UPDATE, 11:30 am, Thursday, Evidence is growing that the March 11 earthquake itself caused major damage to the Fukushima Daiichi reactors even before the accompanying tsunami knocked out offsite power and ensured the subsequent meltdowns.

UPDATE, 2:30 pm, Friday, The world’s media are shocked (shocked, we tell you…) that three Fukushima reactors melted down. Where have they been the past 10 weeks? Where did they think all that radiation was coming from? You know, that radiation that has caused the evacuation/relocation of people as far as 25 miles from the reactor site? Not to mention contamination of food, seawater, etc…..

UPDATE, 12:30 pm, Monday, On March 27, we reported on a press conference by a Japanese nuclear engineer who believed that the meltdown at Unit 1 was caused by a loss-of-coolant accident initiated by the earthquake itself, which was exacerbated by the ensuing tsunami and loss of power. It now appears that assessment was correct. Tepco said today that radiation levels inside Unit 1 were measured at 300 MilliSieverts/hour within hours of the earthquake—meaning that fuel melting already had begun. For melting to have begun that early, coolant must have been lost almost immediately. It’s now believed that fuel melted and dropped to the bottom of the containment—melting a hole into it, within 16 hours. Most likely, a major pipe carrying cooling water to the core was damaged by the earthquake, which should lead to a new evaluation of the ability of key reactor components to withstand seismic events.

UPDATE, 11:30 am, Thursday, At a Tokyo press briefing today, Tepco officials said that there is likely a hole inside the Unit 1 containment which is allowing highly radioactive water to leak—where the water is leaking to isn’t known at this point. Tepco has flooded Unit 1 with some 11 million liters of water so far, and the unit can only physically hold less than 8 million liters—although much of that loss could have been by evaporation and release of radioactive steam. But now Tepco admits that the fuel rods inside Unit 1 are essentially uncovered—meaning that much of the water poured into the reactor has leaked back out. Much of the fuel—exactly how much isn’t known–is now a molten mass on the bottom of the reactor vessel.

UPDATE, 2:30 pm, Tuesday, Japanese Prime Minister Naoto Kan announced today that Japan is scrapping plans to build 14 new nuclear reactors and instead will rethink its energy policy with a focus toward renewable energy sources and efficiency.

UPDATE, 12:30 pm, Friday, Speculation in some media reports that Unit 1 will reach a cold shutdown within a week appears unwarranted; at best it will take about a month to achieve that goal—and that’s if all goes well. Of course, Units 2 and 3 need to reach cold shutdown (and fuel pools, esp. for Units 3 and 4 need to be brought fully under control) before this can move from an “ongoing accident” situation to a clean-up situation. Temperatures in all three units with fuel in the core (Units 1, 2 & 3) remain above the boiling point, meaning water continues to boil off and fuel rods remain exposed.

UPDATE, 12:30 pm, Thursday, Radiation levels in the seabed near Fukushima are reported at 100 to 1,000 times above normal. Japanese officials reportedly are agreeing to help from Britain in measuring radiation in the sea, but continue to bar the Greenpeace ship Rainbow Warrior from coming closer to the site than the 12-mile international water zone. Greenpeace wants to conduct independent radiation monitoring of the water in the area.

UPDATE, 12:30 pm, Friday, Toshiso Kosako, a University of Tokyo professor and radiation expert, resigned as a special nuclear advisor to Japan’s Prime Minister Naoto Kan today, in protest over the government’s handling of the Fukushima crisis. Kosako was appointed as an advisor on March 16. He told a news conference—apparently holding back tears– that ”The prime minister’s office and administrative organizations have made impromptu policy decisions, like playing a whack-a-mole game, ignoring proper procedures.” Kosako specifically pointed to the government’s decision to increase allowable exposures to workers from 100 to 250 MilliSieverts/year (from 10 to 25 rems/year; U.S. allowable level for workers is 5 rems/year) and to the decision to allow schoolchildren in Fukushima Prefecture to be exposed to 20 MilliSieverts/year (2 rems/year; 20 times higher than international standards).