According to an article in today’s issue of The Telegraph:
The operator of Japan’s crippled Fukushima nuclear plant has conceded defeat in its effort to create a frozen plug in a tunnel to stop water flowing into the No. 2 reactor building and becoming contaminated with radiation.
Since early June, engineers from Tokyo Electric Power Co. (TEPCO) have injected more than 400 tons of ice and dry ice into the tunnel in an effort to freeze a section of the passage solid.
Halting the flow of water through the tunnel, which was originally used to run cables into the reactor’s turbine building, would have made it possible to pump highly radioactive water out to be treated.
Never fear, TEPCO has a Plan B, (which is very similar to what most of us would have considered as Plan A,):
Tepco said that it will now experiment with cement and other sealant materials in an effort to stop the water moving through the tunnel, as well as installing a filter to try to slow the flow of water.
TEPCO also said that the failure of the ‘ice plug’ doesn’t mean that the company’s ‘ice wall’ on the other side of the site won’t work, though:
Officials have also emphasised that the failure of the effort to freeze water in the tunnels is not connected with the construction of an impermeable wall of soil frozen with chemicals on the landward side of the plant in order to stop groundwater seeping into the reactor buildings and becoming contaminated before escaping into the Pacific Ocean.