Japan moves to revive Kashiwazaki-Kariwa nuclear plant

Japan has taken a decisive step towards restarting the Kashiwazaki-Kariwa nuclear power station, the largest such facility in the world by capacity, marking a pivotal moment in the country’s post-Fukushima energy policy. The move follows regulatory clearance and political backing after more than a decade of safety reviews, legal scrutiny and local opposition stemming from the 2011 nuclear disaster.

The plant, located in Niigata prefecture on the Sea of Japan coast, has been idle since the Fukushima Daiichi accident triggered the shutdown of all nuclear reactors nationwide. Kashiwazaki-Kariwa, operated by Tokyo Electric Power Company Holdings, has a combined capacity of more than 8,000 megawatts across seven reactors, making it a critical asset in efforts to stabilise electricity supply and curb fuel imports.

The Nuclear Regulation Authority has already concluded that the reactors meet Japan’s post-Fukushima safety standards, which are among the strictest in the world. Those standards include enhanced tsunami defences, upgraded emergency power systems, reinforced containment structures and stricter evacuation planning. The latest phase involves securing consent from local authorities and completing operational readiness checks, including security and staffing requirements.

Government officials view the restart as essential to addressing structural challenges in the power sector. Electricity demand remains high due to industrial activity, data centres and climate-driven cooling needs, while the country relies heavily on imported liquefied natural gas and coal. The depreciation of the yen has amplified energy costs, placing pressure on households, utilities and manufacturers.

Prime Minister Fumio Kishida’s administration has framed the nuclear restart policy as part of a broader strategy to balance energy security, economic stability and emissions reduction. Nuclear power is positioned as a low-carbon baseload source that can complement renewables, which have expanded but still face intermittency and grid constraints. Officials argue that restarting existing reactors is faster and cheaper than building new capacity or sustaining long-term fossil fuel dependence.

Tokyo Electric Power Company, which also operates the damaged Fukushima Daiichi plant, has spent years addressing safety lapses and governance issues highlighted by regulators. Kashiwazaki-Kariwa faced additional delays after security breaches were uncovered in 2021, including failures in access control systems. These issues prompted renewed oversight and leadership changes within the utility, as well as tighter regulatory monitoring.

Local sentiment remains divided. Niigata’s governor has insisted on a thorough examination of the Fukushima accident’s causes and consequences before granting final approval. Community leaders and residents continue to voice concerns about evacuation feasibility, seismic risks and trust in the operator. Japan is one of the world’s most earthquake-prone countries, and Kashiwazaki-Kariwa itself sits near known fault lines, a factor that has shaped prolonged safety debates.

At the same time, business groups and energy experts point to the economic implications of prolonged nuclear inactivity. Higher electricity prices have weighed on competitiveness, particularly in energy-intensive sectors such as chemicals, steel and advanced manufacturing. Utilities have warned that tight supply margins increase the risk of power shortages during peak demand periods, especially in summer and winter.

Internationally, Japan’s decision aligns with a broader reassessment of nuclear power among advanced economies. Several countries are extending reactor lifetimes or reconsidering shutdown plans amid concerns over energy security and climate targets. Japan’s approach, however, is shaped by its unique history, public sensitivity and the scale of the Fukushima disaster’s social and environmental impact.

The restart of Kashiwazaki-Kariwa is also symbolically significant. As the largest nuclear plant globally, its return to operation would signal that Japan is prepared to reintegrate nuclear energy into its mainstream power mix after years of caution. Analysts note that successful operation could pave the way for additional reactor restarts elsewhere, provided local consent is secured.