AN EXPERIMENTAL STUDY ON THE DEGRADATION OF UO₂/FE(0) BY BACTERIA

Abstract

The diffusion of components of nuclear fuel debris formed during the Fukushima Daiichi nuclear accident to cooling water is the root cause of the contaminated water. This study aims to investigate the role of microorganisms in the dissolution process of fuel debris. Mixed powder of UO₂ and Fe(0) was used to simulate the fuel debris because it has been estimated that they account for more than 60 wt%. By exposing the UO₂/Fe(0) to microorganisms in a medium for some days, the dissolution phenomena of U and Fe were observed. It was found that microorganisms significantly accelerated the dissolution of U and Fe from fuel debris into the medium. The dissolution ratio of U and Fe was not in the same order of magnitude, i.e., heterogeneous dissolution. These results suggest that microorganisms can lead to the disintegration of nuclear fuel debris.