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Journal Articles

Comparison of the therapeutic effects of [$$^{211}$$At]NaAt and [$$^{131}$$I]NaI in an NIS-expressing thyroid cancer mouse model

Watabe, Tadashi*; Liu, Y.*; Kaneda, Kazuko*; Sato, Tatsuhiko; Shirakami, Yoshifumi*; Oe, Kazuhiro*; Toyoshima, Atsushi*; Shimosegawa, Eku*; Wang, Y.*; Haba, Hiromitsu*; et al.

International Journal of Molecular Sciences (Internet), 23(16), p.9434_1 - 9434_11, 2022/08

 Times Cited Count:7 Percentile:78.48(Biochemistry & Molecular Biology)

In this study, we compare the therapeutic effect between [$$^{211}$$At]NaAt and [$$^{131}$$I]NaI. In vitro analysis of double-stranded DNA break (DSB) and colony formation assay were performed using K1-NIS cells. [$$^{211}$$At]NaAt induced higher numbers of DSBs and had a reduced colony formation than [$$^{131}$$I]NaI. In K1-NIS mice, dose-dependent therapeutic effects were observed in both [$$^{211}$$At]NaAt and [$$^{131}$$I]NaI. The superior therapeutic effect of [$$^{211}$$At]NaAt suggests the promising clinical applicability of targeted alpha therapy using [$$^{211}$$At]NaAt in patients with differentiated thyroid cancer refractory to standard [$$^{131}$$I]NaI treatment.

Journal Articles

Atmospheric resuspension of insoluble radioactive cesium bearing particles found in the difficult-to-return area in Fukushima

Tang, P.*; Kita, Kazuyuki*; Igarashi, Yasuhito*; Satou, Yukihiko; Hatanaka, Kotaro*; Adachi, Koji*; Kinase, Takeshi*; Ninomiya, Kazuhiko*; Shinohara, Atsushi*

Progress in Earth and Planetary Science (Internet), 9(1), p.17_1 - 17_15, 2022/03

 Times Cited Count:5 Percentile:69.58(Geosciences, Multidisciplinary)

JAEA Reports

Interim activity status report of "the group for investigation of reasonable safety assurance based on graded approach" (from September, 2019 to September, 2020)

Yonomoto, Taisuke; Nakashima, Hiroshi*; Sono, Hiroki; Kishimoto, Katsumi; Izawa, Kazuhiko; Kinase, Masami; Osa, Akihiko; Ogawa, Kazuhiko; Horiguchi, Hironori; Inoi, Hiroyuki; et al.

JAEA-Review 2020-056, 51 Pages, 2021/03

JAEA-Review-2020-056.pdf:3.26MB

A group named as "The group for investigation of reasonable safety assurance based on graded approach", which consists of about 10 staffs from Sector of Nuclear Science Research, Safety and Nuclear Security Administration Department, departments for management of nuclear facility, Sector of Nuclear Safety Research and Emergency Preparedness, aims to realize effective graded approach (GA) about management of facilities and regulatory compliance of JAEA. The group started its activities in September, 2019 and has had discussions through 10 meetings and email communications. In the meetings, basic ideas of GA, status of compliance with new regulatory standards at each facility, new inspection system, etc were discussed, while individual investigation at each facility were shared among the members. This report is compiled with expectation that it will help promote rational and effective safety management based on GA by sharing contents of the activity widely inside and outside JAEA.

Journal Articles

Feasibility study of PGAA for boride identification in simulated melted core materials

Tsuchikawa, Yusuke; Abe, Yuta; Oishi, Yuji*; Kai, Tetsuya; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Kimura, Atsushi; Nakamura, Shoji; Harada, Masahide; et al.

JPS Conference Proceedings (Internet), 33, p.011074_1 - 011074_6, 2021/03

In the decommissioning of the Fukushima-Daiichi (1F) Nuclear Power Plant, it is essential to understand characteristics of the melted core materials. The estimation of boride in the real debris is of great importance to develop safe debris removal plans. Hence, it is required to investigate the amount of boron in the melted core materials with nondestructive methods. Prompt gamma-ray activation analysis (PGAA) is one of the useful techniques to determine the amount of borides by means of the 478 keV prompt gamma-ray from neutron absorption reaction of boron. Moreover, it is well known that the width of the 478 keV gamma-ray peak is typically broadened due to the Doppler effect. The degree of the broadening is affected by coexisting materials, and can be recognized by the width of the prompt gamma-ray peak. As a feasibility study, the prompt gamma-ray from boride samples were measured using the ANNRI, NOBORU, and RADEN beamlines at the Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Complex (J-PARC).

Journal Articles

Structural and compositional characteristics of Fukushima release particulate material from Units 1 and 3 elucidates release mechanisms, accident chronology and future decommissioning strategy

Martin, P. G.*; Jones, C. P.*; Bartlett, S.*; Ignatyev, K.*; Megson-Smith, D.*; Satou, Yukihiko; Cipiccia, S.*; Batey, D. J.*; Rau, C.*; Sueki, Keisuke*; et al.

Scientific Reports (Internet), 10, p.22056_1 - 22056_17, 2020/12

 Times Cited Count:1 Percentile:7.05(Multidisciplinary Sciences)

Journal Articles

Production of $$^{266}$$Bh in the $$^{248}$$Cm($$^{23}$$Na,5$$n$$)$$^{266}$$Bh reaction and its decay properties

Haba, Hiromitsu*; Fan, F.*; Kaji, Daiya*; Kasamatsu, Yoshitaka*; Kikunaga, Hidetoshi*; Komori, Yukiko*; Kondo, Narumi*; Kudo, Hisaaki*; Morimoto, Koji*; Morita, Kosuke*; et al.

Physical Review C, 102(2), p.024625_1 - 024625_12, 2020/08

 Times Cited Count:6 Percentile:59.56(Physics, Nuclear)

Journal Articles

Development of event-type neutron imaging detectors at the energy-resolved neutron imaging system RADEN at J-PARC

Parker, J. D.*; Harada, Masahide; Hayashida, Hirotoshi*; Hiroi, Kosuke; Kai, Tetsuya; Matsumoto, Yoshihiro*; Nakatani, Takeshi; Oikawa, Kenichi; Segawa, Mariko; Shinohara, Takenao; et al.

Materials Research Proceedings, Vol.15, p.102 - 107, 2020/05

Journal Articles

An Experimental setup for creating and imaging $$^{4}$$He$$_{2}$$$$^{ast}$$ excimer cluster tracers in superfluid helium-4 via neutron-$$^{3}$$He absorption reaction

Sonnenschein, V.*; Tsuji, Yoshiyuki*; Kokuryu, Shoma*; Kubo, Wataru*; Suzuki, So*; Tomita, Hideki*; Kiyanagi, Yoshiaki*; Iguchi, Tetsuo*; Matsushita, Taku*; Wada, Nobuo*; et al.

Review of Scientific Instruments, 91(3), p.033318_1 - 033318_12, 2020/03

 Times Cited Count:0 Percentile:0(Instruments & Instrumentation)

Journal Articles

Classification of the insoluble particles including radioactive Cs found in Okuma town and Futaba town, Fukushima prefecture

Igarashi, Junya*; Zhang, Z. J.*; Ninomiya, Kazuhiko*; Shinohara, Atsushi*; Satou, Yukihiko; Minowa, Haruka*; Yoshikawa, Hideki

KEK Proceedings 2019-2, p.54 - 59, 2019/11

no abstracts in English

Journal Articles

First determination of Pu isotopes ($$^{239}$$Pu, $$^{240}$$Pu and $$^{241}$$Pu) in radioactive particles derived from Fukushima Daiichi Nuclear Power Plant accident

Igarashi, Junya*; Zheng, J.*; Zhang, Z.*; Ninomiya, Kazuhiko*; Satou, Yukihiko; Fukuda, Miho*; Ni, Y.*; Aono, Tatsuo*; Shinohara, Atsushi*

Scientific Reports (Internet), 9(1), p.11807_1 - 11807_10, 2019/08

 Times Cited Count:20 Percentile:65.32(Multidisciplinary Sciences)

Radioactive particles were released into the environment during the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. Many studies have been conducted to elucidate the chemical composition of released radioactive particles in order to understand their formation process. However, whether radioactive particles contain nuclear fuel radionuclides remains to be investigated. Here, we report the first determination of Pu isotopes in radioactive particles. To determine the Pu isotopes ($$^{239}$$Pu, $$^{240}$$Pu and $$^{241}$$Pu) in radioactive particles derived from the FDNPP accident which were free from the influence of global fallout, radiochemical analysis and inductively coupled plasma-mass spectrometry measurements were conducted. Radioactive particles derived from unit 1 and unit 2 or 3 were analyzed. For the radioactive particles derived from unit 1, activities of $$^{239+240}$$Pu and $$^{241}$$Pu were (1.70-7.06)$$times$$10$$^{-5}$$ Bq and (4.10-8.10)$$times$$10$$^{-3}$$ Bq, respectively and atom ratios of $$^{240}$$Pu/$$^{239}$$Pu and $$^{241}$$Pu/$$^{239}$$Pu were 0.330-0.415 and 0.162-0.178, respectively. These ratios were consistent with the simulation results from ORIGEN code and measurements from various environmental samples. In contrast, Pu was not detected in the radioactive particles derived from unit 2 or 3. The difference in Pu contents is clear evidence towards different formation processes of radioactive particles, and detailed formation processes can be investigated from Pu analysis.

Journal Articles

Generation of $$^{4}$$He$$_2^{*}$$ clusters via neutron-$$^{3}$$He absorption reaction toward visualization of full velocity field in quantum turbulence

Matsushita, Taku*; Sonnenschein, V.*; Guo, W.*; Hayashida, Hirotoshi*; Hiroi, Kosuke; Hirota, Katsuya*; Iguchi, Tetsuo*; Ito, Daisuke*; Kitaguchi, Masaaki*; Kiyanagi, Yoshiaki*; et al.

Journal of Low Temperature Physics, 196(1-2), p.275 - 282, 2019/07

 Times Cited Count:1 Percentile:4.76(Physics, Applied)

Journal Articles

Activity of $$^{90}$$Sr in fallout particles collected in the difficult-to-return zone around the Fukushima Daiichi Nuclear Power Plant

Zhang, Z.*; Igarashi, Junya*; Satou, Yukihiko; Ninomiya, Kazuhiko*; Sueki, Keisuke*; Shinohara, Atsushi*

Environmental Science & Technology, 53(10), p.5868 - 5876, 2019/05

 Times Cited Count:19 Percentile:63.48(Engineering, Environmental)

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident released abundant radioactive particles into the surrounding environment. Herein, we analyzed the activity of $$^{90}$$Sr in these particles to estimate the contribution of this radionuclide to the overall radiation exposure and shed light on the processes that occurred during the accident. Seven radioactive particles were isolated from the dust and soil samples collected from areas surrounding the FDNPP, and the minimum/maximum $$^{137}$$Cs activities were determined as 224/4,100 Bq. Based on the size, specific activity, and $$^{134}$$Cs/$$^{137}$$Cs activity ratios, we concluded that six of the seven radioactive particles were released from the Unit 1 reactor, while one particle was released from the Unit 3 reactor by a hydrogen explosion. Strontium-90 was detected in all radioactive particles, and the minimal/maximal $$^{90}$$Sr activities were determined as 0.046/1.4 Bq. $$^{137}$$Cs/$$^{90}$$Sr activity ratios above 1000 were observed for all seven particles, that is, compared to $$^{137}$$Cs, $$^{90}$$Sr had negligible contribution to the overall radiation exposure. The $$^{137}$$Cs/$$^{90}$$Sr activity ratios of the radioactive particles were similar to those of terrestrial environmental samples and were higher for particles released from the Unit 1 reactor than for samples collected from the Unit 1 reactor building, which indicates possibility of additional $$^{90}$$Sr -rich contamination after release of the particles.

Journal Articles

Initial quantum levels of captured muons in CO, CO$$_2$$, and COS

Yoshida, Go*; Ninomiya, Kazuhiko*; Inagaki, Makoto*; Higemoto, Wataru; Strasser, P.*; Kawamura, Naritoshi*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Miura, Taichi*; Kubo, Kenya*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 320, p.283 - 289, 2019/05

 Times Cited Count:4 Percentile:41.24(Chemistry, Analytical)

The role of valence electrons for the muon capture process by molecules is experimentally investigated with the aid of cascade calculations. Low-momentum muons are introduced to gas targets below atmospheric pressure. The initial states of captured muons are determined from the measured muonic X-ray structure of the Lyman and Balmer series. We propose that the lone pair electrons in the carbon atom of CO significantly contribute to the capture of a muon with large angular momenta.

Journal Articles

Negative muon capture ratios for nitrogen oxide molecules

Ninomiya, Kazuhiko*; Ito, Takashi; Higemoto, Wataru; Kawamura, Naritoshi*; Strasser, P.*; Nagatomo, Takashi*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Kita, Makoto*; Shinohara, Atsushi*; et al.

Journal of Radioanalytical and Nuclear Chemistry, 319(3), p.767 - 773, 2019/03

 Times Cited Count:12 Percentile:80.27(Chemistry, Analytical)

Journal Articles

Variation of half-life and internal-conversion electron energy spectrum between $$^{235m}$$U oxide and fluoride

Shigekawa, Yudai*; Kasamatsu, Yoshitaka*; Yasuda, Yuki*; Kaneko, Masashi; Watanabe, Masayuki; Shinohara, Atsushi*

Physical Review C, 98(1), p.014306_1 - 014306_5, 2018/07

 Times Cited Count:4 Percentile:36.29(Physics, Nuclear)

The nuclear half-life of $$^{235m}$$U has been reported to vary depending on the chemical environment. In this study, both the half-life and the internal-conversion (IC) electron energy spectrum were measured for $$^{235m}$$U with identical chemical environments for the first time. $$^{235m}$$U oxide and fluoride samples were subjected to these measurements, and clear differences in the half-life and the energy spectrum between these samples were observed. The peaks in the energy spectra were identified with the relativistic density functional theory calculation, and the molecular orbital states of the $$^{235m}$$U oxide and fluoride estimated from the energy spectra and the calculation qualitatively explained the difference in the half-lives between the samples.

Journal Articles

Nihonium, and the next elements...

Sakurai, Hiroshi*; Shinohara, Atsushi*; Koura, Hiroyuki; Kamigaito, Osamu*; Morimoto, Koji*; Haba, Hiromitsu*; Enyo, Hideto*

Isotope News, (特別号2), p.2 - 14, 2018/01

no abstracts in English

Journal Articles

Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.

Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12

The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.

Journal Articles

Development of multi-colored neutron talbot-lau interferometer with absorption grating fabricated by imprinting method of metallic glass

Seki, Yoshichika; Shinohara, Takenao; Parker, J. D.*; Yashiro, Wataru*; Momose, Atsushi*; Kato, Kosuke*; Kato, Hidemi*; Sadeghilaridjani, M.*; Otake, Yoshie*; Kiyanagi, Yoshiaki*

Journal of the Physical Society of Japan, 86(4), p.044001_1 - 044001_5, 2017/03

 Times Cited Count:13 Percentile:66.28(Physics, Multidisciplinary)

For the effective phase imaging at pulsed neutron sources, we have designed and developed the multi-colored Talbot-Lau interferometer which works at several wavelengths. At the Energy Resolved Neutron Imaging System RADEN in J-PARC, we demonstrated its operation by observing the visibilities of moire fringes derived from different wavelengths (0.25, 0.50, and 0.75 nm). We also investigated the variation of moire fringes dependent on the wavelength resolution from 18% to 50% and showed the advantage of pulsed beams. At the central wavelength of 0.5 nm, we have succeeded in interferometric imaging for the samples of metal rods made of aluminum, lead, and copper. An absorption grating as an analyzer was fabricated by imprinting of metallic glass for the first time, and showed a clear moire fringe with the high visibility of 68% and a well-controlled shape in comparison with previous ones fabricated by oblique evaporation of gadolinium.

Journal Articles

Experimental evaluation of neutron absorption grating fabricated by oblique evaporation of gadolinium for phase imaging

Seki, Yoshichika; Shinohara, Takenao; Ueno, Wakana; Parker, J. D.*; Samoto, Tetsuo*; Yashiro, Wataru*; Momose, Atsushi*

Physics Procedia, 88, p.217 - 223, 2017/00

 Times Cited Count:12 Percentile:97.65(Instruments & Instrumentation)

Journal Articles

Investigation of countermeasure against local temperature rise in vessel cooling system in loss of core cooling test without nuclear heating

Ono, Masato; Shimizu, Atsushi; Kondo, Makoto; Shimazaki, Yosuke; Shinohara, Masanori; Tochio, Daisuke; Iigaki, Kazuhiko; Nakagawa, Shigeaki; Takada, Shoji; Sawa, Kazuhiro

Journal of Nuclear Engineering and Radiation Science, 2(4), p.044502_1 - 044502_4, 2016/10

In the loss of forced core cooling test using High Temperature engineering Test Reactor (HTTR), the forced cooling of reactor core is stopped without inserting control rods into the core and cooling by Vessel Cooling System (VCS) to verify safety evaluation codes to investigate the inherent safety of HTGR be secured by natural phenomena to make it possible to design a severe accident free reactor. The VCS passively removes the retained residual heat and the decay heat from the core via the reactor pressure vessel by natural convection and thermal radiation. In the test, the local temperature was supposed to exceed the limit from the viewpoint of long-term use at the uncovered water cooling tube by thermal reflectors in the VCS, although the safety of reactor is kept. Through a cold test, which was carried out by non-nuclear heat input from gas circulators with stopping water flow in the VCS, the local higher temperature position was specified although the temperature was sufficiently lower than the maximum allowable working temperature, and natural circulation of water had insufficient cooling effect on the temperature of water cooling tube below 1$$^{circ}$$C. Then, a new safe and secured procedure for the loss of forced core cooling test was established, which will be carried out soon after the restart of HTTR.

151 (Records 1-20 displayed on this page)