Japan’s damaged nuclear plant in Fukushima has been emitting radioactive iodine and caesium at levels approaching those seen in the aftermath of the Chernobyl accident in 1986. Austrian researchers have used a worldwide network of radiation detectors – designed to spot clandestine nuclear bomb tests – to show that iodine-131 is being released at daily levels 73 per cent of those seen after the 1986 disaster. The daily amount of caesium-137 released from Fukushima Daiichi is around 60 per cent of the amount released from Chernobyl.
The difference between this accident and Chernobyl, they say, is that at Chernobyl a huge fire released large amounts of many radioactive materials, including fuel particles, in smoke. At Fukushima Daiichi, only the volatile elements, such as iodine and caesium, are bubbling off the damaged fuel. But these substances could nevertheless pose a significant health risk outside the plant.
Highlights of the NewScientist article:
•Daily iodine-131 is being released at daily levels 73% of Chernobyl levels. •Daily caesium-137 released from Fukushima Daiichi is around 60% of Chernobyl levels. •Chernobyl only burned for 10 days. Japan nuclear reactors are still emitting nuclear radioactive fallout. •Release of iodine-131 from Japan’s nuclear reactors is estimated at 1.2 to 1.3 × 1017 becquerels per day compared to the Chernobyl put out 1.76 × 1018 becquerels of iodine-131 released from Chernobyl for 10 days. It is not yet clear how long emissions from the Japanese plant will continue. •Caesium-137 emissions are on the same order of magnitude as at Chernobyl. The Sacramento readings suggest it has emitted 5 × 1015 becquerels of caesium-137 per day; Chernobyl put out 8.5 × 1016 in total – around 70 per cent more per day. •Fukushima plant has around 1760 tonnes of fresh and used nuclear fuel on site, and an unknown amount has been damaged. The Chernobyl reactor had only 180 tonnes. •The amount being released is consistent with local and soil radiation levels, because unlike in Chernobyl, Japan’s nuclear radiation is being blown out over the Pacific toward the United States west coast. •During Chernobyl Caesium and Iodine radiation were the most dangerous forms of radiation because they were carried farther and wider by the winds than the other types of radiation. Additionally the human body readily absorbs iodine radiation. •Iodine radiation has a half-life of 8 days in the human body and while cesium remains in the body for 30 years and takes 10 to 100 days to excrete half of what is absorbed. •Children who ingest iodine-131 can develop thyroid cancer 10 or more years later. •A study published in the US last week shows iodine is still causing cancer around at undiminished rates with Ukraine, Belarus and Russia being the most affected regions •Because Caesium-137 stays in the environment for so long researchers are divided over the health consequences of low dosage exposures. Nuclear Radioactive Yellow rain falls on Tokyo