Source of increasing contamination at Fukushima Nuclear Plant unknown

Via VOA: "A leakage detective unit (C) and its detection punch unit on an underground water storage tank are seen at TEPCO's tsunami-crippled Fukushima nuclear power plant in Fukushima, in this undated photograph released by TEPCO on April 6, 2013."

Snip from a report by Voice of America's Steve Herman in Tokyo:

"Fresh revelations about radiation contamination from the operator of the crippled Fukushima nuclear power plant and a government regulator are prompting new concerns in Japan. What is expected to be a decades-long battle to halt radiation leaks and to clean up contaminated soil and water at the Fukushima-1 nuclear plant is back in the public eye following the release of new information this week."

TEPCO, the plant's operator, says there's a steady increase in the levels of radioactive cesium in the groundwater, and in levels of strontium and tritium offshore.