• Constellation Energy plans to restart Three Mile Island's Unit 1 in 2028 through a power purchase agreement with Microsoft.
• The plant will be renamed the Crane Clean Energy Center.
• Here's a look at the plant's main control room, the turbine deck and cooling towers.

Operations at Three Mile Island are poised to restart in four years, the latest sign that the nuclear power industry is undergoing a major turnaround after a wave of plant closures.

The Unit 1 reactor at Three Mile Island, which entered service in 1974, was permanently shut down in 2019 due to economic pressure as nuclear power struggled to compete against natural gas. But the tech sector's growing power needs are breathing new life into the industry.

Constellation Energy plants to restart Unit 1 in 2028 through an agreement with Microsoft to help power the tech company's data centers. The plant will be renamed the Crane Clean Energy Center — after Chris Crane, the late CEO of the plant's former owner, Exelon — and its restart is subject to approval by the Nuclear Regulatory Commission.

The Department of Energy said Unit 1 operated safely and efficiently before being shut down five years ago. However, it lies within walking distance of the site of the worst nuclear accident in U.S. history. The Unit 2 reactor suffered a partial meltdown in 1979 and has not operated since the accident. It is being decommissioned by its owner, Energy Solutions.

Constellation's chief generation officer, Bryan Hanson said Unit 1 is in good condition and the restoration will mostly involve typical maintenance work.

Here is a look at the plant's main control room, the turbine deck that houses the main power generator, and the facility's iconic cooling towers. For more on the restart click here.

Main control room

Turbine deck

Cooling towers

— CNBC's Danielle DeVries contributed to this report.