The operator of the crippled Fukushima Daiichi nuclear complex began work Tuesday to extend an underground ice wall to prevent contaminated water increasing within the facilities.The coolant-filled wall is designed to prevent groundwater from seeping into the facilities and touching melted nuclear fuel or becoming mixed with highly contaminated water inside reactor buildings.Fukushima  nuclear power plant -- ice wall(Pool Photo)The government has spent some 35 billion yen ($320 million) on the project. Work by Tokyo Electric Power Company Holdings Inc. to freeze the wall began in March last year.On Tuesday, the utility opened valve…READ FULL ARTICLE