Japan's Tepco hit by setback in cleanup of crippled Fukushima nuclear plant

In a photo from July 27, 2018, a Tepco employee measures radiation levels at the Fukushima Daiichi nuclear power plant. PHOTO: AFP

TOKYO (REUTERS) - The operator of Japan's crippled Fukushima nuclear power plant has found that a coolant solution, used to create an ice wall halting the seepage of groundwater into reactor buildings, has leaked from two storage tanks.

The leakage has had no impact on the wall or environment, said Tokyo Electric Power Co Holdings (Tepco).

Still, it underscores the unpredictable challenges in the cleanup of the site, nearly 11 year after an earthquake and tsunami ravaged Japan's north-eastern coast, causing the world's worst nuclear disaster since Chernobyl in the Ukraine in 1986.

Only last year, Japan's government approved the release of more than one million tonnes of irradiated water from the site after treatment, starting around spring 2023.

Tepco last month said it would build a tunnel reaching into the sea for the operation.

On Sunday, Tepco spokesman Tsuyoshi Shiraishi said about four tonnes of a calcium chloride solution used to maintain the ice wall had leaked in what was the eighth such leakage.

"We're now confirming the reason," he said.

The last leak in December 2019 saw 16 tonnes spilled, likely due to metal fatigue resulting from vibrations caused by construction vehicles, Mr Shiraishi said.

There was no immediate impact on the wall's function as it takes several months for the wall to thaw in the absence of coolant, he said.

Join ST's Telegram channel and get the latest breaking news delivered to you.