Japanese broadcaster NHK reported on Friday that an ice wall preventing the flow of groundwater at Japan's Fukushima Daiichi Power plant operated by Tokyo Electric (TEPCO) may have partially melted.

TEPCO will start construction work to reinforce the wall as early as early December and will consider future measures, the report said.

The ice wall was built to prevent the contamination of groundwater at the wrecked nuclear power plant.

(With input from Reuters)