(TOKYO) -- UPDATED: The water which caused radiation burns to three workers at the Fukushima Daiichi nuclear power plant was 10,000 times more radioactive than normal. Nuclear experts are now saying that the water could only reach those levels if it had come into contact with uranium, meaning a breach of the core was almost certain.
A somber Prime Minister Naoto Kan Friday called the situation "grave and serious."
"We are not in a position to be optimistic," he said.
"We must remain vigilant," Kan said. "We must treat every development with the utmost care."
The U.S. military is now taking a direct role in attempts to cool reactors at the damaged nuclear plant, according to U.S. and Japanese officials.
As a first step, the U.S. military plans to ship 525,000 gallons of fresh water on two U.S. Navy barges from a U.S. base in Yokosuka, south of Tokyo, according to a spokesman for the U.S. Forces Japan.
Meanwhile, the death toll in Japan was estimated at 10,175 people, according to NHK TV. More than 17,400 were still missing. It has been two weeks since the 9.0-magnitude earthquake and resulting tsunami hit on March 11.
Japan is still trying to feed and relocate hundreds of thousands of homeless survivors, clear away tons of debris and bury the thousands of dead.
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