Tokyo Electric Power Co. on Tuesday reported that a power outage has shut down all eight water transfer pumps at the Fukushima No. 1 nuclear power station and that radioactive water is again leaking into the Pacific Ocean.

The pumps are being used to pump tainted water from a drainage channel to another channel leading to a fence-enclosed artificial bay facing the station. The beleaguered utility said it was checking into what happened and how much water had leaked.

The pumping had begun last Friday, in response to a finding in late February that highly radioactive water in the channel was reaching the ocean. They were confirmed to be working Monday afternoon but found stopped at 8:45 a.m. Tuesday.

The utility said earlier this year that water samples from the drainage channel last May contained concentrations of radioactive materials that surpassed the legal limit.