Tokyo Electric Power Company is worried about Reactor 4, at the Fukushima Daiichi nuke plant.  They think the spent fuel pool has been too damaged by the 9.0 quake, and the many aftershocks, that they can’t inject anymore water to keep fuel rods cool.

On 22 April, the temperature shot up 50 degrees Celsius, above normal, and 200 tons of water had to be injected.  TEPCo is now monitoring the structure of the building as well as the spent fuel pool temps.  The spent fuel pool holds more than 1,000 fuel rods, including active rods that had just been removed from Reactor 4, for scheduled maintenance, before the 11 March disasters.