Japanese authorities have notified the IAEA that efforts to restore power for the Fukushima Daiichi nuclear plant are on-going. As of 19 March at 21:46 UTC, the power centre at Unit 2 had received electricity. Work to restore electricity to Units 3 and 4 is continuing.
White smoke was reported seen emanating from Unit 2 on 21 March at 9:22 UTC. Grayish smoke was reported seen emanating from unit 3 at 6:55 on 21 March, and this was reported to have “died down” two hours later. All workers at Units 1 through 4 evacuated after the smoke at Unit 3 was seen. The IAEA is seeking further information at this time on the status of workers at the site.
Japanese authorities have also reported that water has been sprayed over the Common Spent Fuel Pool.
Things continue to develop slowly, but I think now to an inevitable conclusion — barring any sudden turn of events, a cold shutdown (reactor temperature below 100C) should be achieved in units 1 to 3 within the next week (or two?). The other priority is to get the spent fuel ponds can sufficiently covered with water to make them approachable (and ideally to get AC power systems restored to these ponds, as has been the case already for units 5 and 6). The clean up, diagnostics, and ultimate decommissioning of Fukushima Daiichi, of course, will take months and years to complete.
New pump trucks have arrived and increased the pumping rates for water spraying to 160 tonnes per hour through a 58 metre flexible boom via remote control.