Ball of caesium found in Fukushima river

As we approach the 7th anniversary of the 2011 disasters in northern Japan, reports are coming through of a ball of caesium that has been found in a Fukushima river.

Caesium is one of the radionuclides that was emitted from the Fukushima Daiichi Nuclear Power Plant following the 2011 nuclear disaster. 

According to broadcaster TBS the ball of caesium was found by a team of Tokyo University researchers in a river about 5 km north of the plant, which experienced multiple reactor meltdowns and explosions following massive earthquakes and tsunami that hit the region in March 2011.

Experiments have shown that exposure to radiation from caesium can result in malignant tumors and shortening of life. 

The broadcaster reports that the find of the small glass-like ball of matter was made last year, but has only just been made public.

In the aftermath of the nuclear disaster a huge quality of radioactive caesium was one of a number of poisonous radionuclides that were emitted from the plant, causing the evacuation  of some 160,000 residents. This caesium, however, was said to easily dissolve in water.

The recent find indicates that there are other clumps of the radionuclide that are insoluble in water. It is believed that this means they will remain in the atmosphere considerably longer.

The TBS report stated that this is the first time such caesium balls have been found following the nuclear accident in Fukushima Prefecture, which is located approximately 250 km north of Tokyo.

However, it is not the first solid material thought to have been emitted from the plant that has been found nearby. A recent study by a team of international scientists reported that among other non-gaseous materials emitted from the plant following the March 2011 disasters  were uranium, which has a half-life of 4.5 billion years.

​A type of radioactive caesium called Caesium-137 has a much shorter lifespan of roughly 30 years, but its high fission yield means it is abundant even in spent nuclear fuel and can be harmful to human health for many years.

According to one Stanford University report: "Its half-life of about 30 years is long enough that objects and regions contaminated by cesium-137 remain dangerous to humans for a generation or more, but it is short enough to ensure that even relatively small quantities of cesium-137 release dangerous doses of radiation."

The recent find is reportedly only a small sample and not believed to be a major health hazard to the surrounding environment. However, experts remain unsure how it made its way into the river and remaining in an undissolved state."One high possibility is that caesium balls are carried by the river and into the sea," commented University of Tokyo Professor Yoshio Takahashi.

Further research will be carried out to understand the exact composition of the matter. However, it is believed that this is the first time for such a find to be made in the aftermath of a nuclear disaster and could provide further clarification as to the exact nature of the Fukushima disaster.