Japan’s nuclear crisis took a turn for the worst Wednesday when officials said another reactor at the Fukushima Daiichi plant in northeastern Japan may be releasing radioactive steam, causing the United States embassy to recommend a wider evacuation zone around the complex.

The rupture was reported in reactor 3, a day after plant officials said there was a crack in reactor 2.

The new information seems to be another setback in worldwide efforts to contain a possible meltdown at the nuclear power plant, but Japanese officials said this incident was not as severe as it seemed.

The New York Times reported:

Yukio Edano, the chief cabinet secretary, said the possibility that the No. 3 reactor had “suffered severe damage to its containment vessel is low.” Earlier he said only that the vessel might have been damaged; columns of steam were seen rising from it in live television coverage.

The reactor’s operator, Tokyo Electric Power Company, said it had been able to double the number of people battling the crisis at the plant to 100 from 50, but that was before the clouds of radioactive steam began billowing from the plant. On Tuesday, 750 workers were evacuated, leaving a skeleton crew of 50 struggling to reduce temperatures in the damaged facility. An increasing proportion of the people at the plant are soldiers, but the exact number is not known.

Most concerns are aimed at reactor 4, which seems to be at the greatest risk for overheating, due to low levels of water in its cooling pool. Japanese officials planned to dump water from helicopters on the reactors, but the plans were cancelled today due to the second rupture.

Global concern has grown over the possible meltdown as well. The United Nations called an emergency meeting of their nuclear agency Wednesday in wake of worsening news coming from Japan. 

From Bloomberg:

The United Nations’ nuclear agency will call an emergency meeting to discuss the crisis in Japan as a breach at the stricken Fukushima Dai-Ichi plant increased the risk of a radioactive leak.

IAEA Chief Yukiya Amano is flying to Tokyo to talk with authorities today and will return for the meeting as soon as possible, he told reporters in Vienna yesterday. It will be the first extraordinary meeting of the agency’s 35-member board since his election to succeed Mohamed ElBaradei two years ago.

Japan’s health and welfare minister raised the standard of radiation exposure for workers at the Fukushima plant to five times the legal limit in the United States in order to allow them to return. However, United States officials are taking a cautious approach to aid efforts in northeastern Japan.

The Washington Post reported:

In Washington, the Pentagon announced Wednesday that U.S. forces participating in relief operations in Japan will not be allowed within 50 miles of the Fukushima Daiichi plant. Officials also said some flight crews are being issued potassium iodide tablets, which can reduce the risk of thyroid cancer from radiation exposure. The measure was described as precautionary. Several U.S. helicopter crews have been exposed to low levels of radiation, but no service members have shown signs of illness.