When your swimming pool springs a leak, do you try to plug the hole with an ice cube? When the local river floods, do you attempt to protect your home with blocks of ice? Despite the obvious answers to these questions, the Japanese government is going ahead with plans to build a wall of ice around the Fukushima nuclear plant in an attempt to contain radioactive water that’s been leaking since the tsunami and earthquake in March 2011. What could possibly go wrong?
Japan’s Nuclear Regulation Authority gave $312 million to Kajima Corporation to build the wall of ice around the perimeter of the plant. The project, a year behind schedule, started with digging a 1.5-km (0.9 mile) trench 30 meters (100 feet) deep around the facility. The trench will be lined with refrigeration pipes that are supposed to freeze the soil around them all the way to the surface and deep enough to keep radioactive water from leaking out and clean water from flowing in and getting contaminated.
We hear a lot about border walls but very little about protective ice walls. Have they been used anywhere else? How long will the ice wall last? Will it work against radioactive water that recently killed robots sent in to the plant to clean things up?
The ice wall technology has been used on a limited scale in tunnels and subways, but only to keep out uncontaminated water and only for periods less than six years. Shinichi Nakakuki, a spokesperson for Tokyo Electric Power (TEPCO), says a limited test at Fukushima was successful and the entire wall is expected to be frozen over the next several months. The wall will be constantly monitored and adjustments can be made. The goal is to stop the flow of groundwater into the plant, allowing the interior to dry out by 2020 so that robots could be sent in again. At that point, the cleanup is expected to take 30 to 40 years.
A section of the ice wall was turned on last week between the plant and the Pacific Ocean.
Will it work? Nuclear agency Chairman Shunichi Tanaka cautions against high expectations because the wall depends in part on nature. When pressured, another official said:
Its effect is still unknown, because the expected outcome is based on simulations.
Would you use a wall of ice to protect your home from floods? Does the thought give you the shivers? What could possibly go wrong?