Stop the leaks into the ocean

July 10, 2013

Expert: TEPCO must stop groundwater leaks

http://www3.nhk.or.jp/nhkworld/english/news/20130710_08.html

A Japanese researcher says the operator of the damaged Fukushima Daiichi nuclear plant must step up measures and monitoring to stop radiation-tainted groundwater from seeping into the sea.

The operator of the plant has said radioactive cesium levels at one observation well near the sea soared over the past several days.

Groundwater expert Atsunao Marui of the National Institute of Advanced Industrial Science and Technology made the comment after levels of radioactive substances surged over a 4 day period at one of the plant's observation wells.

Tokyo Electric Power Company said on Tuesday that levels of cesium 137 had risen to 22,000 becquerels per liter of water, or more than 100 times the level logged last Friday. It also reported on Monday that radioactive cesium levels soared 90 times from last Friday.

Marui says TEPCO must take a multi-layered approach to stop what may be new leaks of contaminated groundwater from the building that houses the No.2 nuclear reactor. He suggests that the utility install steel plates around the reactor in addition to reinforcing embankments on the coastal side of the plant, and fill the gaps with clay or other water-resistant materials.

Marui also says TEPCO must grasp the overall flow of the groundwater, including vertical streams. He says the firm should dig more observation wells on the plant compound and monitor groundwater springing forth under the sea.

TEPCO started drilling holes along the sea bank on Monday ahead of pouring in chemicals to harden and waterproof the soil. It also plans to increase observation wells to strengthen monitoring.