Photo/IllutrationTokyo Electric Power Co.'s Kashiwazaki-Kariwa nuclear power plant straddles the city of Kashiwazaki and the village of Kariwa in Niigata Prefecture. (Asahi Shimbun file photo)

Tokyo Electric Power Co. caused a scare in Niigata Prefecture by mistakenly reporting abnormalities at its Kashiwazaki-Kariwa nuclear plant after the June 18 earthquake struck the area.

At 10:52 p.m., TEPCO sent faxes to local governments, including the two municipalities that host the plant, that showed there were problems with electric power sources used to cool spent nuclear fuel pools for all seven reactors there.

Stunned by the report, Kashiwazaki Mayor Masahiro Sakurai instructed a staff member to confirm the information with TEPCO. Officials of the utility then realized their mistake and made a correction.

The mayor summoned Chikashi Shitara, general manager of the plant, on June 19 to give him an earful for the error.

“It is extremely shoddy for you to have made such a mistake on (information about) power sources, which is critically important,” Sakurai told Shitara.

The magnitude-6.7 earthquake struck off the coast of Yamagata and Niigata prefectures at 10:22 p.m. and did not affect plant operations.

The plant’s seven reactors have been offline since the aftermath of the 2011 disaster at TEPCO’s Fukushima No. 1 nuclear plant. But the plant in Niigata Prefecture still poses a high risk during natural disasters because the pools hold spent nuclear fuel from the reactors.

The erroneous faxes were also received by the Niigata prefectural government and the village government of Kariwa, the other host municipality.

Small circles, which indicate “yes” like check marks, were placed on the fields for “abnormalities” concerning electric power sources for cooling equipment for spent nuclear fuel pools of the seven reactors.

After recognizing the error, TEPCO placed circle marks on the “no abnormalities” fields for all seven reactors in a new report. The corrected report was faxed to the local governments 15 minutes after the inquiry from the Kashiwazaki city government.

TEPCO is seeking to resume operations of the No. 6 and No. 7 reactors at the nuclear plant.

“We will not approve the resumption unless TEPCO presents drastic improvement measures,” Sakurai said.