C. Rivasseau, D. de Gouvion Saint Cyr, A. Atteia, M. Gromova, E. Farhi
Commissariat à l'Energie Atomique, France
pp. 246 - 249
Keywords: biotechnology, microalga, nuclear industry, environmental water, radionuclide, decontamination
Nuclear energy technologies generate radioactive and chemically toxic compounds including mainly carbon-14 and radioactive metals. Treatment processes rely on physico-chemical methods, which, though efficient and robust, do not completely remove carbon-14 and are not adapted to large environmental volumes. Alternative technologies are needed to reduce radioactive releases in aqueous effluents or to clean-up accidentally contaminated water. Biological remediation technologies may constitute an interesting alternative. We recently isolated a new microalga from a nuclear facility, Coccomyxa actinabiotis, which withstands huge ionizing radiation doses, up to 20,000 Gy. This microalga very efficiently and rapidly accumulates most of the metallic radionuclides contained in nuclear effluents including 238U, 137Cs, 110mAg, 60Co, 54Mn and 65Zn with decontamination rates above 90%. It decontaminates more than 85% of carbon-14 in a few hours. This alga is an excellent candidate for new biotechnology methods. The process feasibility was demonstrated at real-scale for in situ decontamination and pilote-scale for remote water treatment. These algae-based methods could be used inside nuclear facilities, where they would complement or replace conventional methods and reduce the volume of radioactive waste, at the exit point from nuclear facilities to reduce radioactive emissions into the environment, or for the decontamination of accidentally polluted water.