All this to say: As crazy as it sounds, humans regularly freeze vast chunks of Earth... because we can. (I am reminded of our unofficial motto: This is your world. Look at it.)

The Fukushima plant is not even the largest ice wall ever attempted. Sopko, Andersland's last PhD student at Michigan State, told me that in the 1990s, he'd designed and installed a 3.5 kilometer perimeter wall that required 1,950 pipes, 159,000 meters of drilling, and eight 1,500 horsepower compressors for the Aquarius gold mine in Ontario, Canada. Unfortunately, while the pipes were being installed, the price of gold plummeted and the system was never switched on.

These images of the Aquarius ice wall system provided by Sopko may be a glimpse of Fukushima's future (Joe Sopko).

"Right now, we're currently involved in a pilot test in the oil sands. The proposed job would be 8 kilometers," Sopko told me. "We're right in the middle of freezing a pilot test."

While some technologies need to change a lot as they scale up, ground freezing isn't one of them. As Harris notes in Ground Freezing in Practice, "The method is not limited by problems of scale."

"The three really large jobs that I've looked at, the only thing that makes those different than the small [mining] shaft is the coolant distribution system, being able to pump enough coolant through the pipes," Sopko said. "It's pretty easy to do, though. The pipes are the same and the compressors are the same."

What's really surprising is that the operation does not take that massive an amount of power. Sopko walked me through how much power one might need to get the job done. Japanese authorities have said the wall's perimeter would be roughly 1,400 meters at a depth of 30 meters. We assumed they'd place a freezing pipe every meter and want the wall to be 2 meters thick. With those numbers in mind, Sopko made the back-of-the-envelope calculation that TEPCO would need about 6,000 horsepower of compressor to do the refrigeration during the active freezing period, which would probably take a couple of months. After that, the maintenance of the ice wall would require about 3,000 horsepower. Yarmak thought 6,000 horsepower was a pretty good "guesstimate," as well.

In electrical terms, that's about 4.5 megawatts of power, which is substantial, but less than a percent of a large power plant's output.

The key problem ground freezing projects can run into, Sopko said, was fast flowing groundwater. Flow rates above 1 meter per day can make it difficult for the freeze wall to form. But he said that he'd spoken with people with knowledge of the site, who said the rate was a tenth of that, or about 10 centimeters per day.

The most difficult thing, as in all cryogenic barrier construction, is the drilling.

"The holes have to go in straight. They have to be parallel to each other," Sopko said. "If the pipes deviate too far apart from each other, then, you don't get closure between the two." In other words, you'd have holes in your wall.