TOKYO — Tokyo Electric Power Co. says workers will begin removing radioactive fuel rods Monday from one of four reactors at its crippled nuclear power plant. The painstaking and risky task is a crucial first step toward a full cleanup of the Fukushima Dai-ichi plant.

Unit 4 was offline at the time of the March 2011 earthquake and tsunami, so its core didn't melt down as the other three did. But hydrogen explosions blew the roof off the building and weakened the structure, leaving it vulnerable to earthquakes.

Experts have said keeping so many fuel rods in a storage pool in the building poses a major safety risk.

The full decommissioning of the plant in northeastern Japan is expected to take decades.