Nemoto, Takahiro; Arakawa, Ryoki; Kawakami, Satoru; Nagasumi, Satoru; Yokoyama, Keisuke; Watanabe, Masashi; Onishi, Takashi; Kawamoto, Taiki; Furusawa, Takayuki; Inoi, Hiroyuki; et al.
JAEA-Technology 2023-005, 33 Pages, 2023/05
During shut down of the HTTR (High Temperature engineering Test Reactor) RS-14 cycle, an increasing trend of filter differential pressure for the helium gas circulator was observed. In order to investigate this phenomenon, the blower of the primary helium purification system was disassembled and inspected. As a result, it is clear that the silicon oil mist entered into the primary coolant due to the deterioration of the charcoal filter performance. The replacement and further investigation of the filter are planning to prevent the reoccurrence of the same phenomenon in the future.
Iwamoto, Toshihiro; Saito, Madoka*; Takahatake, Yoko; Watanabe, So; Watanabe, Masayuki; Naruse, Atsuki*; Tsukahara, Takehiko*
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 4 Pages, 2023/05
Applicability of temperature swing extraction technology employing monoamides was examined for uranium contaminated waste treatment procedure. Separation experiments on simulated target solution with three kinds of monoamides with different structure showed that Ce(IV) in the solution was selectively recovered by the temperature swing extraction operation. Based on the experiments, an appropriate monoamide for the procedure was selected.
Omasa, Yoshinori*; Takagi, Shigeyuki*; Toshima, Kento*; Yokoyama, Kaito*; Endo, Wataru*; Orimo, Shinichi*; Saito, Hiroyuki*; Yamada, Takeshi*; Kawakita, Yukinobu; Ikeda, Kazutaka*; et al.
Physical Review Research (Internet), 4(3), p.033215_1 - 033215_9, 2022/09
Yokoi, Naoto*; Saito, Eiji
Journal of Magnetism and Magnetic Materials, 545, p.168673_1 - 168673_12, 2022/03
Higuchi, Kyoko*; Kurita, Keisuke; Sakai, Takuro; Suzui, Nobuo*; Sasaki, Minori*; Katori, Maya*; Wakabayashi, Yuna*; Majima, Yuta*; Saito, Akihiro*; Oyama, Takuji*; et al.
Plants (Internet), 11(6), p.817_1 - 817_11, 2022/03
Genetic diversity in the rate of Fe uptake by plants has not been broadly surveyed among plant species or genotypes, although plants have developed various Fe acquisition mechanisms. We adopted the "Live-autoradiography" technique with radioactive Fe to directly evaluate the uptake rate of Fe by barley cultivars from a nutrient solution containing a very low concentration of Fe. Our observations revealed that the ability to acquire Fe from the low Fe solution was not always the sole determinant of tolerance to Fe deficiency among the barley genotypes.
Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
Sakakibara, Hiroshi; Aoki, Nobuhiro; Muto, Masahiro; Otabe, Jun; Takahashi, Kenji*; Fujita, Naoyuki*; Hiyama, Kazuhiko*; Suzuki, Hirokazu*; Kamogawa, Toshiyuki*; Yokosuka, Toru*; et al.
JAEA-Technology 2020-020, 73 Pages, 2021/03
The decommissioning is currently in progress at the prototype fast breeder reactor Monju. Fuel assemblies will be taken out of its core for the first step of the great task. Fuel assemblies stand on their own spike plugged into a socket on the core support plate and support with adjacent assemblies through their housing pads each other, resulting in steady core structure. For this reason, some substitutive assemblies are necessary for the purpose of discharging the fuel assemblies of the core. Monju side commissioned, therefore, Plutonium Fuel Development Center to manufacture the substitutive assemblies and the Center accepted it. This report gives descriptions of design, manufacture, and shipment in regard to the substitutive assemblies.
Miyajima, Yusuke*; Saito, Ayaka*; Kagi, Hiroyuki*; Yokoyama, Tatsunori; Takahashi, Yoshio*; Hirata, Takafumi*
Geostandards and Geoanalytical Research, 45(1), p.189 - 205, 2021/03
Uncertainty for elemental and isotopic analyses of calcite by LA-ICP-MS is largely controlled by the homogeneity of the reference materials (RMs) used for normalization and validation. In order to produce calcite RMs with homogeneous elemental and isotopic compositions, we incorporated elements including U, Pb, and rare earth elements into calcite through heat- and pressure-induced crystallization from amorphous calcium carbonate that was precipitated from element-doped reagent solution. X-ray absorption spectra showed that U was present as U(VI) in the synthesized calcite, probably with a different local structure from that of aqueous uranyl ions. The uptake rate of U by our calcite was higher in comparison to synthetic calcite of previous studies. Variations of element mass fractions in the calcite were better than 12% 2RSD, mostly within 7%. The Pb/Pb ratio in the calcite showed 1% variations, while the U/Pb ratio showed 3-24% variations depending on element mass fractions. Using the synthetic calcite as primary RMs, we could date a natural calcite RM, WC-1, with analytical uncertainty as low as 3%. The method presented can be useful to produce calcite with controlled and homogeneous element mass fractions, and is a promising alternative to natural calcite RMs for U-Pb geochronology.
Ito, Keita*; Yasutomi, Yoko*; Zhu, S.*; Nurmamat, M.*; Tahara, Masaki*; Toko, Kaoru*; Akiyama, Ryota*; Takeda, Yukiharu; Saito, Yuji; Oguchi, Tamio*; et al.
Physical Review B, 101(10), p.104401_1 - 104401_8, 2020/03
Yokoi, Naoto*; Sato, Koji*; Saito, Eiji
Physical Review D, 100(10), p.106012_1 - 106012_9, 2019/11
Lustikova, J.*; Shiomi, Yuki*; Yokoi, Naoto*; Kabeya, Noriyuki*; Kimura, Noriaki*; Ienaga, Koichiro*; Kaneko, Shinichi*; Okuma, Satoshi*; Takahashi, Saburo*; Saito, Eiji
Nature Communications (Internet), 9, p.4922_1 - 4922_6, 2018/11
Shimada, Hiroyuki*; Minami, Hirotake*; Okuizumi, Naoto*; Sakuma, Ichiro*; Ukai, Masatoshi*; Fujii, Kentaro; Yokoya, Akinari; Fukuda, Yoshihiro*; Saito, Yuji
Journal of Chemical Physics, 142(17), p.175102_1 - 175102_9, 2015/05
Shimada, Hiroyuki*; Fukao, Taishi*; Minami, Hirotake*; Ukai, Masatoshi*; Fujii, Kentaro; Yokoya, Akinari; Fukuda, Yoshihiro*; Saito, Yuji
Journal of Chemical Physics, 141(5), p.055102_1 - 055102_8, 2014/08
Ito, Keita*; Sanai, Tatsunori*; Yasutomi, Yoko*; Zhu, S.-Y.*; Toko, Kaoru*; Takeda, Yukiharu; Saito, Yuji; Kimura, Akio*; Suemasu, Takashi*
Journal of Applied Physics, 115(17), p.17C712_1 - 17C712_3, 2014/05
Yamada, Keisuke; Saito, Yuichi; Ishii, Yasuyuki; Matoba, Shiro; Chiba, Atsuya; Yokoyama, Akihito; Usui, Aya; Sato, Takahiro; Okubo, Takeru; Uno, Sadanori
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 159, 2014/03
no abstracts in English
Uno, Sadanori; Chiba, Atsuya; Yamada, Keisuke; Yokoyama, Akihito; Usui, Aya; Saito, Yuichi; Ishii, Yasuyuki; Sato, Takahiro; Okubo, Takeru; Nara, Takayuki; et al.
JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 179, 2014/03
Three electrostatic accelerators at TIARA were operated on schedule in fiscal year 2012 except changing its schedule by cancellations of users. The yearly operation time of the 3 MV tandem accelerator, the 400 kV ion implanter and the 3MV single-ended accelerator were in the same levels as the ordinary one, whose operation time totaled to 2,073, 1,847 and 2,389 hours, respectively. The tandem accelerator had no trouble, whereas the ion implanter and the single-ended accelerator stopped by any troubles for one day and four days, respectively. The molecular ion beam of helium hydride was generated by the ion implanter, because the users required irradiation of several cluster ions in order to study the effect of irradiation. As a result, its intensity of beam was 50 nA at 200 kV. The ion beam of tungsten (W) at 15 MeV was accelerated by the tandem accelerator, whose intensity was 20 nA at charge state of 4+, because of the request from a researcher in the field of nuclear fusion.
Yoshida, Kenichi; Nara, Takayuki; Saito, Yuichi; Yokota, Wataru
Review of Scientific Instruments, 85(2), p.02A917_1 - 02A917_3, 2014/02
Recent studies about ECRIS have revealed that not only the maximum magnetic field (B) but also the minimum field(B) has effect on the production ability. A superconducting ECRIS which can change the B distribution with plural solenoids shows that a flat distribution of B (flat B) gives better performance in highly charged ion production than classical B. Superconducting device of conduction cooling type is useful, because a Lq-helium system needs a large quantity of Lq-helium to be supplied at after every quench. However, many refrigerators are necessary to keep low temperature against the heat through the current leads of a number of coils to form flat-B. Therefore, we have designed a coil configuration which can adjust B and flat-B with the minimum lead number of four. The flat-B is formed by three central coils connected one another between the mirror coils. There is another pair of coils to adjust B of the injection side keeping flat B unchanged.
Yamada, Keisuke; Saito, Yuichi; Yokota, Wataru
Review of Scientific Instruments, 85(2), p.02A920_1 - 02A920_3, 2014/02