I was going to shut up, but I've heard enough anecdotal accounts of people Stateside having hugely wrong ideas about the level of risk from radiation that I have a few notes. This information is accurate as of 12:30 Wednesday, California time. It's a bit unclear in places, but this reflects the unclear information that the government and Tokyo Electric are announcing. ETA: The New York Times has a good graphic putting radiation levels through Wednesday in perspective. /eta
I watched Chief Cabinet Secretary Edano's latest press conference at about 11:30 Wednesday Japan time. As well as imploring people not to try to stockpile fuel, he confirmed that radiation levels inside the Fukushima One plant were recorded at 1000 miliSievert/hr (mSieverts) as of early Wednesday morning Japan time--inside the plant radiation later decreased to between 600-800 mSieverts, but that's still too high to work safely (1000 mSieverts/hr is the threshold for radiation sickness). His current best guess was that the white smoke observed in the vicinity was venting from somewhere in the No. 3 system and the radiation spike was related to this--this probably represents a rupture of No. 3's primary containment vessel. The plant workers were withdrawn secondary to these increased radiation levels.
As of 4:30 Thursday morning, the No. 3 reactor and the No. 4 fuel pool are no longer being cooled; it's assumed that the white smoke observed from No. 3 is the remaining coolant (i.e. water) in the fuel pool boiling away. Meanwhile, the fuel pools at Nos. 5 and 6 are no longer being cooled, and the temperature in them is rising.
At midnight Thursday (00:00) levels at the plant gate were at 10.85 mSieverts, but decreased by 03:30 to about 3.5 mSieverts. At 25 km away, the max radiation observed Thursday so far was 80 µSieverts/hr; at 20 km away, the edge of the mandatory evacuation zone, it was 330 µSieverts/hr. Flying from Tokyo to New York carries a guaranteed exposure of 190 µSieverts; normal background radiation varies, but is about 2.4 microSieverts worldwide. Note thanks to![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png)
owlectomy there's a difference between mSieverts/hr and mSieverts (like that between speed and distance), and I'm assuming that all the reported numbers here are per hour rather than absolute readings, but it's not clear to me from the coverage.
As of right now the government says that the people who need to be worried about radiation exposure are either in the Fukushima One plant or within the 20km mandatory evacuation zone which was announced at 11:00 Tuesday Japan time--the NHK was reporting on Wednesday that about 650 people in the zone could not evacuate, though thousands have already fled. At the Wednesday morning press conference, Edano confirmed that officials are not extending the mandatory evacuation zone at this time: within 20-30km away, people are still being told to either evacuate or to stay inside, not use the AC, cover their face and hair if they go outside and wash them when they come back in, and abandon any laundry they have on the line. I would certainly take official assurances with a grain of salt if I lived in that zone; the U.S. government has told its citizens to evacuate within 50 miles, and military personnel have been told not to go within 50 miles of the plant absent specific orders to the contrary. The situation remains exceedingly serious. The 50 workers who remained at the plant are true heroes (it's not clear whether they sheltered on or off-site).
The No. 4 fuel pool was reported to be burning on Wednesday morning; it's not clear whether it's the same fire that was there on Tuesday, which was reported to have been extinguished, or whether it's still burning now--photos suggest not. Another serious problem is No. 2, whose primary containment vessel was probably breached on Tuesday and whose roof is still intact, which would prevent the last-ditch option of dumping in coolant (i.e. water) by helicopter--No. 2 was also apparently venting smoke or steam according to photos. The other serious problem is that the coolant in the Nos. 5 and 6 fuel pools will boil away completely by sometime late Thursday or early Friday. Tokyo Electric officials are advising against optimism.
As of approximately 13:00 Wednesday Japan time, the NHK was reporting that the JSDF has begun preparations to attempt to deliver coolant via helicopter, but there's no word on whether or when that will actually take place. As of 4:30 Thursday morning, NHK is now reporting that the national police are going to use fire trucks, which can only operate at a distance of 50m.
The thing to remember is that the situation in Japan is three disasters unfolding in the same general area: the earthquake, the tsunami, and the nuclear crisis. By far the most widely damaging one was the tsunami, and they were reporting heavy snowfall in Minamisanriku and across many of the devastated towns on Wednesday, which will not help the survivors. Aftershocks are continuing throughout the affected area as well.
That said, Japan is a long country with multiple active fault systems, and in a case of "it never rains but it pours," early Wednesday morning Japan time a 6.4 earthquake struck eastern Shizuoka prefecture, centered near the city of Fujinomiya. This is an apparently unrelated fault than that which broke last Friday, and it's another strain on a country that is dealing with a lot. The 6.0 earthquake that struck Chiba at 12:52 Wednesday Japan time is probably related, on the other hand.
The IAEA's website is down due to heavy traffic, but iaea.org remains the single best source in English on the reactors specifically.
As a footnote, the yen has apparently hit a nearly sixteen-year high against the dollar Wednesday morning, New York time. Meanwhile, the confirmed death toll from the tsunami and earthquake has risen to 4377.
I watched Chief Cabinet Secretary Edano's latest press conference at about 11:30 Wednesday Japan time. As well as imploring people not to try to stockpile fuel, he confirmed that radiation levels inside the Fukushima One plant were recorded at 1000 miliSievert/hr (mSieverts) as of early Wednesday morning Japan time--inside the plant radiation later decreased to between 600-800 mSieverts, but that's still too high to work safely (1000 mSieverts/hr is the threshold for radiation sickness). His current best guess was that the white smoke observed in the vicinity was venting from somewhere in the No. 3 system and the radiation spike was related to this--this probably represents a rupture of No. 3's primary containment vessel. The plant workers were withdrawn secondary to these increased radiation levels.
As of 4:30 Thursday morning, the No. 3 reactor and the No. 4 fuel pool are no longer being cooled; it's assumed that the white smoke observed from No. 3 is the remaining coolant (i.e. water) in the fuel pool boiling away. Meanwhile, the fuel pools at Nos. 5 and 6 are no longer being cooled, and the temperature in them is rising.
At midnight Thursday (00:00) levels at the plant gate were at 10.85 mSieverts, but decreased by 03:30 to about 3.5 mSieverts. At 25 km away, the max radiation observed Thursday so far was 80 µSieverts/hr; at 20 km away, the edge of the mandatory evacuation zone, it was 330 µSieverts/hr. Flying from Tokyo to New York carries a guaranteed exposure of 190 µSieverts; normal background radiation varies, but is about 2.4 microSieverts worldwide. Note thanks to
owlectomy there's a difference between mSieverts/hr and mSieverts (like that between speed and distance), and I'm assuming that all the reported numbers here are per hour rather than absolute readings, but it's not clear to me from the coverage. As of right now the government says that the people who need to be worried about radiation exposure are either in the Fukushima One plant or within the 20km mandatory evacuation zone which was announced at 11:00 Tuesday Japan time--the NHK was reporting on Wednesday that about 650 people in the zone could not evacuate, though thousands have already fled. At the Wednesday morning press conference, Edano confirmed that officials are not extending the mandatory evacuation zone at this time: within 20-30km away, people are still being told to either evacuate or to stay inside, not use the AC, cover their face and hair if they go outside and wash them when they come back in, and abandon any laundry they have on the line. I would certainly take official assurances with a grain of salt if I lived in that zone; the U.S. government has told its citizens to evacuate within 50 miles, and military personnel have been told not to go within 50 miles of the plant absent specific orders to the contrary. The situation remains exceedingly serious. The 50 workers who remained at the plant are true heroes (it's not clear whether they sheltered on or off-site).
The No. 4 fuel pool was reported to be burning on Wednesday morning; it's not clear whether it's the same fire that was there on Tuesday, which was reported to have been extinguished, or whether it's still burning now--photos suggest not. Another serious problem is No. 2, whose primary containment vessel was probably breached on Tuesday and whose roof is still intact, which would prevent the last-ditch option of dumping in coolant (i.e. water) by helicopter--No. 2 was also apparently venting smoke or steam according to photos. The other serious problem is that the coolant in the Nos. 5 and 6 fuel pools will boil away completely by sometime late Thursday or early Friday. Tokyo Electric officials are advising against optimism.
As of approximately 13:00 Wednesday Japan time, the NHK was reporting that the JSDF has begun preparations to attempt to deliver coolant via helicopter, but there's no word on whether or when that will actually take place. As of 4:30 Thursday morning, NHK is now reporting that the national police are going to use fire trucks, which can only operate at a distance of 50m.
The thing to remember is that the situation in Japan is three disasters unfolding in the same general area: the earthquake, the tsunami, and the nuclear crisis. By far the most widely damaging one was the tsunami, and they were reporting heavy snowfall in Minamisanriku and across many of the devastated towns on Wednesday, which will not help the survivors. Aftershocks are continuing throughout the affected area as well.
That said, Japan is a long country with multiple active fault systems, and in a case of "it never rains but it pours," early Wednesday morning Japan time a 6.4 earthquake struck eastern Shizuoka prefecture, centered near the city of Fujinomiya. This is an apparently unrelated fault than that which broke last Friday, and it's another strain on a country that is dealing with a lot. The 6.0 earthquake that struck Chiba at 12:52 Wednesday Japan time is probably related, on the other hand.
The IAEA's website is down due to heavy traffic, but iaea.org remains the single best source in English on the reactors specifically.
As a footnote, the yen has apparently hit a nearly sixteen-year high against the dollar Wednesday morning, New York time. Meanwhile, the confirmed death toll from the tsunami and earthquake has risen to 4377.