Thanks for acknowledging the workers. I've been thinking about them a lot, and hoping for their safety & health.

I love the way they throw out things like "a radiation leak of unspecified proportions." Yeah, they're downplaying the risks, but if their government is anything like ours, I wouldn't trust a word they say.

What @1 said. <3

Jonathan, in Charles's post above yours he notes that the reactor building may be flooded with seawater in a last-ditch attempt to cool it. Do you know more detail about this? From the description it doesn't sound like a managed process at all, rather they pump seawater into the building itself.

What comes next? How do they dispose of the seawater afterwards, and will it be radioactive?

That got me thinking.... When we bombed Hiroshima and Nagasaki, did the Puget Sound get any blowback?

You do have to admit, though, if the Japanese can't make nuclear power safe, nobody can.

Why does a nuclear power plant have to be one or two reactors? Why not 1000 mini reactors that could be shut down and cooled by a large arrays of redundant backups and safeguards?

Just heartbreaking. My thoughts go out to all those working to shut it down, to the missing 9500 (according to CNN), and to those who have lost family, friends, homes...

So, so sad. Between this and BP, environmental disasters courtesy of some of the most (ostensibly) advanced nations, just shows that no matter the money behind it, the R&D, that our hubris, and the thought that we can actually control nature, will lead to more of these in the future.

And if Comte is thinking about Blue Oyster Cult, I keep hearing that line from the movie Jurassic Park:
"What you call progress I call the rape of the natural world."

@9: I’m sorry Canuck, but that sound so sanctimonious to me. As predictable as mega natural disasters are bound to occur, so is the inevitable admonishment of humankind’s failures and tribulations. Makes me want to light candles, put on Joan Baez, fold napkins, and cry.

Thank you so much for honoring the workers, Jonathan. Japan made a national energy decision that is biting them hard in the ass, but the scientists, engineers and technicians are performing a vital national and global service by giving their all right now.

Phoebe FTW.

Sanctimonious? Perhaps (my mom did listen to an awful lot of Joan Baez when I was little), but if I may be so bold, it's as though the fervour and indignation of the sixties has given way to this current "Meh, as long as I have gas for my Hummer" attitude that permeates our "more more more" culture these days. I'm also reminded of that post Dan put up a while back about protesting at Target, people were, for the most part, saying, "That's so rude, they should have just emailed."

We are so determined to maintain our current energy-abusive lifestyle that the idea of having a discussion about using less, and perhaps not using forms of energy like nuclear power that have catastrophic results when they fail, is just not going to happen for some people. And I like available energy as much as anyone, and really don't like camping, I just think it's ridiculous to act like we can continue at this level.

Awesomely good and practical advice. Thank you for reminding me! (have a daughter in Tokyo and I'm nagging her about this thanks to you!)

The most concise info I've found thus far is here:

http://www.nirs.org/reactorwatch/acciden…

Read it in your browser and refresh from time to time--updates are being added periodically at the top.

Some useful facts: Fukushima I (Fukushima Dai-ichi) is not one reactor but six. Two are having cooling problems, one had explosive failure of the SECONDARY containment structure (the building around the PRIMARY containment, which holds the reactor core). The explosion was probably from a buildup of hydrogen gas.

Fukushima II (Fukushima Daini), seven miles south, has four reactors. Three of them are having cooling problems and venting is being considered to release pressure.

Some perspective on radiation dose (this is incident whole-body dosage from external sources): Levels AT Fukushima I for some unspecified time were slightly above 1 millisievert per hour (1,000 microsieverts per hour). A common standard for a member of the general public is that radiation from all sources should not exceed 1 millisievert per YEAR. Average exposure for most of us from all background sources is around a third of that (0.36 millisievert/year). People who fly a lot (high-altitude gamma-ray exposure), live downwind of coal power plants, or have radon in their basements get more.

Nuclear workers have a higher occupational exposure limit, around 20 millisieverts per year, occasionally higher but no more than 100 millisieverts total in 5 years under ordinary circumstances. These limits generally give minimal risk (whatever that means) for things like higher cancer rates.

If you're interested in the sociological aspects of nuclear power and nuclear weapons, look for the following photoessays by Robert del Tredici:

The People of Three Mile Island, Sierra Club Books, 1980

At Work in the Fields of the Bomb, Harper & Row, 1987

@19, lots of potential answers, don't know which would apply.

• The main output of the plant's steam turbines would probably go directly to a transformer yard to be stepped up for long-distance transmission. It may be more cost-effective to serve the plant's own control power needs by tapping the same local distribution lines that serve homes and businesses, which were knocked out by the quake.

• Whenever there's a major structural, control, or cooling problem in a reactor, the chain reaction needs to be damped down: "scramming," insertion of control rods, injection of boron or seawater, or whatever other means are available or improvised. As soon as the reaction is damped, steam power for electrical generation is diminished. If core damping can't be accomplished, the secondary/tertiary coolant circuits are isolated anyway to prevent their contamination by breaches (materials failure) in heat exchangers or the containment vessel.

• The main redundancy for cooling pumps was apparently diesel generators, which initially started but had been earlier swamped by tsunami flooding and quit after awhile (probably control wetting or fuel/air compromise. Backup batteries ran the pumps for awhile but had no means of recharge.

• It's kind of like a jet airliner--even though the main engines power onboard systems when flying, when they're at the gate they depend either on umbilical power from the air terminal or their own small gas turbine auxiliary power units, usually buried in the tail with a small visible exhaust port, to run lights and A/C.

@17: Good links and info generally. However, for most U.S. workers, the annual exposure limit is 50 mSv (total effective dose equivalent) per year, not 20 mSv per year. See http://www.nrc.gov/reading-rm/doc-collec…

And this number is NOT risk-based, more convenience-based. To put this 50 mSv per year dose limit into context, the National Academies estimated that the lifetime excess cancer risk from an annual occupational exposure at 10 mSv per year (ages 18 to 65) to be rather startlingly high: 29 cancers per 1000 male workers so exposed, and 43 per 1000 female workers so exposed. Here's the direct link to the relevant part of the National Academies report: http://www.nap.edu/openbook.php?record_i…

Fortunately, few U.S. workers receive doses as high as the exposure limit.

We are in Tokyo, about 160 kilometers away, and can't get out until Tuesday. Are we in significant danger? A lot of people are wearing masks, but they do here anyway to guard against the spread of colds, etc. Will these help us at all?

Great stuff, @21, thanks. I was flying seat-of-the-pants on my decades-old radiation safety training.

All residents in the vicinity had to evacuate and leave their houses for their personal safety. I wonder how is the situation now, hope all those people are well and healthy.