The Kashiwazaki-Kariwa Nuclear Power Plant(NPP), owned by Tokyo Electric Power Company (TEPCO), located in Niigata Prefecture, Japan. The electricity generated there was supplied to the Greater Tokyo Area. Following the 2007 Niigata Chuetsu-Oki Earthquake, all operating reactors were automatically shut down. Subsequently, some reactors resumed operation, but after TEPCO’s Fukushima Daiichi NPP accident in 2011, all reactors were once again halted.

In December 2017, the Nuclear Regulation Authority (NRA) approved an assessment report under the new regulatory standards for Unit 6 and 7. However, since March 2020, a series of problems in nuclear security and safety measures have been revealed, including the unauthorised use of ID cards and the malfunctions in intrusion-detection systems. As a result, in April 2021, the NRA formally issued an administrative order prohibiting TEPCO from transferring or handling nuclear fuel at the Kashiwazaki-Kariwa NPP.

The order was lifted in December 2023, and fuel was loaded into Unit 7 in April 2024. However, because the installation of anti-terrorism facilities for Unit 7 was delayed and would not meet the October 2025 deadline, TEPCO announced it would proceed with restarting Unit 6 first. Fuel loading commenced at Unit 6 in June 2025. Progress toward restart subsequently accelerated, with the Governor of Niigata Prefecture approving the restart in November 2025.