This aerial view shows the damaged No. 4 reactor building at Tokyo Electric Power Co.'s Fukushima Dai-ichi nuclear power plant in Okuma town, Fukushima prefecture, northeastern Japan, Wednesday, July 18, 2012. The operator of the tsunami-crippled nuclear plant in last year's disaster is taking two fuel rods out of a spent-fuel pool Wednesday to start dealing with a major remaining risk there. All of the 1,535 rods next to the reactor must eventually be removed from the pool to safer storage.

TOKYO — A giant crane removed two rods packed with nuclear fuel from the Fukushima nuclear plant on Wednesday, the beginning of a delicate and long process to deal with a remaining risk of more radiation escaping from the disaster-struck plant.

All of the 1,535 rods next to reactor No. 4 at the crippled Fukushima Dai-ichi plant in northeastern Japan must eventually be removed from a spent-fuel pool to safer storage — an effort expected to take through the end of next year, according to the government.

The pool's building was destroyed by explosions from the multiple meltdowns that followed a massive earthquake and tsunami in March 2011.

Fears run deep about the massive radioactive material stored in the damaged building. The pool is not protected by thick containment vessels unlike the core fuel in the plant's three other reactors. The plant's operator intends to remove the rods one-by-one to deal with the risk of the pool stewing radiation into the surrounding area.

Tokyo Electric Power Co. started the work Wednesday by removing two rods and inspecting their condition, according to Gyo Sato, spokesman for the Nuclear and Industrial Safety Agency, the government regulators.

"Everything is going safely so far," he said.

Japanese TV reports showed cranes removing the 4-meter (13-foot) rods. The utility declined to comment, citing secrecy needs for handling nuclear material. But it said in May that fuel rods would be removed from the pool for the first time since the earthquake and tsunami.

In the days following the disasters, Fukushima Dai-ichi plunged into meltdowns and was rocked by at least two hydrogen explosions after backup generators were knocked out. About 150,000 people were evacuated owing to the worst nuclear disaster since Chernobyl. A 20-kilometer (12-mile) zone around the plant remains a no-go zone.

The pool at No. 4 was behind the secret worst-scenario mapped out by the government, which warned millions of people might have to flee from spewing radiation, including parts of the Tokyo area, which has a population of 35 million people. U.S. authorities have also repeatedly expressed worries about the spent-fuel pool at reactor No. 4.

A year and a half after the disaster, the cooling system has been fixed, and reinforcement built to prop up the pool. But fears remain. TEPCO recently said the wall at the spent fuel pool building was bulging, although the pool was not tilting.

Hiroshi Tasaka, a nuclear engineer and professor at Tama University, who served as adviser to the prime minister after the disaster, said the spent-fuel pool in reactor No. 4 posed a danger because the building was not sufficiently secure to stop radiation escaping in the case of strong aftershocks.

The two rods removed Wednesday are among the 204 rods that have not been used to generate power and are not as prone to spewing radiation as the 1,331 spent-fuel rods, also sitting in the pool.

Tasaka said the government target of removing all the rods by the end of next year may prove too optimistic, and the effort may take longer because of the many unknowns, the need to develop new technology and the risk of aftershocks.

"If we are asked whether things are completely safe, we cannot say that," he said. "If there is another major earthquake, we don't know what may happen, although we hope for the best."

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