The Japanese government announced Tuesday that it will spend $470 million on a subterranean ice wall and other steps in a desperate bid to stop leaks of radioactive water from the crippled Fukushima nuclear plant after repeated failures by the plant’s operator.
The decision is widely seen as an attempt to show that the nuclear accident won’t be a safety concern just days before the International Olympic Committee chooses among Tokyo, Istanbul and Madrid as the host of the 2020 Olympics.
The Fukushima Dai-ichi plant has been leaking hundreds of tons of contaminated underground water into the sea since shortly after a massive 2011 earthquake and tsunami damaged the complex. Several leaks from tanks storing radioactive water in recent weeks have heightened the sense of crisis that the plant’s owner, Tokyo Electric Power Co., isn’t able to contain the problem.
“Instead of leaving this up to TEPCO, the government will step forward and take charge,” Prime Minister Shinzo Abe said after adopting the outline. “The world is watching if we can properly handle the contaminated water but also the entire decommissioning of the plant.”
The government plans to spend an estimated $470 million through the end of March 2015 on two projects — $320 million on the ice wall and $150 million on an upgraded water treatment unit that is supposed to remove all radioactive elements except water-soluble tritium — according to energy agency official Tatsuya Shinkawa.
The government, however, is not paying for urgently needed water tanks and other equipment that TEPCO is using to contain leaks. Shinkawa said the funding is limited to “technologically challenging projects,” but the government is open to additional help when needed.
The ice wall would freeze the ground to a depth of up to 100 feet through a system of pipes carrying a coolant as cold as minus 40 degrees. That would block contaminated water from escaping from the facility’s immediate surroundings, as well as keep underground water from entering the reactor and turbine buildings, where much of the radioactive water has collected.
The project, which TEPCO and the government proposed in May, is being tested for feasibility by Japanese construction giant Kajima Corp. and is set for completion by March 2015.
Similar methods have been used to block water from parts of tunnels and subways, but building a 0.9 mile wall that surrounds four reactor buildings and their related facilities is unprecedented.
An underground ice wall has been used to isolate radioactive waste at the U.S. Department of Energy’s former site of the Oak Ridge National Laboratory in Tennessee that produced plutonium, but only for six years, according to the MIT Technology Review magazine.
Some experts are still skeptical about the technology and say the running costs would be a huge burden.
Atsunao Marui, an underground water expert at the National Institute of Advanced Industrial Science and Technology, said a frozen wall could be water-tight but is normally intended for use for a few years and is not proven for long-term use as planned in the outline. The decommissioning process is expected to take about 40 years.
“We still need a few layers of safety backups in case it fails,” Marui said. “Plus the frozen wall won’t be ready for another two years, which means contaminated water would continue to leak out.”
Marui said additional measures should be taken to stop contaminated water from traveling under the seabed during that time and leaking further out at sea.
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