Japan's Tokyo Electric Power Company will soon suspend the excavation of an undersea tunnel where contaminated water from the Fukushima Daiichi nuclear power plant has been discharged into the sea, Kyodo News reported Wednesday.  About 80 percent of the 1km tunnel has been excavated, but priority needs to be given to projects around the outlet.  The resumption of excavation is expected to take place around April next year, which is likely to be delayed until after summer as planned by the Japanese government and Tepco.  

In August, Tepco fully started work on equipment to discharge contaminated water from the nuclear plant, and by December 2 had excavated about 780 meters under the sea floor, the report said.  A temporary stop will be made when the excavation reaches about 800 meters.  

In the meantime, concrete reinforcement works will be carried out around the concrete caissons installed at the exit of the tunnel.  It is expected to take about four months but could be delayed depending on weather and wave conditions.  

According to the report, the construction of the inner wall of the shaft, which will inject contaminated water during the discharge period, will be carried out ahead of schedule.  

The excavation of the tunnel will be resumed around April next year when the two projects are completed, and the remaining 200 meters will be completed in two to three months.