In 1979, the Three Mile Island nuclear plant came to embody Americans fears about atomic energy, after one of its two reactors partially melted down in what became the worst accident in the U.S. industrys history, despite no one dying or getting sick from radiation.

Now the Londonderry, Pennsylvania, facility could become a symbol of nuclear powers turnaround.

In a landmark deal announced Friday, Microsoft agreed to pay $16 billion to restart the plants second reactor, which shut down in 2019 under financial pressure from growing competition with cheap natural gas. Its part of the tech giants efforts to secure enough reliable, low-carbon electricity to supply energy-thirsty data centers powering the boom in artificial intelligence.

While the Unit 2 reactor destroyed in 1979 is undergoing decommissioning, Microsoft said it would buy up to 100% of the electricity produced from refurbishing the more recently shuttered Unit 1 for the next 20 years.

The plants owner, Baltimore-based Constellation Energy, predicted Unit 1 could come back online as early as 2028, and said it would apply for a license to continue operating the unit for at least the next 30 years. The nations largest reactor operator pledged to spend $1.6 billion on the restart project.

Before it was prematurely shuttered due to poor economics, this plant was among the safest and most reliable nuclear plants on the grid, Joe Dominguez, Constellations chief executive, said in a statement. We look forward to bringing it back with a new name and a renewed mission to serve as an economic engine for Pennsylvania.

Deals like this long-term, power-purchase agreements against which energy developers can borrow money to build new generating stations helped buoy the growth of renewables like wind and solar over the past decade, as tech companies sought to offset the planet-heating emissions from their data centers demand for electricity generated with fossil fuels.