6 June 2012, Tokyo Electric revealed that a cooling pump for the spent fuel pool, above Reactor 4, failed on Monday, 4 June.  Japanese media says the pump was burnt.

A back up pump was used the next day, but it failed as well.  TEPCo finally got it working today, however, temps in the spent fuel pool have hit 40 Celsius (104 Fahrenheit)!

TEPCo says it will take 12 to 24 hours to cool down the spent fuel pool.