Ensemble deep learning model for leak detection from multi-channel acoustic signals

Mikami, Nao; Aizawa, Kosuke; Ueki, Yoshitaka*; Michel, F.*; Fache, J.*

Proceedings of 2025 International Congress on Advances in Nuclear Power Plants (ICAPP 2025) (Internet), 10 Pages, 2025/09

Anomaly detection technique based on acoustic measurement for sodium-cooled fast reactor

Aizawa, Kosuke; Ueki, Yoshitaka*

Proceedings of Specialist Workshop on Advanced Instrumentation and Measurement Techniques for Nuclear Reactor Thermal-Hydraulics and Severe Accidents (SWINTH-2024) (USB Flash Drive), 7 Pages, 2024/06

Early detection of an anomaly greatly enhances the safety of nuclear power plants. A detection system called an acoustic measurement has high responsiveness, because sound produced by the anomaly is transmitted from the place at which an anomaly has occurred to a measurement point at a speed of sound, and the acoustic measurement has the potential to directly detect the physical quantity of an anomaly at its occurrence point. For sodium-cooled fast reactors, we have been developing an anomaly detection technique using the acoustic measurement that offers these features. This paper clarifies issues in applying the acoustic measurement to a sodium-cooled fast reactor, how we solve the issues, and the current status of this research.

State sensing of bubble jet flow based on acoustic identification of deep learning

Mikami, Nao*; Ueki, Yoshitaka*; Shibahara, Masahiko*; Aizawa, Kosuke; Ara, Kuniaki

Proceedings of 17th International Heat Transfer Conference (IHTC-17) (Internet), 9 Pages, 2023/08

Boiling sensing based on acoustic recognition and deep learning

Ueki, Yoshitaka*; Hashimoto, Shunsaku*; Shibahara, Masahiko*; Aizawa, Kosuke; Ara, Kuniaki

Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 5 Pages, 2023/05

New result in the production and decay of an isotope, 113 of the 113th element

Morita, Kosuke*; Morimoto, Koji*; Kaji, Daiya*; Haba, Hiromitsu*; Ozeki, Kazutaka*; Kudo, Yuki*; Sumita, Takayuki*; Wakabayashi, Yasuo*; Yoneda, Akira*; Tanaka, Kengo*; et al.

Journal of the Physical Society of Japan, 81(10), p.103201_1 - 103201_4, 2012/10

https://doi.org/10.1143/JPSJ.81.103201

An isotope of the 113th element, 113, was produced in a nuclear reaction with a Zn beam on a Bi target. We observed six consecutive decays following the implantation of a heavy particle in nearly the same position in the semiconductor detector, in extremely low background condition. The fifth and sixth decays are fully consistent with the sequential decays of Db and Lr both in decay energies and decay times. This indicates that the present decay chain consisted of 113, Rg (Z = 111), Mt (Z = 109), Bh (Z = 107), Db (Z = 105), and Lr (Z = 103) with firm connections. This result, together with previously reported results from 2004 and 2007, conclusively leads the unambiguous production and identification of the isotope 113, of the 113th element.

Extraction of chromatographic behavior of Rf, Zr, and Hf in HCl solution with styrenedivinylbenzene copolymer resin modified by TOPO (trioctylphosphine oxide)

Toyoshima, Atsushi; Kasamatsu, Yoshitaka*; Tsukada, Kazuaki; Asai, Masato; Ishii, Yasuo; Tome, Hayato*; Nishinaka, Ichiro; Sato, Tetsuya; Nagame, Yuichiro; Schdel, M.; et al.

Journal of Nuclear and Radiochemical Sciences, 11(1), p.7 - 11, 2010/06

https://doi.org/10.14494/jnrs.11.7

The extraction behavior of rutherfordium (Rf) into trioctylphosphine oxide (TOPO) from 2.0 - 7.0 M HCl solution was studied together with that of the homologues Zr and Hf. The extracted yields of Rf, Zr, and Hf increased with an increase of HCl concentration, and the sequence of their extraction was Zr Hf Rf. It is suggested that the stability of the RfCl2(TOPO) complex is lower than that of the corresponding species of the homologues.

Education program for criticality safety with Monte Carlo method

Sakurai, Kiyoshi; Ueki, Kotaro*; Naito, Yoshitaka*

Nihon Genshiryoku Gakkai-Shi, 43(3), p.219 - 220, 2001/03

no abstracts in English

Methodology of Monte Carlo research

Sakurai, Kiyoshi; Ueki, Kotaro*; Naito, Yoshitaka*

Nihon Genshiryoku Gakkai-Shi, 42(10), p.1048 - 1049, 2000/10

no abstracts in English

Overview of recent research activities of Monte Carlo simulation in Japan

Sakurai, Kiyoshi; Yamamoto, Toshihiro; Ueki, Kotaro*; Mori, Takamasa; Nomura, Yasushi; Naito, Yoshitaka*

Journal of Nuclear Science and Technology, 37(Suppl.1), p.446 - 448, 2000/03

https://doi.org/10.1080/00223131.2000.10874925

no abstracts in English

Electrolytic reduction of Mo and W as lighter homologues of seaborgium (Sg)

Toyoshima, Atsushi; Miyashita, Sunao; Oe, Kazuhiro; Asai, Masato; Sato, Tetsuya; Tsukada, Kazuaki; Kitatsuji, Yoshihiro; Nagame, Yuichiro; Schdel, M.; Omtvedt, J. P.*; et al.

no journal, , 

We plan to determine the redox potential of seaborgium (Sg) in continuous experiments with a flow electrolytic column and a continuous solvent extraction SISAK. In this study, reduction experiments of its lighter homologues, Mo and W, were performed using the flow electrolytic column apparatus. After 200 L of the W radiotracer in 0.1 M HCl was introduced into the apparatus, 1000 L of 0.1 M HCl was fed into the electrode on which an potential was applied between -0.8 and 0.6 V. 1000 L was taken from the effluent from the electrode and was then mixed with 10 M hinokitiol in toluene with the same volume. After shaking for 1 min and then centrifuging for 30 s, 800 L was taken from each phase, which was then separately subjected to -ray spectrometry. As a result, the extraction yield of W was constant against the variation of the applied potential. It seems that once reduced W was again oxidized to the +6 state in the extraction procedure.