Tokyo Electric Power Co (TEPCO) said the sensors, which were rigged to a gutter that pours rain and ground water at the Fukushima Daiichi plant to a nearby bay, detected contamination levels up to 70 times greater than the already-high radioactive status seen at the plant campus.

TEPCO said its emergency inspections of tanks storing nuclear waste water did not find any additional abnormalities, but the firm said it shut the gutter to prevent radioactive water from going into the Pacific Ocean. MORE