[1A09-12] Contaminated Concrete

[1A10] Chemical State Analysis of Strontium Attached to Structural Materials of Reactor Building

*Yuko Kimoto¹, Kai Yoneyama¹, Isamu Sato¹, Haruaki Matsuura¹, Eriko Suzuki² (1. Tokyo City University, 2. Japan Atomic Energy Agency)

Keywords:Fukushima Daiichi Nuclear Power Station, Concrete, Strontium, XRF, EXAFS

In the decommissioning of the TEPCO's Fukushima Daiichi Nuclear Power Plant, it is necessary to manage the associated dismantled waste safely and rationally. It is important to understand the adhesion and permeation mechanisms of Sr to concrete structural materials, which exist in large quantities in nuclear reactor buildings, in order to provide appropriate treatment and disposal according to their properties. In this study, the immersion tests of Sr in concrete using SrCl₂ and Sr(OH)₂ solutions with different anions, and the EXAFS and XRF analyses of the immersed concrete were carried out. XRF showed that the Sr content in both SrCl₂ and Sr(OH)₂ decreased from the surface to the depth, but the penetration rate changed with pH. From the structural analysis of SrCl₂ near Sr by EXAFS, the amount of Sr adsorbed by SrCl₂ was larger than that of Sr(OH)₂, showing a similar trend to that of XRF. The results were similar to those of XRF.