UPDATE: Japan's nuclear crisis - March 13, 2011 (Nature.com blog Fukushima No. 3 fuel exposed)

[jpak]

http://blogs.nature.com/news/thegreatbeyond/2011/03/update_japans_nuclear_crisis.html

The situation at the Fukushima Daiichi power station is evolving rapidly this morning. Last night, even as operators took the drastic measure of filling reactor #1 with seawater to prevent a metldown, officials declared an emergency at the plant's reactor #3. According to a statement from Tokyo Electric Power Company (TEPCO), the crisis arose after the injection of cooling water into the reactor core was interrupted. Reports from the broadcaster NHK paint a grim picture inside unit 3: Fuel elements appear to have been exposed, and hydrogen gas has been vented into the surrounding structure—raising fears of another explosion like the one that rocked unit 1 on Saturday. According to Chief Cabinet Secretary Yukio Edano, seawater and boric acid are now being injected into the unit to try and avert a meltdown. Meanwhile Kyodo news is reporting peak radiation levels of around 1,557 ?Sv (presumably per hour) around the plant.

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[Scuba]

1. Crap. Rats. Damn.

[Rageneau]

2. The tsunami of bad news rolls relentlessly on.

How terrified the people of Japan must be.

[FBaggins]

3. You don't think that maybe 10,000+ deaths is on their mind too?

It's the reactor that's scary?

[LiberalEsto]

4. Can that radiation level be put in context?

Anyone?

"peak radiation levels of around 1,557 ?Sv (presumably per hour) around the plant".

How abnormal is this?

[caraher]

6. It's certainly highly abnormal

I still think in millirem, and 1.6 microSievert/hour would be about 160 millirem/hour. That means that in about 2-3 hours your radiation does would roughly equal a year's worth of background radiation; in 6 hours it would be like a CT scan.

That's a level that cannot result in acute radiation sickness, but is high enough that workers need to be monitored carefully, and high enough that you definitely want to keep the general public away. For comparison, I believe the US annual allowed dose for a radiation worker is 5000 millirem/year. Four 8-hour days in that environment would put someone over that limit.

[kristopher]

5. Accoding to Edano the relief valve isn't functioning and ...

..."#3 reactor vault might be showing some failure".

This is what I transcribed, http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=278398&mesg_id=278411