TEPCO to start work by year-end to block radiation water leak to sea
The work to hammer the shield to a depth of 20 meters in the ground is expected to take some two years for completion, the utility said.
The company, known as TEPCO, plans to work out a basic design for the shield by the end of August.
The designing work was part of the "Step 2" or the second phase of work to bring the plant under control, slated for three to six months from mid-July. On July 19, however, TEPCO changed the schedule and decided to move the design work forward.
The company is also considering surrounding the four reactors with the shield in the end.
The dosage, which was detected at the bottom of a principal exhaust pipe between the two reactors by three plant workers at about 2:30 p.m., may be larger than the measured amount as it exceeds the capacity of measuring equipment.
TEPCO will inspect causes of the high dosage, making the area off-limits.