” (UPDATE) According to @jaikoman who follows and tweets on every single TEPCO and NRA press conferences, TEPCO poured ice and dry ice, thinking ice would float, cooling the top layer of water, and dry ice would sink, cooling the bottom layer of water.
Well they need a Plan C. Dry ice pieces they pour were apparently too small, and they all floated. Water remain unfrozen, and TEPCO says they will know by mid August whether the operation will work.
TEPCO says by dumping ice and dry ice they can lower the temperature of the contaminated water in the trench to about 5 degrees Celsius, then they will be able to form a continuous ice plug.
Here I thought that water freezes at zero degree Celsius. As the whole world is seemingly going crazy afresh this July, maybe TEPCO is correct that water does freeze at 5 degrees Celsius.
From TEPCO’s photos and videos library, 7/24/2014:
On July 24, 2014, TEPCO started the experiment of dumping ice into the Reactor 2 turbine building trench, trying to freeze highly contaminated water which has refused to freeze despite 3 months of freezing effort. Workers dumped only 2 tonnes of ice, or 4 bags with 500 kilograms of ice each. … ”