Japan Says 2nd Reactor May Have Ruptured With Radioactive Release
At the Fukushima Daiichi nuclear plant, reactors No. 3, left, and No. 4, center, have been damaged.
By HIROKO TABUCHI and KEITH BRADSHER
TOKYO — Japan’s nuclear crisis intensified again Wednesday, with Japanese authorities announcing that a containment vessel in a second reactor unit at the stricken Fukushima Daiichi plant in northeastern Japan may have ruptured and appeared to be releasing radioactive steam. That would be the second vessel to be compromised in two days.
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NHK
Japanese television showed what appeared to be steam rising from reactor No. 3 at the Fukushima Daiichi plant about 10 a.m. Wednesday.
The vessel had appeared to be the last fully intact line of defense against large-scale releases of radioactive materials, but it was not clear how serious the possible breach might be.
The announcement came after Japanese broadcasters showed live footage of thick plumes of steam rising above the plant.
Yukio Edano, the chief cabinet secretary, said the government believed the steam was coming from the No. 3 reactor, where an explosion on Monday blew out part of the building surrounding the containment vessel.
The reactor has three layers of protection: that building; the containment vessel, and the metal cladding around fuel rods, which are inside the reactor. The government has said that those rods at the No. 3 reactor were likely already damaged.
Earlier in the morning, the company that runs the plant reported that a fire was burning at a different reactor, just hours after officials said flames that erupted Tuesday had been doused.
A government official at Japan’s nuclear regulatory agency said that flames and smoke were no longer visible, but he cautioned that it was unclear if the fire, at the Reactor No. 4 building, had died out. He also was not clear if it was a new fire or if the fire Tuesday had never gone out.
There are a total of six reactors at the plant.
The developments are troubling reminders of the difficulties the company is having in bringing the plant, which has suffered multiple explosions since Saturday, under control. And the confusion is emblematic of days of often contradictory reports about what is happening at the plant.
The company, Tokyo Electric Power, says it cannot know for sure what is happening in many cases because it is too dangerous for workers to get close to some reactors.
The situation became especially dire on Tuesday, when releases of radiation led the company to pull most of its workers from the plant.
One of the authorities’ main concerns are over pools for spent fuel rods at several reactors at the plant, including Reactor No. 4, where the pool has lost some of the water needed to keep the fuel rods stable. The rods are still radioactive and potentially as hot and dangerous as the fuel rods inside the reactors.
Minoru Ogoda, the official with Japan’s nuclear regulatory agency, said a proposed plan to use helicopters to put more cold water into the pool was looking unlikely.
He said Tokyo Electric would probably try to spray water into the reactor building through a gaping hole in the wall blasted open by an earlier explosion.
The hole or holes in the roof caused by that blast did not appear big enough to allow sufficient amounts of water in, he said.
That explosion on Tuesday was caused by hydrogen gas bubbling up from chemical reactions set off by the fuel rods in the pool, Japanese officials said. Inspectors from the United States Nuclear Regulatory Commission said they had been told by Japanese authorities that what was burning was lubricating oil from machinery near the pool.
Concern remained high about the storage pools at two other reactors, Nos. 5 and 6. None of those three reactors at the plant, 140 miles northeast of Tokyo, were operating on Friday afternoon when an offshore earthquake with a magnitude now estimated at 9.0 shook the site. A tsunami rolled into the northeast Japanese coastline minutes later, swamping the plant.
At least 750 workers were evacuated on Tuesday morning after a separate explosion ruptured the inner containment building at Reactor No. 2 at the Daiichi plant, which was crippled by Friday’s earthquake and tsunami. The closely spaced but apparently coincidental explosions at Reactors Nos. 2 and 4 together released a surge of radiation 800 times as intense as the recommended hourly exposure limit in Japan.
But 50 workers stayed behind, a crew no larger than would be stationed at the plant on a quiet spring day. Taking shelter when possible in the reactor’s control room, which is heavily shielded from radiation, they struggled through the morning and afternoon to keep hundreds of gallons of seawater a minute flowing through temporary fire pumps into the three stricken reactors, Nos. 1, 2 and 3, where overheated fuel rods continued to boil away the water at a brisk pace.
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