Pumping has begun for a groundwater diversion system at Fukushima Daiichi nuclear power plant. A series of uphill wells draws groundwater into tanks where it is held temporarily for testing before discharge into the sea.

The system is intended to reduce the 400t of water that seeps into the contaminated ground underneath the plant and itself becomes contaminated, further adding to the water treatment burden faced by the site.

TEPCO said that the project is one of three measures to help reduce the risk of spreading contamination into seawater. TEPCO is building an impervious piled seawall in front of the plants, and has begun operations to freeze the soil around the reactor buildings in a wall to limit water ingress into the contaminated soil.