NRA allows completion of icewall

August 15, 2017

Completion of Fukushima plant ice wall approved

https://www3.nhk.or.jp/nhkworld/en/news/20170815_24/

Nuclear regulators have approved the completion of an ice wall being built to keep groundwater from entering the damaged Fukushima Daiichi reactor buildings.

The Nuclear Regulation Authority on Tuesday gave permission to complete the remaining part of the underground ice wall. Freezing of the soil started in March last year.

Plant operator Tokyo Electric Power Company is circulating coolant in pipes buried around the buildings to make the 1.5 kilometer-long ice barrier.

The utility hopes to keep groundwater from entering the buildings and being contaminated with radioactive substances.

TEPCO officials had left a 7-meter section of the wall unfrozen. Nuclear regulators were concerned that freezing the entire wall could lead to a sharp drop in the level of groundwater outside the buildings. They said this might cause tainted water inside to leak out.

The utility explained to regulators they don't expect the groundwater level to plunge, and they are prepared to deal with such a case.

TEPCO officials plan to start freezing the remaining section on Tuesday next week. They say the completed ice wall will help to drastically reduce the amount of contaminated water.