There is no even less information coming from the operator of the Fokushima Daiichi plant, Tepco, as well as of the government authorities. They are no reporting any of the all important details and are spinning every issue in a ridiculous positive view. The IAEA, under a Japanese secretary general, isn't much better with even its webserver going down for half a day yesterday and any information on the Japan situation hard to find on it even when it is up.
Action on the ground seems to be chaotic and is missing leadership and decisive will. Japan is a major industrial nation with a big machinery and shipping industry but seems to be organizational incapable to timely provide for mobile generators, high pressure pumps and knowledgeable personal to help in the nuclear emergency.
The U.S. government is calling the radiation levels "extremely high" and advised its nationals to stay away at least 80 kilometer (50 miles) from the damaged plant.
Recent developments:
Recent measurements taken during helicopter overflights 300 m above the ground (240 m above the reactor roof) showed radiation of 4,130 microSievert per hour, in 100 m height above ground they showed 87,700 microSievert per hour (natural background depending on location is below 0.1). The measurments are consistent with large amounts of uncovered and exposed nuclear material.
Japanese Self Defense Force helicopters tried four times to drop 7.5 tons of seawater each onto the unit no. 3 spent fuel pond (full capacity 2,000 tons of water). Video from the operation shows the water mostly missing its target as the helicopter are flying much too fast and too high to be able to hit the appropriate spot. A rather ridiculous operation.
There are plans to use riot police water cannons to spray the reactors and to fill the fuel ponds. As these are some 30+ meters above ground it is unlikely that the pumps in the truck will have enough power and capacity for this to be effective.
A new land line is getting laid to provide electricity to the site.
Status information on the reactor units (unfortunately most of it is over half a day old):
There are six reactor units at the Daiichi plant, three of them are loaded with fuel and were active when the quake hit. Each plant has a spent fuel pond above the reactor core and outside of the primary containment. Once used, nuclear fuel continues to produce heat due to decay and requires continued water cooling.
Unit no. 1 – Water level inside the reactor core was measured at 1.8 meters below the top of the fuel rods. The fuel rods the core are thereby only half covered by water. Partial fuel meltdown. Spent fuel pond exposed after hydrogen explosion.
Unit no. 2 – Water level inside the reactor core was measured at 1.4 meters below the top of the fuel rods. Partial fuel meltdown. Primary containment likely to have been breached. Pressure measurement for the reactor core/primary containment disabled due to lack of battery power.
Unit no. 3 – The water level inside the reactor core was measured at 1.9 meters below the top of the fuel rods. Partial fuel meltdown. Primary containment probably breached. Spent fuel pond exposed after hydrogen explosion. White smoke (steam) is still emitting from this block but much less than yesterday.
Unit no. 4 – According to U.S. authorities the spent fuel pond has run dry. It contains at least 548 fuel assemblies that were in use at the reactor until last November and are thereby still very hot. The fuel is likely to have melted and may penetrate through the metal and concrete basin. Spent fuel pond exposed after hydrogen explosion and fire. The operating company Tepco spokesperson said there is "no particular problem" at the pond as flybys by military helicopters are claimed to have observed water in that pond. I seriously doubt this to be correct.
Unit no. 5 and no. 6 – Temperature in the spent fuel storage pool increased from 60.4 °C to 62.7 °C and 58.5 °C to 60.0 °C within the last 24 hours (100.0 °C = boiling temperature, normal status below 25.0 °C). The water levels decreased but the fuel is still covered.
Two people are missing and two were "suddenly taken ill" at the reactor emergency operation in Fukoshima
I have read some reports/comments which claim that northern Japan will become inhabitable etc. Such is utter nonsense. Japan's main island, Honshu, alone is bigger than Great Britain. The current 20km range evacuation zone and the effected area is a rather tiny spot of the land mass.
About a half million people have been evacuated because of quake and tsunami damage as well as for probable radiation problems in the Fukoshima area. There are food and fuel shortages in the disaster area.
Temperatures overnight were in the slightly freezing range and there was some snow fall. Emergency shelters have heating problems. The wind is currently blowing towards southeast blowing any fallout out to the Pacific but is expected to turn south later on Friday.
The Yen is now at a record high – something the Japanese export economy currently doesn't need.
What is needed now is a serious massive operation to drop hundreds of tons of sand and borsilicate onto the spend fuel ponds and the reactor cores. This could stop further massive radiation being open to the environment. Plans will have to be made to put the reactors 1 to 4 into Chernobyl like sarcophaguses.
Additional resources:
AllThingsNuclear Union of Concerned Scientists
Bulletin of the Atomic Scientists
Digital Globe Sat Pictures
IAEA Newscenter
NISA Japanese Nuclear Regulator
Japan Atomic Industry Forum (regular updates)
Japanese government press releases in English
Kyodo News Agency
Asahi Shimbun leading Japanese newspaper in English
NHK World TV via Ustream
In German language – Status report for the German Federal Government by the Gesellschaft für Reaktorsicherheit