NHK Newsline, Dec. 20, 2013: Engineers are grappling with another problem far below their feet […] Workers have also detected substances that emit beta radiation in groundwater near Reactor 2, The concentration has been rising since last month. It reached a record high on Thursday this week at 1.9 million Bq/liter.
NHK WORLD, Dec. 20, 2013: […] radioactive substances have been detected in water samples taken from deep underground […] Highly radioactive substances had been detected in previous months in shallow groundwater that was found to be leaking into the ocean. But for the first time in December, TEPCO investigators detected radioactivity in groundwater taken from a layer 25 meters [~82 feet] beneath the No. 4 reactor’s well facing the ocean. […] 6.7 becquerels per liter of Cesium 137 and 89 becquerels per liter of strontium and other beta ray-emitting radioactive substances […] they are concerned that if contamination of deeper layers of groundwater is confirmed, it could be another source that is leaking into the ocean. […]