Operator of the tsunami-crippled Fukushima Daiichi nuclear power plant said Friday it will begin removing fuel rods from a damaged storage pool of the No. 4 reactor on Monday. This will be the first major step in a decommissioning process that could take up to 40 years. According to Tokyo Electric Power Co. (TEPCO), the removal work of more than 1,500 nuclear fuel assemblies in the reactor's spent fuel pool is expected to be completed by the end of next year. Workers will transfer 1,331 spent fuel rods and 202 new ones to an outside storage pool about 100 meters away, which gives more stable conditions for keeping the fuel cool. "Removal fuel rods is a very crucial step toward the plant's decommissioning," TEPCO spokesman Masayuki Ono told a press conference. "We will work on a safety first policy," Ono said. The operation requires extreme caution, as any damage to the fuel could unleash high-level radiation. Workers will begin operations for unused fuel rods, which are less radioactive. TEPCO said it has found no damage to the fuel assemblies at the No. 4 unit. Unlike three other units at the plant, the No. 4 reactor did not suffer a meltdown at the time of the 2011 accident, as it was not in operation and all of its fuel rods were in a storage pool on a top floor of the reactor building. But a hydrogen explosion severely damaged the reactor building, raising concern that another major earthquake could cause cracks in the pool to leak water, which would expose the rods to the air. The Fukushima plant was devastated in March 2011, when the magnitude-9 earthquake and tsunami triggered a series of meltdowns and explosions.