TOKYO – Japanese officials began quietly encouraging people to evacuate a larger swath of territory around the Fukushima Daiichi nuclear plant on Friday, a sign that they hold little hope that the crippled facility will soon be brought under control.
The authorities said they would now assist people who want to leave the area from 12 to 19 miles outside the crippled plant and said they were now encouraging “voluntary evacuation” from the area. Those people had been advised March 15 to remain indoors, while those within a 12-mile radius of the plant had been ordered to evacuate.
The United States has recommended that its citizens stay at least 50 miles away from the plant.
Speaking to a national audience at a news conference Friday night to mark the two weeks since the magnitude 9.0 quake and the devastating tsunami that followed it, Prime Minister Naoto Kan dodged a reporter’s question about whether the government was ordering a full evacuation, saying officials were simply following the recommendation of the Japan Nuclear Safety Commission.
In the latest setback to the effort to contain the nuclear crisis, evidence emerged that the reactor vessel of the No. 3 unit may have been damaged, an official said Friday. The development, described at a news conference by Hidehiko Nishiyama, deputy director-general of the Japan Nuclear and Industrial Safety Agency, raises the possibility that radiation from the mox fuel in the reactor — a combination of uranium and plutonium — could be released.
One sign that a breach may have occurred in the reactor vessel, Mr. Nishiyama said, took place on Thursday when three workers who were trying to connect an electrical cable to a pump in a turbine building next to the reactor were injured when they stepped into water that was found to be significantly more radioactive than normal in a reactor.
The No. 3 unit, the only one of the six reactors at the site that uses the mox fuel, was damaged by a hydrogen explosion on March 14. Workers have been seeking to keep it cool by spraying it with seawater along with a more recent effort to restart the reactor’s cooling system. A broken vessel is not the only possible explanation, he said. The water might have leaked from another part of the facility.
The news Friday and the discovery this week of a radioactive isotope in the water supplies of Tokyo and neighboring prefectures has punctured the mood of optimism with which the week began, leaving a sense that the battle to fix the damaged plant will be a long one.
“The situation still requires caution,” Mr. Kan, grave and tired-looking, told the nation. “Our measures are aimed at preventing the circumstances from getting worse.”
Mr. Kan also apologized to the businesses and farmers whose livelihoods have been endangered by the plant. He acknowledged the assistance of the United States and thanked the many people — utility workers, military personnel, policemen and firefighters — who are risking their lives in an effort to restore the cooling functions of the plant and stop the harmful release of radiation.
“Let us take courage, and walk together to rebuild,” he added. “The nation united, as one, to overcome the crisis.”
No one is being ordered to evacuate the second zone around the troubled plant, officials said, and people may choose to remain, but many have already left of their own accord, tiring of the anxiety and tedium of remaining cooped up as the nuclear crisis simmers just a few miles away. Many are said to be virtual prisoners, with no access to shopping and immobilized by a lack of gasoline.
“What we’ve been finding is that in that area life has become quite difficult,” Noriyuki Shikata, deputy cabinet secretary for Prime Minister Naoto Kan, said in a telephone interview. “People don’t want to go into the zone to make deliveries.”
Mr. Shikata said the question of where those who chose to leave would go was still under consideration.
NHK, the Japanese public broadcaster, quoted a Land Self Defense Force official as saying, “We’re trying to quickly locate everyone who remains, so that we can rapidly help in case the nuclear plant situation worsens.”
Officials continue to be dogged by suspicions that they are not telling the entire story about the radiation leaks. Shunichi Tanaka, former acting chairman of the country’s Atomic Energy Commission, told The Japan Times in an interview published Friday that the government was being irresponsible in forcing people from their homes around the damaged plant without explaining the risks they were facing.
“The government has not yet said in concrete terms why evacuation is necessary to the people who have evacuated,” he said.
The National Police Agency said Friday that the official death toll from the March 11 earthquake and tsunami had passed 10,000, with nearly 17,500 others listed as missing.
There was some good news. Levels of the radioactive isotope found in Tokyo’s water supply fell Friday for a second day, officials said, dropping to 51 becquerels per liter, well below the country’s stringent maximum for infants.
On Wednesday, Tokyo area stores were cleaned out of bottled water after the Tokyo authorities said the isotope, iodine 131, had been detected in the city’s water supply and cautioned those in the affected areas not to give infants tap water. On Thursday, cities in two of Tokyo’s neighboring prefectures, Chiba and Saitama, also reported disturbing levels of radiation in their water.
Nuclear workers will have to keep venting radioactive gases from the damaged reactors, adding to the plume of emissions carried by winds and dispersed by rain. The public has been warned not to consume food and milk from the area near the plant.
Japanese officials said nine days ago that there were signs of damage to the reactor vessel at reactor No. 3, particularly warning then that there might have been damage to the suppression pool.
But Michael Friedlander, a former nuclear power plant operator for 13 years in the United States, said that the presence of radioactive cobalt and molybdenum in water samples taken from the basement of the turbine building of reactor No. 3 raised the possibility of a very different leak.
Both materials typically occur not because of fission but because of routine corrosion in a reactor and its associated piping over the course of many years of use, he said.
These materials are continuously removed from the reactor’s water system as it circulates through a piece of equipment called a condensate polisher, which is located outside the reactor vessel. The discovery of both materials in the basement suggests damage to that equipment or its associated piping, as opposed to a breach of the reactor vessel itself, Mr. Friedlander said.
The condensate polisher is also located in the basement of the turbine building, where the tainted water was found. By contrast, the reactor vessel is actually located in a completely different, adjacent building, and would be far less likely to leak into the basement of the turbine building.
The aggressive use of saltwater to cool the reactor and storage pool may mean that more of these highly radioactive corrosion materials will be dislodged and contaminate the area in the days to come, posing further hazards to repair workers, Mr. Friedlander added.
Speaking at a Webcast press conference, Sakae Muto, a Tokyo Electric Power vice president, said that the company did not know how badly the seawater used to cool the reactors had contributed to corrosion. Seawater leaves residue behind as it evaporates and corrosion damages critical pipes, valves and metal assemblies.
He said the company had found the same problem with contaminated water in the basements of the No.1 and No. 2 turbine buildings as that which caused the men’s injuries in the No. 3 unit. Removing the radioactive water will delay the work of restarting cooling systems.
On Friday, the company switched to pumping fresh water to cool the No. 1 unit.
David Jolly and Hiroko Tabuchi reported from Tokyo and Keith Bradsher from Hong Kong. Takeshi Takizawa contributed reporting from Tokyo.