The discharge of treated radioactive water from the crippled Fukushima nuclear power plant into the sea resumed after being temporarily suspended Wednesday due to a partial power outage, the plant operator said.

Tokyo Electric Power Company Holdings Inc. said it believed the power outage, which occurred around 10:43 a.m., was caused when a power cable at the Daiichi plant was damaged during excavation work.

The system to cool reactors and spent fuel pools was not affected by the power cutoff and remained operational, according to the utility.

The operator also said the reading of radioactive levels on monitoring posts showed no abnormal figures. Meanwhile, an excavation worker suffered burns in the power outage and had to be rushed to the hospital, according to TEPCO.

The excavation was under way west of the reactor buildings for the No.1 to 4 units near the location of the damaged cable.

File photo taken on Feb. 11, 2024, shows the Fukushima Daiichi nuclear power plant. (Kyodo)

Following the outage, an International Atomic Energy Agency task force had to delay the start of its on-site inspection due to safety checks but was able to complete it on Wednesday, according to a TEPCO official.

The task force is visiting Japan for a review mission on the safety of the water discharge, its second since the start of the water release in late August.

Wednesday's suspension of the water release came after a major earthquake that struck Fukushima Prefecture and other areas in northeastern Japan temporarily stopped the discharge last month.

Incidents have hit the nuclear facility in recent months. Two men were hospitalized in October after they were exposed to radioactive liquid while cleaning a water filtration facility, and leakage of contaminated water was detected in February.

TEPCO released about 31,200 tons of water in the previous fiscal year through March in four batches, while it plans to discharge 7,800 tons of water through May 7 in the first discharge of the current fiscal year.

The release of the fifth batch of water began last Friday. The utility sees the discharge as a key step in the ongoing decommissioning of the wrecked Fukushima plant, which suffered fuel meltdowns in three reactors following a massive earthquake and tsunami in March 2011.

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