Japanese nuclear reactors and the 11 March 2011 earthquake
Fukushima Nuclear Accident – a simple and accurate explanation (with further updates at MIT here: http://mitnse.com/)
Japan Nuclear Situation – 14 March updates
Further technical information on Fukushima reactors
TEPCO reactor by reactor status report at Fukushima
This is also a useful summary, from William Tucker (published in the Wall Street Journal): Japan Does Not Face Another Chernobyl. See also: Nuclear Overreactions: Modern life requires learning from disasters, not fleeing all risk.
Attention has centred on units #1, 2 and 3 of the Fukushima Daiichi plant (all Boiling Water Reactors built in the 1970s). Current concern is focused on unit #2 (more below). Units 4, 5 and 6 at the site were not in service at the time of the earthquake and their situation is stable.
At a nearby plant, Fukushima Daiini, the situation is now under control, and units are in, or approaching, cold shutdown. I do not expect any further significant developments at that site. To quote WNN:
In the last 48 hours, Tepco (Tokyo Electric Power Company) has carried out repairs to the emergency core coolant systems of units 1, 2 and 4 and one by one these have come back into action. Unit 1 announced cold shutdown at 1.24 am today and unit 2 followed at 3.52 am. Repairs at unit 4 are now complete and Tepco said that gradual temperature reduction started at 3.42pm. An evacuation zone extends to ten kilometres around the plant, but this is expected to be rescinded when all four units are verified as stable in cold shutdown conditions.The rest of this post will focus on the ongoing crisis situation at Fukushim Daiichi. Let me underscore the fact that accurate information is sparse, uncertain and rapidly changing.
• Fukushima Daini Unit 1 reactor
o As of 1:24AM on March 14, TEPCO commenced the cooling process after the pumping system was restored.o At 10:15AM on March 14, TEPCO confirmed that the average water temperature held constant below 212 degrees Fahrenheit.• Fukushima Daini Unit 2 reactor
o At 7:13AM on March 14, TEPCO commenced the cooling process.o As of 3:52PM on March 14, the cooling function was restored and the core temperature was stabilized below 212 degrees Fahrenheit.• Fukushima Daini Unit 3 reactor
o As of 12:15PM on March 13, reactor has been cooled down and stabilized.• Fukushima Daini Unit 4 reactor
o At 3:42PM on March 14, cooling of the reactor commenced, with TEPCO engineers working to achieve cold shutdown.
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