Japan - The operator of the damaged Fukushima Daiichi nuclear plant has begun full operation of a device to cool a spent fuel storage pool.

The pool holds 1,535 fuel rods, the most for any of the plant's reactors. The wall supporting the pool was damaged in a blast on March 15th.

The Tokyo Electric Power Company reinforced the wall with steel pillars and concrete, and installed a cooling device with a heat exchanger to set up a circulatory cooling system.

TEPCO conducted a test-run of the cooling device at the Number 4 reactor's spent fuel pool on Sunday morning. It gradually increased the volume of water flowing into the device before shifting to full operation in the afternoon.
TEPCO says the water temperature of the pool remained above 86 degrees Celsius in the morning and it was around 82 to 84 degrees as of 5 PM.

The company plans to lower the water temperature to around 55 degrees within a month to cool the reactor in a stable manner.

TEPCO is already cooling the water in the spent fuel pools at the Number 2 and 3 reactors. It plans to do the same for the Number 1 reactor soon.

Source: NHK World