[3G04-08] Migration/Sorption

[3G08] Study on elucidation of the mechanism of concrete contamination by radioactive materials and estimation of contamination distribution (15)

Apparent diffusion coefficients of Cs and Sr to mortar and concrete made with river gravel from the Abukuma River under actual contamination conditions

*Kazuo Yamada¹, Norio Muranaka², Keita Himori², Hideyuki Hokora³, Sayuri Tomita³, Haruka Aihara⁴, Yasumasa Tojo², Yoshifumi Hosokawa⁵, Go Igarashi⁶, Ippei Maruyama⁷ (1. NIES, 2. Hokkaido Univ., 3. Taiheiyo Consultant, 4. JAEA, 5. Taiheiyo Cement, 6. Nagoya Univ., 7. UTokyo)

Keywords:Apparent diffusion coefficient, Cs, Sr, Dry carbonated, Seawater

Cs is firmly adsorbed in certain river gravels, and Sr is fixed by substitution with Ca in the concrete, retarding infiltration into the concrete by different mechanisms. Considering the real contamination situation of the underground structure at Fukushima Daiichi, mortar or concrete with a carbonated and dry surface layer was exposed to seawater for one day, and then to contaminated water mixed with seawater for two months or one year, and the penetration profile was evaluated using imaging plates. Compared to penetration from simple chloride solutions into non-carbonated saturated mortar, Cs penetration was retarded and Sr penetration was accelerated.