Reactor Accidents

UPDATE, Noon, Sunday, There appears to be growing confusion and contradictory reports about radiation levels at the Fukushima site and in nearby communities. For example, on Friday we reported (see below, 10 am update), that 3 contaminated workers were said to have experienced a dose rate of about 20 rems/hour, but that that level seemed low for the injuries reported. On Saturday, the New York Times confirmed that the actual levels encountered by the workers were 2-6 Sieverts, or 200-600 rems/hour. The Times noted that a whole body exposure of 400 rems would be expected to kill half the people exposed. It is unlikely that these workers received a whole body dose of that level. However, it is still a serious situation.

UPDATE, 11:00 am, Friday, Greenpeace Germany has released a statement that, according to an analysis of radiation releases by consultant Dr. Helmut Hirsch, Fukushima is now a Level 7 accident on the international scale (currently it is officially ranked as a Level 5, comparable to the Three Mile Island accident of 1979; Level 7 would make it comparable to Chernobyl).

UPDATE, 10:00 am, Friday, Three workers were treated yesterday for contamination after walking in highly radioactive water in Unit 3 that is said to have had a dose rate of 20 rems/hour—about 10,000 times above normal. However, even that rate wouldn’t be high enough to cause the burns that were reported on the workers, so there is suspicion that the rates were even higher. Radioactive elements were found in the water that are not normally found in reactor cooling water.

UPDATE, 3:30 pm, Thursday, Japanese officials said today that infants—even outside the evacuation zone—could have received doses of 10 rems to their thyroids from Iodine-131 over the past two weeks. This would apply to infants who had stayed outdoors every day. Infants are much more susceptible to radiation than adults.

UPDATE, Noon, Wednesday, The Austrian Central Institute for Meteorology and Geodynamics (ZAMG), which is advising the International Atomic Energy Agency, reports that releases of radioactive Cesium (hazardous life: 300-600 years) from Fukushima now are 20-60% those of Chernobyl; releases of Iodine-131 are at 20% Chernobyl releases.

UPDATE, 11:00 am, Wednesday, We have received no recent updates on the condition of the reactors and fuel pools at Fukushima Daiichi. In this case, hopefully no news is good news.

UPDATE, Noon, Tuesday, Reports on power lines and ability to supply offsite power to reactor and fuel pool safety systems have been contradictory for days. It appears now that power lines have indeed been brought to all 6 reactors, and it is likely power has been restored to Units 5 and 6 (we haven’t seen confirmation of this yet). However, Units 1 through 4 have experienced substantial damage to their safety systems and while offsite power appears to be available, it is not operating the safety systems at these reactors. Repairs to the systems must be made first; that will take at least a day and probably considerably longer.

UPDATE, 7:45 pm, Monday, The incident of smoke coming from Unit 3 appears perhaps more significant than TEPCO first stated. Video images showed substantial amounts of smoke from Unit 3 as well as smoke or steam emanating from Unit 4,

UPDATE, Noon, Monday, Radiation doses at Fukushima Daiichi and Fukushima Daini, March 18-21, 2011. Obtained by Dr. Chris Busby at European Committee on Radiation Risk (ECCR). ECCR risk model predicts 120,000 cancers worldwide from Fukushima accident based on current known releases.