On Friday, Tokyo Electric Power Co. representatives told reporters that crews will continue to flood not only the pressure vessels within damaged reactors at the Fukushima Daiichi nuclear plant, but also their containment vessels. The effort to ensure fuel rods are entirely covered with water in the absence of functioning cooling systems has progressed at unit 1, where its suppression pool is filled and its upper containment is believed to be half submerged.
TEPCO, as quoted by the Daily Yomiuri newspaper, said 7,000 tons of water have been pumped into unit 1, which the company does not believe is leaking. Pumping indicates conditions within the plant’s other two damaged reactors, though, are more severe. Each unit's containment should hold about 7,000 tons of water (excluding water inside the pressure vessel). TEPCO said it has injected 9,600 tons of water into unit 3 and 14,000 tons into unit 2 since outside cooling efforts begin, with much of that now believed to have leaked into buildings around and connected to the reactors.
Fearing contaminants from the buildings might leak into groundwater, an advisor to the Japanese Prime Minister told reporters at a press conference Friday that the government is considering building an underground barrier. Reaching far enough into the ground to penetrate a layer of earth impermeable to water from above, the structure would surround units 1 though 4.
Although engineers are still concerned about radioactive contaminants escaping plant grounds, readings taken nearby remain well below their peak last month and did not change significantly over the weekend. On Friday, government regulators lifted restrictions on the sale of spinach from two areas near the plant. On Thursday regulators lifted a ban on shipments of milk from two municipalities nearby.