2022 Annual Meeting

Presentation information

Oral presentation

V. Nuclear Fuel Cycle and Nuclear Materials » 505-2 Waste Disposal and Its Environmental Aspects

[2H01-06] Migration/Sorption 1

Thu. Mar 17, 2022 10:15 AM - 12:00 PM Room H

Chair: Kenso Fujiwara (JAEA)

10:30 AM - 10:45 AM

[2H02] Structural analysis and site selectivity of Cesium adsorption on Calcium Silicate Hydrates

*Keita Higuchi1, Takahiro Ohkubo1, Kumi Negishi2, Masahito Shibata2, Yukio Tachi3 (1. Chiba Univ., 2. Taiheiyo Consultant, 3. JAEA)

Keywords:Calcium Silicate Hydrates, Cs adsorption, Nuclear Magnetic Resonance

Structural analyses of adsorbed Cs on calcium silicate hydrate (C-S-H) were performed by 133Cs solid-state NMR and Cs adsorption experiments. 133Cs solid-state NMR spectra of C-S-H with adsorbed Cs gave one (A) or two peaks (A and B) depending on Ca/Si and Cs content. The peaks A and B were assigned to Cs adsorbed sites on interlayer silanol groups (site A) and exchangeable Ca sites bridging silicate chain (site B). Since the peak A was only observed for the sample with small amount of Cs, adsorption of Cs on C-S-H occurs preferentially at site A. After the saturation of adsorption on site A, adsorption on site B occurs in the sample with higher Cs content.