“We have no choice but to scrap” the No. 1, 2, 3 and 4 units at the Fukushima Daiichi Nuclear Power Station, Tsunehisa Katsumata told a news conference.
Many analysts have said the move was inevitable following the damage the units have suffered since the March 11 earthquake and tsunami, but it marked the first time the company has explicitly acknowledged that much of its multibillion investment is irrecoverable.
He said the No. 5 and 6 units were still operational, but said any restart of those would depend on consultation with the government and local residents.
Mr. Katsumata, 71, is taking over leadership of Tokyo Electric Power after the president, Masataka Shimizu, 66, was hospitalized on Tuesday. Mr. Shimizu was being treated for hypertension and dizziness, the company said.
Other than a news conference on March 13 where he apologized to the public, Mr. Shimizu has been largely absent since the disaster struck. Japanese media had been rife with theories on his disappearance, with some even reporting rumors that he had committed suicide.
Mr. Katsumata also offered his “sincere apologies” to those affected by the nuclear crisis, which has forced thousands of people to evacuate the area around the plant and left farmers unable to sell radiation-tainted produce.
Earlier on Wednesday, Japan’s nuclear safety agency said seawater tested near the Fukushima Daiichi plant was found to contain sharply increased levels of radioactive iodine.
The sampling, taken on Tuesday about 300 yards off the coast from the plant, was found to contain iodine 131 at 3,355 times the safety standard, said Hidehiko Nishiyama, deputy director general of the Nuclear and Industrial Safety Agency. He said the readings posed no immediate threat to public health, and no fishing was being conducted in the area.
In recent days, the announcements of mounting contaminated water in the plant, as well as the discovery of plutonium traces in the soil outside the facility and an increasingly dangerous environment for plant workers have forced government officials to acknowledge the dangerous side effects of measures taken to keep nuclear fuel cool.
Yukio Edano, the chief government spokesman, said on Wednesday the government and nuclear experts are considering new steps to prevent the spread of radiation from the plant, such as covering the reactors with a special cloth to reduce the amount of released radiation. Mr. Edano also said the government is considering using a tanker to collect contaminated water.
Meanwhile, Greenpeace, the antinuclear environmental organization, on Wednesday gave guarded endorsement to the radiation data published by the Japanese government concerning the Fukushima plant.
The organization, which has a well-known anti-nuclear stance, had said that it was coming to Japan to provide “an alternative to the often contradictory information released by nuclear regulators.”
There has been some public mistrust regarding the official data, with fears exacerbated by occasionally contradictory announcements. But Jan van de Putte, a Greenpeace official, said Wednesday that its scientists’ findings largely correlated with the official Japanese data.
“There is no contradiction between Greenpeace data and local data,” he said. “The contradiction is between the data, and action to help people” in the affected areas.
The organization recommended that the government move more aggressively to evacuate residents near the complex.
But Mr. van de Putte declined to say whether he recommended expanding the Japanese government’s evacuation zone beyond the 19-mile band that is now the de facto standard after officials last week began encouraging people 12 to 19 miles from the plant to leave.
The American government has recommended that people stay at least 50 miles away from the plant.
Moshe Komata and Ayasa Aizawa contributed reporting from Tokyo, and Kevin Drew from Hong Kong.