TOKYO: A Japanese military helicopter was deployed on a mission Wednesday to dump water from a huge bucket onto fuel rods at the stricken Fukushima nuclear power plant.

The Self-Defence Forces twin-rotor CH-47 Chinook was shown taking off and flying to the plant by public television NHK, but it did not immediately broadcast images of a water dump.

A defence ministry official said the military had received orders at 4 pm (0700 GMT) to send one CH47 to the Fukushima plant. Several other helicopters were on standby, said the Yomiuri Shimbun online.

"We know how to put out forest fires, but not a nuclear plant," said the official at the ministry's ground staff office. "It's the first time for us so we don't know what the result will be.

"There are unknowns -- what the radioactive risks are and whether dumping the water will be successful. But since this is an emergency, the government has decided to do it this way."