The devastating 9.0 earthquake that rocked northern Japan and the ensuing tsunami have already claimed an estimated 10,000 victims. But the worst may be yet to come. Experts estimated that the next 48 hours will be crucial in determining whether Japan's nuclear disaster unfolds like the U.S. Three Mile Island accident in 1979 or like the meltdown at the Ukraine's Chernobyl plant in 1986.
Two dozen Japanese workers at the Fukushima Daiichi Nuclear Power Station along with17 U.S. crew members of the USS Ronald Reagan have already been decontaminated for radiation exposure. If offshore winds shift, as predicted by Japanese weather forecasters, then airborne radioactive clouds could be headed for the Japanese mainland in the next 24 hours.
Observers said the biggest threat is plutonium fuel. Only one Fukushima
reactor uses plutonium-enriched uranium fuel known as MOX, or "mixed oxide" fuel. A hydrogen explosion at the No. 3 reactor on Sunday (March 13) injured 11 workers. So far, Japanese officials said the
containment vessel in the No. 3 reactor appears to be holding. But
it could take weeks or even months before the MOX fuel cools to levels that no
longer threaten public safety.
"If there is a large-scale release of plutonium into the air this could become the worst nuclear disaster in history," predicted Ira Helfand, a member of the board of Physicians for Social Responsibility. "So far, the venting of radioactive steam has been blown out to sea, but tomorrow [March 15] the wind is forecast to shift to northeast which means any radiation released tomorrow will be blown straight toward Tokyo, which is less than 150 miles away."
A release of deadly plutonium would require heightened precautions to protect Japanese citizens, particularly if winds shift. Helfand said these would include staying indoors and testing water and foods supplies. "Most of the exposure to people at Chernobyl, for instance, was from
children drinking contaminated milk that had not been tested," Helfand said, resulting in high rates of thyroid cancer in children.
Making matters worse, a third explosion, this one inside Fukushima's No. 2 reactor, was
reported Tuesday morning Japan time. Tokyo Electric Power Co. confirmed that radiation from the blast likely leaked after the No. 2 reactor's containment vessel was damaged, Kyodo news service reported.
Despite safety concerns that have prompted the use of backup systems like buried diesel fuel tanks for secondary generators at U.S. nuclear plants, experts are baffled at the lack of adequate backup systems in Japan. The lack of functioning secondary generators, for example, has led directly to cooling problems linked to the three explosions at Fukushima.
Those aging boiling-water reactors were designed by General Electric. The inner reactor core--which generates heat using nuclear fission in a controlled chain reaction--boils circulating water which in turn drives a steam turbine to generate electricity. The heated water is then circulated through cooling pipes which, like a car radiator, cool the water before it re-enters the reactor.
When the earthquake struck last Friday about 80 miles off the coast of Sendai, Japan's nuclear reactors automatically shut down. Control rods were then inserted to dampen the fuel rods and stop the reactor's chain reaction. Electric pumps were supposed to continue running to circulate the hot water through cooling pipes, allowing the reactors to go into an orderly shut-down mode.
Then the power grid went down. Backup generators kicked on when the quake struck to keep cooling water circulating.
I noticed that the German pebble bed reactor has lots of graphite like Chernobyl, which was one of the mistakes to come out of that incident. I'm not sure of the implications for a pebble bed reactor compared to the Chernobyl design, perhaps one of our more knowledgeable members can elaborate?
I agree with you to some extent, but putting your backup systems (diesel generators) in the firing line is a little worrying, but not as much as storing spent fuel where continuous power is required. This is really pushing it. I think spent fuel storage is still the nuclear industry's biggest failing.
No service industry accounts for all possible scenarios. Firstly, all designs are done to meet some specifications. If your specficiation is to withstand an earthquake of 8.0 and Tsunami of 5m, its too bad you got hit by 9 and 6m Tsunami. Secondly, no human being can think of all possible scenarios.
It is not yet clear if the situation could have been controlled better with timely action. I would not blame bad engineering just as yet.
After all the raving on about how pebble bed reactors are so safe and Thorium is so great this really seems to swing the argument away from nuclear doesn't it. It seems like all these "new" technologies just have new risks.
I keep hearing how thorium reactors are the answer to everything.
Check this link out:
Germany built a thorium reactor, then shut it down four years later. It was too expensive to run. The German taxpayers ended up paying about 100 million dollars to shut it down.
A fair enough concern, but if you visit the site you'll see that its coverage of Fukashima (including a real-time discussion forum) is very much focused on the technical facts of the situation.
You can choose to agree or not with the site author's opinion on nuclear energy, which is no secret (in contrast to that of many of the so-called "experts" trotted out by the mainstream media, who are often current or former members of activist organizations like "Friends of the Earth," Greenpeace and "Union of Concerned Scientists").
"Get government out of the nuclear power indemnification business and let the industry settle at a true cost equilibrium."
Yea now there's a good idea! lets have NO government oversight (evil regulation). don't worry, business can regulate itself! the market will take care of EVERYTHING! great idea,.... oh! and the "market" will have a buying opportunity in Japanese real estate just for you VincePG.
the free market economic theory has now been proven false and dangerous on multiple fronts and is merely a useful tool to be implemented for short stretches, not a permanent scenario. freedman style free markets are as much a science as Scientology.
This catastrophe is a perfect storm of stupid ill conceived ideologies such as deregulation (yea i know its Japan and not the US but similar corporate forces are at play), as well as deceitful business interests in the name of profitability.
people die when company's lie.
These conflicting amounts prompted me to look it up, it seems about 10g for one person. I'm assuming quickly as I also found that 1g could cause lung cancer if inhaled. I also found that 1g could cause could kill a few people due to lung cancer. All that said, if you had 100g and let everyone on earth hold it for a time they would probably all be dead or dying. It's important to have the how explained. Regarding your sperm, I'm assuming you mean in one "sitting", I'm afraid you flatter yourself :-) as apparently there are between 2 and 500 million sperm in one shot, you will at best only manage 1/4 to 1/3 of the women of child baring age.
Blog Doing Math in FPGAs Tom Burke 16 comments For a recent project, I explored doing "real" (that is, non-integer) math on a Spartan 3 FPGA. FPGAs, by their nature, do integer math. That is, there's no floating-point ...