TOKYO -- Six months since the work began, the "ice wall" has failed to produce its intended results as groundwater continues to flow in and out of damaged facilities at the Fukushima Daiichi nuclear power plant.
An encircling wall of frozen soil, created by pumping a subzero coolant through underground pipes, is getting closer to completion, the Japanese government and plant operator Tokyo Electric Power Co. Holdings reported Tuesday at a meeting of experts convened by the Ministry of Economy, Trade and Industry.
The ocean-facing side of the wall is nearly finished, though gaps remain on the inland side, officials reported. Some of the expert panelists questioned the basis for determining such progress.
Groundwater runs down from the highland and seeps into the damaged reactor buildings, where it becomes tainted with radioactive material. The frozen wall has been built to stop this flow. But the problem was exacerbated by heavy rains starting around mid-August, as northern Japan was swept by multiple typhoons. This resulted in massive amounts of groundwater rushing into plant buildings, making it difficult to assess the wall's effectiveness.
The operator, Tepco, thinks the inflows are concentrated at seven unfrozen sections on the inland side. Kunio Watanabe, an associate professor of environmental science at Mie University, blames the utility for having "fallen behind in its responses to address problems" at the Fukushima plant.
"If dealing with the contaminated water takes too long," warns Masashi Kamon, professor emeritus at Kyoto University, "the entire decommissioning process may be set back."
More than five and a half years have gone by since the March 2011 earthquake and tsunami that crippled Fukushima Daiichi.
The government and Tepco hope to complete the wall soon. But some outside experts at a meeting held by Japan's nuclear regulator last month declared the effort a failure.