Irradiation test using foreign reactor, 2; Study of irradiation test with capsule temperature control system (Joint research)

Omori, Takazumi; Fuyushima, Takumi; Sayato, Natsuki; Saito, Nagatsuki; Takabe, Yugo; Endo, Yasuichi; Inoue, Shuichi; Wojtania, G.*; Migdal, M.*; Takeuchi, Tomoaki; et al.

JAEA-Technology 2026-006, 47 Pages, 2026/06

JAEA-Technology-2026-006.pdf:3.01MB

Japan Materials Testing Reactor (JMTR), which served as the core facility for neutron irradiation research including materials research and radioisotope production, has been decommissioned. As a result, it has become difficult to continue conducting irradiation tests domestically, as well as to transfer the operational expertise and irradiation technologies associated with test reactors, to address these challenges, it was decided to initiate JMTR alternative irradiation, in which foreign irradiation reactors are utilized to partially substitute for JMTR's irradiation capabilities. As a first step, based on the "Arrangement between the National Centre for Nuclear Research and the Japan Atomic Energy Agency for Cooperation in Research and Development on Testing Reactor". The MARIA reactor (30 MW) owned by the National Centre for Nuclear Research (NCBJ) was selected as the neutron irradiation facility, a temperature control system, which is one of JMTR's irradiation technologies, was introduced into the MARIA reactor, and irradiation tests were conducted. The results of this irradiation test confirmed that the combination of the newly introduced temperature control device and the JMTR irradiation test system operates without issues even after an irradiation period exceeding 150 days, it was also demonstrated that the tests could be conducted while continuously measuring the thermocouple temperature inside the capsule during irradiation, as well as the output of the LVDT and SPGD. Furthermore, regarding the constant temperature control of the irradiation capsule at 300C constant temperature control test, which is highly demanded in materials irradiation testing, was conducted, during reactor power increases, when temperature fluctuations become significant, temperature control was maintained within 6.3C, while during power decreases, it was controlled within 26.0C. These results indicate that irradiation testing with irradiation temperature control system developed by JMTR, can also be performed in the MARIA reactor, it was confirmed that it can be offered as an alternative irradiation field.

Vortex rectenna powered by environmental fluctuations

Lustikova, J.*; Shiomi, Yuki*; Yokoi, Naoto*; Kabeya, Noriyuki*; Kimura, Noriaki*; Ienaga, Koichiro*; Kaneko, Shinichi*; Okuma, Satoshi*; Takahashi, Saburo*; Saito, Eiji

Nature Communications (Internet), 9, p.4922_1 - 4922_6, 2018/11

https://doi.org/10.1038/s41467-018-07352-1

HCM12A Cr-rich oxide layer investigation using 3D atom probe

Kikuchi, Kenji*; Okada, Noriyuki*; Kato, Mikio*; Uchida, Hiroshi*; Saito, Shigeru

Journal of Nuclear Materials, 450(1-3), p.237 - 243, 2014/07

https://doi.org/10.1016/j.jnucmat.2013.09.011

Three-dimensional atom probe techniques were applied to the investigation on the oxide scale in 12Cr ferritic-martensitic steel, HCM12A. A duplex oxide scale was formed in lead bismuth eutectic at 450-500C, during 5500 h. Samples were located 500-700 nm away from the boundary between magnetite and Fe-Cr spinel layers, while the total oxide layer thickness is 18 m. It detected super enrichment of Cr with a size of ten nm roughly, as well as depletion of Fe and enrichment of O at the same site. Surrounding the Cr super enrichment area, enrichment of Si was newly noticed due to the scanned profile of detected atom counts. It is also confirmed that Pb and Bi concentration in the observed spinel region is almost null or less than 0.01 atomic percent, which is possible detecting lowest limit.

Research and development on waste management for the Fukushima Daiichi NPS by JAEA

Koma, Yoshikazu; Ashida, Takashi; Meguro, Yoshihiro; Miyamoto, Yasuaki; Sasaki, Toshiki; Yamagishi, Isao; Kameo, Yutaka; Terada, Atsuhiko; Hiyama, Toshiaki; Koyama, Tomozo; et al.

Proceedings of International Nuclear Fuel Cycle Conference; Nuclear Energy at a Crossroads (GLOBAL 2013) (CD-ROM), p.736 - 743, 2013/09

Fukushima Daiichi Nuclear Power Station (F1NPS), TEPCO, was severely damaged with the hydrogen explosions caused by losing their cooling functions due to the earthquake and the tsunami occurred on March 11, 2011. Radioactive wastes generated from the current FINPS and future their decommission and demolition are greater huge amount than those from general reactors and nuclear fuel facilities. Toward accomplishing safe and reasonable management of the wastes, great effort of R&Ds has been strongly required and performed in bringing together the knowledge and experience of all of Japan. This report outlines the current status of the R&Ds performed in JAEA.

Design, fabrication and transportation of Si rotating device

Kimura, Nobuaki; Imaizumi, Tomomi; Takemoto, Noriyuki; Tanimoto, Masataka; Saito, Takashi; Hori, Naohiko; Tsuchiya, Kunihiko; Romanova, N. K.*; Gizatulin, S.*; Martyushov, A.*; et al.

JAEA-Technology 2012-012, 34 Pages, 2012/06

JAEA-Technology-2012-012.pdf:12.91MB

Si semiconductor production by Neutron Transmutation Doping (NTD) method using the Japan Materials Testing Reactor (JMTR) has been investigated in Neutron Irradiation and Testing Reactor Center, Japan Atomic Energy Agency (JAEA) in order to expand industry use. As a part of investigations, irradiation test of silicon ingot for development of NTD-Si with high quality was planned using WWR-K in Institute of Nuclear Physics (INP), National Nuclear Center of Republic of Kazakhstan (NNC-RK) based on one of specific topics of cooperation (STC), Irradiation Technology for NTD-Si (STC No.II-4), on the implementing arrangement between NNC-RK and the JAEA for "Nuclear Technology on Testing/Research Reactors" in cooperation in research and development in nuclear energy and technology. As for the irradiation test, Si rotating device was fabricated in JAEA, and the fabricated device was transported with irradiation specimens from JAEA to INP-NNC-RK. This report described the design, the fabrication, the performance test of the Si rotating device and transportation procedures.

Plunger design and RF leakage measurement of choke stub for JT-60 ICRF heating system

Kobayashi, Noriyuki; Kimura, Haruyuki; Saigusa, Mikio; Fujii, Tsuneyuki; Ikeda, Yoshitaka; Saito, Yasushi*

Fusion Engineering and Design, 12(4), p.481 - 491, 1990/07

https://doi.org/10.1016/0920-3796(90)90041-4

no abstracts in English

New insights of the radiation biology from the abortive colony size analysis

Sakashita, Tetsuya; Hamada, Nobuyuki*; Kawaguchi, Isao*; Ouchi, Noriyuki; Hara, Takamitsu*; Kobayashi, Yasuhiko; Saito, Kimiaki

no journal, , 

Clonogenicity gives important information about the cellular reproductive potential following ionizing irradiation, but an abortive colony that fails to continue to grow remains poorly characterized. By applying the simple model of branching processes to the linear relationship of the abortive colony size distribution, we found the persistent reproductive cell death (RCD) over several generations following irradiation. Radiation-induced RCD, i.e. excess probability, lasted over 16 generations and mainly consisted of two components in the early (3 generations) and late phases. Intriguingly, the survival curve was sensitive to the excess probability over 5 generations, whereas abortive colony size distribution was robust against it. These results suggest that, whereas short-term RCD is critical to the abortive colony size distribution, long-lasting RCD is important for the dose response of the surviving fraction.

A Framework for understanding the production kinetics of abortive colony size distributions in irradiated normal human fibroblasts

Sakashita, Tetsuya; Hamada, Nobuyuki*; Kawaguchi, Isao*; Ouchi, Noriyuki; Hara, Takamitsu*; Kobayashi, Yasuhiko; Saito, Kimiaki

no journal, , 

The production kinetics of abortive colonies was investigated using a model of branching processes. We experimentally determined the colony size distribution of abortive colonies exposed to low linear energy transfer (LET) -rays, and found its linear relationship on the log-log plot. By applying the simple model of branching processes to the linear relationship, we found the persistent reproductive cell death (RCD) over several generations following irradiation. To verify the estimated probability of RCD, the Monte Carlo simulation was used. Radiation-induced RCD lasted over 16 generations and mainly consisted of two components in the early and late phases. Intriguingly, the survival curve was sensitive to the excess probability over 5 generations. Such framework for the combined analysis with a branching process model and a colony formation assay was also applicable to determination of cellular responses to high-LET carbon-ion radiation.

A Framework for analysis of abortive colony size distributions using a model of branching processes in irradiated normal human fibroblasts

Sakashita, Tetsuya; Hamada, Nobuyuki*; Kawaguchi, Isao*; Ouchi, Noriyuki; Hara, Takamitsu*; Kobayashi, Yasuhiko; Saito, Kimiaki

no journal, , 

The production kinetics of abortive colonies was investigated using a model of branching processes. We experimentally determined the colony size distribution of abortive colonies exposed to low linear energy transfer (LET) -rays, and found its linear relationship on the log-log plot. By applying the simple model of branching processes to the linear relationship, we found the persistent reproductive cell death (RCD) over several generations following irradiation. To verify the estimated probability of RCD, the Monte Carlo simulation was used. Radiation-induced RCD lasted over 16 generations and mainly consisted of two components in the early and late phases. Intriguingly, the survival curve was sensitive to the excess probability over 5 generations. Such framework for the combined analysis with a branching process model and a colony formation assay was also applicable to determination of cellular responses to high-LET carbon-ion radiation.