Peter-

Thanks for the update:

"Tepco said it did not know the cause of the apparent temperature rise, but speculated that it might be due to problems with the supply of coolant or a faulty thermometer."

I still wonder what happened in the spent fuel pool of Reactor 4. I don't think there has ever been a public update. It was also the site of an explosion and fire, and in this case the reactor itself had no nuclear fuel inside.

Charley Noble