Tokyo Electric Power Shares Surge as Kashiwazaki-Kariwa Nuclear Reactor Restart Nears

Shares of Tokyo Electric Power Company Holdings Inc. (TYO:9501), commonly known as TEPCO, rose sharply on Monday after the utility announced plans to restart a nuclear reactor at its Kashiwazaki-Kariwa power station, the largest nuclear power facility in the world by capacity. The announcement marked a significant milestone for the company, more than a decade after the Fukushima Daiichi nuclear disaster led to the shutdown of its entire nuclear fleet.

Tokyo-listed shares of TEPCO climbed as much as 9%, reaching 715 yen during morning trading, their highest level in roughly one month. Investor sentiment improved on expectations that the nuclear restart could materially strengthen the company’s earnings outlook and reduce its exposure to volatile global energy markets.

The Kashiwazaki-Kariwa nuclear power plant, located in Niigata prefecture, has long been viewed as a cornerstone asset for TEPCO. The company said it aims to restart one of its advanced boiling water reactors as early as later this month, subject to final approval from local authorities and continued progress in meeting Japan’s strict nuclear safety and regulatory standards. If approved, the restart would represent TEPCO’s first major step toward restoring nuclear generation capacity since the Fukushima crisis in 2011.

Restarting nuclear output is expected to significantly reduce TEPCO’s reliance on imported fossil fuels such as liquefied natural gas and coal. This shift could help stabilize operating costs and improve profit margins, particularly at a time when global energy prices remain volatile due to geopolitical tensions and supply uncertainties. Analysts also note that increased nuclear generation could strengthen Japan’s overall power supply resilience.

The planned restart aligns with Japan’s broader energy strategy to revive nuclear power in order to enhance energy security, curb carbon emissions, and lower dependence on costly fuel imports. As the government seeks to balance economic growth with climate commitments, nuclear energy is increasingly seen as a key component of the country’s long-term energy mix.

For investors, TEPCO’s progress at Kashiwazaki-Kariwa represents a potentially transformative development, signaling a gradual return to nuclear operations and a more stable financial outlook for the utility.