Sentaro Takahashi, a professor at Kyoto University’s Research Reactor Institute, said an announcement by Japan’s nuclear safety agency that 130,000 tera becquerels of iodine 131 has been released from the Fukushima Dai-Ichi power plant since the March 11 earthquake was within estimates and “shouldn’t cause panic.” The disclosure came as the agency today raised the incident level of the nuclear accident to 7 from 5, on par with Chernobyl.
On today’s number:
“The government’s announcement would be the total radioactivity as converted for iodine 131. We already last month estimated that emissions from the nuclear plant may reach that level, so it’s not a surprise. The number shouldn’t cause panic.”
On cesium levels:
“The level of radioactive iodine has been decreasing with its natural decay. More attention should be paid to radioactive cesium, which can cause cancer in almost every part of the body. Radioactive iodine only causes thyroid cancer. It’s possible the amount of cesium released is about one-twentieth of the iodine emitted.
On future risks:
“There is a lot of radioactive material still inside the plant. I think 130,000 tera becquerels is only just several percentage points of the total. We can’t say what’s going to happen to the reactors. If there’s another hydrogen explosion like the one in March, it may send radioactive materials as far away as Tokyo (about 220 kilometers away).
“The government should assess the impact from inhaling dust that was sent from the earlier explosion and should be active in directing people as to which areas are safe for activities like rice planting, livestock farming and growing mountain vegetables.
“Precautions recommended by the government for the evacuation area, including covering up with clothing and using an umbrella in the rain, could also be applied to areas farther from the plant, depending on measurements of radioactive dust.”