UPDATE, 6:00 pm, Friday, Activists in Japan are putting out an urgent appeal to stop schools in contaminated zones from opening. In Japan, schools are scheduled to open for the year over the next two weeks. Radiation levels in many areas outside the evacuation zone remain high. For example, measurements taken April 5 in Iitate Village (40 km northwest of Fukushima Daiichi) range from 9.5 to 18.2 MicroSievert/hour, or nearly 1-2 millirems/hour. Allowable annual exposure level in the U.S. is 100 millirems/year, meaning people exposed to this level of radiation could receive their annual dose in 50 to 100 hours. But it’s even worse in the town of Namie, also northwest of the site: levels there were measured April 5 at 18.8 to 23 MicroSievert/hour. Children are more susceptible to radiation exposure than adults.

UPDATE, 3:15 pm, Thursday, Today’s earthquake (which we have seen variously reported as between 7.1 and 7.9 in magnitude) has knocked out power in some sections of northeast Japan. The single-unit Higashidori Boiling Water Reactor and the Rokkasho reprocessing plant have lost offsite power and are running on emergency diesel generators. Offsite power may also have been lost to the three unit Onagawa nuclear complex, although there is a report that power remains for the reactors themselves, but not for the fuel pools and that those are relying upon emergency diesel generators.

UPDATE, 12:30 pm, Thursday, A 7.1 earthquake struck northeast Japan about an hour ago (11:30 pm Japan time); workers were temporarily evacuated from the Fukushima Daiichi nuclear site. There are no immediate reports of additional damage at the site.

UPDATE, 10:30 am, Monday, Japan’s government has acknowledged the obvious: that it will be months before the Fukushima nuclear crisis can be considered under control, and likely there will continue to be radiation releases for an extended period.