[2I06-09] Waste Management 2

[2I06] Atmospheric effects on the formation of cesium-bearing deposits on concrete and aggregate at 200 ^oC

*NHUT VU LUU¹, KUNIHISA NAKAJIMA¹ (1. JAEA)

Keywords:Cesium-bearing materials, Shield plug concrete, Cesium, Concrete, Severe accident

Chemisorption tests of CsOH onto concrete and aggregate were carried out at 200 ^oC in both dry and humid conditions to investigate the source of high dose rates at the concrete shield plugs of Units 2 and 3 at 1F. Post-test analyses using XRD, Raman, and SEM revealed that water-insoluble Cs-bearing deposits formed different morphologies under dry and humid conditions. Namely, uniform and large Cs deposits were formed under humid conditions, while heterogenous growth and smaller size Cs deposits were observed under dry conditions.