30-fold radiation spike in groundwater after leak

March 12, 2015

Groundwater radiation levels surge after leak

http://www3.nhk.or.jp/nhkworld/english/news/20150312_11.html

Mar. 12, 2015 - Updated 02:10 UTC+1

The operator of the Fukushima Daiichi nuclear plant says levels of radioactive material in groundwater have surged 30-fold, apparently after contaminated rainwater leaked outside a barrier.

Workers at Tokyo Electric Power Company, or TEPCO, discovered the problem on Tuesday at an area in the hillside part of the complex where radioactive water is stored in tanks.

TEPCO says rainwater that is pooled outside the double barrier surrounding the complex had spread and apparently seeped into the ground.

The company estimates the leak at about 750 tons of rainwater, and it says levels of beta ray-emitting substances in water inside the barrier registered a maximum 8,300 becquerels per liter.

On Wednesday, TEPCO measured 11,000 becquerels per liter in groundwater from nearby monitoring wells. That's up from 370 becquerels on Monday, the day before the leak was found.

The utility says it does not know yet if the contaminated rainwater has seeped into the Pacific Ocean. It says the water leaked from seams in the barrier.