A locked-down factory with a… heavy past will reopen just for Microsoft to meet the tech giant’s increased energy needs.

This is the Three Mile Island Nuclear Power Plant, which is responsible for the worst accident in the history of US nuclear power.

The accident

A system malfunction, technical problems and mishandling resulted in the partial collapse of one of the nuclear plant’s two reactors.

It all started on March 28, 1979, at 4:00 in the morning. A failure in the Unit 2 (TMI-2) reactor resulted in it operating at 97% power. A mechanical or electrical failure prevented the main feedwater pumps from sending water to the steam generators that remove heat from the reactor core (3). This caused the station’s turbine-generator to shut down automatically, and then the reactor itself. The pressure in the primary system (the nuclear piping section) began to increase. To check this pressure, the pilot relief valve was opened. The valve should have closed when the pressure reached the appropriate levels, however it stuck and stayed open. Something that was not picked up by the instruments in the control room, with the factory staff believing that the valve had closed. As a result, water used for cooling, contaminated with radioactivity, flowed through the open valve into adjacent buildings, while the core began to overheat dangerously. Alarms began to sound and staff, unaware that the controls were malfunctioning and that the reactor had overheated, shut off the emergency water system.

The partial meltdown of Reactor II resulted in the release of (an unknown amount of) radioactive gases and radioactive iodine into the environment.

The factory ceased operation, and plans to build new factories were rejected in the 80s and 90s as well.

The factory closed permanently in 2019.

It reopens after 5 years

Constellation Energy announced on Friday that the Unit 1 reactor, which was shut down five years ago, is to be “revived” in 2028, subject to approval by the Nuclear Regulatory Commission.

Microsoft will buy the carbon-free energy produced by it to power its data centers and thus support the energy needs of building artificial intelligence.

The financial terms of the 20-year deal, which Constellation called its largest ever, have not yet been “locked in.”

“Energy powering industries, including data centers, is critical to our nation’s global economy and technological competitiveness. It also requires abundant energy, which does not use carbon and is available every hour and every moment of every day. Nuclear is the only energy source that is consistent with these goals and can meet them,” Constellation CEO Joe Dominguez said in a press release.

Clean energy advocates and businesses alike see nuclear power as an energy source that has zero requirements for burning coal and is inexhaustible. A major advantage of nuclear duration is that it is available at all hours of the day, day and night, unlike wind and solar power.

However, nuclear power also has its critics. These are mainly environmental groups, which criticize the decades-long pollution of nuclear power.

Reopening the Unit 1 reactor will add 3,400 direct and indirect jobs and boost the grid with 800 megawatts of electricity, according to Constellation. It is also projected to add $16 billion to the GDP of Pennsylvania, where the nuclear bases are located.

Energy needs are expected to increase as tech giants need more energy to power their AI creation needs. In particular, the need for nuclear energy, which does not use carbon and thus contributes to the achievement of climate goals, will increase.

The move is also bolstered by President Joe Biden’s climate bill, which includes billions in tax credits to incentivize clean energy from nuclear, in addition to wind, solar and clean hydrogen. The Biden administration and Congress have simultaneously poured billions in funding to stop the closing of old plants.

“This agreement is a milestone in Microsoft’s efforts to free its energy grid from burning coal and thereby support its commitment to negative carbon use,” said Bobby Hollis, Microsoft’s vice president of energy.