Radioactive material from the Fukushima Daiichi nuclear plant in Japan has been detected nationwide in Korea in very small amounts. On Monday, radioactive iodine was picked up by all 12 detecting centers across the country, including Seoul.

“We have found miniscule amounts of radioactive iodine in all 12 regional detection areas from aerial samples, and the detection center in Chuncheon picked up radioactive cesium,” said Yun Choul-ho, the head of the Korea Institute of Nuclear Safety, during a press briefing yesterday.

The institute detected the radiation Monday morning and announced the results yesterday, as it takes about 22 hours to fully analyze the materials found, it said.

Korea has state-of-the-art technology when it comes to radiation detection, which was installed originally “not to detect environmental radiation,” Yun said, “but for underground nuclear tests, very small amounts of radioactive isotopes and xenon.”

	A radiation detector at the Korea Institute of Nuclear Safety in Haengdang, Seongdong District, indicates levels of 11.2 microroentgens per hour, the equivalent of 112 nanosieverts, within the normal 110 to 210 nanosieverts range. By Kim Do-hoon

Yun said the radiation detection technology was of a “military” nature. Xenon detected by the centers in October 2006 was used as supporting evidence that North Korea had tested a nuclear device that month.

“Because of this, our [technological] ability is among the highest in the world,” Yun said. 

According to Yun, radiation levels for iodine found in the country varied from as low as 0.049 millibecquerels to 0.356 millibecquerels. The KINS chief did not say which area had the highest radiation level.

“At this rate, these levels are 1/200,000 or 1/30,000 of 1 millisievert that Koreans are exposed to annually and have basically no effect on the human body,” said Yun.

Workers at nuclear plants and other occupations that involve handling nuclear material are subject to an annual limit of 20 millisieverts a year.

“On special occasions it can be raised to 50 millisieverts a year, but there is also a cap of 100 millisieverts for five years,” Yun said.

Kim Seung-dae, a spokesman for the Korea Meteorological Administration, said that the iodine and cesium were thought to have traveled the same way xenon found in Gangwon had: on winds from Japan that traveled north to the Arctic and then south through Siberia to the Korean Peninsula.

Yun said that cesium was found only in the Chuncheon area. Cesium is the heaviest of the three materials found and can’t drift as far.

“The radiation is coming now, but these are very miniscule amounts, and the same thing is happening all over the world,” Yun said. 

“With the amounts detected in our country, I will tell you there is no need for change, not even in the slightest, in your lives,” Yun said.

In Japan, however, Prime Minister Naoto Kan is being pressured to expand the evacuation area in Fukushima Prefecture after plutonium was found in the soil at the stricken power plant yesterday, according to Tokyo Electric Power Co. The highly carcinogenic material, found in five different locations at the plant, may have come from spent fuel rods stored in the reactors at the site, said Tepco. 

Japan’s Nuclear and Industrial Safety Agency said that though the plutonium levels were not harmful to humans, the material found on the site could signify a breach in the containment vessel at one or more reactors.

Japan’s chief government spokesman Yukio Edano said early yesterday that the discovery of plutonium at the plant was possible evidence that some of the fuel rods had partially melted down and called it a “very serious situation.”

After trying for days to cool the reactors at the plant, Tepco is now making massive efforts to keep the turbine rooms and pipes from overflowing with contaminated water. 

Seawater pumped into the reactor buildings is now radioactive after having come into contact with fuel rods.


By Christine Kim [christine.kim@joongang.co.kr]