Updated August 6, 2013, 12:37 p.m. ET
At Fukushima, Fear of a Losing Battle
Tepco Builds Sunken Barrier to Ring-Fence Site, but Water May Have Already Overtopped Wall
MARI IWATA and PHRED DVORAK
To stem the advance of radioactive water to the sea, the operator of the stricken Fukushima Daiichi nuclear power plant has tried plugs, walls, pumps and chemicals that harden the ground into a solid barrier. But as Tokyo Electric Power Co.9501.TO +3.16% prepares this week to start work on a new set of measures that would ring off and cap the area where the most highly contaminated water has been found, some experts and regulators are saying that the battle to completely contain radioactivity to the site of one of the world’s worst nuclear accidents may be a losing one.In the most recent example of Tepco’s Sisyphean struggle, the company said late last week that rising levels of contaminated groundwater may have already overtopped a sunken barrier that the utility started only a month ago, and wasn’t even expecting to complete until late this week.