To reduce the flow of groundwater into the crippled reactor buildings at Tokyo Electric Power Co.'s Fukushima No. 1 atomic plant, the government told Tepco on Thursday to freeze the soil around them.

Walls of frozen soil can be created by inserting pipes into the soil and injecting them with coolant. Tokyo-based major general contractor Kajima Corp. came up with the idea.

A panel under the Ministry of Economy, Trade and Industry discussing ways to lessen the radioactive water at the Fukushima plant drew up a draft report the same day that suggests using frozen-soil walls to keep the groundwater at bay. METI Minister Toshimitsu Motegi told Tepco President Naomi Hirose to take measures based on the report.