4:30 PM - 4:45 PM
[1A11] Study on the Radionuclide Contamination Mechanisms of Concrete and the Estimation of Distribution of Radionuclides
(12)The Cs/Sr penetration in the real concentration ranges in concrete for 1 year
Keywords:penetration, Cs, Sr, concrete, imaging plate, real concentration, degradation, carbonation, drying
Regarding the penetrations of Cs and Sr in concrete of Fukushima-Daiichi NPP, the long-term results (around 1 year) are compared with the short-term results (56 days) reported before.
Samples examined were normal Portland cement mortar and were prepared in the conditions of water-saturated sound (WS-S), water-saturated carbonated (WS-C), and dried carbonated (D-C). Samples were immersed in CsCl solution of concentration between 100 mM to 10 μM and SrCl2 solution of 10 μM labelled by 137Cs and 90Sr. By using imaging plate, material concentration profiles were obtained.
In WS-S, concentration gradient became flat even in deep position and Cs reached more than 30 mm depth in all concentration. In WS-C, although strong condensation was observed in carbonated region, Cs was penetrated in deep position in long-term. In D-C, for Cs, the surface concentration increased and simultaneously that in deep position increased. On the other hand, for Sr, although the surface concentration increased also, the concentration in deeper position was kept constant, suggesting the much slower penetration than Cs.
Samples examined were normal Portland cement mortar and were prepared in the conditions of water-saturated sound (WS-S), water-saturated carbonated (WS-C), and dried carbonated (D-C). Samples were immersed in CsCl solution of concentration between 100 mM to 10 μM and SrCl2 solution of 10 μM labelled by 137Cs and 90Sr. By using imaging plate, material concentration profiles were obtained.
In WS-S, concentration gradient became flat even in deep position and Cs reached more than 30 mm depth in all concentration. In WS-C, although strong condensation was observed in carbonated region, Cs was penetrated in deep position in long-term. In D-C, for Cs, the surface concentration increased and simultaneously that in deep position increased. On the other hand, for Sr, although the surface concentration increased also, the concentration in deeper position was kept constant, suggesting the much slower penetration than Cs.