Reactor Accidents

UPDATE, 10:30 am, Monday, Gray smoke began emitting from the area around the Unit 3 fuel pool today, and workers were temporarily evacuated. It is as yet unclear what caused the smoke. TEPCO says radiation levels did not increase at ground level because of the smoke. As has been the case since the beginning, air radiation levels are either not being taken or not being made public. Ground radiation levels at the Fukushima site are currently over 2,000 Micro/Sievert/hour, or approximately 200 millirems/hour. There are likely hot spots of far higher levels.

UPDATE, 10:30 am, Saturday, Officials believe they are having some success using a variety of methods to cool the damaged reactors at the Fukushima site, including fire trucks and a remotely-operated system that can spray water for seven hours at a time. A power cable has apparently finally been placed at the site (after several incorrect reports that this already had happened), and may be hooked up later on Saturday. If successful, this would provide power to the site. However, the condition of the safety systems inside the reactors is unknown, so it is also unknown whether offsite power will prove to be the savior it would have been a week ago.

UPDATE, 5:00 pm, Thursday, Efforts by TEPCO to cool reactors and fuel pools by using water cannons (in the past sometimes used to quell anti-nuclear demonstrators…) and water drops from helicopters appear to have had little effect.

Audio of Physicians for Social Responsibility news briefing on radiation and health, with three experts,

UPDATE, 4:30 pm, Wednesday, NRC Chairman Greg Jazcko told a Congressional committee this afternoon that the Unit 4 fuel pool has no water and is releasing massive amounts of radiation. The U.S. Nuclear Regulatory Commission is recommending that the current 30-kilometer (18 miles) evacuation zone be expanded to 50 miles.

UPDATE, 10:00 am, Wednesday, The situation at Fukushima Daiichi continues to deteriorate. All plant workers were evacuated for some hours due to extremely high radiation levels onsite, but a skeleton crew is said to have returned. Solid information is sketchy and even the Japanese government is publicly complaining about the quality and quantity of information coming from Tokyo Electric Power.

UPDATE, 6:15 pm, Tuesday, We have just learned that TEPCO has announced that at 5:45 am Tokyo time (4:45 pm eastern us time) flames have appeared again at the northwest side of Fukushima Daiichi (Unit 4). According to TEPCO, it is impossible to go near the fire since the radiation is so high.

UPDATE 8:15 am, Tuesday, The situation at Fukushima is going from bad to worse. There was briefly a fire in the irradiated fuel pool at Unit 4. The fire is said to be extinguished for now.

UPDATE 7:30 pm, Monday, Tokyo Electric Power is holding a press conference at this hour. NHK TV reports that there has been an explosion at Unit 2 at Fukushima Daiichi. There is speculation that this explosion has damaged the primary containment (inside the concrete containment building, which is the secondary containment. Tepco is evacuating some nonessential personnel from the reactor site. 2.5 meters of the core are currently uncovered by water—which means it is almost certainly melting. Winds from the site are currently blowing toward the North.