The civil nuclear emergency in Japan took a turn on Tuesday, with the authorities announcing the detection of “traces of plutonium” in samples of soil at the quake-and-tsunami-hit Fukushima Daiichi atomic energy plant.
“Plutonium, believed to have been derived from the nuclear fuel [at the plant], has been detected …. If you look at the concentration, it is indeed plutonium which is originating from the reactor. So, if there has been some melting of the [nuclear] fuel, we are working to the fullest to overcome the situation,” said Japan's Chief Cabinet Secretary Yukio Edano in Tokyo.
“The concentration of plutonium now detected is in comparison to the fallout in the atmosphere which is considered to be the effect of nuclear experiments [conducted] in other corners of the world. However, the make-up of the plutonium that has been detected [now] seems to be different from what is detected in the fallout generally. Therefore, this seems to be the result of the nuclear power station accident.” So, the “monitoring of plutonium at the periphery of the plant will be strengthened”, said Mr. Edano.
The IAEA said: “Traces of plutonium are not uncommon in soil, because they were deposited worldwide during the atmospheric nuclear testing era” which ended when such weapon-tests were banned.
However, the IAEA emphasised that “the isotopic composition of the plutonium found at [the Fukushima plant] suggests that the material came from the reactor site”. Yet, “the quantity of plutonium does not exceed the background levels tracked by Japan's ministry over the past 30 years.”
IAEA Director-General Yukiya Amano emphasised “the crisis at the Fukushima Daiichi Plant has still not been overcome and it will take some time to stabilise the reactors”. On the overall radiation crisis in Japan, Mr. Amano said: “For now, radioactivity in the environment, foodstuffs and water —including the sea — is a matter of concern in the vicinity of the Fukushima plant and beyond.”