Tepco estimated from May 2011 to the start of August, about 40 trillion becquerels of radioactive tritium, 20 trillion becquerels of cesium and 10 trillion becquerels of strontium may have flowed from the damaged Fukushima No. 1 nuclear complex into the sea, The Japan Times reported.
On Sept. 6, an expert panel set up by the Nuclear Regulation Authority is to begin studying the radioactive materials' effect on marine life, focusing on tritium.
Tritium, which has a half life of about 12 years, cannot be removed from water even with Tepco's advanced liquid processing system that will be used to clean contaminated water used to cool reactors damaged by the 2011 earthquake and tsunami, the news report said.
Jota Kanda, oceanographer at Tokyo University of Marine Science and Technology, told The Japan Times Friday tritium contaminating waters surrounding the Fukushima No. 1 nuclear plant will likely have little effect on marine life because it has been diluted by seawater.
Meanwhile, a cooperative is suspending fishing in the waters near the Fukushima plant, officials said Thursday.
The announcement by the Soma Futaba fisheries cooperative followed Tepco's admission highly contaminated water is leaking into the ocean from the plant, Kyodo News reported.
The Soma Futaba announcement followed an earlier one from another cooperative that it will not resume fishing.