(TOKYO) -- After workers successfully plugged the highly radioactive leak seeping into the Pacific Ocean, a new confidential assessment by the Nuclear Regulatory Commission obtained by The New York Times suggests that the damaged Fukushima Daiichi plant is far from stable.
Fragments of incredibly dangerous nuclear fuel were blown out of the reactors "up to one mile from the units," and then simply bulldozed over to protect workers on site, according to the NRC report.
Until now, flooding the damaged reactors with water has been considered the most efficient cooling method but the latest assessment raises concerns that the water may have introduced a new set of dangerous complications. U.S. engineers now worry that the enormous amount of water is actually weakening the containment vessels, making them more vulnerable to possible ruptures.
In an effort to avoid the continued spread of radiation and worse, a hydrogen explosion due to the hydrogen and oxygen present in seawater, plant operator Tokyo Electric Power Company announced that it will begin injecting nitrogen into reactor one and likely reactors two and three. Nitrogen is normally present inside the containment that surrounds the reactor core and can prevent highly combustible hydrogen from exploding as it did three times in the early days after the March 11 disaster.
ABC News contributor and president of Ploughshares Fund, Joe Circinione told ABC News that a hydrogen explosion, while not expected, is not totally out of the question.
"A new hydrogen explosion could happen, there could be a failure of one of the fuel rods, the fuel ponds that could cause a fire and if so, it could be a major release of radiation," said Circinione.
While the newest threat is concentrated on land, nearly 11,500 tons of radioactive sea water is slowly diluting in the Pacific Ocean. Many worry that migrating fish such as albacore tuna might be contaminated as they make their way from Japan to the Pacific Northwest.
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