Three Mile Island Nuclear Reboot Faces Growing Backlash Over AI Data Centres and Energy Costs

A 262-tonne transformer shipped from South Korea arrived in Pennsylvania this week as the US state advances plans to revive the Three Mile Island nuclear reactor. The restart of the plant, which experienced a partial meltdown in 1979, has become a critical test for tech companies fueling the artificial intelligence race to secure new power sources without sparking public outrage amid growing concerns over rising energy costs and environmental impacts.

On Wednesday, Constellation Energy released footage of the first of three massive transformers arriving at the site in Middletown on an oversized lorry. Constellation Energy is reviving the reactor's Unit 1, having renamed it the Crane Clean Energy Centre. The initiative is driven by the AI boom, which demands substantial energy to power the proliferation of data centres required to handle massive processing workloads. This effort stems from a 2024 partnership between Constellation and Microsoft, under which Microsoft committed to a 20-year power purchase agreement to supply energy for its data centres.

Public sentiment regarding AI and data centres has shifted significantly since 2024. A rapidly growing backlash against data centre construction has emerged as a major issue ahead of the US midterm elections in November. Communities have expressed frustration over data centre noise, heavy water consumption for cooling, and rising electricity bills, alongside increasing voter anxiety regarding AI's impact on the labour market.

Pennsylvania Governor Josh Shapiro addressed the rising public discontent by signing new regulations intended to increase accountability for data centre developers in Pennsylvania, making it harder to build without meeting specific requirements. Governor Shapiro, frequently mentioned as a potential 2028 presidential candidate, remains a vocal supporter of restarting Unit 1 at Three Mile Island, which has been offline since 2019. A representative from his office stated that the governor continues to support the Constellation and Microsoft partnership despite the new restrictions, describing him as an all-of-the-energy governor who supports nuclear power. The representative also noted that the reboot addresses some AI criticisms because the Microsoft partnership ensures the tech giant contributes energy back to the grid.

Nevertheless, the collaboration between Constellation Energy and Microsoft continues to draw criticism. Unit 1 is situated near Three Mile Island Unit 2, the location of one of the worst nuclear accidents in US history. In March 1979, the core of Unit 2 was partially exposed, leading to a temporary evacuation and an extensive cleanup around Middletown that persists today. That disaster prompted the formation of Three Mile Island Alert, a grassroots energy safety organisation in Pennsylvania.

Eric Epstein, director of Three Mile Island Alert, stated that his group is actively opposing the restoration and restart of Unit 1 at every turn. Beyond safety concerns, Mr Epstein criticized the $1 billion taxpayer loan granted to Constellation last year to expedite the restart, as well as the plant's proposed use of water from the adjacent Susquehanna River. Although the Susquehanna River Basin Commission permitted increased water consumption, almost all 440 public comments submitted were in opposition. Mr Epstein warned that despite Governor Shapiro's support, the anti-AI movement will gain momentum, noting that elections will ultimately decide the fate of Three Mile Island before the proposed restart in November 2026. He argued that blind support for data centres and nuclear power has driven up electricity prices and caused water depletion. Three Mile Island Alert is currently pursuing legal action in federal court and challenging the Pennsylvania Department of Environmental Protection's decision to approve a licence for the reactor.

Constellation Energy still faces numerous regulatory hurdles from the US Nuclear Regulatory Commission before resuming operations, but the company remains undeterred. In a statement accompanying the video of the transformer's arrival, Constellation Energy emphasized that the delivery marks a major milestone in bringing 835MW of reliable, emissions-free power back online in 2027.