The operator of the wrecked Fukushima nuclear power plant informed Japan's industry minister on Wednesday that a lack of sufficient confirmation on simple-task procedures led to an error, resulting in the suspension of efforts to extract small amounts of melted fuel from one of the reactors last month.
"In the high radiation environment, our confirmation process on simple tasks in the preparation stage was not enough," said Tokyo Electric Power Company Holdings Inc President Tomoaki Kobayakawa during a meeting with Economy, Trade and Industry Minister Ken Saito at the ministry.
TEPCO plans to retrieve up to 3 grams of fuel debris from the No. 2 unit using a telescopic device over about two weeks. However, the operation was suspended on the first day in late August after it was discovered that the pipes used in the trial extraction had been placed in the wrong order during preparations.
The setup of necessary devices was primarily handled by subcontractors, and TEPCO officials did not directly confirm the procedures, leading to errors in the retrieval device setup, according to TEPCO. The restart date for the operation is still pending.
Saito said, "We strongly demand that TEPCO directly confirm details of the procedures from the preparatory stage."
Shortly after the suspension of the operation, Saito instructed TEPCO to find and report what had caused the error.
Retrieving melted fuel is regarded as one of the most challenging tasks in the decades-long decommissioning plan for the Fukushima Daiichi complex, which was damaged following a massive earthquake and tsunami in March 2011.
An estimated 880 tons of fuel debris remains in the Nos. 1, 2 and 3 reactors, which suffered core meltdowns after losing cooling function due to a power failure during the disaster.
TEPCO initially planned to start retrieving debris from the No.2 unit in 2021 but postponed its plans three times due to the novel coronavirus pandemic and technical difficulties.
