Here’s a quick roundup of the day’s news from the Fukushima nuclear reactors in Japan.
In its daily briefing, the International Atomic Energy Agency (IAEA) said that water is still being pumped into the reactors to keep overheated fuel rods cool.
Iodine-131 and cesium-137 is still being deposited in at least 8 prefectures around Japan. In four prefectures, levels of those isotopes in green leafy vegetables exceed safe levels.
Kyodo News reports that the Japanese Ministry of Health, Labor and Welfare said 510 Bq/kg of radioactive cesium was detected in beef from a farm 70km away from the Fukushima nuclear plant. The legal radiation limit in food is 500 Bq/kg. UPDATE: this finding was subsequently retracted.
Austria’s weather service, the Central Institute for Meteorology and Geodynamics in Vienna, predicted that a potential radioactive cloud could be transported by weather patterns to inland areas north of the reactor today.
World Nuclear News reports that four more pumping trucks are on their way to Fukushima, to continue efforts to bathe fuel rods in seawater.
The Institute for Science and International Security, a non-profit based in Washington DC, is arguing that the Fukushima disaster should be upgraded to a category six on the seven point scale of nuclear accidents. The Japanese Nuclear and Industrial Safety Agency still classes the accident as a category five incident.
As ISIS points out:
The Japanese authority’s rating of level 5 indicates that in their opinion, the release of radiation is limited, and only some planned countermeasures need to be implemented. However, unlike the accident at Three Mile Island, the Fukushima Daiichi situation involves three reactors as well as on-site spent fuel ponds with exposed fuel rods, instead of only one reactor core. The amount of radioactivity released, particularly in the first week after the accident, was significant. It was perhaps even worse than initially assumed because much of the radiation released in the days immediately following the tsunami may not have been detected because of inoperative or limited radiation monitoring equipment at the site. Additionally, much radiation has been released into water on-site and into the sea. This contamination will likely have significant environmental implications and require the implementation of additional countermeasures.
Finally, the Guardian reports:
Tepco said it was considering using “jumpers”, or workers who enter highly radioactive reactors to perform short but essential tasks, then evacuate quickly to avoid prolonged exposure to radiation.
This sounds bleakly reminiscent of Chernobyl’s ‘biorobots’ – workers sent into the area around reactor 4 in the days after the accident there in 1986. Their task was to spend just minutes at a time shovelling highly radioactive debris back inside the broken reactor vessel, before exposure to massive radiation doses forced them to retreat.