Japanese military fire trucks were ready to cool an overheating nuclear reactor in north-eastern Japan to prevent a potential disaster, news reports said Friday.
If requested, military fire trucks will start dousing the fuel storage pool at reactor 3 of Fukushima I nuclear power plant, which was damaged by the earthquake and tsunami that devastated the region a week ago, public broadcaster NHK said.
Cooling systems at the reactors failed after the electricity system was knocked out in the disaster, dpa reported.
Five military firefighting vehicles late Thursday sprayed water onto the fuel storage pool inside the reactor 3 after police water cannons could not get close enough earlier in the day.
The plant's operator, Tokyo Electric Power Company (TEPCO), said that the move had been effective as steam was seen rising from the damaged building.
Radiation readings around the reactor fell slightly after the move, Japan's nuclear safety commission said Friday.
The radiation reading came to 279.4 microsievert per hour at the point roughly 1 kilometre west of the reactor number 2 as of 5 am (2000 GMT), compared with 292.2 microsievert per hour at 8:40 pm (1100 GMT) Thursday, shortly after the fire trucks doused water, Kyodo News reported citing the commission.
Levels of 1,000 millisievert per hour can cause radiation poisoning.
High levels of radiation at plant were hindering efforts to cool the reactor Thursday.
The dumping of 30 tons of seawater over the reactor by military helicopters early Thursday had failed to reduce the level of radiation.