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Yakushev, A.*; Lens, L.*; D
llmann, Ch. E.*; Khuyagbaatar, J.*; J
ger, E.*; Krier, J.*; Runke, J.*; Albers, H. M.*; Asai, Masato; Block, M.*; et al.
Frontiers in Chemistry (Internet), 10, p.976635_1 - 976635_11, 2022/08
Times Cited Count：9 Percentile：79.28(Chemistry, Multidisciplinary)Flerovium (Fl, element 114) is the heaviest element chemically studied so far. The first chemical experiment on Fl suggested that Fl is a noble-gas-like element, while the second studies suggested that Fl has a volatile-metal-like character. To obtain more reliable conclusion, we performed further experimental studies on Fl adsorption behavior on Si oxide and gold surfaces. The present results suggest that Fl is highly volatile and less reactive than the volatile metal, Hg, but has higher reactivity than the noble gas, Rn.
Taniguchi, Yoshinori; Udagawa, Yutaka; Amaya, Masaki
Annals of Nuclear Energy, 139, p.107188_1 - 107188_7, 2020/05
Times Cited Count：1 Percentile：12.16(Nuclear Science & Technology)
and chromia-alumina additive fuels under simulated reactivity-initiated accidents; A Comparative analysis with FEMAXI-8Udagawa, Yutaka; Mihara, Takeshi; Taniguchi, Yoshinori; Kakiuchi, Kazuo; Amaya, Masaki
Annals of Nuclear Energy, 139, p.107268_1 - 107268_9, 2020/05
Times Cited Count：3 Percentile：35.51(Nuclear Science & Technology) and Au surfaces in preparation for chemical investigations on Cn, Nh, and Fl at TASCALens, L.*; Yakushev, A.*; Dllmann, Ch. E.*; Asai, Masato; Ballof, J.*; Block, M.*; David, H. M.*; Despotopulos, J.*; Di Nitto, A.*; Eberhardt, K.*; et al.
Radiochimica Acta, 106(12), p.949 - 962, 2018/12
Times Cited Count：8 Percentile：62.99(Chemistry, Inorganic & Nuclear)Online gas-solid adsorption studies with single atom quantities of Hg, Tl, and Pb on SiO and Au surfaces were carried out using short-lived radioisotopes with half-lives in the range of 4-49 s. This is a model study to measure adsorption enthalpies of superheavy elements Cn, Nh, and Fl. The short-lived isotopes were produced and separated by the gas-filled recoil separator TASCA at GSI. The products were stopped in He gas, and flushed into gas chromatography columns made of Si detectors whose surfaces were covered by SiO or Au. The short-lived Tl and Pb were successfully measured by the Si detectors with the SiO surface at room temperature. On the other hand, the Hg did not adsorb on the SiO surface, but adsorbed on the Au surface. The results demonstrated that the adsorption properties of short-lived Hg, Tl, and Pb could be studied with this setup, and that this method is applicable to the experiment for Cn, Nh, and Fl.
at the single-atom levelSteinegger, P.*; Asai, Masato; Dressler, R.*; Eichler, R.*; Kaneya, Yusuke*; Mitsukai, Akina*; Nagame, Yuichiro; Piguet, D.*; Sato, Tetsuya; Schdel, M.; et al.
Journal of Physical Chemistry C, 120(13), p.7122 - 7132, 2016/04
Times Cited Count：23 Percentile：60.73(Chemistry, Physical)A new experimental method "vacuum chromatography" has been developed to measure adsorption enthalpy of superheavy elements, and its feasibility has been examined using short-lived thallium isotopes. The short-lived thallium isotopes were produced at the JAEA tandem accelerator. The thallium ion beam prepared with an on-line isotope separator which ionized and mass-separated the thallium isotopes was injected into an isothermal vacuum chromatography apparatus. A temperature-dependent adsorption property of thallium atom on SiO surface were measured. The adsorption enthalpy of thallium was determined to be 158 kJ/mol. The thallium is a homolog of element 113. Thus, the vacuum chromatography developed in this study enables us to perform chemical experiments for short-lived superheavy elements with half-lives of a order of one second.
Sasajima, Hideo; Sugiyama, Tomoyuki; Nakamura, Takehiko*; Fuketa, Toyoshi
JAERI-Research 2004-022, 113 Pages, 2004/12
JAERI-Research-2004-022.pdf:47.48MB
Results from power burst tests, GK-1 and GK-2, conducted at the NSRR, are summarized. The tests were performed on a 14
14 PWR fuel rod irradiated to a burnup of 42 MWd/kgU in the Genkai unit #1 of Kyushu Electric Power Co., Inc. The instrumented test fuel rod in a double-container-type capsule was subjected to the pulse-irradiation with stagnant water cooling condition at 0.1 MPa and 293 K. Deposited energy and peak fuel enthalpy were 505 J/g and 389 J/g in the Test GK-1, and 490 J/g and 377 J/g in the Test GK-2, respectively. During the pulse-irradiations, DNB occurred and the cladding surface temperature reached 581 K and 569 K in the Tests GK-1 and -2, respectively. The maximum cladding hoop strain was 2.7% in the Test GK-1 and 1.2% in the Test GK-2. However, the test fuel rods did not fail. Estimated fission gas releases during the pulse-irradiations were 11.7% and 7.0% in the Tests GK-1 and -2, respectively.
Nomura, Mikihiro; Kasahara, Seiji; Onuki, Kaoru
JAERI-Research 2002-039, 24 Pages, 2003/01
JAERI-Research-2002-039.pdf:1.01MB
Thermal efficiency to produce hydrogen from water through the IS process was evaluated by a viewpoint of thermodynamics. Thermal efficiency is decided by a temperature from a heat source and limited by the works calculated by the Carnot efficiency for any hydrogen production methods. The maximum thermal efficiency is 81.3% for a thermal cycle between 1123K and 733K. The thermal efficiency of the IS process was evaluated by G-T diagrams of each reactions and separation processes. The maximum value is 78.2% without considering the works for separations of acids from water. However, the effects of the works for separations on thermal efficiency are essential for the IS process, because Gibbs energies of separations of acids from water are always positive. The thermal efficiency could be changed from 53.5% to 76.6% by the calculation with or without the separation processes.
Yamashita, Toshiyuki; Kuramoto, Kenichi; Akie, Hiroshi; Nakano, Yoshihiro; Shirasu, Noriko; Nakamura, Takehiko; Kusagaya, Kazuyuki*; Omichi, Toshihiko*
Journal of Nuclear Science and Technology, 39(8), p.865 - 871, 2002/08
Times Cited Count：25 Percentile：81.52(Nuclear Science & Technology)Research on the plutonium rock-like oxide (ROX) fuels and their once-through burning in light water reactors has been performed to establish an option for utilizing and disposing effectively the excess plutonium. The ROX fuel is a sort of the inert matrix fuels and consists of mineral-like compounds such as yttria stabilized zirconia, spinel and corundum. A particle-dispersed fuel was devised to reduce damage by heavy fission fragments. Some preliminary results on swelling, fractional gas release and microstructure change for five ROX fuels were obtained from the irradiation test and successive post-irradiation examinations. Inherent disadvantages of the Pu-ROX fuel cores could be improved by adding 238U or 232Th as resonant materials, and all improved cores showed a nearly the same characteristics as the conventional UO2 core during transient conditions. The threshold enthalpy of the ROX fuel rod failure was found to be comparable to the fresh UO2 rod by pulse-irradiation tests simulating reactivity initiated accident conditions.
Fujino, Takeo*; Sato, Nobuaki*; Yamada, Kota*; Okazaki, Manabu*; Fukuda, Kosaku; Serizawa, Hiroyuki; Shiratori, Tetsuo*
Journal of Nuclear Materials, 289(3), p.270 - 280, 2001/03
Times Cited Count：2 Percentile：19.66(Materials Science, Multidisciplinary)no abstracts in English
Nakamura, Takehiko; Takahashi, Masato*; Yoshinaga, Makio
JAERI-Research 2000-048, 77 Pages, 2000/11
JAERI-Research-2000-048.pdf:6.04MB
no abstracts in English
Nakamura, Takehiko; Sasajima, Hideo; Fuketa, Toyoshi; *; Takahashi, Masato*; *; Ishijima, Kiyomi
JAERI-Research 98-052, 55 Pages, 1998/09
JAERI-Research-98-052.pdf:2.6MB
no abstracts in English
Ogawa, Toru; Omichi, Toshihiko; Maeda, Atsushi; Arai, Yasuo;
Journal of Alloys and Compounds, 224, p.55 - 59, 1995/00
Times Cited Count：23 Percentile：78.26(Chemistry, Physical)no abstracts in English
-UZr; Comment on the paper: K.Nagarajan,R.Babu and C.K.Mathews,enthalpy of formation of UZr by calorimetryOgawa, Toru
Journal of Nuclear Materials, 209, p.107 - 108, 1994/00
Times Cited Count：5 Percentile：66.44(Materials Science, Multidisciplinary)no abstracts in English
Omichi, Toshihiko; Arai, Yasuo
Proc. of the 4th Int. Symp. on Advanced Nuclear Energy Research (JAERI-CONF 1/JAERI-M 92-207), p.204 - 208, 1992/12
no abstracts in English
by solid state EMF techniqueNakamura, Akio; Fujino, Takeo
Journal of Nuclear Materials, 149(1), p.80 - 100, 1987/01
Times Cited Count：44 Percentile：95.53(Materials Science, Multidisciplinary)no abstracts in English
at relatively small deviation from stoichiometry between 600 and 1400
CNakamura, Akio; Fujino, Takeo
Journal of Nuclear Materials, 140, p.113 - 130, 1986/09
Times Cited Count：17 Percentile：83.75(Materials Science, Multidisciplinary)no abstracts in English
; Naito, Keiji; *
Nihon Genshiryoku Gakkai-Shi, 4(2), p.111 - 117, 1962/00
no abstracts in English
Kaneya, Yusuke*; Asai, Masato; Sato, Tetsuya; Tomitsuka, Tomohiro; Tsukada, Kazuaki; Toyoshima, Atsushi; Mitsukai, Akina; Makii, Hiroyuki; Hirose, Kentaro; Osa, Akihiko; et al.
no journal, ,
To study the influence of the valence 7p
electronic orbital on chemical properties of lawrencium, a measurement of the adsorption enthalpy of lawrencium was carried out. A new method using a surface ionization technique coupled to an on-line isotope separator was developed, which enabled one to measure temperature dependence of lawrencium surface adsorption on a metallic tantalum surface at high temperature up to 2800 K. The temperature dependences of adsorption of lawrencium as well as various lanthanide elements were investigated with this method, and the adsorption enthalpy of lawrencium was successfully extracted.
