Partial Meltdowns Presumed at Crippled Reactors

By HIROKO TABUCHI and MATTHEW L. WALD
Published: March 13, 2011


TOKYO — Japanese officials struggled on Sunday to contain a quickly escalating nuclear crisis in the aftermath of a devastating earthquake and tsunami, saying they presumed that partial meltdowns had occurred at two crippled reactors, and that they were bracing for a second explosion, even as problems were reported at two more nuclear plants.

That brings the total number of troubled plants to four, including one that is about 75 miles north of Tokyo.

The emergency at the hardest hit plant, Fukushima Daiichi Nuclear Power Station, appeared to be the worst involving a nuclear plant since the Chernobyl disaster 25 years ago, and at least 22 residents near the plant showed signs of radiation exposure, according to local officials. The crisis at that plant, which is much further from Tokyo, continued late Sunday.

A day after an explosion at one reactor there, Japanese nuclear officials said Sunday that operators at the plant had suffered a setback trying to bring the second reactor thought to be in partial meltdown there under control. The operators need to inject water to help cool the reactor and keep it from proceeding to a full meltdown, but a valve malfunctioned on Sunday, hampering their efforts for much of the day.

Pressure at the reactor rose during the delay, leading to increased worries of an explosion. At a late-night press conference, officials at Tokyo Electric Power Co., which runs the plant, said the valve had been fixed, but said water levels had not yet begun rising.

Until late Sunday, the government had declared an emergency at only two nuclear plants, Daiichi and the nearby Fukushima Daini.

Then, the International Atomic Energy Agency announced that Japan had added a third to the list because radiation had been detected outside the plant, which is about 60 miles from Sendai, a city of 1 million people in Japan’s northeast. The government did not immediately confirm the report from the I.A.E.A., which said it was not yet clear what caused the release of radiation.

Soon after that announcement, Kyodo News reported that a plant about 75 miles north of Tokyo was having cooling system problems.

The government was scrambling Sunday to test people who lived near the Daiichi plant, with local officials saying that about 170 people had likely been exposed, but it was unclear if they or the 22 who showed signs of exposure had received dangerous doses. Early Sunday, the government said three workers were suffering full-out radiation illness.
The developments at Daiichi and Daini prompted the evacuation of about 80,000 people.
On Sunday, Kumiko Fukaya, 48, who fled the area with several family members, she had been lulled into a false sense of complacency because, she said, the plant 12 miles from her home had not had serious problems before. Then, on 7:30 Saturday morning, loudspeakers throughout her town of Tomioka blared a call for evacuation.
“The entire town was enriched by Tokyo Power,â€