Probing carbon edge exposure of iron phthalocyanine-based oxygen reduction catalysts by soft X-ray absorption spectroscopy

Niwa, Hideharu*; Saito, Makoto*; Kobayashi, Masaki*; Harada, Yoshihisa*; Oshima, Masaharu*; Moriya, Shogo*; Matsubayashi, Katsuyuki*; Nabae, Yuta*; Kuroki, Shigeki*; Ikeda, Takashi; et al.

Journal of Power Sources, 223, p.30 - 35, 2013/02

https://doi.org/10.1016/j.jpowsour.2012.09.031

To design non-platinum, inexpensive, but high performance carbon-based cathode catalysts for polymer electrolyte fuel cells, it is important to elucidate the active site for oxygen reduction reaction (ORR). However, it is difficult to directly identify the active site by applying conventional structural or electronic probes to such complex systems. Here, we used C 1 X-ray absorption spectroscopy (XAS) to observe electronic structure of carbon in iron phthalocyanine-based catalysts, and found a signature of edge exposure below the edge, whose intensity is well correlated with the ORR activity. These results demonstrate that C 1 XAS can be used to characterize the ORR activity of carbon-based cathode catalysts in terms of the edge exposure.

Efficient computation of Hamiltonian matrix elements between non-orthogonal Slater determinants

Utsuno, Yutaka; Shimizu, Noritaka*; Otsuka, Takaharu*; Abe, Takashi*

Computer Physics Communications, 184(1), p.102 - 108, 2013/01

https://doi.org/10.1016/j.cpc.2012.09.002

no abstracts in English

Fabrication of Mach-Zehnder polimer waveguides by a direct-drawing technique using a focused proton beam

Miura, Kenta*; Sato, Takahiro; Ishii, Yasuyuki; Kiryu, Hiromu*; Ozawa, Yusuke*; Koka, Masashi; Takano, Katsuyoshi*; Okubo, Takeru; Yamazaki, Akiyoshi; Kada, Wataru; et al.

Key Engineering Materials, 534, p.158 - 161, 2013/00

https://doi.org/10.4028/www.scientific.net/KEM.534.158

Mine-by experiment in a deep shaft in Neogene sedimentary rocks at Horonobe, Japan

Sanada, Hiroyuki; Nakamura, Takahiro*; Sugita, Yutaka

International Journal of Rock Mechanics and Mining Sciences, 56, p.127 - 135, 2012/12

https://doi.org/10.1016/j.ijrmms.2012.07.029

A Mine-by Experiment was carried out to investigate the development of an EDZ in one of the deep vertical shafts excavated in Neogene sedimentary rocks at the Horonobe URL site. The objective of this experiment is to understand the deformation and failure behavior and the hydraulic properties of the EDZ developed during sinking of the deep shaft. Before and after shaft sinking, BTV, borehole expansion tests, permeability tests and seismic velocity logging were carried out to determine initial conditions and changes in the mechanical and hydraulic properties. During shaft sinking, instruments such as extensometers and stress sensors were installed in the rock mass and in the shaft lining for stress measurements around the shaft circumference and to determine rock mass response to excavation. The variation of both mechanical and hydraulic properties was largest within 1 m of the shaft wall and the variation in hydraulic conductivity was in the range of one order of magnitude.

Development status of low activation ternary Au-In-Cd alloy decoupler for a MW class spallation neutron source; 1st production of Au-In-Cd alloy

Oi, Motoki; Teshigawara, Makoto; Wakui, Takashi; Nishi, Tsuyoshi; Harada, Masahide; Maekawa, Fujio; Futakawa, Masatoshi

Journal of Nuclear Materials, 431(1-3), p.218 - 223, 2012/12

https://doi.org/10.1016/j.jnucmat.2011.11.017

The Japan Spallation Neutron Source (JSNS) at the Japan Proton Accelerator Research Complex (J-PARC) is developed as a 1 MW spallation neutron source. The Ag-In-Cd (AIC) alloy was adopted as a decoupler material for two decoupled moderators. A high decoupling energy at 1 eV was for the first time achieved in MW class spallation neutron source due to the adoption of the AIC alloy. Although the AIC decoupler is superior in the neutronic performance, it has a demerit in high residual radioactivity due to production of Ag-110m and Ag-108m. To overcome this demerit, Au-In-Cd alloy was proposed. We studied to make ternary Au-In-Cd alloy and successfully done it at the maximum temperature of 1123 K with diffusion of the cadmium into the gold. Uniformity of the alloy was confirmed with EDX analysis. Thermal conductivity of Au-In-Cd alloy was 87.7 W/m/K. These results show enough performance as a decoupler.

Assessment of load-following capability of VHTR cogeneration systems

Sato, Hiroyuki; Yan, X.; Tachibana, Yukio; Kato, Yukitaka*

Annals of Nuclear Energy, 49, p.33 - 40, 2012/11

https://doi.org/10.1016/j.anucene.2012.05.019

Licensable Patent Information Database

Patent publication (In Japanese)

A control system design for the GTHTR300C is designed to follow significant seasonal variations of electric load demand. It combines inventory control used to adjust primary coolant pressure, flow bypass control used to regulate the coolant flow rate and turbine inlet temperature, and additional flow control to vary the IHX heat rate. The goal of the control system design is such that the wide range of load-following capability can be performed at constant reactor power and thermal efficiency, which maximizes plant economics, while minimizing transient thermal stresses in the reactor equipment. The original control system design shows that load-following operation at constant reactor power and thermal efficiency it to be feasible to allow peak electricity generation by a VHTR power and heat cogeneration system is feasible at constant reactor power and thermal efficiency.

Examinations of fuel debris samples from Three Mile Island Unit 2

Nagase, Fumihisa

Enerugi To Doryoku, 62(279), p.1 - 7, 2012/11

http://ci.nii.ac.jp/naid/40019486362

In the accident at the Fukushima-Daiichi Nuclear Power Plants, fuels were molten due to loss of coolant and heat-up of the reactor core. Information on properties of molten fuels (debris) is important to analyze progress of the accident, estimate the status inside the damaged reactors and work on a plan for debris removal. Extensive examinations have been conducted after the accident at the Three Mile Island Unit 2 (TMI-2) in 1979. The Japan Atomic Energy Agency conducted a part of the examinations in the frame of the OECD/NEA Three Mile Island Vessel Investigation Program. This issue reports outline and the main results of the TMI-2 debris examination programs.

Benchmark analysis and numerical investigation on probabilistic fracture mechanics analysis codes for NPPs piping

Li, Y.*; Ito, Hiroto*; Osakabe, Kazuya*; Onizawa, Kunio; Yoshimura, Shinobu*

International Journal of Pressure Vessels and Piping, 99-100, p.61 - 68, 2012/11

https://doi.org/10.1016/j.ijpvp.2012.08.004

A benchmark analysis was conducted using two probabilistic fracture mechanics analysis codes for aged piping in nuclear power plants, in order to confirm their reliability and applicability. These analysis codes have been improved or developed in Japan for the structural integrity evaluation and risk assessment considering the age related degradation mechanisms. In the benchmark analysis, the primary loop recirculation system piping in the boiling water reactor was selected as the typical piping system and stress corrosion cracking and fatigue were taken into account as the typical aging mechanisms. Moreover, a criterion was proposed for judging whether the differences between analysis results from the two codes are acceptable. Based on the benchmark analysis results and numerical investigation, it was concluded that the analysis results of these two codes agree very well.

Influence of oversized elements (Hf, Zr, Ti and Nb) on the thermal stability of vacancies in type 316L stainless steels

Yabuuchi, Atsushi*; Maekawa, Masaki; Kawasuso, Atsuo

Journal of Nuclear Materials, 430(1-3), p.190 - 193, 2012/11

https://doi.org/10.1016/j.jnucmat.2012.07.005

Infinite multiplication factor of low-enriched UO-concrete system

Izawa, Kazuhiko; Uchida, Yuriko; Okubo, Kiyoshi; Totsuka, Masayoshi; Sono, Hiroki; Tonoike, Kotaro

Journal of Nuclear Science and Technology, 49(11), p.1043 - 1047, 2012/11

AA2012-0375.pdf:0.63MB

https://doi.org/10.1080/00223131.2012.730893

Possibility of criticality of fuel debris in a form of UO-concrete mixture is evaluated by calculating infinite multiplication factor () for a study of criticality control on the fuel debris generated through the molten core concrete interaction (MCCI) in a severe accident of a light water reactor (LWR). The infinite multiplication factor can be greater than unity, which means that handling of the mixture is subject to criticality control. This paper shows that concrete have efficient slowing-down capability of neutron and points out the necessity of further investigations on the criticality of low-enriched UO-concrete system for actual handling of fuel debris.

Magnetization reversal in TmCrO

Yoshii, Kenji

Materials Research Bulletin, 47(11), p.3243 - 3248, 2012/11

https://doi.org/10.1016/j.materresbull.2012.08.005

The perovskite chromite TmCrO shows magnetization reversal at two temperatures. The reversal at 28 K is attributed to the antiparallel coupling between Tm and Cr moments, while that at the lower temperature (6-7 K) is rooted in a rotation of the magnetic moments. Magnetocaloric measurements offer a relatively large entropy change (4-5 Jkg K) at the lower temperature. The reversal at 28 K is accompanied by a sign change of an exchange-bias-like field. The absence of the training effect suggests that this behavior is rooted in unidirectional magnetic anisotropy. The existence of the two magnetization reversals offers the characteristic switching of magnetization. For example, the magnetization is flipped without changing the direction of the applied magnetic field.

Numerical analysis of key factors for the appearance of grassy ELMs in tokamak plasmas

Aiba, Nobuyuki; Oyama, Naoyuki

Nuclear Fusion, 52(11), p.114002_1 - 114002_8, 2012/11

https://doi.org/10.1088/0029-5515/52/11/114002

In this paper, we developed a simplified model that is used for the MHD stability analysis with the kinetic effects, and applied this to the numerical analysis of small amplitude ELM, called grassy ELM. As the result, we found that the stabilizing effect due to the ion diamagnetic drift can be canceled by taking into account the plasma compressibility and the electron diamagnetic drift, and this cancelation moves the stability boundary of small ELM closer to the ideal ballooning stability boundary. This trend is consistent with the experimental results of JT-60U grassy ELM plasma, and implies that the short-wavelength electromagnetic instability like ideal ballooning mode is thought as the origin of grassy ELM.

Analytical approach to evaluate coupling impedances of traveling kicker magnets

Shobuda, Yoshihiro; Irie, Yoshiro*; Toyama, Takeshi*

Nuclear Instruments and Methods in Physics Research A, 691, p.135 - 151, 2012/11

https://doi.org/10.1016/j.nima.2012.06.066

Mechanism of antioxidant interaction on polymer oxidation by thermal and radiation ageing

Seguchi, Tadao*; Tamura, Kiyotoshi; Shimada, Akihiko; Sugimoto, Masaki; Kudo, Hisaaki*

Radiation Physics and Chemistry, 81(11), p.1747 - 1751, 2012/11

https://doi.org/10.1016/j.radphyschem.2012.06.011

The mechanism of polymer oxidation by radiation and thermal ageing was investigated for the life evaluation of cables installed in radiation environments. The antioxidant as a stabilizer was much effective for thermal oxidation with a small content in polymers, but was not effective for radiation oxidation. The ionizing radiation induced the oxidation to result chain scission even at low temperature, because the free radicals were produced and the antioxidant could not stop the oxidation of radicals with the chain scission. A new mechanism of antioxidant effect for polymer oxidation was proposed. The effect of antioxidant was not the termination of free radicals in polymer chains such as peroxy radicals, but was the depression of initial radical formation in polymer chains by thermal activation. The antioxidant molecule was assumed to delocalize the activated energy in polymer chains by Boltzmann statics (distribution) to result decrease the probability of radical formation at a given temperature. The interaction distance (delocalization area) by one antioxidant molecule was estimated to be 5-10 nm in polymer matrix, though the value would depend on the chemical structure of antioxidant.

Effective dose conversion coefficients for radionuclides exponentially distributed in the ground

Saito, Kimiaki; Ishigure, Nobuhito*; Petoussi-Henss, N.*; Schlattl, H.*

Radiation and Environmental Biophysics, 51(4), p.411 - 423, 2012/11

https://doi.org/10.1007/s00411-012-0432-y

Efficient arsenic(V) removal from water by ligand exchange fibrous adsorbent

Awual, M. R.; Shenashen, M. A.*; Yaita, Tsuyoshi; Shiwaku, Hideaki; Jo, Akinori*

Water Research, 46(17), p.5541 - 5550, 2012/11

https://doi.org/10.1016/j.watres.2012.07.038

Simple determination method using ICP-MS for I in radioactive liquid waste solidified with bitumen

Kameo, Yutaka; Ishimori, Kenichiro; Shimada, Asako; Takahashi, Kuniaki

Bunseki Kagaku, 61(10), p.845 - 849, 2012/10

https://doi.org/10.2116/bunsekikagaku.61.845

A simple determination method was developed to measure I in low level radioactive liquid waste solidified with bitumen. A simulated bituminized product sample was cut to 0.02 g pieces, subsequently these pieces and sodium carbonate were heated in an electric furnace. This procedure could well decompose the bituminized sample without volatilizing I. Sixty to seventy percent of I was recovered by a solid phase extraction disk from a solution containing the decomposed sample. A dynamic reaction cell inductively coupled plasma mass spectrometer was applied to measure I, and as a result, detection limit of I was reduced to by a factor of about 6 comparing with conventional ICP-MS measurement. Determined radioactivity concentration for the simulated bituminized sample containing I was good agreement with expected value within 6% error.

Decontamination technology

Kawase, Keiichi

Funtai Gijutsu, 4(10), p.971 - 979, 2012/10

http://ci.nii.ac.jp/naid/40019463218

no abstracts in English

Applying vegetation indices to detect high water table zones in humid warm-temperate regions using satellite remote sensing

Koide, Kaoru; Koike, Katsuaki*

International Journal of Applied Earth Observation and Geoinformation, 19, p.88 - 103, 2012/10

https://doi.org/10.1016/j.jag.2012.03.017

This paper presents a method for detecting high water-table areas based on vegetation information in a humid warm-temperate forest area using remotely sensed data (SPOT). The purpose is to develop methodologies for characterizing hydrogeological structures at a regional scale. To detect differences in vegetation conditions due to groundwater supply, a new vegetation index (AgbNDVI) and a segmentation analysis based on geographical characteristics were proposed. A study area was selected in the Tono region of central Japan. As a result, most of the high-VI points are located on the concave/convex slopes, in the vicinity of geologic boundaries, around groundwater seeps and in high water-table areas. Therefore, high-VI points can be a crucial marker for estimating hydraulic properties of geologic structures and groundwater flow regime. Consequently, the proposed method can be an useful tool to detect high water-table areas in humid warm-temperate forest areas.

Design evaluation method of steel-plate reinforced concrete structure containment vessel for sodium-cooled fast reactor

Yamamoto, Tomohiko; Kato, Atsushi; Chikazawa, Yoshitaka; Negishi, Kazuo

Journal of Disaster Research, 7(5), p.645 - 655, 2012/10

http://www.fujipress.jp/finder/xslt.php?mode=present&inputfile=DSSTR000700050016.xml

Japan Sodium-cooled Fast Reactor (JSFR) adopts a new concept of a containment vessel called steel plate reinforced concrete containment vessel (SCCV). The SCCV is considered to be effective to shorten construction period thanks for elimination of rebar work at a site compared with applying a reinforced concrete CV. An SFR CV is lower pressure environment than the LWR CV, although environmental temperature of the SFR is much higher than that of LWR in the accident of coolant leakage. Therefore it is important to investigate its characteristics under high temperature to adopt the SC structure to the JSFR CV because the CV shall keep their containment function in the accidents to be assumed in design. This paper describes the construction of design evaluation method from design, experimental and analytical point of view.

Flow visualization and frequency characteristics of velocity fluctuations of complex turbulent flow in a short elbow piping under high Reynolds number condition

Takamura, Hiroyuki*; Ebara, Shinji*; Hashizume, Hidetoshi*; Aizawa, Kosuke; Yamano, Hidemasa

Journal of Fluids Engineering, 134(10), p.101201_1 - 101201_8, 2012/10

https://doi.org/10.1115/1.4007436

By means of 2D PIV (2-dimensional Particle Image Velocimetry), flow visualization experiments are carried out for a single short elbow piping which is a 1/7-scale model of the cold-leg piping of Japan Sodium-cooled Fast Reactor in order to investigate the minute flow field related especially to flow separation appearing in the intrados side of the elbow and frequency characteristics of the flow velocity fluctuation for various Reynolds number flow. A periodic motion with St of 0.5 appeared near the separation region if the Reynolds number changes.

Study on the mechanism of diametral cladding strain and mixed-oxide fuel element breaching in slow-ramp extended overpower transients

Uwaba, Tomoyuki; Maeda, Seiichiro; Mizuno, Tomoyasu; Teague, M. C.*

Journal of Nuclear Materials, 429(1-3), p.149 - 158, 2012/10

https://doi.org/10.1016/j.jnucmat.2012.05.042

Cladding strain caused by fuel/mechanical interaction (FCMI) was evaluated for mixed-oxide fuel elements subjected to 70-90% slow-ramp extended overpower transient tests in EBR-II. Calculated transient-induced cladding strains were correlated with cumulative damage fractions (CDFs) using cladding strength correlations. In a breached high-smeared density solid fuel element with low strength cladding, cladding thermal creep strain was significantly increased to approximately half the transient-induced cladding strain due to the tertiary creep when the CDF was close to the breach criterion (= 1.0). In low-smeared density annular fuel elements, FCMI load was significantly mitigated and resulted in little cladding strain. The CDFs of the annular fuel elements were lower than 0.01 at the end of the overpower transient, indicating a substantial margin to breach. A substantial margin to breach was also maintained in a high-smeared density fuel element with high strength cladding.

New result in the production and decay of an isotope, 113 of the 113th element

Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.

Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10

https://doi.org/10.1143/JPSJ.81.103201

An isotope of the 113th element, 113, was produced in a nuclear reaction with a Zn beam on a Bi target. We observed six consecutive decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of Db and Lr both in decay energies and decay times. This indicates that the present decay chain consisted of 113, Rg (Z = 111), Mt (Z = 109), Bh (Z = 107), Db (Z = 105), and Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope 113, of the 113th element.

Numerical research on fluid mixing characteristics in a non-heated parallel channel by supercritical freon

Kitamura, Tatsuaki*; Sakamoto, Kensaku; Takase, Kazuyuki

Kashika Joho Gakkai-Shi, 32(Suppl.2), p.239 - 240, 2012/10

In the thermal-hydraulic design of supercritical water-cooled reactors, it is required to establish a thermal-hydraulic analysis method which can simulate the heat transfer and fluid flow characteristics of supercritical fluids precisely. A crossing flow is a phenomenon in which the fluid flowing through the inside of a fuel bundle in the perpendicular direction moves between subchannels to a transverse direction. The crossing flow influences the removal heat of a reactor core greatly. In the present study, results of the preliminary crossing flow simulation are described.

Crystallographic observation of diffusional phase transformation behavior of a low alloy steel using neutron diffraction

Xu, P. G.; Tomota, Yo*; Vogel, S. C.*

Keikinzoku Gakkai Heisei-24-Nendo Dai-2-kai Kako To Netsu Shori Ni Yoru Yusen Hoi Seigyo Kenkyu Bukai Kokai Koenkai Shiryo, p.21 - 22, 2012/10

no abstracts in English

First-principles calculation to explore mechanisms of coherent phonon generation

Shinohara, Yasushi*; Otobe, Tomohito; Iwata, Junichi*; Yabana, Kazuhiro*

Nihon Butsuri Gakkai-Shi, 67(10), p.685 - 689, 2012/10

https://doi.org/10.11316/butsuri.67.10_685

Coherent phonon is the macroscopic coherent oscillation of atoms in a solid state generating under the ultrafast laser pulse which is shorter than the frequency of the phonon. Some physical processes for the coherent phonon have been proposed. We are studying the computational method describing the dynamics of the electron and atom employing the time-dependent density functional theory. Our computational results show the origine of the coherent phonon in Si quantitatively.

Measurements and Monte Carlo calculations of forward-angle secondary-neutron-production cross-sections for 137 and 200 MeV proton-induced reactions in carbon

Iwamoto, Yosuke; Hagiwara, Masayuki*; Matsumoto, Tetsuro*; Masuda, Akihiko*; Iwase, Hiroshi*; Yashima, Hiroshi*; Shima, Tatsushi*; Tamii, Atsushi*; Nakamura, Takashi*

Nuclear Instruments and Methods in Physics Research A, 690, p.10 - 16, 2012/10

https://doi.org/10.1016/j.nima.2012.06.038

Secondary neutron-production double-differential cross sections (DDXs) have been measured from interactions of 137 MeV and 200 MeV protons in a natural carbon target. The data were measured between 0 and 25 in the laboratory. Benchmark calculations were carried out with the PHITS code using the evaluated nuclear data files of JENDL/HE-2007 and ENDF/B-VII, and the theoretical models of Bertini-GEM and ISOBAR-GEM. For the 137 MeV proton incidence, calculations using JENDL/HE-2007 generally reproduced the shape and the amount of experimental spectra well including the ground state of the N state produced by the C(p,n)N reaction. ISOBAR predicts the nucleon emission to the forward angles qualitatively better than the Bertini model and JENDL/HE-2007. These experimental data will be useful to evaluate the carbon data and as benchmark data for investigating the validity of the Monte Carlo simulation for the shielding design of accelerator facilities.

Ion acceleration from thin foil and extended plasma targets by slow electromagnetic wave and related ion-ion beam instability

Bulanov, S. V.; Esirkepov, T. Z.; Kando, Masaki; Pegoraro, F.*; Bulanov, S. S.*; Geddes, C. G. R.*; Schroeder, C. B.*; Esarey, E.*; Leemans, W. P.*

Physics of Plasmas, 19(10), p.103105_1 - 103105_10, 2012/10

https://doi.org/10.1063/1.4757981

Production of the ORIGEN2 library based on JENDL-4.0 for high temperature engineering test reactor

Kojima, Kensuke; Okumura, Keisuke; Okamoto, Tsutomu; Goto, Minoru

Proceedings of 6th International Topical Meeting on High Temperature Reactor Technology (HTR 2012) (USB Flash Drive), 7 Pages, 2012/10

A set of the ORIGEN2 library for High Temperature engineering Test Reactor (HTTR) was newly produced in order to improve prediction accuracy of burn-up characteristics such as spent fuel composition, radioactivity and decay heat. In the library, cross sections and decay data are adopted from JENDL-4.0 and from ENSDF. In the production of effective cross sections and neutron spectrum, MVP-BURN based on the continuous-energy Monte Carlo method and a statistical geometry model is applied to the HTTR fuel with many coated fuel particles. In this way, the double heterogeneous effect of the HTTR fuel can be accurately taken into account. By using the neutron spectrum obtained in the MVP-BURN calculation, infinite dilution cross sections from JENDL-4.0 are condensed to one-group cross sections. The burn-up calculation results of ORIGEN2 with the produced library and those of MVP-BURN with detail modeling and much calculation cost show good agreement for burn-up changes of fuel composition.

Shell evolution around and beyond =28 studied with large-scale shell-model calculations

Utsuno, Yutaka; Otsuka, Takaharu*; Brown, B. A.*; Homma, Michio*; Mizusaki, Takahiro*; Shimizu, Noritaka*

Progress of Theoretical Physics Supplement, (196), p.304 - 309, 2012/10

https://doi.org/10.1143/PTPS.196.304

no abstracts in English

Inter-atomic force constants of AgO from diffuse neutron scattering measurement

Wada, Tamotsu*; Sakuma, Takashi*; Sakai, Ryutaro*; Uehara, Hiroyuki*; Xianglian*; Takahashi, Haruyuki*; Kamishima, Osamu*; Igawa, Naoki; Danilkin, S. A.*

Solid State Ionics, 225, p.18 - 21, 2012/10

https://doi.org/10.1016/j.ssi.2012.02.007

Diffuse neutron scattering measurement on AgO crystals was performed at 8 K and 295 K. The observed diffuse scattering intensities were analyzed by including the correlation effects among thermal displacements of atoms in AgO. Using the values of correlation effects among neighboring atoms and the values of Debye-Waller temperature parameter, force constants among first, second and third nearest neighboring atoms have been evaluated.

Reduction of salt-requirement of halophilic nucleoside diphosphate kinase by engineering S-S bond

Ishibashi, Matsujiro*; Uchino, Manami*; Arai, Shigeki; Kuroki, Ryota; Arakawa, Tsutomu*; Tokunaga, Masao*

Archives of Biochemistry and Biophysics, 525(1), p.47 - 52, 2012/09

https://doi.org/10.1016/j.abb.2012.05.021

Nucleoside diphosphate kinase (HsNDK) from Halobacterium salinarum requires salt at high concentrations for folding. A D148C mutant, in which Asp148 was replaced with Cys, was designed to enhance stability and folding in low salt solution by S-S bond. It showed increased thermal stability by about 10C in 0.2 M NaCl over the wild type HsNDK. It refolded from heat-denaturation even in 0.1 M NaCl, while the wild type required 2 M NaCl to achieve the same level of activity recovery. This enhanced refolding is due to the three S-S bonds between two basic dimeric units in the hexameric HsNDK structure. Moreover, salt concentration dependency of heat-denaturation process and refolding process of the wild type and D148C mutant HsNDKs were investigated by the circular dichroism and native-PAGE analysis.

Overview and issues to be solved on emergency response of robots to Fukushima NPP accidents

Kawatsuma, Shinji

Dekomisshoningu Giho, (46), p.14 - 26, 2012/09

http://www.randec.or.jp/publish/documents/gihou/Decommissioning%20gihou_46.pdf

Fukushima NPP accident was occurred according to the earthquake of East Japan on the Pacific Ocean, on March 11th, 2011. Nuclear Disaster Robots, developed after JCO criticality accident, had been discarded, or stored but not maintained, so that those robots could not been deployed immediately. After that, Unmanned heavy construction machines, PackBOTs, BROKKs, Quince and other robots have been deployed. Development of the remote equipments for decommissioning of the Fukushima Nuclear Power Plants and preparation of maintenance and employment of the remote equipments in case of nuclear urgent are advanced. This paper summarized robots' emergency response to Fukushima NPP accident and future subjects, in order for the development and preparation mentioned above.

A Study on rock mass behaviour induced by shaft sinking in the Horonobe Underground Research Laboratory

Tsusaka, Kimikazu; Tokiwa, Tetsuya; Inagaki, Daisuke; Hatsuyama, Yoshihiro*; Koike, Masashi*; Ijiri, Yuji*

Doboku Gakkai Rombunshu, F1 (Tonneru Kogaku) (Internet), 68(2), p.40 - 54, 2012/09

https://doi.org/10.2208/jscejte.68.40

Japan Atomic Energy Agency has excavating three deep shafts through soft sedimentary rock at Horonobe Underground Research Laboratory. In this paper, the author discussed rock mass behaviour induced by the 6.5 m diameter shaft sinking. They conducted geological mapping in an excavation face and boreholes digged around the shaft wall, field measurements such as convergence measurements and monitoring of rock displacements using multi-interval borehole extensometers around a shaft at around 160 m and 220 m in depths, and three-dimensional numerical analysis which models the shaft excavation procedure such as timing of installation of support elements and setting and removal of a concrete form. As a result, it was clarified that remarkablely large compressive strains occurred within about 1 m into the shaft wall since the rock mass behaviour was controlled by the concrete lining and that the behaviour would predominantly be induced by the fractures closing which opened significantly and propagated during excavation steps before the installation of a concrete lining and the directions where the strains occurred heavily depended on the fracture orientation around the shaft.

Post-adsorption process of Yb phosphate nano-particle formation by

Jiang, M. Y.*; Onuki, Toshihiko; Tanaka, Kazuya*; Kozai, Naofumi; Kamiishi, Eigo; Utsunomiya, Satoshi*

Geochimica et Cosmochimica Acta, 93, p.30 - 46, 2012/09

https://doi.org/10.1016/j.gca.2012.06.016

We have investigated the post-adsorption process of ytterbium (Yb) phosphate nano-particle formation by . We have elucidated the nano particle formation by TEM and EXAFS analyses, that adsorbed Yb reacts on the cell surface with the released pohosphate from inside the cell.

Product data models for the life cycle management system of tunnel construction

Xu, Z.*; Itakura, Kenichi*; Yamachi, Hiroshi*; Otsu, Shinichi*; Hayano, Akira; Matsui, Hiroya; Sato, Toshinori

Heisei-24 Nendo (2012 Nen) Shigen, Sozai Gakkai Shuki Taikai Koenshu, p.63 - 66, 2012/09

no abstracts in English

Effects of alumina powder characteristics on H and HO production yields in -radiolysis of water and 0.4M HSO aqueous solution

Yamada, Reiji; Kumagai, Yuta

International Journal of Hydrogen Energy, 37(18), p.13272 - 13277, 2012/09

https://doi.org/10.1016/j.ijhydene.2012.06.062

The effects of powder characteristics on H and HO2 productions in Co -radiolysis were studied in pure water and in 0.4M HSO aqueous solutions containing alumina powders. In 0.4 M HSO solution, the H yields strongly depended on alumina structures and decreased in the order of , , alumina, although the specific surface areas increased as , , . The yields increased with increasing specific surface area when compared am-alumina. In pure water, similar dependence was observed but not as strong as that for 0.4 M HSO solution. The HO yields were strongly decreased by adding the alumina powders in both water and 0.4 M HSO aqueous solution, although the amounts of decrease were almost neither correlated with specific surface areas nor structures. The enhancing H production was discussed in terms of the electron supply from alumina to aqueous solution as well as the adsorption of OH radicals on alumina surfaces.

Adsorbent for arsenic(V) removal synthesized by radiation-induced graft polymerization onto nonwoven cotton fabric

Hoshina, Hiroyuki; Takahashi, Makikatsu*; Kasai, Noboru; Seko, Noriaki

International Journal of Organic Chemistry, 2(3), p.173 - 177, 2012/09

https://doi.org/10.4236/ijoc.2012.23026

Development of a multi-interval displacement sensor using Fiber Bragg Grating technology

Sanada, Hiroyuki; Sugita, Yutaka; Kashiwai, Yoshio*

International Journal of Rock Mechanics and Mining Sciences, 54, p.27 - 36, 2012/09

https://doi.org/10.1016/j.ijrmms.2012.05.020

In this paper, application of the multi-interval displacement sensor using Fiber Bragg Grating (FBG) technology in the Horonobe URL is described. Laboratory tests were carried out to obtain the relational expression computed from the relationship of the variation in the Bragg wavelength, temperature and displacement. From the results of laboratory test, accuracy of sensor was evaluated better than 0.5% of the measurement range. In situ monitoring at the Horonobe URL using the developed sensor was carried out in parallel with nearby monitoring using a conventional extensometer, which is electrical signal system type, for verification of the developed sensor. In situ test results indicate that the displacement values from both the developed sensor and the conventional extensometer are almost equivalent. One of the advantages of the developed sensor was that there was no noise in the obtained monitoring data, while the data from the conventional extensometer shows some noise.

Numerical reconstruction of high dose rate zones due to the Fukushima Dai-ichi Nuclear Power Plant accident

Katata, Genki; Terada, Hiroaki; Nagai, Haruyasu; Chino, Masamichi

Journal of Environmental Radioactivity, 111, p.2 - 12, 2012/09

AA2011-0339.pdf:1.57MB

https://doi.org/10.1016/j.jenvrad.2011.09.011

For future planning of preventive measures against possible nuclear accident, it is important to understand how the high dose rate zones was created in the northwest area of the plant during the Fukushima Dai-ichi nuclear reactor accident. Because most of the observation equipment did not work due to the severe earthquakes, temporal information of release rates of radionuclides into the atmosphere and environmental monitoring data were limited to analyze the movements of radioactive plume in a significant release of radionuclides on 15 March, 2011. Here we reconstructed the atmospheric dispersion of radionuclides during the period from 15 to 16 March using computer-based nuclear emergency response system, WSPEEDI-II. We found that high dose rate zones were created by a significant deposition of radionuclides discharged during the afternoon on 15 March and two factors, i.e., rainfall and topography, strongly affected the distribution of surface deposition.

Dynamics of decadally cycling carbon in subsurface soils

Koarashi, Jun; Hockaday, W.*; Masiello, C.*; Trumbore, S.*

Journal of Geophysical Research; Biogeosciences, 117, p.G03033_1 - G03033_13, 2012/09

https://doi.org/10.1029/2012JG002034

Subsurface horizons contain more than half of the global soil carbon (C), yet the dynamics of this C remains poorly understood. We estimated the amount of decadally-cycling subsurface C from the incorporation of "bomb' radiocarbon (C) using samples taken over 50 years from grassland and forest soils in the Sierra Nevada Mountains, California. The C content of all organic matter fractions increased from the pre- to post-bomb samples, indicating about half of the subsoil C consists of C fixed since 1963. The C content of mineral-associated C increased rapidly from 1992-2009, indicating a significant time lag (20 years) for the arrival of "bomb" C to this fraction. Our results demonstrate that a lagged response of the large subsurface C stores to changes in environmental conditions is possible.

Sensitivity analysis of a passive decay heat removal system under a post-loss of coolant accident condition

Liu, Q.; Homma, Toshimitsu

Journal of Nuclear Science and Technology, 49(9), p.897 - 909, 2012/09

https://doi.org/10.1080/00223131.2012.712481

Passive safety features are now of interest to the design of future generation reactors. Though passive safety systems are considered to be more reliable, the large uncertainty associated with the system response can not be ignored. It is necessary to identify the uncertain inputs that have the important impact on the uncertainty of the system performance. In this study, two global sensitivity measures, the first-order sensitivity index and the total-order sensitivity index, are applied to a passive decay heat removal system of a gas-cooled fast reactor for identifying the key uncertainty inputs. It is found that the uncertainty in the system pressure contributes the most to the uncertainty in the system outputs. In addition, the cooler wall temperature, the Nusselt number and the friction factor in the mixed convectional flow regime also have small impact on the uncertainty of the system outputs.

Probing the Ba 5d states in BaTiO and BaSO; A Resonant X-ray emission study at the Ba-L edge

Yoshii, Kenji; Jarrige, I.; Suzuki, Chikashi; Matsumura, Daiju; Nishihata, Yasuo; Yoneda, Yasuhiro; Fukuda, Tatsuo; Tamura, Kazuhisa; Ito, Yoshiaki*; Mukoyama, Takeshi*; et al.

Journal of Physics and Chemistry of Solids, 73(9), p.1106 - 1110, 2012/09

https://doi.org/10.1016/j.jpcs.2012.04.009

We have directly probed the Ba 5d states in the ferroelectric barium titanate BaTiO using resonant X-ray emission spectroscopy (RXES) and X-ray absorption spectroscopy in the partial fluorescence mode (PFY-XAS) at the Ba-L edge. The results are compared with those of the non-ferroelectric BaSO. While the RXES spectra point to a localized character for the Ba 5d states in both compounds, the main peak of the PFY-XAS spectrum, corresponding to the dipolar transitions from 2p to 5d, is found to be significantly broader for BaTiO than for BaSO. On the basis of band structure calculations, this broadening is ascribed to strong hybridization between the unoccupied Ba 5d and O 2p states in the ferroelectric. This suggests that the hybridization between the conduction states of the Ba and O ions, and not only Ti and O, plays a central role in determining the electronic structure of BaTiO.

Multiphase technology in nuclear engineering area; Development of two-phase flow analysis codes for reactor design

Akimoto, Hajime

Konsoryu, 26(3), p.266 - 272, 2012/09

https://doi.org/10.3811/jjmf.26.266

Research and development activities for two-phase analysis codes for nuclear reactor design and safety analyses have been reviewed focusing in recent twenty five years. For reactor safety evaluation, large-scale tests were performed to confirm effectiveness of ECCS in 1980's and 1990's. These test results were succeeded to so-called best-estimate codes such as RELAP5, TRAC codes. Severe accident researches were performed in 1980's and 1990's and accident management methods were studied. Detailed simulation methods such as subchannel analysis, multi-dimensional analyses have been developed based on test results and computational technology enhancement in 1990's and 2000's. Future scope is summarized briefly.

Development of evaluation methodology for effects of cementitious grouting materials on groundwater and rock in fractured media

Sasamoto, Hiroshi; Yui, Mikazu; Takase, Hiroyasu*

Nihon Genshiryoku Gakkai Wabun Rombunshi, 11(3), p.233 - 246, 2012/09

https://doi.org/10.3327/taesj.J11.038

Leachates from cementitious grouting materials used for reducing water-inflow are hyperalkaline and chemically reactive with the engineered barriers and host rock of deep repository of high level radioactive waste. Evaluation methods for long-term alteration of host rock have been developing since the extent of chemical modification may influence the transport and retardation properties of radionuclides in the far-field. Not only conventional Ordinary Portland Cement (OPC) but also low-pH (alkaline) cement (LoAC) has been considered as the grouting material in order to reduce the extent of alteration of host rock. Comparative simulations for long-term alteration of host rock considering both OPC and LoAC grouts are conducted to propose an idea for evaluation of applicability of cementitious grouting materials from view points of reducing uncertainty and conservatism of safety assessment.

Anomalous enhancement in radiation induced conductivity of hydrogenated amorphous silicon semiconductors

Sato, Shinichiro; Sai, Hitoshi*; Oshima, Takeshi; Imaizumi, Mitsuru*; Shimazaki, Kazunori*; Kondo, Michio*

Nuclear Instruments and Methods in Physics Research B, 286, p.29 - 34, 2012/09

https://doi.org/10.1016/j.nimb.2012.02.039

Electric conductivity variations of undoped hydrogenated amorphous silicon (a-Si:H) semiconductors induced by swift protons are investigated. The results show that the conductivity drastically increases at first and then decreases on further irradiation. The conductivity enhancement observed only in the low fluence regime lasts for a prolonged period of time when proton irradiation stops in this fluence regime. On the other hand, the photosensitivity has a minimum value around the conductivity peak. This fact indicates that non-equilibrium carriers do not play a dominant role in the electric conduction in this fluence regime. It is found that the anomalous conductivity enhancement is dominated by donor center generation in the low fluence regime. At higher fluences the variation in electric conductivity becomes dominated by non-equilibrium carriers as the generated donor centers disappear. This is a general interpretation of radiation induced conductivity in semiconductors.

The Decontamination of the atomic energy institution and the dismantling

Daido, Hiroyuki

Oputoronikusu, 31(9), p.140 - 142, 2012/09

no abstracts in English

Resonant inelastic X-ray scattering study of charge excitations in superconducting and nonsuperconducting PrFeAsO

Jarrige, I.*; Nomura, Takuji; Ishii, Kenji; Gretarsson, H.*; Kim, Y.-J.*; Kim, J.*; Upton, M.*; Casa, D.*; Gog, T.*; Ishikado, Motoyuki*; et al.

Physical Review B, 86(11), p.115104_1 - 115104_4, 2012/09

https://doi.org/10.1103/PhysRevB.86.115104

We report the first observation by momentum-resolved resonant inelastic X-ray scattering of charge excitations in an iron-based superconductor and its parent compound, PrFeAsO and PrFeAsO respectively, with two main results. First, using calculations based on a 16 band model, we show that the energy of the lowest-lying excitations, identified as interband transitions of dominant , orbital character, exhibits a dramatic dependence on electron correlation. This enables us to estimate the Coulomb repulsion and Hund's coupling , and to highlight the role played by in these peculiar orbital-dependent electron correlation effects. Second, we show that short-range antiferromagnetic correlations, which are a prerequisite to the occurrence of these excitations at the point, are still present in the superconducting state.

Small ion-temperature-gradient scale length and reduced heat diffusivity at large hydrogen isotope mass in conventional -mode plasmas

Urano, Hajime; Takizuka, Tomonori*; Kikuchi, Mitsuru; Nakano, Tomohide; Hayashi, Nobuhiko; Oyama, Naoyuki; Kamada, Yutaka

Physical Review Letters, 109(12), p.125001_1 - 125001_5, 2012/09

https://doi.org/10.1103/PhysRevLett.109.125001

The dependence of the ion temperature gradient scale length on the hydrogen isotope mass was examined in conventional -mode plasmas in JT-60U tokamak. While identical profiles for density and temperature were obtained for hydrogen and deuterium plasmas, the ion conductive heat flux necessary for hydrogen to sustain the same thermal stored energy was two times that required for deuterium, resulting in a clearly higher ion heat diffusivity for hydrogen at the same ion temperature gradient scale length. The ion temperature gradient scale length for deuterium is less than that for hydrogen at a given ion heat diffusivity.

Dual frequency gyrotron development for JT-60SA

Kobayashi, Takayuki; Isayama, Akihiko; Sawahata, Masayuki; Suzuki, Sadaaki; Terakado, Masayuki; Hiranai, Shinichi; Wada, Kenji; Sato, Yoshikatsu; Hinata, Jun; Yokokura, Kenji; et al.

Proceedings of 37th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz 2012) (USB Flash Drive), 2 Pages, 2012/09

A new dual frequency (110 GHz and 138 GHz) gyrotron development began for JT-60SA. An output power and efficiency higher than 1 MW and 30% with a peak heat load lower than 1.4 kW/cm were obtained for both frequencies in calculation. High mode conversion efficiencies of the quasioptical mode converter (96.8% for 110 GHz and 98.3% for 138 GHz), which is higher than the previously developed 110 GHz long pulse gyrotron (96.5%), was obtained. The new gyrotron was fabricated and conditioning operation has been started from the middle of June 2012. The gyrotron output power of approximately 200 kW was obtained, so far, as we expected in the design of the gyrotron at low beam current of 10 A and low beam voltage of 75 kV.

Effectiveness of AM measures for long-term core cooling during PWR vessel bottom small-break LOCA based on RELAP5 analyses of ROSA/LSTF experiment

Takeda, Takeshi; Watanabe, Tadashi; Nakamura, Hideo

Proceedings of 9th International Topical Meeting on Nuclear Thermal-Hydraulics, Operation and Safety (NUTHOS-9) (CD-ROM), 12 Pages, 2012/09

Global sensitivity analysis for core hot spot evaluation under natural circulation decay heat removal in sodium-cooled fast reactor

Doda, Norihiro; Kamide, Hideki; Ohshima, Hiroyuki; Watanabe, Osamu*

Proceedings of 9th International Topical Meeting on Nuclear Thermal-Hydraulics, Operation and Safety (NUTHOS-9) (CD-ROM), 11 Pages, 2012/09

In the design study for Japan Sodium Cooled Fast Reactor (JSFR), fully natural circulation system is adopted as the decay heat removal system. We have been developing a new evaluation method of core hot spot in transition from rated operation to natural circulation decay heat removal conditions. Since the method is currently based on conservative assumptions and data, there is room for further rationalization of the safety margin which can be achieved by conducting best estimate analyses with confidence and with quantified uncertainty of results. This paper describes a development of PIRT (Phenomena Identification and Ranking Table) and the global sensitivity analyses of the uncertainties in the event of loss of external power as the first step to improve the evaluation method.

Uncertainty quantification scheme in V&V of fluid-structure thermal interaction code for thermal fatigue issue in a sodium-cooled fast reactor

Tanaka, Masaaki

Proceedings of OECD/NEA and IAEA Workshop on Experimental Validation and Application of CFD and CMFD Codes in Nuclear Reactor Technology (CFD4NRS-4) (CD-ROM), 16 Pages, 2012/09

Thermal fatigue on the structure caused by thermal striping phenomena is one of the significant issues in design and safety of fast breeder reactors. A numerical simulation code MUGTHES has been developed to predict fluid mixing phenomena and thermal response in structure. Uncertainty quantification in V&V process for the thermal-hydraulics analysis module was examined with simple laminar flow problems according to the existing guidelines and that of the structure heat conduction analysis module including conjugate heat transfer model was also done for theoretical unsteady heat conduction problems as verification. After the verification, the MUGTHES code was validated for a practical fluid-structure thermal interaction problem in T-junction piping system and applicability of the code to the thermal fatigue issue was confirmed.

Stability of pyrrolidone derivatives against -ray irradiation

Nogami, Masanobu*; Sugiyama, Yuichi*; Kawasaki, Takeshi*; Harada, Masayuki*; Kawata, Yoshihisa*; Morita, Yasuji; Kikuchi, Toshiaki*; Ikeda, Yasuhisa*

Science China; Chemistry, 55(9), p.1739 - 1745, 2012/09

https://doi.org/10.1007/s11426-012-4698-3

Stability of N-alkylated pyrrolidone derivatives (NRPs) against radiation was examined by irradiation tests with Co -ray. We have been developed a novel reprocessing system using NRPs which have precipitation ability to haxa- and tetravalent actinides in nitric acid media. Degradation rates of NRPs are evaluated by irradiation in 3M nitric acid solutions and mechanism of degradation are discussed in the present paper.

Analysis of radicals induced in irradiated foods

Kishida, Keigo*; Kaimori, Yoshihiko*; Kawamura, Shoei*; Sakamoto, Yuki*; Nakamura, Hideo*; Kikuchi, Masahiro; Shimoyama, Yuhei; Kobayashi, Yasuhiko; Ukai, Mitsuko*

Shokuhin Shosha, 47(1), p.1 - 5, 2012/09

https://doi.org/10.5986/jrafi.47.1

no abstracts in English

Analysis on the atmospheric dispersion by WSPEEDI for the Fukushima Dai-ichi Nuclear Power Plant accident

Nagai, Haruyasu

Shuninsha Nyusu, (18), p.6 - 8, 2012/09

no abstracts in English

The Physical origin of the InSb(111)A surface reconstruction transient

Proessdorf, A.*; Rodenbach, P.*; Grosse, F.*; Hanke, M.*; Braun, W.*; Riechert, H.*; Hu, W.; Fujikawa, Seiji*; Kozu, Miwa; Takahashi, Masamitsu

Surface Science, 606(17-18), p.1458 - 1461, 2012/09

https://doi.org/10.1016/j.susc.2012.05.017

One-dimentional nanotemplate structure of a Si(110) substrate

Yokoyama, Yuta; Asaoka, Hidehito; Sinsarp, A.*; Sasaki, Masahiro*

e-Journal of Surface Science and Nanotechnology (Internet), 10, p.509 - 512, 2012/09

https://doi.org/10.1380/ejssnt.2012.509

The Si(110) surface has a quite unique one-dimensional (1-D) structure with 162 reconstruction. Since the perfectly straight rows extend over micrometers, the 162 structure can be a superior template for 1-D nanostructures. In this study, we tried to control the clustering of Ge atoms on the Si(110) - 162 substrate. When Ge is deposited at 523 K, clustering of Ge atoms is found. The size of the cluster was 12 nm and many of them were located in a step edges. This trend is previously reported by vicinal Si(111) surface. With increasing temperature, the sizes of Ge clusters became larger. These results indicated that the size and alignment of the Ge cluster can be well controlled on the Si(110) - 162 template surface.

Fabrication of micro capsule containing fluorescent magnetic particles for advanced inspection of heat exchanger tubes

Ito, Fuyumi; Nishimura, Akihiko

E-Journal of Advanced Maintenance (Internet), 4(2), p.57 - 63, 2012/08

http://www.jsm.or.jp/ejam/Vol.4No.2/AA/AA40/40.html

Stress corrosion cracking sometimes occurs in the heat exchanger tubes of aging nuclear power plants. At the present time, Eddy Current Testing (ECT) is used to inspect these heat exchanger tubes. When symptoms of corrosion or cracks are found on the inside wall of the tubes, they are usually repaired. As repaired tubes increase in number, the cost of repair work rises considerably. Therefore, discovering tiny cracks has the purpose of ensuring not only progress on safety but also economical benefit. Cracks are observed not only by ECT but also by Magnetic particle Testing (MT), which facilitates visual observation. In the case of MT, a dispersed liquid with magnetic particles is applied to a magnetized sample. However, this dispersed liquid could potentially enter inside the crack. To solve this problem, this paper proposes that magnetic particles be contained inside a micro capsule, this capsule calls Magnetic Particle Micro Capsule (MPMC).

Carbon isotopes of water-extractable organic carbon in a depth profile of forest soil imply a dynamic relationship with soil carbon

Nakanishi, Takahiro; Atarashi-Andoh, Mariko; Koarashi, Jun; Kokubu, Yoko; Hirai, Keizo*

European Journal of Soil Science, 63(4), p.495 - 500, 2012/08

https://doi.org/10.1111/j.1365-2389.2012.01465.x

To elucidate the origin and behavior of the water extractable organic carbon (WEOC), we first determined both the C andC of fractionated WEOC by DAX-8 resin in a cool-temperate beech forest soil. The enrichment of C in WEOC with depth reflected the increasing proportion of the hydrophilic (HPI) fraction to the hydrophobic acid (HPOA) fraction. The changes in C indicated that the major source of WEOC and its fractions was old organic matter in the mineral soil. Our results strengthened previous suggestion that the preferential adsorption of HPOA fraction and the preferential leaching of the indigenous soluble organic carbon in the mineral soils. This dynamic equilibrium between WEOC and the much greater soil organic carbon fraction plays an important role in carbon transport and accumulation throughout the soil profile.

Verification test results of a cutting technique for the ITER blanket cooling pipes

Shigematsu, Soichiro; Tanigawa, Hisashi; Aburadani, Atsushi; Takeda, Nobukazu; Kakudate, Satoshi; Mori, Seiji*; Nakahira, Masataka*; Raffray, R.*; Merola, M.*

Fusion Engineering and Design, 87(7-8), p.1218 - 1223, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.02.108

The current design of the ITER blanket system is a modular configuration and a total of 440 blanket modules are to be installed in the ITER vacuum vessel. Each blanket module consists of the first wall (FW) and the shield block (SB). The FW receives a high heat load from the plasma. The SB shields components from the neutrons generated by the nuclear fusion reaction. The FW will be damaged by the heat load and neutrons, so it requires scheduled replacement. For the FW replacement, cutting/welding tools for the cooling pipes must be able to conduct the following operations: access and cut/weld the pipe from the inside of the cooling pipe. The cutting tool for the pipe end is required to cut flat plate circularly from the surface side of the FW. This paper describes the current status of R&D of the cutting tools for maintenance of the cooling pipe of the FW.

Development of fabrication technologies for advanced breeding functional materials for DEMO reactors

Hoshino, Tsuyoshi; Nakamichi, Masaru

Fusion Engineering and Design, 87(5-6), p.486 - 492, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.01.005

DEMO reactors require advanced tritium breeder and neutron multiplier that have higher stability at high temperature. LiTiO with added Li (LiTiO) have been developed such as advanced tritium breeder. LiTiO have higher stability at high temperatures with reduction atmosphere. We have been promoting the development of fabrication technique of LiTiO pebbles by the emulsion method, one of the sol-gel methods. The average diameter and the sphericity of pebbles by the emulsion method were 0.95 mm and 1.02, respectively. On the other hand, beryllium intermetallic compounds (beryllides) are promising material for advanced neutron multipliers. In this study, trial fabrication examinations were carried out. The formation of BeTi intermetallic was identified using a mixture of Be and Ti particles for the plasma sintering method.

Conceptual study of vertical sector transport maintenance for DEMO fusion reactor

Uto, Hiroyasu; Tobita, Kenji; Someya, Yoji; Takase, Haruhiko

Fusion Engineering and Design, 87(7-8), p.1409 - 1413, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.03.024

In BA DEMO design activity assessment of various maintenance schemes for DEMO reactor has been studied. The maintenance scheme is one of the critical issues for DEMO design, and required high availability. SlimCS designed in JAEA adopts the horizontal sector transport hot cell maintenance scheme. In order to decide a most probable DEMO reactor maintenance scheme, assessment of various maintenance schemes for DEMO are important. In this presentation the maintenance concept vertical sector transport is presented. In the sector maintenance scheme, the number of cutting/re-welding points of piping is minimized. The sector including blanket modules and high temperature shield was divided into 36 segments in toroidal direction. The sectors are removed and inserted through upper alternately-layered vertical maintenance ports. In the case of the vertical sector transport maintenance scheme, the inter-coil structures against turnover force in TF coils could be adopted.

Development of the water cooled ceramic breeder test blanket module in Japan

Enoeda, Mikio; Tanigawa, Hisashi; Hirose, Takanori; Suzuki, Satoshi; Ochiai, Kentaro; Konno, Chikara; Kawamura, Yoshinori; Yamanishi, Toshihiko; Hoshino, Tsuyoshi; Nakamichi, Masaru; et al.

Fusion Engineering and Design, 87(7-8), p.1363 - 1369, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.03.007

The development of a Water Cooled Ceramic Breeder (WCCB) Test Blanket Module (TBM) is being performed as one of the most important steps toward DEMO blanket in Japan. For the TBM testing and evaluation toward DEMO blanket, the module fabrication technology development by a candidate structural material, reduced activation martensitic/ferritic steel, F82H, is one of the most critical items from the viewpoint of realization of TBM testing in ITER. Fabrication of a real scale first wall, side walls, a breeder pebble bed box and assembling of the first wall and side walls have succeeded. Recently, the real scale partial mockup of the back wall was fabricated. The fabrication procedure of the back wall, whose thickness is up to 90 mm, was confirmed toward the fabrication of the real scale back wall by F82H. This paper overviews the recent achievements of the development of the WCCB TBM in Japan.

Determination and prediction of axial/off-axial mechanical properties of SiC/SiC composites

Nozawa, Takashi; Ozawa, Kazumi; Choi, Y.-B.*; Koyama, Akira*; Tanigawa, Hiroyasu

Fusion Engineering and Design, 87(5-6), p.803 - 807, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.02.026

A SiC/SiC composite is a candidate material for a demonstration fusion power reactor. Considering the inherent anisotropy of composites with variety of fabric architecture is required to precisely predict axial and off-axial mechanical properties by various failure modes. This study evaluated crack propagation behavior by the various modes to provide a strength anisotropy map and we discussed a methodology to analytically predict this trend. The strength anisotropy maps identified for various fabric orientations clearly indicate that the composites failed by the mixed modes. Specifically, due to the axial anisotropy, five individual modes such as tensile/compressive strengths in the axial/transverse directions, respectively, as well as the in-plane shear strength, are identified to be essential. In this study, with the analytical criterion based on the Tsai-Wu model, the strength anisotropy could satisfactorily be described.

Waste management strategy focused on maintenance, storage and recycling

Someya, Yoji; Tobita, Kenji; Uto, Hiroyasu; Asakura, Nobuyuki

Fusion Engineering and Design, 87(7-8), p.1282 - 1285, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.02.117

Waste management needs to include how to handle the waste in maintenance and how to manage the waste in the hot cell and the interim storage facility as well as the classification, processing for recycling or reuse and disposal. This paper highlights the waste management in the maintenance, interim storage and recycling of blanket and divertor. In a fusion reactor, maintenance equipments must be tolerant in severe radiation environment. In addition, the waste conditions may require a relatively small port size or a shielding plate for used blanket and divertor for radiation safety during maintenance. Furthermore, the blanket and divertor need to be actively cooled during maintenance and several year storage. The decay heat makes the handling of the waste difficult but, on the other hand, the heat may be utilized to keep the waste temperature high enough to facilitate detriation.

Development of the plasma facing components in Japan for ITER

Suzuki, Satoshi; Ezato, Koichiro; Seki, Yohji; Mori, Kensuke; Yokoyama, Kenji; Enoeda, Mikio

Fusion Engineering and Design, 87(5-6), p.845 - 852, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.02.035

After the successful completion of the prequalification activity for ITER divertor procurement, Japanese Domestic Agency (JADA) and ITER Organization (IO) have entered into the procurement arrangement of divertor outer vertical target (OVT) in June 2009. In accordance with the arrangement, JADA has started to manufacture an OVT full-scale prototype in order to pick out and solve technical and quality issues, then to establish a rational manufacturing process toward the start of the series of production of the OVT components to be installed in tokamak. This paper presents the overview of JADA's activity on the divertor outer target procurement and also procurement schedule will be presented.

JT-60SA vacuum vessel manufacturing and assembly

Masaki, Kei; Shibama, Yusuke; Sakurai, Shinji; Shibanuma, Kiyoshi; Sakasai, Akira

Fusion Engineering and Design, 87(5-6), p.742 - 746, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.02.014

The JT-60SA vacuum vessel (VV) has a D-shaped poloidal cross section and a toroidal configuration with 10 segmented facets. A double wall structure is adopted to ensure high rigidity at operational load and high toroidal one-turn resistance. The material is 316L stainless steel with low cobalt content ( 0.05wt%). In the double wall, boric-acid water (max. 50C) is circulated at plasma operation to reduce the nuclear heating of the superconducting magnets. For baking, nitrogen gas (200C) is circulated in the double wall after draining of the boric-acid water. The manufacturing of the VV started in November 2009 after a fundamental welding R&D and a trial manufacturing of 20 upper half mock-up. A basic VV assembly scenario and procedure were studied to complete the 360 VV including positioning method and joint welding between sectors considering misalignment.

Effect of sweep gas species on tritium release behavior from lithium titanate packed bed during 14MeV neutron irradiation

Kawamura, Yoshinori; Ochiai, Kentaro; Hoshino, Tsuyoshi; Kondo, Keitaro*; Iwai, Yasunori; Kobayashi, Kazuhiro; Nakamichi, Masaru; Konno, Chikara; Yamanishi, Toshihiko; Hayashi, Takumi; et al.

Fusion Engineering and Design, 87(7-8), p.1253 - 1257, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.02.125

Tritium generation and recovery study on lithium ceramic packed bed was started by use of FNS in JAEA. Lithium titanate was selected as tritium breeding material. In this work, the effect of sweep gas species on tritium release behavior was investigated. In case of sweep by helium with 1% of hydrogen, tritium in water form was released sensitively corresponding to the irradiation. This is due to existence of the water vapor in the sweep gas. On the other hand, in case of sweep by dry helium, tritium in gaseous form was released first, and release of tritium in water form was delayed and was gradually increased.

New integral experiments for large angle scattering cross section data benchmarking with DT neutron beam at JAEA/FNS

Onishi, Seiki*; Kondo, Keitaro*; Azuma, Tetsushi*; Sato, Satoshi; Ochiai, Kentaro; Takakura, Kosuke; Murata, Isao*; Konno, Chikara

Fusion Engineering and Design, 87(5-6), p.695 - 699, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.02.002

A new integral experiment with a deuteron-triton fusion (DT) neutron beam started in order to validate scattering cross section data. First the DT neutron beam was constructed with a collimator. The characteristics of the DT neutron beam were examined experimentally. Second a new integral experiment for type 316 stainless steel (SS316) was carried out with this DT neutron beam. Reaction rates of the Nb(n,2n)Nb reaction on the center of the beam axis and at 15 cm and 30 cm apart from the axis in the assembly were measured with the activation foil method and were calculated with the Monte Carlo transport calculation code MCNP and nuclear data libraries, JENDL-4.0, JENDL-3.3 and ENDF/B-VI.8. The ratios of calculation to experiment became smaller than 1 with the distance from the beam axis for all the nuclear libraries. It was pointed out that the diagonally forward cross section data had some problems.

Nuclear engineering of diagnostic port plugs on ITER

Pitcher, C. S.*; Barnsley, R.*; Feder, R.*; Hu, Q.*; Loesser, G. D.*; Lyublin, B.*; Padasalagi, S.*; Pak, S.*; Reichle, R.*; Sato, Kazuyoshi; et al.

Fusion Engineering and Design, 87(5-6), p.667 - 674, 2012/08

https://doi.org/10.1016/j.fusengdes.2012.01.043

Damage and recovery of JAEA instruments and neutron guides at JRR-3

Wakimoto, Shuichi; Sasajima, Fumio; Nagahori, Kazuhisa; Tamura, Itaru

Hamon, 22(3), p.242 - 245, 2012/08

https://doi.org/10.5611/hamon.22.3_242

The journal of Japanese Society of Neutron Science "Hamon" will publish a special issue of "Recovery from the earthquake" in August. Authors were asked to right the recovery of instruments and neutron guides. In this article, we review the damage and recovery process done in FY2011.

Landslides in the western part of Horonobe area, northern Hokkaido, Japan

Miyasaka, Seigo*; Niizato, Tadafumi; Shigeno, Kiyoyuki*

Hokkaido No Jisuberi, 2012, p.61 - 66, 2012/08

no abstracts in English

Spatial, LET and range dependence of enhanced charge collection by single ion strike in 4H-SiC MESFETs

Onoda, Shinobu; Makino, Takahiro; Ono, Shuichi*; Katakami, Shuji*; Arai, Manabu*; Oshima, Takeshi

IEEE Transactions on Nuclear Science, 59(4), p.742 - 748, 2012/08

https://doi.org/10.1109/TNS.2012.2195199

no abstracts in English

Merit assessment of nuclear hydrogen steelmaking with very high temperature reactor

Inagaki, Yoshiyuki; Kasahara, Seiji; Ogawa, Masuro

ISIJ International, 52(8), p.1420 - 1426, 2012/08

https://doi.org/10.2355/isijinternational.52.1420

The merit assessment of the nuclear hydrogen steelmaking (NHS) was performed for reduction of CO emissions from the steelmaking process. The NHS process is composed of the steelmaking process by hydrogen reduction and hydrogen production process, namely IS process, using a very high temperature reactor (VHTR). VHTR has the excellent safety features outstanding as compared with the other nuclear reactors that the reactor can be shut down inherently and cooled down passively using natural heat radiation from outside of the reactor pressure vessel even in a loss of coolant flow accident caused by loss of power and so on. Therefore, hydrogen can be supplied directly to a shaft furnace using piping from VHTR installed near the steelmaking plant. The NHS process with VHTR and IS process can decrease the CO emissions by approximately 9% of those of the conventional blast furnace process, and be economically competitive to the blast furnace and the shaft furnace processes.

Observation of inside structures of live biological cells by laser plasma X-ray microscope

Kado, Masataka

Isotope News, (700), p.8 - 11, 2012/08

http://www.jrias.or.jp/member/pdf/201208_TENBO_KADO.pdf

http://www.jrias.or.jp/books/cat3/2012/700.html

Soft X-ray microscope is expected as a powerful tool to observe cellular organelles and to investigate radiation effects on biological cells. However in vivo observation of cellular organelles were not realized because long exposure time was needed due to insufficient X-ray intensity. Combining high intense soft X-ray sources, which were generated by irradiating high power laser onto thin foil gold target, to contact X-ray microscopy we have developed a laser plasma soft X-ray microscope which can observe cellular organelles of live biological cells with high spatial resolution. As a result we have observed mitochondria surrounding nucleus and chromatin structures inside.

Nonadiabatic generation of coherent phonons

Shinohara, Yasushi*; Sato, Shunsuke*; Yabana, Kazuhiro*; Iwata, Junichi*; Otobe, Tomohito; Bertsch, G. F.*

Journal of Chemical Physics, 137(22), p.22A527_1 - 22A527_8, 2012/08

https://doi.org/10.1063/1.4739844

The time-dependent density functional theory (TDDFT) is the leading computationally feasible theory to treat excitations by strong electromagnetic fields. Here the theory is applied to coherent optical phonon generation. We examine the process in the crystalline semimetal antimony (Sb), where nonadiabatic coupling and optical phonon of different symmetries can be observed. The TDDFT is able to account for a number of qualitative features of the observed coherent phonon.

Fundamental study on a grout penetration model for a HLW repository

Fujita, Tomoo; Shinkai, Fumiaki*; Nobuto, Jun*

Journal of Energy and Power Engineering, 6(8), p.1191 - 1203, 2012/08

http://www.davidpublishing.com/show.html?7526

This study aims at validating applicability of the theoretical formula by Gustafson and Still to analysis of permeation behavior of Bingham fluid into a one-dimensional micro-fissure by comparing analysis results with laboratory tests data conducted using bentonite slurry as a Bingham fluid. The results showed that the calculation values by Gustafson and Stille model agreed well with values of laboratory penetration test.

Determining the shear fracture properties of HIP joints of reduced-activation ferritic/martensitic steel by a torsion test

Nozawa, Takashi; Noh, S.; Tanigawa, Hiroyasu

Journal of Nuclear Materials, 427(1-3), p.282 - 289, 2012/08

https://doi.org/10.1016/j.jnucmat.2012.05.019

A hot isostatic press (HIP) process is a key technology to fabricate a first wall with cooling channels of the fusion blanket system utilizing a reduced-activation ferritic/martensitic steel. This study aims to develop the torsion test method with a special emphasis to provide a reasonable and comprehensive method to determine interfacial shear properties of HIP joints during the torsional fracture process. Torsion test results identified that the torsion process shows yield of the base metal and following non-elastic deformation due to work hardening of the base metal. By considering this work hardening issue, we could propose a reasonable and realistic solution to determine the torsional yield shear stress and the ultimate torsional shear strength of the HIPped interface. Finally, representative torsion fracture process was identified.

Intrinsic edge asymmetry in narrow zigzag hexagonal heteroatomic nanoribbons causes their subtle uniform curvature

Avramov, P.; Fedorov, D. G.*; Sorokin, P. B.*; Sakai, Seiji; Entani, Shiro; Otomo, Manabu; Matsumoto, Yoshihiro; Naramoto, Hiroshi*

Journal of Physical Chemistry Letters (Internet), 3(15), p.2003 - 2008, 2012/08

https://doi.org/10.1021/jz300625t

Spectroscopic study of Ni via cold neutron capture reaction, 1; Nuclear structure of Ni

Oshima, Masumi; Kin, Tadahiro*; Nakamura, Shoji; Homma, Michio*; Minato, Futoshi; Hayakawa, Takehito; Hara, Kaoru; Kimura, Atsushi; Koizumi, Mitsuo; Harada, Hideo; et al.

Journal of the Physical Society of Japan, 81(8), p.084201_1 - 084201_15, 2012/08

https://doi.org/10.1143/JPSJ.81.084201

The -radiation has been investigated produced by cold neutron capture in an enriched Ni sample. The 315 -rays have been placed in the Ni level scheme of which 272 placements are new. We have determined excitation energies with 0.2-0.8 keV error and branching ratios of 62 bound levels in Ni, including 30 new levels. The Q-value of the Ni (n,) Ni reaction amounts to 6837.75 (18) keV. A large-scale shell-model calculation has been performed and the energies of the low-lying Ni states are successfully reproduced. A mean-field statistical model calculation has been also made by using a self-consistent interaction between the Hartree-Fock + BCS method and the statistical calculation. The calculation result is consistent with the experimental level density of Ni.

Spinmotive force; Basic concepts and developments

Ieda, Junichi; Maekawa, Sadamichi

Kotai Butsuri, 47(8), p.339 - 353, 2012/08

http://ci.nii.ac.jp/naid/40019420875

The mutual interaction between spin current and magnetization is a key phenomenon in spintronics. This interaction leads to a spinmotive force, a mechanism of energy-transfer from magnetization into conduction electrons. In this review, the basic concepts and recent developments of the spinmotive force are introduced.

Validation of fast reactor analysis methods using reactor physics experiments

Ando, Masaki

Nihon Genshiryoku Gakkai Dai-44-Kai Robutsuri Kaki Semina Tekisuto, p.139 - 163, 2012/08

Mock-up experiments for "JOYO" and "MONJU" using FCA and the JUPITER program using ZPPR are introduced. As a validation of the fast reactor analysis method, a process to make a benchmark model, examples of reactivity experiment (Doppler effect and sodium void effect) and benchmark experiments to evaluate nuclear data libraries are described.

Visualization of low-speed upflow in a cylindrical vesse

Kamiji, Yu; Terada, Atsuhiko; Hino, Ryutaro

Nihon Kikai Gakkai Kanto Shibu Ibaraki Koenkai 2012 Koen Rombunshu, p.63 - 64, 2012/08

Low-speed up-flow is generated due to the water radiolysis in the spent vessel used by contaminated water treatment facility of Fukushima Dai-ichi Nuclear Power Plant. Though it is important to understand the inside flow of the vessel for storage, it is not clear. Thus flow test was performed with a simulated acrylic cylindrical vessel. This paper reports results of visualization of low-speed upflow in a cylindrical vessel by using LASER light sheet and high speed camera. It was confirmed that stagnant flow was generated around the stepped section, and the stagnant flow repeated appearance and dissipation. It was also found that the behavior of the stagnation depended on gas flow rate.

LDV flow measurement of a deflected inflow using a 1/10-scale hot-log piping test facility of a primary circuit hot-leg piping in a sodium-cooled fast reactor

Iwamoto, Yukiharu*; Kondo, Manabu*; Ogawa, Shota*; Tanaka, Masaaki; Yamano, Hidemasa

Nihon Kikai Gakkai Rombunshu, B, 78(792), p.1383 - 1387, 2012/08

https://doi.org/10.1299/kikaib.78.1383

LDV measurements in a 90 degrees elbow which curvature radius coincides with the diameter have been conducted. This paper especially focuses on a result of the deflected inflow, comparing with a result of the short pipe. The result shows that the deflected inflow reinforced a convex velocity distribution occurring near the curvature inside in the downstream region, concluding that the deflected inflow promotes the secondary flow of Prandtl's first kind in the elbow. Its Strouhal number increases to 0.6 from 0.5, compared with the short pipe case. Results of frequency analyses are also shown for other cases that we have been examined. Dominant Strouhal numbers in most of the cases become 0.5, except for 0.6 in cases of the inflow from the long pipe and deflector. This frequency shift might be related with the boundary layer size and the local flow velocity, since the corresponding fluctuation is caused by vortex shedding from the boundary layer at the elbow inside.

Prediction of unsteady flow field in a primary circuit hot-leg piping of a sodium-cooled fast reactor

Tanaka, Masaaki; Sago, Hiromi*; Iwamoto, Yukiharu*; Ebara, Shinji*; Ono, Ayako; Murakami, Takahiro*; Hayakawa, Satoshi*

Nihon Kikai Gakkai Rombunshu, B, 78(792), p.1392 - 1396, 2012/08

https://doi.org/10.1299/kikaib.78.1392

A study on flow induced vibration in the primary cooling system of Japan Sodium cooled Fast Reactor (JSFR) consisting of large diameter pipe and pipe elbow with short curvature radius ("short-elbow") has been conducted. Flow-induced vibration in the short-elbow is an important issue in design study of JSFR, because it may affect to structural integrity of the pipe. In this paper, unsteady flow characteristics in the JSFR short-elbow pipe related to the large-scale eddy motion were estimated based on knowledge from existing studies for curved pipes and scaled water experiments and numerical simulations for the JSFR hot-leg piping.

Laser therapy for twin-to-twin transfusion syndrome; Today and near-future

Yamashita, Hiromasa*; Oka, Kiyoshi; Yamanaka, Noriaki*; Seki, Takeshi; Kim, K.*; Kuwana, Kenta*; Masamune, Ken*; Naganawa, Akihiro*; Dohi, Takeyoshi*; Chiba, Toshio*

Nihon Reza Igakkai-Shi, 33(2), p.122 - 130, 2012/08

https://doi.org/10.2530/jslsm.33.122

no abstracts in English

Development of measurement technology for surface heat fluxes and temperatures

Liu, W.; Takase, Kazuyuki

Nuclear Engineering and Design, 249, p.166 - 171, 2012/08

https://doi.org/10.1016/j.nucengdes.2011.06.036

A system for measuring the surface temperature and the surface heat flux of a heating block was developed that has no need for a sensor set on the surface. The system consisted of two parts: (1) inner block temperatures were measured using micro-thermocouples; (2) using the measured temperatures, an inverse heat conduction problem was solved to get the surface heat flux and surface temperature. For the inner block temperature measurement, special T-type micro thermocouples with a common positive pole were developed. A total of 10 thermocouples were set at a depth of 3.1 m beneath the boiling surface, in a circle with a radius of 5 mm. The developed system was used to measure the change of surface heat flux and surface temperature in a pool nucleate boiling process. Experiments were performed at atmospheric pressure. The experiments showed that the developed special T-type micro thermocouples can successfully measure the temperature change in a boiling process. By using the measured temperature, a semi-infinite inverse heat conduction problem was solved to get the surface heat flux and surface temperature. The change in surface heat flux and surface temperature in a bubble cycle was derived.

Criticality evaluation for the Monju restart core

Hazama, Taira; Kitano, Akihiro; Kishimoto, Yasufumi*

Nuclear Technology, 179(2), p.250 - 265, 2012/08

https://doi.org/10.13182/NT12-A14097

The Japanese prototype fast breeder reactor Monju restarted its system startup test in May 2010 after a 14-year interruption. In the first stage of the test, reactor physics parameters have been measured at a zero power level. The present paper describes the evaluation of the criticality data. The best-estimate value and its uncertainty are evaluated as accurately as possible. The restart core contains 1.5 wt% of Am which is three times larger than the previous test. To extract an influence of the Am accumulation on calculation accuracy, criticality data obtained in the previous test is evaluated in the same level of detail. The calculation accuracy is investigated with four major nuclear data libraries. It is confirmed that the accuracy is within 0.3%, 2 value of experimental uncertainty, with JENDL-3.3, JENDL-4.0, and ENDF/B-VII.0. The reactivity change due to the Pu decay can be simulated within an accuracy of 1% with JENDL-4.0 and JEFF-3.1.

Control rod worth evaluation for the Monju restart core

Takano, Kazuya; Fukushima, Masahiro; Hazama, Taira; Suzuki, Takayuki

Nuclear Technology, 179(2), p.266 - 285, 2012/08

https://doi.org/10.13182/NT12-A14098

The present paper describes the evaluation of the control rod worth data obtained in the Monju restart core. The best-estimate value and its uncertainty are evaluated in detail. As in the criticality evaluation, data obtained in the previous test is evaluated in the same level of detail. The correlation in the uncertainties is also evaluated among different control rods and tests of the previous and the restart cores. Based on the evaluated data, calculation accuracy is investigated with JENDL-3.3 and JENDL-4.0. It is confirmed that the calculation accuracy is within the experimental uncertainty of 2% for each layer and B content. A reduction in the uncertainty related to the delayed neutron fraction is effective for a further improvement in the calculation accuracy.

High hydrogen-adsorption-rate material based on graphane decorated with alkali metals

Antipina, L. Y.*; Avramov, P.; Sakai, Seiji; Naramoto, Hiroshi*; Otomo, Manabu; Entani, Shiro; Matsumoto, Yoshihiro; Sorokin, P. B.*

Physical Review B, 86(8), p.085435_1 - 085435_7, 2012/08

https://doi.org/10.1103/PhysRevB.86.085435

Contrasting fission potential-energy structure of actinides and mercury isotopes

Ichikawa, Takatoshi*; Iwamoto, Akira; Mller, P.*; Sierk, A. J.*

Physical Review C, 86(2), p.024610_1 - 024610_8, 2012/08

https://doi.org/10.1103/PhysRevC.86.024610

Fission-fragment mass distributions are asymmetric in fission of typical actinide nuclei for nucelon number in the range and proton number in the range . For somewhat lighter systems it has been observed that fission mass distributions are usually symmetric. However, a recent experiment showed that fission of Hg following electron capture on HI is asymmetric. An earlier experiment has shown fission of Hg and nearby nuclei is symmetric, but with hints of asymmetric yield distributions up to about 10 MeV above the saddle-point energy. We calculate potential-energy surfaces for a typical actinide nucleus and for 12 even isotopes in the range Hg-Hg, demonstrating the radical differences between actinide and mervury potential surfaces. We discuss these differences and how the changing potential-energy structure along the mercury isotope chain affects the observed (a)symmetry of the fission fragments. We show that the mechanism of asymmetric fission is very different in proton-rich mercury isotopes compared to the actinide region.

Synthesis of arsenic graft adsorbents in pilot scale

Hoshina, Hiroyuki; Kasai, Noboru; Shibata, Takuya*; Aketagawa, Yasushi*; Takahashi, Makikatsu*; Yoshii, Akihiro*; Tsunoda, Yasuhiko*; Seko, Noriaki

Radiation Physics and Chemistry, 81(8), p.1033 - 1035, 2012/08

https://doi.org/10.1016/j.radphyschem.2012.02.018

Two-mode fission; Experimental verification and characterization of two fission-modes

Nagame, Yuichiro; Nakahara, Hiromichi*

Radiochimica Acta, 100(8-9), p.605 - 614, 2012/08

https://doi.org/10.1524/ract.2012.1968

Imaging of ablation dynamics by soft X-ray laser

Tomita, Takuro*; Hasegawa, Noboru; Nishikino, Masaharu; Kawachi, Tetsuya; Suemoto, Toru

Reza Kenkyu, 40(8), p.592 - 597, 2012/08

http://joi.jlc.jst.go.jp/JST.Journalarchive/lsj1973/18.8_592

A single-shot soft X-ray laser pulse was used as a probe to investigate the early stage of the laser ablation process on platinum caused by the femtosecond near-infrared pump pulse. From time-resolved interferometry, we observed the dilation of the ablation front on a scale of 10 nm in the picosecond region. In the reflective imaging, we found three distinct types of dynamical responses, depending on the radial position in the pump beam spot. These characteristic behaviors correspond to different laser fluence and were attributed to different ablation schemes: spallation, homogeneous nucleation, and fragmentation/vaporization, which have been predicted from molecular dynamics simulation.

Design of soft X-ray wide-band multilayer gratings for constant deviation monochromators

Koike, Masato; Imazono, Takashi

AIP Conference Proceedings 1465, p.202 - 206, 2012/07

https://doi.org/10.1063/1.4737560

Soft X-ray multilayer has a potential to improve diffraction efficiency of diffraction gratings in the multi-kilo electron volts region. However, to use a conventional multilayer grating at the maximum diffraction efficiency, the incidence and diffraction angles should be varied with photon energy. Recently we developed a wide-band laminar-type multilayer grating for the flat-field spectrograph used in the energy range of 2-4 keV. The structure of the multilayer consists of two regions of massive and few periods having short and long period lengths, respectively, to widen the bandwidth. This method worked successfully that a diffraction efficiency of 1-2 % was obtained experimentally. Another interest on this method is the application to the monochromators. In this paper, we design the diffraction efficiency of the multilayer laminar-type grating covering 1.5-2.5 keV and estimate the throughput of a Monk-Gillieson type monochromator employing this grating.

Improvement of the Soft X-ray Polarimeter and Ellipsometer (SXPE) for complete polarization analysis

Imazono, Takashi; Sano, Kazuo*; Koike, Masato

AIP Conference Proceedings 1465, p.28 - 32, 2012/07

https://doi.org/10.1063/1.4737534

Incorporation of the effect of the composite electric fields of molecular ions as a simulation tool for biological damage due to heavy ion irradiation, 2

Moribayashi, Kengo

AIP Conference Proceedings 1465, p.241 - 245, 2012/07

https://doi.org/10.1063/1.4737566

Interaction of soft X-ray laser pulse radiation with aluminum surface; Nano-meter size surface modification

Ishino, Masahiko; Faenov, A.*; Tanaka, Momoko; Hasegawa, Noboru; Nishikino, Masaharu; Tamotsu, Satoshi*; Pikuz, S.*; Inogamov, N. A.*; Zhakhovsky, V. V.*; Skobelev, I.*; et al.

AIP Conference Proceedings 1465, p.236 - 240, 2012/07

https://doi.org/10.1063/1.4737565

We irradiated the focusing soft X-ray laser pulses having a wavelength of 13.9 nm and the duration of 7 ps to aluminum surface. After the irradiation process, the irradiated surface was observed with a scanning electron microscope. The surface modifications caused by soft X-ray laser single pulse exposure were clearly seen. In addition, it was found that the conical structures having around 100 nm in diameters were formed in the shallow features. The nano-meter size modified surface structures on aluminum induced by the soft X-ray laser pulse is interesting as the newly surface structure. Hence, the soft X-ray laser beam would be a candidate for a tool of micromachining. We also provide a thermomechanical modeling of the soft X-ray laser interaction with aluminum briefly to explain the surface modification.

Extreme field limits in the interaction of laser light with ultrarelativistic electrons

Bulanov, S. V.; Esirkepov, T. Z.; Hayashi, Yukio; Kando, Masaki; Kiriyama, Hiromitsu; Koga, J. K.; Kondo, Kiminori; Kotaki, Hideyuki; Pirozhkov, A. S.; Bulanov, S. S.*; et al.

AIP Conference Proceedings 1465, p.87 - 96, 2012/07

https://doi.org/10.1063/1.4737545