Tokyo Electric Power Co. expects to begin freezing a soil barrier by the end of the year to stop a torrent of water entering the wrecked Fukushima nuclear facility, moving a step closer to fulfilling a promise the government made to the international community more than two years ago.
“In the last half-year we have made significant progress in water treatment,” Akira Ono, chief of the Fukushima No. 1 plant, said Friday during a tour of the facility northeast of Tokyo.
The frozen wall, along with other measures, “should be able to resolve the contaminated water issues before the (2020) Olympic Games.”
Solving the water management problems will be a major milestone, but Tepco is still faced with a number of challenges at the site. The company must still remove highly radioactive debris from inside three wrecked reactors, a task for which no applicable technology exists. The entire facility must eventually be dismantled.
Currently, about 300 tons of water flow into the reactor building daily from the nearby hills. Tepco has struggled to decommission the reactors while also grappling with the buildup of contaminated water.
Even four years after the meltdowns and despite promises from policymakers, water management remains one of Tepco’s biggest challenges in coping with the fallout of Japan’s worst nuclear disaster.
The purpose of the ice wall — a barrier of soil 30 meters (98 feet) deep and 1,500 meters (0.9 mile) long which is frozen to -30 degrees Celsius (-22 Fahrenheit) — is to prevent groundwater from flooding reactor basements and becoming contaminated.
“As the radiation levels decrease via natural decay, water management becomes the main issue,” Dale Klein, an independent adviser for Tepco and a former chairman of the U.S. Nuclear Regulatory Commission, said by e-mail. “It is a very important issue for the public, and good water management is needed for Tepco to restore the public’s trust.”
Tepco is currently testing the freezing system, aiming to have the fence fully operational by the end of December, company spokesman Yuichi Okamura said.
At the moment, the deluge of groundwater entering the reactor buildings is purified, lowering its radioactive content. The water is then stored in one of numerous barrels at the site, each of which can hold 1,000 tons of water.
To make room for the 1,000 or so barrels required to hold the water, Tepco flattened a 500 square meter (5,382 square foot) bird sanctuary on the outskirts of the facility. The company doesn’t have government approval to release the water into the ocean, and there’s no clear plan for its disposal, Okamura said.
Prime Minister Shinzo Abe promised in 2013 that the government would take the lead in resolving the water management issues at the site ahead of the 2020 Tokyo Olympics. Two years later, hundreds of tons of water continue to pour into the reactor building, while tainted water at other parts of the site overflows into the ocean.
Since January, slightly tainted water has spilled from a drainage system into the ocean on nine occasions, according to company spokeswoman Yukako Handa.
The company aims to end these leaks by reconfiguring a drainage system and building a wall running 30 meters into the seabed. The drainage work will be completed next year, and the sea wall will be completed this month.
The proposed ice wall has never been done on such a scale, and there could be operational issues due to the complicated nature of the project, according to Lake Barrett, former head of the U.S. Department of Energy’s Office of Civilian Nuclear Waste Management.
“Some of these areas may have different freezing and sealing capabilities,” he said by e-mail. “These types of problems were encountered when Tepco tried and failed to seal the seawater trenches by freezing.”