On March 11, 2011, a one-two, earthquake-tsunami punch knocked out the safety systems at the Fukushima Dai-ichi nuclear power plant, triggering an explosion of hydrogen gas and meltdowns in three of its six reactors—the world’s worst nuclear disaster since Chernobyl. Fukushima’s facility was built with 1960s technology, designed at a time when engineers underestimated plant vulnerabilities during natural disasters. In the US, 20 plants with similar designs are currently operating.

One of them is slated for a head-on collision with Hurricane Florence.

Duke Energy Corp’s dual-reactor, 1,870-megawatt Brunswick plant sits four miles inland from Cape Fear, a pointy headland jutting out into the Atlantic Ocean just south of the city of Wilmington, North Carolina. Brunswick has survived decades of run-ins with hurricanes, but Florence could be its biggest test yet. The plant perches near the banks of the Cape Fear River, which drains 9,000 square miles of the state’s most densely populated regions. Like Hurricane Harvey in 2017, Florence is predicted to stall out for days, pounding the Carolinas with unrelenting amounts of water, leading to life-threatening storm surges and catastrophic flooding. NOAA’s National Hurricane Center is projecting 110 mile-per-hour winds, waves as high as 13 feet, and in some places, up to 40 inches of rain.

Officials at Brunswick say the plant is bracing for the impending destruction. “We’re monitoring the meteorological conditions, and if we have certainty that the winds onsite will reach 73 miles per hour, then we’ll begin an orderly shutdown of the units,” said Karen Williams, a spokeswoman for Duke Energy, reached by phone Wednesday afternoon.

The company also brought in workers ahead of the storm’s landfall who will stay through its duration, sleeping on cots and blow-up mattresses, so that the facility has enough staff to handle multiple shifts. In the last few days they’ve been doing walk-throughs of the plant, inspecting diesel-powered backup generators and installing waterproof steel barriers on nine doors that house important safety equipment.

These precautions are relatively new for Brunswick. They’re part of a sweep of changes nuclear plants around the US have adopted post-Fukushima.

Following the accident in Japan, a task force of senior Nuclear Regulatory Commission staff used the lessons from that disaster to draft new rules for the US. When the earthquake’s tremors hit Fukushima, knocking out the electrical grid, the plant’s emergency diesel generators kicked in as expected to provide emergency power. It was the wave of water that hit 40 minutes later that damaged that backup equipment, plunging the plant into total blackout. Without power, operators lost the ability to pump water into the reactors, exposing the cores, and leading to the explosive meltdown. From this, the NRC’s big initiative to make US nuclear plants better prepared for such extreme events included the particular goal of making them less vulnerable to flooding.