Main points
- A specific bacterial community has formed in the sub-reactor rooms of the Fukushima Daiichi nuclear power plant, which can affect the condition of damaged structures.
- About seventy percent of the bacteria detected are associated with metal corrosion processes, which can accelerate the destruction of steel and other structures.
Water from the Fukushima nuclear power plant hides bacteria capable of destroying metal / Collage by Channel 24
Water with high levels of radioactive contamination was stored in the sub-reactor rooms of the Fukushima Daiichi nuclear power plant for almost a decade. A new study has shown that even under such conditions, a specific bacterial community has formed that can have a direct impact on the condition of damaged structures.
What lives in the water from the reactor?
After the 2011 Fukushima Daiichi nuclear power plant accident, seawater that entered the reactor buildings during the tsunami remained in the so-called torus room – an underground part of the reactor designed to release steam. This water remained there for about nine years, containing a high concentration of radioactive cesium, writes Popular Mechanics.
Japanese scientists have conducted the first detailed analysis of microorganisms directly from inside the reactor building. To do this, back in 2020, two water samples were taken from different depths – from the middle layer and from the very bottom, where a brown sediment rich in iron had accumulated.
The results showed an unexpectedly low diversity of bacteria. Only eight genera of bacteria were found in the top layer of water, and thirty-two in the bottom layer.
By comparison, forty to ninety-five genera are typically recorded in uncontaminated seawater and freshwater near Fukushima.
More than ninety-six percent of all microorganisms identified belonged to the group Proteobacteria. Two genera dominated: Limnobacter, which is capable of oxidizing sulfur compounds, and Brevirhabdus, which is associated with manganese oxidation. Both types of bacteria are often found in biofilms and man-made environments.
A key finding of the study, published in Applied and Environmental Microbiology, is that approximately 70 percent of the bacteria identified have a direct or indirect link to metal corrosion processes. These microorganisms can accelerate the destruction of steel and other structures by forming acids, oxides or electrochemical potentials on the metal surface.
However, the expected “super-resistant” bacteria to radiation were almost not found. The proportion of known radioresistant genera was less than one percent. Additional experiments showed that the most common bacterium, Limnobacter thiooxidans, has a level of radiation resistance similar to ordinary bacteria, and not extremophiles.
Main conclusions
The researchers concluded that the microbial community in the torus chamber was a mixture of marine bacteria brought in by the tsunami and microorganisms typical of biofilms, sludge, and industrial wastewater. This combination makes them potentially dangerous for long-term storage of damaged nuclear facilities.
Researchers emphasize that during the multi-year dismantling of nuclear power plants, controlling microorganisms may be no less important than controlling radiation, as microbiological corrosion can accelerate the degradation of infrastructure.