[1I01-08] Severe Accident/Effective Utilization of FP

[1I02] Formation of Cs-compounds by chemical interaction of CsOH and concrete at various temperatures

*Vu Nhut Luu¹, Kunihisa Nakajima¹ (1. JAEA)

Keywords:Cesium, chemical interaction, CsAlSiO4, concrete shield plug, Fukushima

To investigate the source of high dose rates at the concrete shield plugs of Unit 2 and 3 at 1F, high temperature tests on the mixture of CsOH and pulverized concrete/main components were conducted. Results showed that both water-soluble and -insoluble phases were formed below 300^oC. Namely, Cs₂CO₃(H₂O)₃ was formed due to chemical reaction with CaCO₃ at room temperature. The authors will discuss the possibility that this might be one of the main trapping mechanisms on shield plugs.