[3E04-07] Cs behavior, Decontamination, Radiolysis, Corrosion

[3E04] Study on deposition behavior of CsOH present in the gas phase on CaCO₃ at temperature range 170 - 290 ^oC

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

Keywords:deposition rate, chemisorption, concrete, severe accident, cesium, shield plugs

A recent field survey revealed extremely high radioactivity on the concrete shield plugs, exceeding 20 PBq for Cs-137 at units 2, 3 of 1F. This leads to significant interest in the retention of Cs on concrete during severe accident. Despite this, the interaction of Cs vapors and/or aerosols in the gas phase with concrete surfaces at high temperatures remains inadequately explored. In this work, we investigated the deposition behavior of CsOH on CaCO₃, as a primary phase on the concrete surface, under humid atmosphere. As a result, the chemical reaction enhanced deposition rate, and increased linearly with CsOH concentration.