Nagai, Takayuki; Okamoto, Yoshihiro; Yamagishi, Hirona*; Ota, Toshiaki*; Kojima, Kazuo*; Inose, Takehiko*; Sato, Seiichi*; Hatakeyama, Kiyoshi*
JAEA-Research 2020-009, 48 Pages, 2020/09
The local structure of glass-forming elements and waste elements in waste glass varies with its chemical composition. In this study, borosilicate glass frit and simulated waste glass samples were prepared and the local structure and chemical state regarding boron (B), oxygen (O), and waste elements of cerium (Ce), cesium (Cs) were estimated by using XAFS measurement in soft X-ray region. Following results were obtained by XAFS measurements of prepared glass frit and simulated waste glass samples: (1) The existence ratio of four coordinate sp structure (BO) tends to increase with increasing NaO content in glass samples. (2) The height of a pre-edge which appears by K-edge XANES spectrum of O is so high that the Fe content in glass samples. Following results were obtained by XAFS measurements of simulated waste glass samples after immersion test to investigate long chemical stability. (1) The existence ratio of four coordinate sp structure (BO) increases by immersion test. (2) Ce which exists in the surface layer is oxidized by immersion test, and much of Cs in surface layer is lost after leach testing. Even if the glass frit form (fiber cartridge or beads) and manufacturing method were changed and a glass sample of the similar chemical composition was prepared, these observed Raman spectra of samples were different.
Abe, Yuta; Tsuchikawa, Yusuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Parker, J. D.*; Shinohara, Takenao; Oishi, Yuji*; Kamiyama, Takashi*; Nagae, Yuji; Sato, Ikken
Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 6 Pages, 2020/08
Nagai, Takayuki; Sasage, Kenichi; Okamoto, Yoshihiro; Shiwaku, Hideaki; Yamagishi, Hirona*; Ota, Toshiaki*; Inose, Takehiko*; Sato, Seiichi*; Hatakeyama, Kiyoshi*; Takahashi, Tomoe*; et al.
JAEA-Research 2019-003, 94 Pages, 2019/09
The local structures of glass-forming elements and waste elements would change by the chemical composition of waste glass including those elements. In this study, simulated waste glass samples were prepared from borosilicate glass frit including phosphorus (P) or vanadium (V), and we investigated local structures of boron, sodium, and waste elements in these P glass and V glass samples by using synchrotron XAFS measurements in soft and hard X ray region.
Iwamoto, Yosuke; Matsuda, Hiroki; Meigo, Shinichiro; Satoh, Daiki; Nakamoto, Tatsushi*; Yoshida, Makoto*; Ishi, Yoshihiro*; Kuriyama, Yasutoshi*; Uesugi, Tomonori*; Yashima, Hiroshi*; et al.
Proceedings of 61st ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2018) (Internet), p.116 - 121, 2018/07
The radiation damage model in the radiation transport code PHITS has been developed to calculate the basic data of the radiation damage including the energy of the target Primary Knock on Atom (PKA). For the high-energy proton incident reactions, a target PKA created by the secondary particles was more dominant than a target PKA created by the projectile. To validate the radiation damage model in metals irradiated by 100 MeV protons, we developed a proton irradiation device with a Gifford-McMahon cryocooler to cryogenically cool wire samples. By using this device, the defect-induced electrical resistivity changes related to the DPA cross section of copper and aluminum were measured under irradiation with 125 and 200 MeV protons at cryogenic temperature. A comparison of the experimental data with the calculated results indicates that the DPA cross section with defect production efficiencies provide better quantitative descriptions.
Sato, Yuji*; Tsukamoto, Masahiro*; Shobu, Takahisa; Yamashita, Yoshihiro*; Yamagata, Shuto*; Nishi, Takaya*; Higashino, Ritsuko*; Okubo, Tomomasa*; Nakano, Hitoshi*; Abe, Nobuyuki*
Applied Physics A, 124(4), p.288_1 - 288_6, 2018/04
The dynamics of titanium (Ti) melted by laser irradiation was investigated in a synchrotron radiation experiment. As an indicator of wettability, the contact angle between a selective laser melting (SLM) baseplate and the molten Ti was measured by synchrotron X-rays at 30 keV during laser irradiation. As the baseplate temperature increased, the contact angle decreased, down to 28 degrees at a baseplate temperature of 500C. Based on this result, the influence of wettability of a Ti plate fabricated by SLM in a vacuum was investigated. It was revealed that the improvement of wettability by preheating suppressed sputtering generation, and a surface having a small surface roughness was fabricated by SLM in a vacuum.
Naito, Fujio*; Anami, Shozo*; Ikegami, Kiyoshi*; Uota, Masahiko*; Ouchi, Toshikatsu*; Onishi, Takahiro*; Oba, Toshiyuki*; Obina, Takashi*; Kawamura, Masato*; Kumada, Hiroaki*; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1244 - 1246, 2016/11
The proton linac installed in the Ibaraki Neutron Medical Research Center is used for production of the intense neutron flux for the Boron Neutron Capture Therapy (BNCT). The linac consists of the 3-MeV RFQ and the 8-MeV DTL. Design average beam current is 10mA. Target is made of Beryllium. First neutron production from the Beryllium target was observed at the end of 2015 with the low intensity beam as a demonstration. After the observation of neutron production, a lot of improvement s was carried out in order to increase the proton beam intensity for the real beam commissioning. The beam commissioning has been started on May 2016. The status of the commissioning is summarized in this report.
Iwamoto, Yosuke; Yoshiie, Toshimasa*; Yoshida, Makoto*; Nakamoto, Tatsushi*; Sakamoto, Masaaki*; Kuriyama, Yasutoshi*; Uesugi, Tomonori*; Ishi, Yoshihiro*; Xu, Q.*; Yashima, Hiroshi*; et al.
Journal of Nuclear Materials, 458, p.369 - 375, 2015/03
To validate Monte Carlo codes for the prediction of radiation damage in metals irradiated by 100 MeV protons, defect-induced electrical resistivity changes of copper related to the displacement cross-section were measured with 125 MeV proton irradiation at 12 K. The cryogenic irradiation system was developed with a Gifford-McMahon cryocooler to cool the sample via an oxygen-free high-conductivity copper plate by conduction cooling. The sample was a copper wire with a 250m diameter and 99.999% purity sandwiched between two aluminum nitride ceramic sheets. The resistivity increase did not change during annealing after irradiation below 15 K. The experimental displacement cross-section for 125 MeV irradiation shows similar results to the experimental data for 1.1 and 1.94 GeV. Comparison with the calculated results indicated that the defect production efficiency in Monte Carlo codes gives a good quantitative description of the displacement cross-section in the energy region 100 MeV.
Kitamura, Akihiro; Kurikami, Hiroshi; Yamaguchi, Masaaki; Oda, Yoshihiro; Saito, Tatsuo; Kato, Tomoko; Niizato, Tadafumi; Iijima, Kazuki; Sato, Haruo; Yui, Mikazu; et al.
Nuclear Science and Engineering, 179(1), p.104 - 118, 2015/01
The prediction of the distribution and fate of radioactive materials eventually deposited at surface in the Fukushima area is one of the main objectives and expected to be achieved in an efficient manner. In order to make such prediction, a number of mathematical models of radioactive contaminants, with particular attention on cesium, on the land and in rivers, lakes, and estuaries in the Fukushima area are developed. Simulation results are examined with the field investigations simultaneously implemented. The basic studies of the adsorption/absorption mechanism of cesium and soils have been performed to shed light on estimating distribution coefficient between dissolved contaminant and particulate contaminant.
Yamaguchi, Masaaki; Kitamura, Akihiro; Oda, Yoshihiro; Onishi, Yasuo*
Journal of Environmental Radioactivity, 135, p.135 - 146, 2014/09
We applied a model, to predict long term cesium distribution on Fukushima area, based on the USLE and simple sediment discharge formulas. Sensitivity analysis was conducted here to narrow the range of the output results due to the uncertainties of parameters. The preliminary calculation indicated significant deposition of sand portion within river basins. On the other hand the most of the eroded silt and clay portions were transported downstream to the river mouths. Annual sediment outflow into the ocean from Abukuma River and its total from the other 13 river basins vary between calculation cases based on the variation of land use, landform or precipitation. On the other hand, contributions of those parameters are relatively small for Cs concentration within transported soil. This indicates the total amount of Cs outflow into the ocean could be controlled by amount of soil erosion and transport, and total amount of Cs remaining within the basin.
Yamaoka, Shingo; Shimizu, Yuka*; Fukuda, Yoshihiro*; Shobu, Takahisa; Konishi, Hiroyuki
JAEA-Technology 2014-027, 21 Pages, 2014/08
At SPring-8 synchrotron radiation beamlines, it is essential to maintain a vacuum between the radiation source and the experimental station. This is achieved by using scroll pumps and turbo molecular pumps. However, scroll pump malfunctions have been reported at BL22XU. Since many of the pumps are located inside radiation-shielding hutches, malfunctions often go un-noticed. As a result, operations can continue despite the malfunction. To facilitate the early detection of scroll pump malfunctions, we have developed a "scroll pump operating status monitoring system (SCP-MS)". The system simultaneously measures motor current and vacuum pressure at the scroll pump. It is possible to monitor pumps from outside of the shielding hutch, something which was not possible until now. The (SCP-MS) has been installed to monitor scroll pumps in actual operation, to monitor the change of the motor current value and vacuum pressure. We report on the detail of the system.
Sasaki, Yuji; Tsubata, Yasuhiro; Kitatsuji, Yoshihiro; Sugo, Yumi; Shirasu, Noriko; Ikeda, Yasuhisa*; Kawasaki, Takeshi*; Suzuki, Tomoya*; Mimura, Hitoshi*; Usuda, Shigekazu*; et al.
JAEA-Research 2014-008, 220 Pages, 2014/06
The researches on Development of mutual separation technology of minor actinides by the novel hydrophilic and lipophilic diamide compounds, entrusted to Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan, from 2010 to 2012 are summarized. This project was composed of three themes, those are (1) Development of total recovery of MA+Ln: basic researches for new extractant, DOODA, (2) Development of mutual separation of Am/Cm/Ln: basic researches of Ln-complex, solvent extraction, and extraction chromatography, and (3) Evaluation of separation technique: process simulation. For topic (1), we summarized the information on characteristic of DOODA extractant. For topic (2), we summarized the information on structures of Ln-complexes, solvent extraction and chromatography. For topic (3), we summarized the information on conditions of mixer-settler and evaluation of each fraction separated.
Kitamura, Akihiro; Yamaguchi, Masaaki; Oda, Yoshihiro; Kurikami, Hiroshi; Onishi, Yasuo*
Transactions of the American Nuclear Society, 109(1), p.153 - 155, 2013/11
Long term Cs transport and its future distribution on the territory of Fukushima were predicted based on the USLE and the GIS. By modeling the soil erosion, transport, and deposition, we simulated the future distributions of air dose rates of Cs in mSv/h for 2, 6 and 21 years after the accident. The predictions made by METI were compared with the present results. The predictions of relatively high air dose rate areas were consistently matched between the two models over time. However, our model seemed to predict the decreasing rate of the Cs concentration with time to be slightly less than that of METI prediction. Some portions of the results obtained in the present study were used to provide influxes of sediments and Cs as boundary conditions and lateral inflows for the hydraulic river model.
Yoshida, Kiyoshi; Kizu, Kaname; Murakami, Haruyuki; Kamiya, Koji; Honda, Atsushi; Onishi, Yoshihiro; Furukawa, Masato; Asakawa, Shuji; Kuramochi, Masaya; Kurihara, Kenichi
Fusion Engineering and Design, 88(9-10), p.1499 - 1504, 2013/10
The modifying of the JT-60U magnet system to the superconducting coils (JT-60SA) is progressing as a satellite facility for ITER by both parties of Japanese government and European commission (EU) in the Broader Approach agreement. The magnet system for JT-60SA consists of 18 Toroidal Field (TF) coils, a Central Solenoid (CS) with 4 modules, and 6 Equilibrium Field (EF) coils. The manufacturing of the JT-60SA magnet system is in progress in EU and Japan. The JT-60SA superconducting magnet system generates an average heat load of 3.2 kW at 4 K to the cryoplant, from nuclear and thermal radiation, conduction and electromagnetic heating, and requires current supplies 20 kA for 4 CS modules and 6 EF coils, 25.7 kA to 18 TF coils. The helium flow to remove this heat, consisting of supercritical helium at pressures up to 0.5 MPa and temperature between 4.4-4.8 K, is distributed to the coils and structures through the valve box (VB) from the cryoline connecting to the auxiliary cold box located outside the torus hall. The feeders also contain the electrical supplies from the current lead transitions to room temperature to the coil. The feeder components consist of the in-cryostat feeders with flexible parts to allow coil operational displacements from the connection pipes out of the cryostat, including S-bend conductor to allow differential thermal contraction and the coil terminal boxes (CTBs) with HIS current leads. A measurement and control system is required to monitor and control these coils and feeders for safety and optimal operational availability. For each coil, both current and supercritical helium are supplied from external systems and are controlled from a central system as part of the regular operation with plasma pulses. Quench detection instruments for superconducting coils, feeders and HTS current leads are provided as a separate, stand alone system.
Koma, Yoshikazu; Ashida, Takashi; Meguro, Yoshihiro; Miyamoto, Yasuaki; Sasaki, Toshiki; Yamagishi, Isao; Kameo, Yutaka; Terada, Atsuhiko; Hiyama, Toshiaki; Koyama, Tomozo; et al.
Proceedings of International Nuclear Fuel Cycle Conference; Nuclear Energy at a Crossroads (GLOBAL 2013) (CD-ROM), p.736 - 743, 2013/09
Fukushima Daiichi Nuclear Power Station (F1NPS), TEPCO, was severely damaged with the hydrogen explosions caused by losing their cooling functions due to the earthquake and the tsunami occurred on March 11, 2011. Radioactive wastes generated from the current FINPS and future their decommission and demolition are greater huge amount than those from general reactors and nuclear fuel facilities. Toward accomplishing safe and reasonable management of the wastes, great effort of R&Ds has been strongly required and performed in bringing together the knowledge and experience of all of Japan. This report outlines the current status of the R&Ds performed in JAEA.
Takano, Nao*; Takahashi, Yuko*; Yamamoto, Mitsuru*; Teranishi, Mika*; Yamaguchi, Hiroko*; Sakamoto, Ayako; Hase, Yoshihiro; Fujisawa, Hiroko*; Wu, J.*; Matsumoto, Takashi*; et al.
Journal of Radiation Research, 54(4), p.637 - 648, 2013/07
Ishikawa, Satoru*; Ishimaru, Yasuhiro*; Igura, Masato*; Kuramata, Masato*; Abe, Tadashi*; Senoura, Takeshi*; Hase, Yoshihiro; Arao, Tomohito*; Nishizawa, Naoko*; Nakanishi, Hiromi*
Proceedings of the National Academy of Sciences of the United States of America, 109(47), p.19166 - 19171, 2012/11
Rice ( L.) is one of major sources of dietary intake of cadmium (Cd) for the human. However, the reliable technique to reduce substantially rice Cd contamination has not been offered so far. Here, we report the ion-beam irradiated rice mutants that do not nearly accumulate Cd in the grains and the mutant gene responsible for the Cd limitation. We found three mutants in which a favorable low-Cd trait is expressed by the different mutations on the same gene (), and the transporter encoded by the mutant gene had a defective function of root Cd influx. The mutants adapted well in the Cd-polluted paddy fields by exhibiting nearly non-detectable Cd concentrations in their grains in accordance with no adverse economic traits. The DNA marker has been developed to breed new cultivars carrying . Our findings would be useful for greatly reducing the Cd level of paddy rice.
Suzuki, Masayuki; Kiriyama, Hiromitsu; Daito, Izuru; Okada, Hajime; Ochi, Yoshihiro; Sato, Masatoshi*; Yoshii, Takehiro*; Tamaoki, Yoshinori*; Maeda, Junya*; Matsuoka, Shinichi*; et al.
AIP Conference Proceedings 1465, p.53 - 57, 2012/07
We have reported hundred mJ level, femtosecond pulse duration with the high temporal contrast in an OPCPA/Yb:YAG ceramic thin disk laser system at 10 Hz repetition rate. At an input laser pulse energy of 3.8 mJ from the OPCPA preamplifer the output energy of 130 mJ with spectral bandwidth of 2.5 nm has been obtained from multipass Yb:YAG ceramic thin disk amplifier, and the optical efficiency from LD energy to amplified laser pulse is 9.6%. The recompressed laser pulse duration was measured to be 450 fs. Because the compressor efficiency exceeds 73% the compressed pulse energy can potentially be as high as 95 mJ. The contrast level of this laser pulse was measured to be less than 7.210 at -150 ps. This novel laser system after further amplification using additional amplifiers can be useful for the laser-driven proton acceleration in future.
Kamiya, Koji; Onishi, Yoshihiro; Ichige, Toshikatsu; Furukawa, Masato; Murakami, Haruyuki; Kizu, Kaname; Tsuchiya, Katsuhiko; Yoshida, Kiyoshi; Mizumaki, Shoichi*
Proceedings of 24th International Cryogenic Engineering Conference (ICEC 24) and International Cryogenic Materials Conference 2012 (ICMC 2012) (CD-ROM), p.587 - 590, 2012/05
The JT-60 plans to be upgraded to a full-superconducting tokamak referred as the JT-60 Super Advance (JT-60SA) as one of the JA-EU broader approach projects. In the JT-60SA, the superconducting magnets are surrounded by thermal shield cooled at 80 K, which is categorized into 3 groups; the vacuum vessel thermal shield (VVTS), the port thermal shield (PTS) and the cryostat thermal shield (CTS). In this study, seismic analysis was conducted for the thermal shield to confirm the soundness of the latest design, taking the dynamical analysis into account. Trial manufacturing of a 10 degree outer VVTS was also conducted. The outer VVTS was subsequently assembled with already existing inner VVTS to measure the total tolerance (manufacturing plus assembly). It was found that the total tolerance was 5.2 mm which is less than the target tolerance of 10 mm. Finally, concept and the current status of the JT-60SA cryodistribution design are reported.
Osaka, Masahiko; Donomae, Takako; Ichikawa, Shoichi; Sasaki, Shinji; Ishimi, Akihiro; Inoue, Toshihiko; Sekio, Yoshihiro; Miwa, Shuhei; Onishi, Takashi; Asaka, Takeo; et al.
Proceedings of 1st Asian Nuclear Fuel Conference (ANFC), 2 Pages, 2012/03
Support system for training and education of future expert in hot laboratories of Oarai-JAEA, named FEETS, is presented. The system has been established based on research results on both characterization of Oarai hot laboratory and user-needs. Various programs under FEETS are also introduced.
Kiriyama, Hiromitsu; Suzuki, Masayuki*; Daito, Izuru; Okada, Hajime; Ochi, Yoshihiro; Sato, Masatoshi*; Tamaoki, Yoshinori*; Yoshii, Takehiro*; Maeda, Junya*; Matsuoka, Shinichi*; et al.
Reza Kenkyu, 40(2), p.143 - 145, 2012/02
We demonstrate a compact, high-spatiotemporal-quality, high-intensity diode-pumped Yb:YAG thin-disk chirped-pulse amplification (CPA) laser system that incorporates a nonlinear preamplifier based on optical parametric chirped-pulse amplification (OPCPA). The stretched pulses are amplified in the OPCPA preamplifier and the following Yb:YAG main amplifier to 100 mJ at 10 Hz. The broadband amplified beam quality of 1.1 (horizontal direction) and 1.4 (vertical direction) times diffraction limited and pulse compression down to 470 fs with contrast of better than 10 have been achieved successfully.