A Niigata Prefecture nuclear power plant run by Tepco, the operator of the crippled Fukushima No. 1 facility, received the lowest possible rating during preparation drills in the event of a severe incident, the nation's nuclear watchdog agency said in a report released Wednesday.
None of three nuclear power plants operated by Tokyo Electric Power Company Holdings Inc. received top marks on a three-grade scale that rates the performance of off-site coordination centers that are to be put in place to share information with the watchdog in times of emergency.
The Nuclear Regulation Authority and major utilities including Tepco conducted drills at each site in fiscal 2017 that simulated a shut down of the cooling system of an atomic reactor. The results of the drills were disclosed at the watchdog's meeting on Wednesday.
The Kashiwazaki-Kariwa plant in Niigata Prefecture received the lowest rating, while the Fukushima No. 1 and Fukushima No. 2 plants were given mid-level marks.
The regulator deems information sharing, said to be one of the factors that worsened the 2011 Fukushima disaster, as the most important item out of the nine-point evaluation.
A member of the watchdog criticized Tepco's performance, calling it "unforgivable that the operator responsible for the nuclear disaster at the Fukushima No. 1 plant 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 company's 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 issues continue to happen, Tepco should have to repeat its training," said Akira Ishiwatari, a geologist and member of the NRA.