuhiro; Iijima, Hokuto; Minehara, Eisuke
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.16-18(2007) ; (JAEA-J 03465)

We are proposing energy-recovery linac (ERL) based photon sources, which are a next generation X-ray light-source, a γ-ray source for a radioactive waste management, and an EUV-FEL for a next generation lithography. Related R&D is in progress. In this paper, we summarize these proposed ERL photon sources and research activities.

36000132
Design of pencil beam formation system for high-accuracy carbon-ion microsurgery (in Japanese)
Arakawa, Kazuo; Oikawa, Masakazu*; Shimada, Hirofumi*; Kamiya, Tomihiro; Nakano, Takashi*; Yusa, Ken*; Kato, Hiroyuki*; Sato, Takahiro; Agematsu, Takashi; Kashiwagi, Hirotsugu; Fukuda, Mitsuhiro*; Sakai, Takuro; Okumura, Susumu; Kurashima, Satoshi; Miyawaki, Nobumasa; Yuri, Yosuke; Saito, Yuichi; Ishii, Yasuyuki; Yokota, Wataru; Kishi, Shoji*; Sato, Taku*; Horiuchi, Yasushi*; Yamada, Satoru*
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.279-281(2007) ; (JAEA-J 03466)

36000133
Performance test of low beta superconducting twin quarter wave resonator (in Japanese)
Kabumoto, Hiroshi; Takeuchi, Suehiro; Ishizaki, Nobuhiro; Matsuda, Makoto; Otokawa, Yoshinori
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.469-471(2007) ; (JAEA-J 03467)

JAEA and KEK have started acceleration of radioactive nuclear beam (RNB) and stable ion beam (SNB) from Tokai Radioactive Ion Accelerator Complex (TRIAC) in 2005. RNB and SNB are accelerated by SCRFQ and IH linac up to the energy of 1.1 MeV/u. We were planning to re-accelerate the beams in the future by superconducting booster up to energy of 5-8 MeV/u. In order to inject the beams into superconducting booster, we need a pre-booster which is capable of acceleration from 1.1 MeV/u to 2.0 MeV/u. We have started development of superconducting twin quarter wave resonator (Twin-QWR), and have fabricated a prototype Twin-QWR in FY2005. We have carried out performance test of prototype Twin-QWR in FY2006.

36000134
RF characteristic of eccentric-fluted beam pipe (in Japanese)
Sawamura, Masaru; Umemori, Kensei*; Furuya, Takaaki*; Sakanaka, Shogo*; Takahashi, Takeshi*; Suwada, Tsuyoshi*; Sakai, Hiroshi*; Shinoe, Kenji*
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.472-474(2007) ; (JAEA-J 03468)

An eccentric-fluted beam pipe has been proposed to damp quadrupole modes. The eccentric-flute acts as a mode converter from quadrupole to dipole. Optimized parameters permit to damp both degenerate modes of quadrupole with the eccentric-flute. External Q-values measured with a low power model agree well with those calculated with MAFIA.

36000135
An Interrogation method for radioactive waste by using an ERL-based high-flux γ-ray source (in Japanese)
Kikuzawa, Nobuhiro; Hajima, Ryoichi; Hayakawa, Takehito; Minehara, Eisuke
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.577-579(2007) ; (JAEA-J 03469)

Laser-Compton-backscattered photons from an energy-recovery linac (ERL) and a high power laser realize a high-efficiency, high-flux and tunable monochromatic γ-ray source. A non-destructive interrogation method by using nuclear resonance fluorescence (NRF) make possible to measure the discrimination of clearance levels of a concrete solidification radioactive waste. The purpose of our work is to design and evaluation of the NRF-based detection system. For this evaluation, we are developing a GEANT4-based Monte Carlo simulation code. Some simulations have been performed with simple models of a concrete solidification radioactive waste cask and detectors. We present a recent result of the simulation.

36000136
Study of beam profile modification for beam uniformization using multipole magnets (in Japanese)
Yuri, Yosuke; Okumura, Susumu; Yuyama, Takahiro; Agematsu, Takashi; Miyawaki, Nobumasa; Ishibori, Ikuo; Ishizaka, Tomohisa
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.607-609(2007) ; (JAEA-J 03470)

The development of the uniform-beam irradiation system using multipole magnets is now in progress at the TIARA AVF cyclotron facility. It is necessary that the transverse intensity distribution of the beam should be initially Gaussian to form a uniform beam. However, the beam extracted from the cyclotron is not always Gaussian but asymmetric. We have, therefore, carried out experiments on the modification of the initial beam profile using a scatterer. The beam was multiply scattered by a thin foil installed at a location of the beam transfer line. The transverse profile was measured by profile monitors, installed in separate positions It is found that the transverse profile is approached toward Gaussian distribution, dependent on the betatron phase advance from the scatterer to the profile monitor.

36000137
Estimation of HOM-BBU threshold current for an energy recovery linac (in Japanese)
Nagai, Ryoji; Hajima, Ryoichi; Sawamura, Masaru; Nishimori, Nobuyuki; Iijima, Hokuto; Kikuzawa, Nobuhiro; Minehara, Eisuke
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.637-639(2007) ; (JAEA-J 03471)

A collaborative project towards an ERL light source has been launched in Japan. In this project, the superconducting cavity is optimized for a high-average current beam. The latest design is a 9-cell cavity of 1.3 GHz with enlarged beam pipes and on-axis HOM absorbers. In this paper, beam breakup instabilities for the newly designed cavity is investigated. Threshold current of beam breakup at a 5-GeV ERL and possible extention to multi-turn configuration is presented.

36000138
Emittance compensation solenoid of a DC photo-cathode electron gun (in Japanese)
Nagai, Ryoji; Hajima, Ryoichi; Nishimori, Nobuyuki; Iijima, Hokuto; Sawamura, Masaru; Kikuzawa, Nobuhiro; Minehara, Eisuke
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.673-675(2007) ; (JAEA-J 03472)

An emittance compensation solenoid magnet is designed for a DC photo-cathode electron gun. The DC gun is now in fabrication at JAEA for an energy-recovery linac (ERL) light-source. The ERL light-source requires very low emittance electron beam to generate coherent X-rays. In order to produce the very low emittance electron beam from the DC gun, a focusing lens is indispensable to compensate the linear emittance growth. A solenoid magnet is employed for the emittance compensation lens. The solenoid magnet consists of a main coil, pure iron yoke, and a backing coil. The compensated emittance is estimated less than 0.6 mm-mrad in the bunch charge of 77 pC by PARMELA simulation.

36000139
High-voltage stability requirement of a DC electron gun for an ERL light-source (in Japanese)
Nagai, Ryoji; Hajima, Ryoichi; Iijima, Hokuto; Nishimori, Nobuyuki; Sawamura, Masaru; Kikuzawa, Nobuhiro; Minehara, Eisuke
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.676-678(2007) ; (JAEA-J 03473)

A DC electron gun is employed for an electron source of an energy-recovery linac (ERL). The electron beam parameters are fluctuated due to the instability of a high-voltage power supply of the gun. The fluctuations of the electron beam parameters are estimated for the ERL light-source. In the result of the estimation, the bunch length of the electron beam is mainly fluctuated by the instability of the high-voltage power supply. For the bunch length fluctuation of 1% or less, the required high-voltage stability is less than 1×10^-4. The main part of the instability of the high-voltage is the ripple of the Cockcroft-Walton circuit. The compensation of the ripple utilizing an LC filter is proposed, and the required stability is easily achieved in the preliminary design of the power supply.

36000140
Development of the heavy ion injector in the high voltage terminal (in Japanese)
Matsuda, Makoto; Nakanoya, Takamitsu; Kutsukake, Kenichi; Hanashima, Susumu; Takeuchi, Suehiro
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM) , p.736-738(2007) ; (JAEA-J 03474)

36000141
Development of a method for robust smoothing of MT data and application to robust stacking methos for EDI files (in Japanese)
Negi, Tateyuki; Umeda, Koji; Matsuo, Koichi*; Asamori, Koichi
Shadan Hojin Butsuri Tansa Gakkai Dai-117-Kai (Heisei-19-Nendo Shuki) Gakujutsu Koenkai Koen Rombunshu , p.195-198(2007) ; (JAEA-J 03475)

MT survey has been applied to various fields in recent years. It is recognized as effective method to know deep resistivity structure. However, it is difficult to acquire interpretable quality data in highly noisy environments, because natural electromagnetic fields are used in the MT survey. To apply MT survey in such environments, it is important to develop robust stacking method to improve the quality of MT spectrum data. In the last SEGJ conference held in Spring 2007, we have reported effective robust stacking method based on MT reliability index shown in Negi et al (2005). In the fall conference, we report the development of robust smoothing method of MT data to compile with the robust stacking method. As a result of application to poor quality data, it was improved to interpretable quality data in short time. Therefore, it is expected to be effective and practical stacking method for the poor quality data.

[ page top ]

JAEA > JAEA Library > JOPSS > Papers Published in Journals [Back Issues] > January 2008