Fukushima Radiation Zone

After maintaining a parsly 20-km radiation zone for the past month, despite the urgings of many experts from around the world (including the IAEA), the Japanese government is finally admitting publicly that leaks from the plant pose dangers to people located in vicinities  far closer than had been previously conceded. No decision on exactly how large the expanded evacuation area will be has been announced yet, but local media in Japan is reporting that the zone will be extended to 30km.

This is still insufficient, if the word of international nuclear experts can be believed. In fact, such an evacuation zone would fly in the face of the government’s own calculations regarding how much radiation people are being exposed to in the area around Fukushima, and is inconsistent with their recent raising of the INES level 7 – the highest rating possible.

According to preliminary data released by the Japanese government, the cumulative amount of external exposure to radiation in areas extending more than 60 kilometers northwest of the plant already exceeds the yearly limit of 1 millisievert. In the face of these numbers, it behooves the government to expand the zone to at least 60km.

As we have been reporting for the past month, you cannot trust a thing that comes out of any government, let alone this one. The Japanese government has proven that it is completely untrustworthy, and I feel really awful for all those people who have and continue to make their personal health and safety decisions based on official recommendations.

With the fallout in Japan continuing into its forth week, people are starting to become anxious about the potential for food and water contamination, not only within Japan but elsewhere as well. Bowing to public pressure, the government of Japan finally set a legal limit today for the permitted level of radioactive iodine in seafood. The limit the Japanese government has picked for iodine-131 contamination in marine products such as fish and shellfish is 2,000 bequerels per kilogram, according to Chief Cabinet Secretary Yukio Edano.

The government of South Korea has also become increasingly vocal about the safety of not only food products coming out of Japan, but of the contamination of sea water in the pacific as well, in light of the fact that so much of the water being pumped in to cool the reactors is being dumped right back into the ocean.

And concerns are mounting across the pacific as well. A rooftop water monitoring program managed by UC Berkeley’s Department of Nuclear Engineering detected substantial spikes in rain-borne iodine-131 during torrential downpours a week ago, according to an article published by the Bay Citizen. The levels measured by the department exceeded federal drinking water thresholds, known as maximum containment levels (MCL), by as much as 181 times. This water is also being ingested by cows that are then passing it through their milk, where above normal levels of iodine-131 have already been measured.

Although the half-life for radioactive iodine is only 8 days (meaning that it dissipates quickly and does not remain in the environment for long, as is the case with plutonium and uranium) it’s effects on the human body can be devastating. One of the most common cancers associated with Hiroshima, Nagasaki, and Chernobyl was thyroid cancer, which can be caused by excessive exposure to iodine-131. Eating kelp and other sea vegetables that are rich in iodine are a great and natural way to protect yourself against low levels of exposure to the radioactive isotope, but given the fact that so much of the contamination is taking place in the pacific ocean, it is hard to know if what you are eating is actually helping or hurting you.

The important part of this story that was not really covered by the reporter but that was mentioned by the anchor is the “blue flash of light.” This is associated with an accidental increase of nuclear chain reactions in fissile material, which can lead to a surge in neutron radiation. It is what is known as a “criticality accident.”

This is not the first time we have heard of this news. In fact, over a week ago, Kyodo news in Japan reported that a Neutron beam had been observed 13 times at Fukushima:

Tokyo Electric Power Co. said Wednesday it has observed a neutron beam, a kind of radioactive ray, 13 times on the premises of the Fukushima Daiichi nuclear plant after it was crippled by the massive March 11 quake-tsunami disaster.

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant’s No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level.

The utility firm said it will measure uranium and plutonium, which could emit a neutron beam, as well.

In the 1999 criticality accident at a nuclear fuel processing plant run by JCO Co. in Tokaimura, Ibaraki Prefecture, uranium broke apart continually in nuclear fission, causing a massive amount of neutron beams.

In the latest case at the Fukushima Daiichi nuclear plant, such a criticality accident has yet to happen.

But the measured neutron beam may be evidence that uranium and plutonium leaked from the plant’s nuclear reactors and spent nuclear fuels have discharged a small amount of neutron beams through nuclear fission.