Measurement methods proposal for gamma-rays and neutrons for the decommissioning of the Fukushima Daiichi Nuclear Power Plant

Kanno, Ikuo

no journal, , 

no abstracts in English

Effect of boric acid addition on potassium-based Alkali-Activated Materials

Hiraki, Yoshihisa; Sato, Junya; Chaerun, R. I.; Niu, X.*; Elakneswaran, Y.*; Yoshida, Yukihiko; Osugi, Takeshi

no journal, , 

None

Tagawa, Akihiro

no journal, , 

no abstracts in English

The Impact of radioactive cesium-bearing microparticles on Cs transfer factor of brown rice on the paddy field in the first year of resumption of farming

Tatsuno, Takahiro*; Nihei, Naoto*; Yoshimura, Kazuya

no journal, , 

Remote strain measurement based on FBG sensing for fuel debris handling and its related applications

Nishimura, Akihiko; Ide, Tsugio*; Ishihara, Nobuyuki*

no journal, , 

The technologies surrounding the 1F decommissioning work are gradually forming a network with various industrial fields. Here, we report on the technical collaboration related to remote strain measurement centered on Fiber Bragg Grating (FBG) sensing. Strain monitoring can be used for gripping force measurement of manipulators in case of handling fragile debris due to weathering effects. FBG sensing for pipeline maintenance and heat exchanger device are introduced.

Demonstration of COMRIS, a 3-D visualization software for radioactive substances based on Compton cameras and SLAM devices

Sato, Yuki; Minemoto, Kojiro*; Nemoto, Makoto*

Proceedings of Waste Management Conference 2025 (WM2025) (Internet), 9 Pages, 2025/03

Development of technologies for containing, transportation and storage of fuel debris, 5; Numerical analysis of temporal structural changes of oxide powder inside water suspension

Terada, Atsuhiko; Nagaishi, Ryuji; Thwe Thwe, A.; Ito, Tatsuya

no journal, , 

In the Development of Technologies for Containing, Transportation and Storage of Fuel Debris, efforts have been made to develop methods for evaluating the amount of hydrogen (H) generated from lump-shaped debris, and we are now developing methods for powdered debris. As a new attempt, we started computational fluid dynamics (CFD) analysis to visually capture the state of powdered debris over time, such as movement and changes in a mixture of powdered debris and water. As this movement or change, we are currently conducting numerical analysis of two-phase systems, focusing on the growth and behavior of H bubbles in viscoelastic fluids (liquid and gas phases), as well as the structural changes (im-homogenization) over time within the mixture (liquid and solid phases) in relation to H bubbles (H pools) that are predicted to be generated during the radiolysis of water and retained in the mixture. In this report, oxides such as ceria and zirconia were used as debris simulants, and we will introduce the results of an analysis of the time-dependent im-homogenization of oxide powder inside water suspensions, as well as future challenges and developments.

Experimental analysis of behaviors of Cs and I in CsMP

Onuki, Toshihiko*; Utsunomiya, Satoshi*; Nakase, Masahiko*; Takano, Masahide; Dohi, Terumi

no journal, , 

Micro particles containing cesium (Cs) and iodine (I) were synthesized with stainless steel, ZrO and boron by light-concentrating heating technique on a concrete piece in laboratory scale. Elemental composition of the synthesized micro particles and also the effect of water-immersing were analyzed by SEM-EDS. Behaviors of Cs and I were examined from these data.

Modification of STACY for the study of criticality characteristics of fuel debris, 21; Experimental validation for non-uniform core configuration effects

Gunji, Satoshi; Araki, Shohei; Dechenaux, B.*; Brovchenko, M.*; Aizawa, Eiju; Seki, Masakazu; Arakaki, Yu; Yoshikawa, Tomoki; Izawa, Kazuhiko

no journal, , 

Non-uniformity of the composition is an issue when evaluating fuel debris's criticality characteristics. Critical experiments using the modified STACY are planned to validate the criticality effects of the non-uniformity. In this presentation, the results of the critical experiment their experimental core arrangements have large non-uniformity effects, and their experimental analyses are shown.

Development of analysis and estimation techniques to determine the properties of fuel debris, 7; Research and development of passive gamma-ray method

Terashima, Kenichi; Matsumura, Taichi; Sakamoto, Masahiro; Kaburagi, Masaaki; Shiba, Tomooki; Sugizaki, Saki*; Okumura, Keisuke

no journal, , 

no abstracts in English