Late Monday, a power outage at Tepco's Fukushima nuclear generation plant, stopped the cooling for four pools that contain over 8,000 contaminated fuel rods.

The power outage, attributed to a faulty switch board according to the Tokyo Electric Power Company, cut power to pumps that cooled spent and contaminated fuel rods at the Fukushima power plant. The pools affected were 1, 3, and 4. Power has since been restored to pools 1 and 3, but 4 is still offline. Power is expected to be restored in that pool by sometime tommorrow morning.

Temperatures in the pool in the number four pool is currently at approximately 86.9 degrees fahrenheit (30.5 degrees C) the safety limit for the spent rod pool is 149 degrees F. (65 C) A spokesman for TEPCO stated that it would take four days with low water levels for the fuel rods to reach a critical level in the pools at its present rate of warming. At that time the water in the pools will quickly begin boiling away, exposing the rods.

TEPCO says that if they fail to restore power to the pools in time to avert the rising temperatures, that they have other measures onhand to slow down the heating of the rods. TEPCO spokesman Kenichi Tanabe said, “We are prioritising recovering power and restarting operations. But if it takes a long time we can pour cooling water whenever necessary so that the worst case scenario can be avoided.”

The Japanese disaster that occurred on March 11th, 2011 severely damaged three of the four reactors at the Fukushima site when first, a tremendous earthquake shook the region and then a massive tsunami struck, causing the meltdown of three of the reactors and causing damage to the cooling pools.

The power plants have been in a very vulnerable state since the disaster two years ago and will remain so for decades as the complex cleanup continues at the sites. Experts warn that another earthquake could cause another catastrophe connected with the cooling systems that were quickly put together to avert even larger contamination than actually occured in 2011.