An Investigation of microbial effect as biofilm formation on radionuclide migration

Yoshikawa, Hideki; Kawakita, Masakazu*; Fujiwara, Kazuhiro*; Sato, Tomofumi; Asano, Takahiro*; Sasaki, Yoshito 

Since it was suggested that the microbes have ability to generate their biofilm in deep underground condition, we examined the effects of biofilm on radionuclide migration scenario. To estimate the effect on matrix diffusion, through diffusion experiment for a biofilm of Desulfovivrio desullfuricans were performed. The effective diffusion coefficient of the biofilm was 10 m/s order which was about ten times smaller than that in free water. It is suggesting that the microbes and biofilm will not interfere with matrix diffusion as a retardation of radionuclide in rock.