Development of a fiber laser-based method to generate Cs-bearing microparticles from glass fiber filters

Hagiwara, Hiroki  ; Kosuge, Atsushi ; Saito, Junichi  ; Namie, Masanari ; Kisohara, Naoyuki ; Minehara, Eisuke*; Tsuboi, Akihiko ; Ishimori, Yuu 

To understand how Type-A Cs-bearing microparticles were generated at the Fukushima Daiichi nuclear power plant, identifying the materials from which these particles originated is important. In this study, we focus on a methodological approach for generating Cs-bearing microparticles by laser irradiation of glass-fibers-based filter materials, with the aim of producing surrogate particles under controlled laboratory conditions. To evaluate this approach, a series of experiments was conducted, including vapor-phase exposure and aqueous loading of Cs, Fe, and Zn onto filter substrates, followed by laser irradiation to induce rapid, localized high-temperature effects. Morphology and size distributions of the Cs-containing surrogate particles were found to be comparable to those reported for Type-A particles, within the scope of the applied analytical methods. Overall, a reproducible laboratory framework was established for producing Cs-bearing surrogate microparticles suitable for systematic characterization, while not aiming to fully reproduce specific accident conditions.