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UPDATE 1-Japan trying to fix nuclear plant cooling problem(Adds details)
TOKYO, March 11 (Reuters) - A cooling system for a nuclear reactor was not working after a powerful earthquake in Japan, prompting the government to declare an emergency situation as a precaution although it said there was no radioactive leakage at present.
Residents that live within a 3 km radius of Tokyo Electric Power's Fukushima Daiichi nuclear plant have been told to evacuate, Japan's Chief Cabinet Secretary Yukio Edano told a news conference.
TEPCO confirmed that water levels inside the reactors at its Fukushima-Daiichi nuclear plant were on a falling trend, but added it was working to maintain water levels to avert the exposure of nuclear fuel rods.
The company has been trying to restore power to its emergency power system so that it can add water to the inside of the reactors, a TEPCO spokesman said. (Reporting by Osamu Tsukimori; Writing by Edwina Gibbs; Editing by Joseph Radford)