[3F05-09] Decommissioning Technology

[3F09] Volume reduction of concrete contaminated by ¹⁴CO₂

(2) Infiltration of ¹⁴CO₂ in mortar

*Norikazu Kinoshita¹, Hitoshi Nakashima¹, Kazuyuki Torii¹, Yuki Sasaki¹, Mamoru Hanzawa¹, Aya Sakaguchi², Keisuke Sueki² (1. Shimizu, 2. Univ. of Tsukuba)

Keywords:exposure test, diffusion coefficient, mortar

The ¹⁴CO₂ produced during long-time operation of nuclear power plants has been adsorbed in the surrounding concretes. The amount of ¹⁴C cannot be ignored for the decommissioning. In this study, we aimed to predict depths of the contamination infiltrated in the concretes. Diffusion coefficients of ¹⁴CO₂ in mortar samples were experimentally obtained by the exposure test on the mortar samples which were dry and wet condition. We will show the infiltration mechanism of ¹⁴CO₂ in the samples as well as trend of diffusion coefficients observed in the dry and wet samples. In addition, we will present the feature of the contamination predicted by the diffusion coefficients for decommissioning.