Highly radioactive water at the crippled Japan's Fukushima Daiichi nuclear plant has leaked into a nearby bay, but the cause and amount of the leakage have yet to be investigated, Tokyo Electric Power Co. said Monday.
A company official said the bay is surrounded by fences and the plant operator believes the water did not flow into the ocean outside the bay, but details remain unknown, according to Japan's (Kyodo) News Agency.
According to TEPCO, radiation levels more than 70 times greater than usual were detected in a gutter on the premises of the complex on Sunday.
The levels of beta ray-emitting substances, such as strontium, measured up to 7,230 becquerels per liter as of Sunday morning, but fell to 20 becquerels by around 10 p.m. the same day.