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Source: TEPCO Unveils Plan To Deal With Fukushima Crisis

Source: Robots Enter Fukushima Reactor Building

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.

What’s Similar:

• A Level 7 accident is a “major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures,” according to the IAEA. Both plants clearly meet these criteria: Fukushima will require an extensive clean-up effort, and the international community is still working to make the area near Chernobyl safe.
• The situation at Fukushima also qualifies as Level 7 by the numbers. Japanese officials estimate the reactors have released between 370,000 and 630,000 terabecquerels (or, between 370 and 630 quadrillion becquerels) of radioactive material, far more than the equivalent of tens of thousands of terabequerels iodine-131 that is the cutoff for a Level 7 accident.
• A spokesman for Japan’s Industrial and Nuclear Safety agency said in a press conference that the Fukushima reactors are still releasing radiation, and total levels could eventually exceed those released by Chernobyl.

What’s Different:

• The Fukushima reactors have containment structures, an extra safety layer that has helped limit the spread of radioactivity; Chernobyl had no containment structures.
• The two accidents happened under very different conditions: Fukushima’s reactors shut down after the March earthquake, then overheated as a result of later cooling system malfunctions. The reactor at Chernobyl, on the other hand, was still running when it exploded, causing a much larger release of heat.
• The accident at Chernobyl’s reactor was a full core meltdown, while the accident at Fukushima was a possible partial meltdown.
• The accident at Chernobyl unfolded much more quickly. The explosion there spewed debris and radioactive materials over a wide distance, and sparked a fire that burned for days. The surroundings had to be evacuated within hours. At Fukushima, the reactors have been releasing radiation at a much slower rate.
• To date, the Fukushima plant has released much less radiation: only one-tenth as much as Chernobyl, according to Japan’s Nuclear and Industrial Safety Agency.
• Dr. Robert Peter Gale, leader of the medical team that responded to the Chernobyl accident, estimated that, if the situation doesn’t worsen, radiation from the Fukushima accident would cause fewer excess cancer cases an Chernobyl did. Chernobyl resulted in 6,000 additional cases of thyroid cancer, says Gale, while Fukushima would lead to few additional thyroid cancer cases, and 200 to 1,500 total additional cancer cases over the next half-century.
• Precautions taken by Japan—including monitoring of food and water supplies and timely distribution of potassium iodide tablets—may lessen the severity of human health effects of the Fukushima accident, according to World Nuclear News.

What’s the Context:

• The raising of Fukushima to a Level 7 accident doesn’t mean that the situation at Fukushima is worsening; in fact, the reactors’ condition seems increasingly stable.

Source: Fukushima and Chernobyl: Same Level on Disaster Scale; Very Different Disasters

Source: Fukushima: What Happened and What Needs To Be Done

What’s the News: With Congress yet to pass a budget, the country is facing a government shutdown unless lawmakers reach an agreement by midnight tonight. In addition to shuttering many government offices, the shutdown would likely cause present serious difficulties for federal government-funded research.

Difficulties Such As…

• A wide range of government-backed research—from biologists studying stem cell lines to oceanographers gleaning climate information from maritime sensors—wouldn’t be funded during the shutdown. The delay will ruin some experiments, and leave others with large gaps in their data. One stem cell researcher estimated the shutdown would cost his lab $10,000 per person, and told NatureNews, “One day is tolerable, three days is a killer.”
• Scientists working on NASA’s IceBridge project—a study using special aircraft to survey ice in Greenland—would get on their planes and (dejectedly, one assumes) head back to the States.
• Clinical trials at the National Institutes of Health would be stopped or, at best, slowed. The NIH Clinical Center has an estimated 640 trials, 285 of which are for people suffering from cancer—but those studies would stop taking all new patients, including one child flown to the NIH Sunday on a Miles for Kids Program to take part in a trial.
• Overall, about 10% of the $31 billion NIH budget goes to research within the institutes (as opposed to funding research at other institutions, like universities), meaning a shutdown would leave most of the NIH’s hundreds of labs and thousands of scientists without funding. “The last time we had a government shut-down, they told us that at the NIH the scientists doing the research on cancer and cures had to go home,” Senator John Kerry said today. “The only person deemed essential was the guy who came in to feed the lab rats so they’d still be alive when the government came to its senses.”
• Not all research programs would be interrupted, however. Workers monitoring the National Oceanic and Atmospheric Administration’s weather satellites would stay on the job, as would nine scientists monitoring radiation drifting from Japan’s Fukushima Daiichi nuclear power plant towards the US, and researchers working on some long-term climate studies.
• Toxic waste clean-up projects were stopped at 609 sites during the last government shutdown, an indicator that such projects might be stopped again.
• Upgrades to GPS would be pushed back, since the government won’t able to pay for them as scheduled. Lockheed Martin has a $1.4 billion contract to make 30 new-and-improved Block III satellites, for instance—but to get the satellites, the government needs to provide that $1.4 billion. This might be an inconvenience in the short term, but could have major impacts on GPS availability and quality down the road.
• Many federal websites may go dark. (Select sites would stay online, such as the IRS, since taxes are still due April 18.) A memo from the White House Office of Budget and Management said “The mere benefit of continued access by the public to information about the agency’s activities would not warrant” the expense of keeping the sites running. In addition, thousands of IT professionals would stop coming to work, potentially leaving government computer systems more vulnerable to attack.
• The Endeavor space shuttle launch set for April 29 would be delayed. This was set to be the shuttle’s last launch. (We won’t comment on any symbolism there…)

Image: Wikimedia Commons / Albertyanks

Source: What Would a Government Shutdown Mean for Science, Medicine, & Engineering?

Source: 30 Years To Clean Up Fukushima Dai-Ichi

Source: Fukushima Radiation Levels High, But Leak Plugged

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.

How the Heck:

• Over three days beginning March 13—two days after the earthquake and resulting tsunami—Tokyo Electric Power Company detected a neutron beam, a stream of radioactive particles that could be evidence of continued chain-reaction fission.
• The company observed the neutron beam 13 times, about a mile away from the reactors. The beam itself doesn’t pose a health risk, with radiation levels between 0.01 and 0.02 microsieverts per hour. (You’d get about as much radiation exposure from eating one-tenth to one-fifth of a banana.)
• After seawater was used to cool the reactors, the water had unusually high levels of chlorine-38, a radioactive isotope of chlorine. Chlorine-38 isn’t much of a radiation risk; its half-life is 37 minutes, so it disappears quickly. What’s strange is that chlorine-38 is formed when an atom of chlorine-37 (the stable, common chlorine isotope) absorbs a neutron. High levels of chlorine-38 mean there were lots of neutrons around, raising the possibility that melted bits of fuel may have gone critical.

What’s the Context:

• An explosion at the Fukushima nuclear plant came shortly after the earthquake and tsunami hit Japan. Workers are still pumping in seawater to keep the reactors’ fuel rods cool, with leaks and disposal of the now-radioactive water presenting a new set of problems.
• These localized criticalities, if they’re happening, could cause surges of radiation and heat, making cooling and containment work at the reactors even more perilous for workers.

Not So Fast:

• Other experts are divided as to whether there’s even a chance that there are accidental fission reactions occurring. The dangerous conditions at the reactor make it difficult to get a good read on what, exactly, is going on. Nuclear safety expert Edwin Lyman told Time that he’d “be wary of attributing too much significance to a single anomalous measurement.” But Denis Flory, head of the International Atomic Energy Agency‘s nuclear safety department, said in a press conference that such reactions could potentially be occurring.

Image: Wikimedia Commons / derek visser

Source: Study: Nuclear Fission Reactions May Have Continued After Fukushima’s Alleged Shutdown

Source: Crack In Fukushima Structure May Be Leaking Radiation

Source: Nuclear Risk Expert: Fukushima Fuel May Be Leaking