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Fukushima’s “red alert” sparks questions about rating system

ines.jpgEvery day the International Atomic Energy Agency (IAEA) has been putting out reports that describe the situation at Fukushima as ‘serious, with signs of recovery’. It seems like a very appropriate way of putting it: there are indeed some positive signs, but the situation leaves much to be desired.

On the plus side, workers have finally managed to start pumping water out of the Unit 2 building, which has been home to some of the worst-contaminated water on site. The water is going into the “condenser”, a part of the now-defunct reactor’s cooling circuit that will (for now at least) act as a storage pool for the water. Water is still being pumped into the reactors, while nitrogen is being injected into the unit 1 reactor, which should help prevent a further hydrogen explosion. Radiation levels outside the plant continue to fall, and yesterday Tokyo reached pre-accident levels, according to Japanese government data.

On the minus side, radioactive contamination in the sea continues to be a serious issue. Kyodo News reports that a sand lance caught off the coast of Fukushima had 12,500 becquerels of caesium per kilogram, 25 times the legal limit. Radiation in the marine environment is likey to be a problem for some time to come, and scientists are already gearing up to study its effects.

Moreover, the Tokyo Electric Power Company (TEPCO) has been reporting a temperature of around 90 C in the spent fuel pool of the unit 4 reactor, which previously caught fire on 15 March, according to NHK, the Japanese broadcaster. That’s far above what it should be, and has prompted the company to pump more water into the spent fuel pool. The report says samples taken from the pool indicate fuel damage, but it’s a little unclear whether any of it is new.

Given that the status quo remains the same, it comes as no surprise that many are questioning why the Japanese government and the IAEA decided to upgrade Fukushima from a 5 to a 7 on the International Nuclear and Radiological Events Scale (INES) yesterday. Many in the mainstream press erroneously, but understandably, believed the change was the result of new events at the reactor, and many more remain confused about how this relates Fukushima to Chernobyl (you can read my initial take on that in yesterday’s post).

One of the most interesting pieces I’ve seen today is from the Christian Science Monitor, which argues that the scale is the demon spawn of an unholy marriage between diplomats and engineers. OK, I admit it doesn’t use those words, but it does say that the INES fails to tell people anything about the danger level at Fukushima, and has only instilled unnecessary panic. Given the confusing press coverage that was triggered by the change in rating, I’m inclined to agree.

For full coverage of the Fukushima disaster, go to Nature’s news special.

For a selection of our coverage in Japanese, see Nature Asia Pacific.

Credit: IAEA


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