Tokyo Electric Power Co (Tepco) said on 7 April that it will accept a penalty imposed by the Nuclear Regulation Authority (NRA) over inadequate anti-terrorism measures at its Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture. This will prevent restart of the facility for at least a year. Tepco made the announcement in response to a decision by NRA in late March banniing it from moving any nuclear materials at unit 7 of the Kashiwazaki-Kariwa plant.

NRA found malfunctioning anti-terrorism equipment and inadequate protection of nuclear materials at multiple locations at the plant from at least 2018. The chairman of the authority, Toyoshi Fuketa, said Tepco has since restored the safety functions, but the problems were deemed serious and systematic.

The plant was partially damaged in a 2007 earthquake, causing mistrust among local municipalities. It was closed again in the wake of the 2011 Fukushima accident along with the rest of Japan’s NPPs. Of the 54 nuclear reactors Japan used to have, nine have been restarted under tougher post-Fukushima safety standards and four are currently operating.

The authority gave the Kashiwazaki-Kariwa plant’s nuclear security a “red” rating, meaning its management had deteriorated to levels that could allow intruders. “I hope Tepco will make efforts to analyse the problem … and fully cooperate with our inspections,” Fuketa said, adding that Tepco's ability to keep its licence to operate the plant depends on the results of future checks.

Tepco president Tomoaki Kobayakawa apologised for causing safety concerns and said he and three other company executives are taking 30% salary cuts for six months. “We take the problem seriously and will investigate the cause and pursue efforts to make drastic reforms,” he told a news conference.

He also said an investigation will be launched into why such incidents took place by inviting experts on security of nuclear materials and corporate governance. The investigation is expected to examine whether its employees shared heightened awareness of the vital importance of safeguarding nuclear material and security of their nuclear plants. It will also look into systemic problems of the utility concerning security. Tepco will submit its findings to NRA by September.

“As for what the management should have done concerning security, we are determined to improve what needs to be improved based on the findings of the probe,” Kobayakawa said.

The penalty comes just as Tepco was making final preparations to restart the plant after NRA granted safety approvals for units 6&7 in 2017. Restarting the two reactors is considered necessary to enable Tepco to reduce its financial burden in paying for damage caused by the Fukushima disaster.