A storm knocks out the power, a tree drops across a line somewhere, and by morning a crew in a bucket truck has the lights back on. That is the usual arrangement between weather and the grid: annoying, temporary, fixable.
The derecho that ripped across eastern Iowa on August 10, 2020 did not follow that script. It was a 770-mile wall of straight-line wind, gusting an estimated 140 mph around Cedar Rapids, and it became the costliest thunderstorm in modern U.S. history at roughly $11 billion in damage. Eight miles northwest of that city, it also tore up the cooling towers at Duane Arnold, the only nuclear plant in the state. The reactor never ran again.
Five years later, Google is paying to switch it back on.
NextEra Energy, which owns Duane Arnold, said in late October that it plans to have the plant generating power again by early 2029. The whole effort is bankrolled by a 25-year power purchase agreement with Google, which wants the electricity for the AI and cloud data centers it keeps building across Iowa, according to the American Nuclear Society.
The reactor was already weeks from the finish line
The “storm killed a nuclear plant” version of this story leaves one thing out. Duane Arnold was on its way out before the derecho ever showed up.
Back in 2018, its main power customer and NextEra had agreed to end the plant’s supply contract five years early, which set its shutdown for October 2020. Demolition planning had already started that June, with a price tag NextEra put at just over $1 billion to take the place apart.
So when the storm wrecked the cooling towers in August, the math was simple. NextEra was weeks away from switching the reactor off anyway. Paying to rebuild towers on a plant it was about to retire made no sense, so it pulled the plug a few weeks early and started the teardown.
The reactor itself was fine. It was a single General Electric boiling water unit rated at about 615 megawatts, running since February 1975, and licensed to keep going well into the 2030s. In its last full year of normal operation it ran at better than 99 percent of capacity, which put it among the more reliable units in the country. What ended it early was not age or a safety problem. It was a windstorm and an accounting decision.
Google’s power bill made “permanent” negotiable
Once a reactor gets defueled and handed to a decommissioning crew, that is normally the end. The industry even has a term for it, permanent shutdown, and Duane Arnold checked every box: fuel pulled from the core in October 2020, a billion-dollar plan to dismantle it, the works.
What changed is the electricity market. AI data centers are hungry in a way the grid has not seen in decades, and they want power that runs around the clock without a cloud rolling over it. Some developers are impatient enough to build their own power plants from scratch rather than wait years for a grid connection. Google went the other way and found a reactor that already exists.
That is why the company signed up for 25 years of Duane Arnold’s output before a single new megawatt exists. NextEra puts the deal’s value to Iowa at more than $9 billion and says it will bring back roughly 400 permanent jobs at the site.
Iowa ratepayers are not covering Google’s share. NextEra has said the power Google buys will not land on anyone else’s utility bill, and a local nonprofit, Central Iowa Power Cooperative, which serves about 300,000 Iowans, is taking the rest of the plant’s output on the same terms.
Google is no newcomer to the state either. It says it has already spent $6.8 billion on Iowa data centers, with another $7 billion announced for the next couple of years. A reactor down the road is one way to keep all of that fed.
You cannot just flip the breaker back on
Waking a mothballed reactor is not a switch on a wall. It is a heavy-industry rebuild.
NextEra has already ordered the big hardware, including a new power generator and a fresh set of cooling towers. The exact component the storm wrecked is the exact component the company is now buying new.
Then there is the paperwork, and with nuclear the paperwork is the hard part. Restarting the plant means getting the Nuclear Regulatory Commission to restore an operating license that was surrendered when the plant closed. That runs through equipment inspections, an environmental review, and emergency-planning checks.
The NRC has been at this since NextEra filed its first licensing request in January 2025. Inspectors have already published reports on gear like the reactor vessel, and an early one flagged nothing more serious than minor issues.
Where it actually stands this summer
The most recent win for the project came on June 18, when Iowa’s utility regulators signed off on NextEra’s certificate to build, operate, and maintain the plant, the state-level green light the restart needed.
The federal side moves slower. At an April public meeting in Cedar Rapids, an NRC restart-team member said the agency could approve the license around January 2028, assuming inspections keep coming back clean. NextEra is aiming to have the reactor generating again in the first quarter of 2029.
That is still years away, with a lot of steel and paperwork between now and then. But the direction is set: Iowa said yes in June, and the federal review is grinding forward.
The third dead American reactor in line, and none has finished yet
Duane Arnold is not doing anything the rest of the industry has missed. It is the third shuttered U.S. reactor with a comeback plan, and so far not one of them has produced a watt since being switched off. No fully closed American reactor has ever been brought back to life.
The one furthest along is Palisades, on the Lake Michigan shore in Michigan, where Holtec is trying to become the first company in U.S. history to pull a reactor out of decommissioning and turn it on. It has fresh fuel on site and a target of sometime this year, after missing a string of earlier dates.
Then there is Three Mile Island’s surviving reactor in Pennsylvania, the healthy twin of the unit that melted down in 1979, which Constellation is reviving on Microsoft’s dime and aiming to restart in 2027.
None of this has been free of pushback. Critics of the restart wave point out that the country still has no permanent home for the radioactive waste these plants generate, an unresolved problem that predates every one of the comeback projects.
The setup is the same across all three: a closed reactor, a Big Tech company with a data-center power problem, and a long regulatory climb back to the grid. Duane Arnold is the newest name on that list, and the only one that got there because of the weather.
“Permanent” turned out to be a soft word
For a plant that had its fuel pulled and a billion-dollar demolition plan already drawn up, “permanent” did not hold. A windstorm knocked Duane Arnold off the grid a few weeks early in 2020, and the paperwork said that was the end of it.
If NextEra and Google hit their marks, a search company’s electricity bill will put it back by 2029, new towers and new license and all. Whether that date holds is a fair question, given how the other restart timelines have slipped. But the reactor Iowa wrote off five years ago is no longer being taken apart. It is being rebuilt.
