Radioactivity levels of strontium and tritium well above their legal limits were detected in well water at the stricken Fukushima No. 1 nuclear plant, Tokyo Electric Power Co. said June 19.
Radioactivity levels of strontium and tritium well above their legal limits were detected in well water at the stricken Fukushima No. 1 nuclear plant, Tokyo Electric Power Co. said June 19.
The company cited readings of about 1,000 becquerels of strontium per liter of water--30 times the safety standard--and about 500,000 becquerels of tritium--eight times the limit.
TEPCO detected the radioactive materials between late May and mid-June in water samples taken from the well on the seaside of the turbine buildings for the No. 1 and 2 reactors.
The well is 27 meters from the sea.
TEPCO said it has yet to confirm if the contaminated water reached the ocean, but it said it has found no significant changes in the concentration of radioactive materials in the seawater.
The company said it will inject a sealing agent into the ground between the well and the sea to prevent the contaminated water from leaking into the ocean.
Strontium readily dissolves in water and tends to accumulate in human bones.
TEPCO said the radioactive water likely entered the ground immediately after the accident started in March 2011, and later mixed with groundwater and flowed into the well.
The well is one of three that TEPCO dug late last year to measure radioactivity levels in groundwater at the plant.
In April 2011, water with high levels of radioactivity leaked into the sea from near a water intake system of the No. 2 reactor. That area is close to the well containing the high levels of strontium and tritium.