So says Japan's Nuclear and Industrial Safety Agency. NHK World has the details here:
The Nuclear and Industrial Safety Agency spoke to reporters on Friday about an accident in which 3 workers were exposed to radiation in the turbine building of the No. 3 reactor.
It said 3.9 million becquerels of radiation was detected from 1 cubic centimeter of water sampled from the floor of the building. The radiation level was about 10,000 times higher than the water inside a normally operating nuclear reactor.
The agency said the water sample indicated it is highly likely the leak comes from the reactor itself, not from the pool storing spent nuclear fuel.
According to the officials, pressure inside the reactor core is stable and the agency doesn't believe the reactor is cracked or broken. But it says it is highly possible that radioactive materials are leaking from somewhere in the reactor.
The agency also said high levels of radiation have been measured at reactors No. 1 and 2, and speculates there may also be leakage from them. Cooling operations using seawater are continuing at the reactors.
