Tokyo Electric Power Company (Tepco) has begun construction of a wall of frozen soil at the Fukushima Daiichi nuclear power plant following approval from Japan's Nuclear Regulation Authority.
The ice wall will prevent groundwater entering the reactor buildings and is expected to take nine months to complete, reports World Nuclear News.
The full-scale use of ice wall technology at Fukushima amounts to the largest ground-freezing operation in the world. Tepco plans to drill holes 30-35m into the ground and insert pipes through which refrigerant will be then be pumped. This cooling will freeze the soil surrounding the pumps creating an impenetrable barrier around the reactor buildings. In total, some 1,550 pipes will be placed in the ground to create a 1.5km-long ice wall around units 1 to 4.
A Tepco official was cited by media sources as saying: "We plan to end all construction work in March 2015 before starting trial operations."
The construction of the ice wall is estimated to cost 32 billion yuan ($313 million). It was mandated by the government as part of a concerted effort to bring the contaminated water situation at Fukushima Daiichi under control.
