Part 2 of 2 Parts (Please read Part 1 first)
Tom Scott is a professor of nuclear materials at the University of Bristol. His team works with the Japan Atomic Energy Agency on the Fukushima cleanup. They found slightly larger radioactive beads near the plant. Tom Scott’s group has theorized that each reactor may have formed a specific combination of particles in the beads created when they were destroyed. This would help scientists understand exactly how the meltdowns were similar and different.
Scott’s group is using information from its study of these radioactive glass beads to create and refine maps of contamination and radiation risk around the ruins of the Fukushima plant. The cesium contaminated beads were not distributed as widely by the disaster as other forms of cesium in the radioactive plume which were carried around the world. They are mainly found in the contamination zone establish around the Fukushima plant. Some beads were also found in an air filter in Tokyo which is over one hundred and fifty miles from the Fukushima plant.
Researchers found that while less cesium fell on Tokyo than near the Fukushima site, more of the Tokyo cesium was in the form of the glass beads. These research finding were scheduled to be published in 2017 in Scientific Reports but publication of the report was delayed because a group that provided an air filter to the researchers were unhappy with its mention in the report.
There was no evidence of wrong doing and the conclusions of the report were not questioned. After two years of arguments about the rights to use the information about the air filter, the journal dropped its offer to publish the study. Fortunately, a description of the key findings of the unpublished study was eventually published.
A deep understanding of the nature of the glass beads, how they moved and how far they spread is critical to assessing any potential health and environmental risks they may pose. Researchers are trying to determine how long it may take for such beads to dissolve in water. It is known that they will disintegrate very slowly, releasing their radioactive contents like a time release capsule releases medication. If their disintegration takes long enough, the radioactive materials they contain may decay before they are released. It turns out that there is little reason for serious concern with respect to the cesium in the beads.
Some of the radioactive glass bead contain uranium and may contain plutonium. Both of these elements are chemically toxic and could be a danger to health. Particles with uranium have only been found near the ruins of the power plant. It is not clear how much a threat these particular beads constitute.
Researchers have found that these radioactive glass beads tend to accumulate at particular points on the Japanese landscape such as river bends or in rain drain downspouts after being washed off roofs by rain. This fact could result in the creation of radioactive hotspots. There is also concern that some of these particles might become airborne again and spread further. Some research has indicated that these beads quickly become buried in soil and are unlikely to become airborne.
A clear understanding of the nature and behavior of these radioactive glass bead will assist in decontamination work around Fukushima. So far, top layers of soil are being removed and buildings are being pressure washed. Research on these radioactive beads continues today.