NEA Horonobe International Project - HIP Interim report for Phase 1 (February 2023 - March 2025)

Tachi, Yukio; Aoyagi, Kazuhei; Ozaki, Yusuke; Hayano, Akira; Ono, Hirokazu; Takeda, Masaki; Mochizuki, Akihito; Dei, Shuntaro; Minaka, Jumpei; Murakami, Hiroaki; et al.

NEA/NE(2025)20 (Internet), 118 Pages, 2025/11

https://www.oecd-nea.org/jcms/pl_111824/nea-horonobe-international-project-hip-interim-report-for-phase-1-february-2023-march-2025

sp. nov., a novel hydrogen-producing bacterium isolated from a deep diatomaceous shale formation

Ueno, Akio*; Sato, Kiyoshi*; Tamamura, Shuji*; Murakami, Takuma*; Inomata, Hidenori*; Tamazawa, Satoshi*; Amano, Yuki; Miyakawa, Kazuya; Naganuma, Takeshi*; Igarashi, Toshifumi*

International Journal of Systematic and Evolutionary Microbiology, 75(6), p.006802_1 - 006802_11, 2025/06

https://doi.org/10.1099/ijsem.0.006802

no abstracts in English

Complete genome sequence of sp. strain V2501 isolated from 250 m below the ground level in Horonobe, Hokkaido, Japan

Ueno, Akio*; Sato, Kiyoshi*; Tamamura, Shuji*; Murakami, Takuma*; Inomata, Hidenori*; Tamazawa, Satoshi*; Amano, Yuki; Miyakawa, Kazuya; Naganuma, Takeshi*; Igarashi, Toshifumi*

Microbiology Resource Announcements (Internet), 13(11), p.e00108-24_1 - e00108-24_4, 2024/11

https://doi.org/10.1128/mra.00108-24

Application of Bayesian estimation to X-ray fluorescent image

Matsuyama, Tsugufumi*; Igarashi, Momo*; Yasuda, Sora*; Murakami, Masashi; Yoshida, Yukihiko; Hayashi, Kazunori*; Machida, Masahiko; Tsuji, Koichi*

Analytical Chemistry, 9 Pages, 2024/01

http://dx.doi.org/10.2139/ssrn.4697562

Intruder configurations in Ne at the transition into the island of inversion; Detailed structure study of Ne

Wang, H.*; Yasuda, Masahiro*; Kondo, Yosuke*; Nakamura, Takashi*; Tostevin, J. A.*; Ogata, Kazuyuki*; Otsuka, Takaharu*; Poves, A.*; Shimizu, Noritaka*; Yoshida, Kazuki; et al.

Physics Letters B, 843, p.138038_1 - 138038_9, 2023/08

https://doi.org/10.1016/j.physletb.2023.138038

Detailed -ray spectroscopy of the exotic neon isotope Ne has been performed using the one-neutron removal reaction from Ne. Based on an analysis of parallel momentum distributions, a level scheme with spin-parity assignments has been constructed for Ne and the negative-parity states are identified for the first time. The measured partial cross sections and momentum distributions reveal a significant intruder p-wave strength providing evidence of the breakdown of the N = 20 and N = 28 shell gaps. Only a weak, possible f-wave strength was observed to bound final states. Large-scale shell-model calculations with different effective interactions do not reproduce the large p-wave and small f-wave strength observed experimentally, indicating an ongoing challenge for a complete theoretical description of the transition into the island of inversion along the Ne isotopic chain.

Fundamental research of X-ray absorption imaging for elemental identification using a secondary target

Nakae, Masanori*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Tsuji, Koichi*

Advances in X-Ray Chemical Analysis, Japan, 54, p.89 - 99, 2023/03

Fundamental research on X-ray absorption imaging for elemental identification was studied. A secondary target was applied to obtain X-ray absorption images above and below the X-ray absorption edge of the target element. X-rays from an X-ray tube were irradiated to the secondary target, where the characteristic X-rays were emitted that were irradiated to the sample. X-ray absorption images were acquired with an exposure time of a few seconds with an X-ray camera. In this technique, it is difficult to change the energy of X-rays as we want, however we can apply this technique for imaging the specific element. Metal foil sample composed of Al, Cu, and Ni was analyzed. To obtain an X-ray elemental image of Ni, two X-ray absorption images were taken using the X-rays above and below the Ni K-edge. X-rays of Cu K and Zn K were prepared by using Cu and Zn plates as the secondary target. Finally, the Ni elemental image was obtained by subtracting two images. Furthermore, the X-ray camera had a function of setting critical energies for imaging, thus it was demonstrated that an X-ray elemental image of Ni was obtained using a single secondary target without changing the secondary target.

Spectrum prediction in X-ray fluorescence analysis using Bayesian estimation

Matsuyama, Tsugufumi*; Nakae, Masanori*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Tsuji, Koichi*

Spectrochimica Acta, Part B, 199, p.106593_1 - 106593_6, 2023/01

https://doi.org/10.1016/j.sab.2022.106593

Fuel unloading work in decommissioning of the prototype fast breeder reactor Monju; Fuel treatment and storage work in 2018 and 2019

Shiota, Yuki; Yabe, Takanori; Murakami, Makio; Isobe, Yuta; Sato, Masami; Hamano, Tomoharu; Takagi, Tsuyohiko; Nagaoki, Yoshihiro

JAEA-Technology 2022-001, 117 Pages, 2022/07

JAEA-Technology-2022-001.pdf:25.55MB

In the first stage of Monju decommissioning project, fuel unload work began to be carried out. There are two tasks in this work. One is fuel treatment and storage work that gets rid of sodium on the fuel assemblies unloaded from Ex-Vessel fuel Storage Tank (EVST) and carries it in the storage pool, and the other is fuel unloading that the fuel assemblies in the reactor core is replaced with dummy fuels and stored in EVST. Fuel treatment and storage work and fuel unloading work are performed alternately, and 370 bodies in the core and 160 pieces in EVST are all carried to the storage pool. 86 fuel assemblies was carried to the storage pool in fuel treatment and storage work in 2018 and 76 dummy fuels were stored in EVST for fuel unloading work. During the work, 86 types and 232 alarms / malfunctions occurred, but there was no impact on safety. There was one equipment's failure at gripper's claw open / close clutch of ex-vessel fuel transfer machine B, but it was repaired and restarted. Also it was eliminated the cause of problem or concession that the equipment failure due to the sticking of the sodium compound and continuous use of the equipment. Some problems related to system control occurred, but the work was done after checking the safety. With estimation of various troubles, reduction of frequency of trouble occurrence and minimization of impacts on schedule performed.

Development and evaluation of XRF imaging instrument for moving objects

Fuchita, Tomoki*; Urata, Taisei*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Ueda, Akihiko; Machida, Masahiko; Sasaki, Toshiki; Tsuji, Koichi*

Advances in X-Ray Chemical Analysis, Japan, 53, p.77 - 87, 2022/03

X-ray fluorescence (XRF) analysis is an analytical method to obtain elemental information by detecting fluorescence X-rays emitted from a sample irradiated with X-rays. It is possible to obtain two-dimensional elemental distribution images by scanning a sample with micro X-ray beam. In this study, we developed an XRF analytical instrument to rapidly obtain the elemental distributions for moving samples on a belt conveyor by applying the micro XRF technique. X-rays were widely irradiated to the belt conveyor. The elemental distributions were measured by scanning an X-ray detector, crossing above the belt conveyor. A collimator was attached to the top of the detector to limit the analyzing area. Both detection limit and spatial resolutions for moving directions of the detector and the belt conveyor were evaluated. Finally, it was demonstrated that the multi-elemental imaging was possible with the developed XRF instrument.

Basic policy for rational measures of radioactive waste processing and disposal; Results of studies for acceleration of waste processing

Nakagawa, Akinori; Oyokawa, Atsushi; Murakami, Masashi; Yoshida, Yukihiko; Sasaki, Toshiki; Okada, Shota; Nakata, Hisakazu; Sugaya, Toshikatsu; Sakai, Akihiro; Sakamoto, Yoshiaki

JAEA-Technology 2021-006, 186 Pages, 2021/06

JAEA-Technology-2021-006.pdf:54.45MB

Radioactive wastes generated from R&D activities have been stored in Japan Atomic Energy Agency. In order to reduce the risk of taking long time to process legacy wastes, countermeasures for acceleration of waste processing and disposal were studied. Work analysis of waste processing showed bottleneck processes, such as evaluation of radioactivity concentration, segregation of hazardous and combustibles materials. Concerning evaluation of radioactivity concentration, a radiological characterization method using a scaling factor and a nondestructive gamma-ray measurement should be developed. The number of radionuclides that are to be selected for the safety assessment of the trench type disposal facility can decrease using artificial barriers. Hazardous materials, will be identified using records and nondestructive inspection. The waste identified as hazardous will be unpacked and segregated. Preliminary calculations of waste acceptance criteria of hazardous material concentrations were conducted based on environmental standards in groundwater. The total volume of the combustibles will be evaluated using nondestructive inspection. The waste that does not comply with the waste acceptance criteria should be mixed with low combustible material waste such as dismantling concrete waste in order to satisfy the waste acceptance criteria on a disposal facility average. It was estimated that segregation throughput of compressed waste should be increased about 5 times more than conventional method by applying the countermeasures. Further study and technology development will be conducted to realize the plan.