The operator of the crippled Fukushima Daiichi nuclear plant was rated poorly over drills assuming a severe accident at a nuclear power plant, Japan's nuclear watchdog said in a report released Wednesday.

The report showed none of three nuclear power plants operated by Tokyo Electric Power Company Holdings Inc. received the highest marks on a three-grade scale for the performance of off-site centers of its plants in information sharing with the watchdog.

(Fukushima Daiichi nuclear power plant)

The Nuclear Regulation Authority and major utilities including Tepco conducted drills at each site in fiscal 2017 through March on the assumption that the cooling of an atomic reactor has stopped. The results of their drills were disclosed at the watchdog's meeting on Wednesday.

The Kashiwazaki-Kariwa plant in Niigata Prefecture had the lowest rating, while the Fukushima Daiichi and Fukushima Daini plants received middle marks.


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The regulator deems information sharing as the most important item out of the nine-point evaluation. A lack of information sharing is said to be one of the factors that worsened the 2011 Fukushima disaster.

A member of the watchdog criticized Tepco's performance, calling it "unforgivable that the operator which caused the nuclear disaster of Fukushima Daiichi complex had a low rating."

According to the report, Tepco staff members at the plant drafted countermeasures to bring the situation under control but failed to properly inform the headquarters in Tokyo.

Tepco is aiming to reactivate its No. 6 and 7 reactors at the Kashiwazaki-Kariwa plant, which cleared government safety standards in December.

"If similar things continue to happen, Tepco should do its training all over," said Akira Ishiwatari, a geologist and another member of the NRA.