TOKYO - Tokyo Electric Power (TEPCO) will this month start removing fuel from a storage pool at Japan's Fukushima nuclear plant, the most challenging operation since runaway reactors were brought under control two years ago.
Here are some key facts about the operation.
Q: What's the state of nuclear fuel at the site?
A: Reactors No. 1, 2 and 3 went into meltdown after their cooling systems were knocked out by the March 2011 tsunami. The temperature of the cores and spent fuel pools at all reactors is now stable and water is being used to keep them cool.
Reactor No. 4, whose outer building was damaged by fires and an explosion, has an empty core but a total of 1,533 fuel assemblies - 1,331 spent fuel bundles and 202 unused ones - are in its storage pool.
Q: Why does TEPCO have to take fuel from the pool?
A: According to the firm, it is safer to store all fuel in a shared pool that is reinforced against possible future earthquakes and tsunamis.
This will be the first post-tsunami attempt to move any fuel from one part of the plant to another.