Updating fission product chemistry database based on recent investigation in Fukushima-Daiichi Nuclear Power Station, 2; Temperature effects on the deposition behavior of CsOH aerosols on concrete main phase-CaCO

福島第一原子力発電所における最近の調査に基づくFP化学挙動データベースの更新,2; コンクリート主成分CaCO上へのCsOHエアロゾルの堆積に対する温度の影響

Luu, V. N. ; 中島 邦久  ; Rizaal, M.   ; 三輪 周平  

Luu, V. N.; Nakajima, Kunihisa; Rizaal, M.; Miwa, Shuhei

The trapping behavior of cesium (Cs) on concrete, such as pedestal and shield plugs, was assessed through multiple deposition tests of CsOH aerosols on concrete phase-CaCO within a temperature range of 170C to 570C under humid conditions. The deposition rate of CsOH aerosols on CaCO as a function of temperature was examined. X-ray diffraction analysis revealed the presence of water-soluble CsCO on CaCO samples up to 420C, but negligible detection above this temperature. This finding is supported by quantitative analyses of Cs weight gain and chemical analysis, demonstrating an increase in deposition rate up to 420C, followed by a decline thereafter. The increased deposition rate is attributed to the chemical interaction between CsOH and CaCO, while the diminished rate beyond 420C may result from the decomposition of CaCO under steam, thereby reducing the available reactant for the chemical reaction with CsOH.