from rt.com: The source of the radioactive leak at the earthquake-stricken Fukushima Daiichi nuclear power plant was finally identified by the facility’s operator TEPCO to be in the primary containment vessel of reactor 3, authorities reported. It was in January when the crew of the plant first noticed that water was leaking through to the drain on the first level of the building housing the reactor. Engineers probed the space with a camera and found the water leakage to be near a pipe joint that connects directly to the containment vessel.