Speciation of cesium in a radiocesium-bearing microparticle emitted from Unit 1 during the Fukushima nuclear accident by XANES spectroscopy using transition edge sensor

Takahashi, Yoshio*; Miura, Hikaru*; Yamada, Shinya*; Sekizawa, Oki*; Nitta, Kiyofumi*; Hashimoto, Tadashi*; Yomogida, Takumi; Yamaguchi, Akiko; Okada, Shinji*; Itai, Takaaki*; et al.

Journal of Hazardous Materials, 495, p.139031_1 - 139031_19, 2025/09

https://doi.org/10.1016/j.jhazmat.2025.139031

In this presentation, we analyzed the chemical state of cesium in radiocesium-bearing microparticles (CsMPs) released during the 2011 Fukushima Daiichi Nuclear Power Plant accident using high-resolution X-ray absorption spectroscopy (XANES) and micro X-ray fluorescence (-XRF). The results identified two forms of cesium: one dissolved in glass and the other enriched on the surfaces of internal voids. The latter is considered to have originally existed as a gas and became concentrated during the cooling and solidification of the molten glass. These findings are crucial for understanding the formation process of CsMPs during the accident, as well as for future decommissioning and safety assessments.

High-sensitive XANES analysis at Ce L-edge for Ce in bauxites using transition-edge sensors; Implications for Ti-rich geological samples

Li, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.

Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02

https://doi.org/10.1016/j.aca.2022.340755

no abstracts in English

Annual report of STACY operation in F.Y. 1998, 2; 800mm-diameter cylindrical core10% enriched uranyl nitrate solution (Contract research)

Onodera, Seiji; Sono, Hiroki; Hirose, Hideyuki; Tanino, Shuichi; Nagasawa, Makoto*; Murakami, Kiyonobu; Sakuraba, Koichi; Miyauchi, Masakatsu; Yamane, Yuichi; Ono, Akio

JAERI-Tech 2000-013, p.57 - 0, 2000/03

JAERI-Tech-2000-013.pdf:2.43MB

no abstracts in English

Quantitative tracing of water-rock interactions by IR spectoroscopy; An Example of alkaline alteration of granitic rocks

Nakashima, Satoru*; Kirino, Yusuke*; Nishiyama, Naoki*; Tonoue, Ryota*; Yokoyama, Tadashi*; Nagasawa, Makoto*; Harui, Rika*; Walker, C.; Sasamoto, Hiroshi

no journal, , 

Cementitious grout material will be used to reduce groundwater inflow into the repository of high level radioactive waste. High pH solution derived from cementitious grout material may cause alteration of rock mass by grout-rock interactions. With regard to evaluation of radionuclide migration, it is important to evaluate the long-term behavior of rock mass affected by grout-rock interactions since such altered rock mass potentially affects on migration behavior (e.g., diffusion and sorption) of radionuclide. This study presents the results of identification for trace secondary minerals (alteration products) by (micro)infrared spectroscopy and determination of reaction rate constants of formation for secondary minerals.

Systematic understanding of enrichment process of rare earth elements by adsorption/coprecipitation process in natural systems

Takahashi, Yoshio*; Nagasawa, Makoto*; Qin, H.-B.*; Yamaguchi, Akiko; Kashiwabara, Teruhiko*; Tanaka, Kazuya

no journal, , 

no abstracts in English