The Japanese now estimate that the clean-up costs will be about $45 billion, most of which is covered by insurance. It's unclear if that estimate includes the construction of replacement reactors or alternative power plants.

Still no explanation from the Japanese of the steam seen yesterday from Units 2 and 3 at the Fukushima-1 nuclear complex, which triggered a temporary evacuation.

I'm also not sure what the operational status is of Units 5 and 6 at this complex, whether they were also cooled by salt water which would render them useful for further operation. They are now reported in "cold shutdown" but there was also a period when temperatures were becoming elevated in their spent fuel pools.

Charley Noble