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JAEA Reports

Stabilization treatment of nuclear fuel material contained with organic matter

Senzaki, Tatsuya; Arai, Yoichi; Yano, Kimihiko; Sato, Daisuke; Tada, Kohei; Ogi, Hiromichi*; Kawanobe, Takayuki*; Ono, Shimpei; Nakamura, Masahiro; Kitawaki, Shinichi; et al.

JAEA-Testing 2022-001, 28 Pages, 2022/05

JAEA-Testing-2022-001.pdf:2.33MB

In preparation for the decommissioning of Laboratory B of the Nuclear Fuel Cycle Engineering Laboratory, the nuclear fuel material that had been stored in the glove box for a long time was moved to the Chemical Processing Facility (CPF). This nuclear fuel material was stored with sealed by a polyvinyl chloride (PVC) bag in the storage. Since it was confirmed that the PVC bag swelled during storage, it seems that any gas was generated by radiolysis of the some components contained in the nuclear fuel material. In order to avoid breakage of the PVC bag and keep it safety for long time, we began the study on the stabilization treatment of the nuclear fuel material. First, in order to clarify the properties of nuclear fuel material, radioactivity analysis, component analysis, and thermal analysis were carried out. From the results of thermal analysis, the existence of organic matter was clarified. Then, ion exchange resin with similar thermal characteristics was selected and the thermal decomposition conditions were investigated. From the results of these analyzes and examinations, the conditions for thermal decomposition of the nuclear fuel material contained with organic matter was established. Performing a heat treatment of a small amount of nuclear fuel material in order to confirm the safety, after which the treatment amount was scaled up. It was confirmed by the weight change after the heat treatment that the nuclear fuel material contained with organic matter was completely decomposed.

Journal Articles

Design and actual performance of J-PARC 3 GeV rapid cycling synchrotron for high-intensity operation

Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.

Journal of Nuclear Science and Technology, 32 Pages, 2022/02

 Times Cited Count:0 Percentile:0.02(Nuclear Science & Technology)

In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.

Journal Articles

First observation of a nuclear $$s$$-state of a $$Xi$$ hypernucleus, $$^{15}_{Xi}{rm C}$$

Yoshimoto, Masahiro*; Fujita, Manami; Hashimoto, Tadashi; Hayakawa, Shuhei; Ichikawa, Yudai; Ichikawa, Masaya; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; et al.

Progress of Theoretical and Experimental Physics (Internet), 2021(7), p.073D02_1 - 073D02_19, 2021/07

Journal Articles

Commissioning of Versatile Compact Neutron Diffractometer (VCND) at the B-3 beam port of Kyoto University Research Reactor (KUR)

Mori, Kazuhiro*; Okumura, Ryo*; Yoshino, Hirofumi*; Kanayama, Masaya*; Sato, Setsuo*; Oba, Yojiro; Iwase, Kenji*; Hiraka, Haruhiro*; Hino, Masahiro*; Sano, Tadafumi*; et al.

JPS Conference Proceedings (Internet), 33, p.011093_1 - 011093_6, 2021/03

no abstracts in English

Journal Articles

Dynamics of proteins with different molecular structures under solution condition

Inoue, Rintaro*; Oda, Takashi*; Nakagawa, Hiroshi; Tominaga, Taiki*; Saio, Tomohide*; Kawakita, Yukinobu; Shimizu, Masahiro*; Okuda, Aya*; Morishima, Ken*; Sato, Nobuhiro*; et al.

Scientific Reports (Internet), 10, p.21678_1 - 21678_10, 2020/12

 Times Cited Count:2 Percentile:17.23(Multidisciplinary Sciences)

Incoherent quasielastic neutron scattering (iQENS) is a fascinating technique for investigating the internal dynamics of protein. However, both low flux of neutron beam and absence of analytical procedure for extracting the internal dynamics from iQENS profile have been obstacles for studying it under physiological condition (in solution). Thanks to the recent development of neutron source, spectrometer and computational technique, they enable us to decouple internal dynamics, translational and rotational diffusions from the iQENS profile. The internal dynamics of two proteins: globular domain protein (GDP) and intrinsically disordered protein (IDP) in solution were studied. It was found that the average relaxation rate of IDP was larger than that of GDP. Through the detailed analyses on their internal dynamics, it was revealed that the fraction of mobile H atoms in IDP was much higher than that in GDP. Interestingly, the fraction of mobile H atoms was closely related to the fraction of H atoms on highly solvent exposed surfaces. The iQENS study presented that the internal dynamics were governed by the highly solvent exposed amino acid residues depending upon protein molecular architectures.

Journal Articles

Evaluation of oxidation efficiency of hydrophobic palladium catalyst for $$^{3}$$H monitoring in radioactive gaseous waste

Furutani, Misa; Kometani, Tatsunari; Nakagawa, Masahiro; Ueno, Yumi; Sato, Junya; Iwai, Yasunori*

Hoken Butsuri (Internet), 55(2), p.97 - 101, 2020/06

Herein, an oxidation catalyst was introduced after heating it to 600$$^{circ}$$C to oxidize tritium gas (HT) existing in exhaust into tritiated water vapor (HTO). This study aims to establish a safer $$^{3}$$H monitoring system by lowering the heating temperature required for the catalyst. In these experiments, which were conducted in the Nuclear Science Research Institute, Japan Atomic Energy Agency, cupric oxide, hydrophobic palladium/silicon dioxide (Pd/SiO$$_{2}$$), and platinum/aluminum oxide (Pt/Al$$_{2}$$O$$_{3}$$) catalysts were ventilated using standard hydrogen gas. After comparing the oxidation efficiency of each catalyst at different temperatures, we found that the hydrophobic Pd/SiO$$_{2}$$ and Pt/Al$$_{2}$$O$$_{3}$$ catalysts could oxidize HT into HTO at 25$$^{circ}$$C.

Journal Articles

Development of blue diode laser for additive manufacturing

Higashino, Ritsuko*; Sato, Yuji*; Masuno, Shinichiro*; Shobu, Takahisa; Funada, Yoshinori*; Abe, Nobuyuki*; Tsukamoto, Masahiro*

Laser 3D Manufacturing VII (Proceedings of SPIE Vol.11271), p.1127114_1 - 1127114_7, 2020/05

 Times Cited Count:3 Percentile:95.1

Journal Articles

Measurement of the angular distribution of $$gamma$$-rays after neutron capture by $$^{139}$$La for a T-violation search

Okudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.

EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12

Parity violating effects enhanced by up to 10$$^6$$ times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,$$gamma$$) reaction was measured with $$^{139}$$La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized $$^{139}$$La target and a 70% polarized $$^3$$He spin filter whose thickness is 70 atm$$cdot$$cm are needed. Therefore high quality $$^3$$He spin filter is developed in JAEA. The measurement result of the (n,$$gamma$$) reaction at J-PARC and the development status of the $$^3$$He spin filter will be presented.

Journal Articles

Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.

Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07

 Times Cited Count:7 Percentile:62.04(Physics, Multidisciplinary)

Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for $$^{107}$$Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.

JAEA Reports

Report of the erosion-corrosion of metallic materials under solid-liquid two phase flow

Otani, Kyohei; Sato, Tomonori; Kaji, Yoshiyuki; Yamamoto, Masahiro

JAEA-Review 2019-007, 15 Pages, 2019/06

JAEA-Review-2019-007.pdf:2.35MB

Metallic pipes under solid-liquid two phase flow is damaged by collision of solid particle to the pipe walls, and this phenomenon is named "erosion". In the case of the liquid is corrosive solution, further damage is occurred on the pipe walls chemically, and this named "erosion-corrosion". In the Fukushima Daiichi decommissioning project, the fuel debris will be crushed during removal operation of the debris and micro debris particles would be generated. It is estimated that the pipes of the circulating cooling system would be damaged under the solid-liquid two phase flow containing fuel debris particles. For the reason, the previous study about erosion and erosion-corrosion of metallic materials under solid-liquid two phase flow was surveyed. The survey showed that the damage rate by erosion and erosion-corrosion is influence by a lot of parameter in comparison to the corrosion rate which occurred in no-flow solution. Therefore, it is necessary to pay attention to selecting the experimental method and condition before the investigation about erosion-corrosion of metallic materials under solid-liquid two phase flow is carried out.

Journal Articles

Effects of environmental factors inside the crevice on corrosion of stainless steel in high temperature water

Yamamoto, Masahiro; Sato, Tomonori; Igarashi, Takahiro; Ueno, Fumiyoshi; Soma, Yasutaka

Proceedings of European Corrosion Congress 2017 (EUROCORR 2017) and 20th ICC & Process Safety Congress 2017 (USB Flash Drive), 6 Pages, 2018/09

The authors have studied the differences between outer surface and the crevice-like portion of SUS316L in high pressurized and high temperature water containing dissolved oxygen. We have already introduced that changes in the characteristics of corrosion products along the crevice directions and gap width. It is suggested that the environmental conditions are different with the features of crevice from these results. In this report, we introduce the changes in oxide films with crevice gaps and comparison with the numerical simulation data utilizing of FEM calculation.

Journal Articles

Progress status of proof-of-principle demonstration of 400 MeV H$$^{-}$$ laser stripping at J-PARC 3-GeV RCS

Saha, P. K.; Harada, Hiroyuki; Kinsho, Michikazu; Miura, Akihiko; Yoshimoto, Masahiro; Okabe, Kota; Suganuma, Kazuaki; Yamane, Isao*; Irie, Yoshiro*; Liu, Y.*; et al.

Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.806 - 810, 2018/08

Journal Articles

Electronic structure of Li$$^{+}$$@C$$_{60}$$; Photoelectron spectroscopy of the Li$$^{+}$$@C$$_{60}$$[PF$$_{6}$$$$^{-}$$] salt and STM of the single Li$$^{+}$$@C$$_{60}$$ molecules on Cu(111)

Yamada, Yoichi*; Kuklin, A. V.*; Sato, Sho*; Esaka, Fumitaka; Sumi, Naoya*; Zhang, C.*; Sasaki, Masahiro*; Kwon, E.*; Kasama, Yasuhiko*; Avramov, P. V.*; et al.

Carbon, 133, p.23 - 30, 2018/07

 Times Cited Count:11 Percentile:46.47(Chemistry, Physical)

We report first STM observation of the Li$$^{+}$$ ion endohedral C$$_{60}$$, which is of a new class of endohedral fullerenes, prepared by means of evaporation of high-purity Li$$^{+}$$@C$$_{60}$$[PF$$_{6}$$$$^{-}$$] salt in ultra-high vacuum. Prior to the STM measurements, the electronic structure of Li$$^{+}$$@C$$_{60}$$ in the Li$$^{+}$$@C$$_{60}$$[PF$$_{6}$$$$^{-}$$] salt was also precisely determined. In the salt, it is shown that Li and PF$$_{6}$$ have nearly single positive and negative charge, respectively, and the C$$_{60}$$ cage is nearly neutral, suggesting that Li$$^{+}$$@C$$_{60}$$ in the salt retains its original electronic state.

Journal Articles

Preheat effect on titanium plate fabricated by sputter-free selective laser melting in vacuum

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

 Times Cited Count:13 Percentile:63.7(Materials Science, Multidisciplinary)

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 500$$^{circ}$$C. 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.

Journal Articles

Design of HTTR-GT/H$$_{2}$$ test plant

Yan, X.; Sato, Hiroyuki; Sumita, Junya; Nomoto, Yasunobu*; Horii, Shoichi*; Imai, Yoshiyuki; Kasahara, Seiji; Suzuki, Koichi*; Iwatsuki, Jin; Terada, Atsuhiko; et al.

Nuclear Engineering and Design, 329, p.223 - 233, 2018/04

 Times Cited Count:15 Percentile:88.99(Nuclear Science & Technology)

The pre-licensing design of an HTGR cogeneration test plant to be coupled to JAEA's existing test reactor HTTR is presented. The plant is designed to demonstrate the system of JAEA commercial plant design GTHTR300C. With construction planned to be completed around 2025, the test plant is expected to be the first-of-a-kind nuclear system operating on two of the advanced energy conversion systems attractive for the HTGR closed cycle helium gas turbine for power generation and thermochemical iodine-sulfur water-splitting process for hydrogen production.

Journal Articles

One-dimensional spinon spin currents

Hirobe, Daichi*; Sato, Masahiro*; Kawamata, Takayuki*; Shiomi, Yuki*; Uchida, Kenichi*; Iguchi, Ryo*; Koike, Yoji*; Maekawa, Sadamichi; Saito, Eiji

Nature Physics, 13(1), p.30 - 34, 2017/01

 Times Cited Count:80 Percentile:96.78(Physics, Multidisciplinary)

Journal Articles

Studies of high density baryon matter with high intensity heavy-ion beams at J-PARC

Sako, Hiroyuki; Harada, Hiroyuki; Sakaguchi, Takao*; Chujo, Tatsuya*; Esumi, Shinichi*; Gunji, Taku*; Hasegawa, Shoichi; Hwang, S.; Ichikawa, Yudai; Imai, Kenichi; et al.

Nuclear Physics A, 956, p.850 - 853, 2016/12

 Times Cited Count:11 Percentile:67.72(Physics, Nuclear)

Journal Articles

HTTR-GT/H$$_{2}$$ test plant; System design

Yan, X.; Sato, Hiroyuki; Sumita, Junya; Nomoto, Yasunobu; Horii, Shoichi; Imai, Yoshiyuki; Kasahara, Seiji; Suzuki, Koichi*; Iwatsuki, Jin; Terada, Atsuhiko; et al.

Proceedings of 8th International Topical Meeting on High Temperature Reactor Technology (HTR 2016) (CD-ROM), p.827 - 836, 2016/11

Pre-licensing basic design for a cogenerating HTGR test plant system is presented. The plant to be coupled to existing 30 MWt 950$$^{circ}$$C test reactor HTTR is intended as a system technology demonstrator for GTHTR300C plant design. More specifically the test plant of HTTR-GT/H$$_{2}$$ aims to (1)demonstrate the licensability of the GTHTR300C for electricity production by gas turbine and hydrogen cogeneration by thermochemical process and (2) confirm the operation control and safety of such cogeneration system. With construction and operation completion by 2025, the test plant is expected to be the first of a kind HTGR-powered cogeneration plant operating on the two advanced energy conversion systems of closed cycle helium gas turbine for power generation and thermochemical iodine-sulfur water-splitting process for hydrogen production.

JAEA Reports

Radiation monitoring using manned helicopter around the Nuclear Power Station in the fiscal year 2015 (Contract research)

Sanada, Yukihisa; Munakata, Masahiro; Mori, Airi; Ishizaki, Azusa; Shimada, Kazumasa; Hirouchi, Jun; Nishizawa, Yukiyasu; Urabe, Yoshimi; Nakanishi, Chika*; Yamada, Tsutomu*; et al.

JAEA-Research 2016-016, 131 Pages, 2016/10

JAEA-Research-2016-016.pdf:20.59MB

By the nuclear disaster of Fukushima Daiichi Nuclear Power Station (FDNPS), Tokyo Electric Power Company (TEPCO), caused by the East Japan earthquake and the following tsunami occurred on March 11, 2011, a large amount of radioactive materials was released from the NPS. After the nuclear disaster, airborne radiation monitoring using manned helicopter was conducted around FDNPS. In addition, background dose rate monitoring was conducted around Sendai Nuclear Power Station. These results of the aerial radiation monitoring using the manned helicopter in the fiscal 2015 were summarized in the report.

Journal Articles

Evaluation of oxidation efficiency of hydrophobic palladium catalyst for $$^{14}$$C monitoring in gaseous radioactive waste

Ueno, Yumi; Nakagawa, Masahiro; Sato, Junya; Iwai, Yasunori

Hoken Butsuri, 51(1), p.7 - 11, 2016/03

In the Nuclear Science Research Institute, Japan Atomic Energy Agency (JAEA), in order to oxidize $$^{14}$$C, which exists in various chemical forms in exhaust, into $$^{14}$$CO$$_{2}$$, a copper oxide (CuO) catalyst is introduced after heating to 600$$^{circ}$$C. Our goal was to establish a safer $$^{14}$$C monitoring system by lowering the heating temperature required for the catalyst; therefore, we developed a new hydrophobic palladium/silicon dioxide (Pd/SiO$$_{2}$$) catalyst that makes the carrier's surface hydrophobic. In these experiments, catalysts CuO, platinum/aluminum oxide (Pt/Al$$_{2}$$O$$_{3}$$), palladium/zirconium dioxide (Pd/ZrO$$_{2}$$), hydrophobic Pd/SiO$$_{2}$$, and hydrophilic Pd/SiO$$_{2}$$ were ventilated with standard methane gas, and we compared the oxidation efficiency of each catalyst at different temperatures. As a result, we determined that the hydrophobic Pd/SiO$$_{2}$$ catalyst had the best oxidation efficiency. By substituting the currently used CuO catalyst with the hydrophobic Pd/SiO$$_{2}$$ catalyst, we will be able to lower the working temperature from 600$$^{circ}$$C to 300$$^{circ}$$C and improve the safety of the monitoring process.

296 (Records 1-20 displayed on this page)