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.

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.