TOKYO - Radioactive water leaked inside a nuclear power plant in southwestern Japan but did not escape into the environment, the government said Saturday.
The leak Friday at Kyushu Electric Power Co.'s Genkai plant occurred as Japan attempts to stabilize a tsunami-hit nuclear plant on its northeastern coast where three reactor cores melted and large amounts of radiation were released into the air and ocean.
Tetsuya Saito, spokesman for Japan's Nuclear and Industrial Safety Agency, said 1.8 tons of radioactive water leaked from a pump in Genkai's No. 3 reactor, and the cause was still under investigation.
The water was funneled into a storage area and posed no safety risk, he said.
Kyushu Electric issued a statement Friday about a pump problem but did not mention the leak. Officials at the utility were not immediately available for comment Saturday.
"There have been various problems at Genkai," Saito said. "But there is no safety problem as a result of what happened this time."
He said it was up to Kyushu Electric to determine whether to announce the leak.
Genkai Mayor Hideo Kishimoto complained that the utility has not been fully open with information.
"The local government needs to know," Kyodo News agency quoted him as saying. "I have repeatedly demanded the utility change its ways."
Last month, Kyushu Electric restarted Genkai's No. 4 reactor after it automatically shut down following an abnormality in a steam condenser that did not cause any radiation leaks or injuries. The No. 3 reactor was halted for a routine inspection when the pump problem developed.
The government has said it will gradually decrease Japan's dependence on nuclear power and has sought to restart nuclear plants halted for inspections.
On Friday, Japanese Prime Minister Yoshihiko Noda said work to stabilize the tsunami-hit Fukushima Dai-ichi nuclear power plant was on track.
Noda said temperatures in the three melted reactor cores have fallen below the boiling point and radiation leaks have declined. But some experts say the state of the cores won't be known for years.
A March 11 earthquake and tsunami destroyed the plant's power and cooling systems, in the world's worst nuclear disaster since Chernobyl.
Radiation believed to be from Fukushima has been detected in a wide range of Japanese products, including rice, beef, fish and baby formula.