A mutated butterfly
Japanese authorities may have cleared out the human population around the ruined Fukushima Daiichi nuclear power plant, but the native wildlife is still there. A month after the accident, scientists who study the pale grass blue butterfly collected 144 near the plant, and found that they had begun to show mutations like dented eyes and deformed wings.
Last year, after the Fukushima Daiichi nuclear meltdown, the Japanese parliament requested an independent report on the causes of the disaster. The 10 members of the report committee were not connected with the nuclear industry or the government bureaucracy and included distinguished scientists, doctors, lawyers, and even a science journalist.
The resulting report, released this week, is damning. It was already more or less known that the disaster was at least in part caused by negligence on the part of the utility company TEPCO and the failure of government agents to enforce safety regulation, but the committee has had access to all of the documents and resources involved, and they write that even given the unusual force of the tsunami that struck the plant, had regulations been enforced, the nuclear meltdown would not have happened:
The TEPCO Fukushima Nuclear Power Plant accident was the result of collusion between the government, the regulators, and TEPCO, and the lack of governance by said parties. They effectively betrayed the nation’s right to be safe from nuclear accidents. Therefore, we conclude that the accident was clearly “manmade.”
Two new reports on radiation doses received by workers and civilians near the Fukushima Daiichi nuclear meltdown last year indicate that there will be very little, if any, increase in their cancer risk.
The reports, put together by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and the World Health Organization and slated to be presented in Vienna this week, draw on all the available data about the crisis and include detailed information about exposure, according to Nature News, which has the exclusive:
[UNSCEAR] scoured anonymized medical data for 20,115 workers and contractors employed by the Tokyo Electric Power Company, which runs the plant. It found that 146 employees and 21 contractors received a dose of more than 100 millisieverts (mSv), the level at which there is an acknowledged slight increase in cancer risk. Six workers received more than the 250 mSv allowed by Japanese law for front-line emergency workers, and two operators in the control rooms for reactor units 3 and 4 received doses above 600 mSv, because they had not taken potassium iodide tablets to help prevent their bodies from absorbing radioactive iodine-131. So far, neither operator seems to have suffered ill effects as a result of their exposure.
The levels of exposure for civilians was much, much smaller, and neither employees nor civilians are expected to have statistically higher rates of cancer. But not everyone Nature News spoke to was totally at ease with the reports; after the way the Japanese government and energy utilities handled the disaster, many people are extremely distrustful of official estimates claiming that there is little risk:
Tatsuhiko Kodama, head of the radioisotope centre at the University of Tokyo and an outspoken critic of the government, questions the reports’ value. “I think international organizations should stop making hasty reports based on very short visits to Japan that don’t allow them to see what is happening locally,” he says.
How do you do to measure radiation levels in the hard-to-reach forests near Japan’s Fukushima Daiichi plant? Why, fit wild monkeys with radiation sensors, of course! Researcher Takayuki Takahashi tells CNN that his team plans to fit three monkeys in early 2012 with collars that measure radiation, as well as GPS units that record location and distance from the ground. The researchers plan to leave the monitors in place for about a month, before detaching them via remote control and picking up them up to retrieve their stored data.
The nuclear disaster at the Fukushima Daiichi power plant this spring may have released twice as much radiation into the atmosphere as the Japanese government estimated, a new preliminary study says. While the government estimates relied mostly on data from monitoring stations in Japan, the European research team behind the new report looked at radioactivity data from stations scattered across the globe. This wider approach factored in the large amounts of radioactivity that were carried out over the Pacific Ocean, which the official tallies didn’t.
Clean-up teams at Fukushima struggled to control the melting fuel rods.
What’s the News: After the disastrous March 11 earthquake and tsunami in Japan, the world waited, mostly in vain, for details about the events that led to meltdown at the Fukushima Daiichi nuclear plant. Since then, scientists across the Pacific in California have been watching the dials of instruments that detect radioactive molecules, to see what might come across on the winds.
This week, scientists at Scripps published their readings of radioactive sulfur collected in the atmosphere in San Diego after the meltdown. These allowed them to extrapolate backwards to learn roughly how many neutrons were shed by the melting cores as workers desperately doused them in sea water, helping scientists understand the damage undergone by the cores and demonstrating the kind of remote science that may be required to help understand the events that led to meltdown.
What’s the News: Japan raised its assessment of the severely damaged Fukushima Daiichi nuclear power plant to Level 7, “Major Accident,” the highest ranking on the International Atomic Energy Agency’s International Nuclear and Radiological Event Scale. The explosion at Chernobyl in 1986 is the only other nuclear accident to be ranked at Level 7. Both accidents were extremely severe, the two largest nuclear power accidents ever—but there are some big, important differences between them.
Reactor 3 at the Fukushima Daiichi plant, on March 24
What’s the News: A non-peer-reviewed study (pdf) publicized last week by radioactivity-detection expert Ferenc Dalnoki-Veress suggests that nuclear fission reactions continued at Japan’s Fukushima nuclear power station well after the plant’s operators had allegedly shut down the reactors there. The paper says there may be what are called “localized criticalities” have occurred in the plutonium and uranium left in the reactors—little pockets of fuel that have gone critical, propagating the nuclear chain reaction and generating potentially harmful radiation. The existence of criticalities is controversial: some researchers say there are certainly none; Dalnoki-Veress himself says it’s only a possibility.