New failing in halting water

November 18, 2014

Attempt to stop water flowing into trench at Fukushima plant fails

http://mainichi.jp/english/english/newsselect/news/20141118p2a00m0na005000c.html

An effort to stop contaminated water from flowing into a trench at the crippled Fukushima No. 1 Nuclear Power Plant failed to completely halt the flow, announced Tokyo Electric Power Co. (TEPCO), the plant's operator, on Nov. 17.

A TEPCO representative said, "We believe we have not completely stopped the water. Groundwater may also be entering the trench. We will closely analyze the changes in water level in the trench."

TEPCO says that when around 200 tons of contaminated water was removed from the trench, the water level in the trench should have fallen by around 80 centimeters if the point of leakage between the plant's No. 2 reactor turbine building and the trench had been fully sealed. However, the water level only fell by 21 centimeters, so TEPCO determined that the leak must be continuing.

Around 5,000 tons of contaminated water from the turbine building is in the trench, and critics have pointed out the possibility of it escaping into the ocean. Originally TEPCO planned to freeze the water at the point where the turbine building and the trench meet in order to stop the flow of water, after which it planned to remove the water from the trench. However, the water was insufficiently frozen to stop the flow, and while an effort continued until Nov. 6 to fill in the gaps in the ice with special cement, this effort also failed to provide a complete seal.

While the water remains in the trench, TEPCO cannot create a planned underground wall of frozen soil around the No. 1 through 4 reactor buildings to stop water leakages. TEPCO is considering filling in the trench by pouring in cement as it removes the built up water. Discussion on the particulars of this strategy is to be held at a meeting of the Nuclear Regulation Authority on Nov. 21.

November 18, 2014(Mainichi Japan)

November 17, 2014

Radioactive water to tunnels unlikely stopped

http://www3.nhk.or.jp/nhkworld/english/news/nuclear.html

Nov. 17, 2014 - Updated 21:22 UTC+1

The officials overseeing the decommissioning of the Fukushima Daiichi nuclear power plant say a barrier designed to prevent radioactive water from entering underground tunnels is likely not doing its job.

The decommissioning work includes a plan to remove highly-radioactive water from tunnels under the facility grounds and then fill them with concrete to prevent leaks to surrounding soil.

A barrier to hold out water during this process was under construction until November 6th.

On Monday, workers removed 200,000 liters of water, estimating that water levels in the tunnels would drop by 80 centimeters.

However, the levels went down by only 20 centimeters. This led officials to conclude that more water was likely entering the tunnels from the reactor building while water was being pumped out.

The officials considered the effects of radioactive water on ground water, and decided on a plan to fill tunnels in with cement before they are completely drained.

They say the operation will require carefully handling to prevent any overflow of contaminated water.