Sitting on a hill about a half-mile from the Calvert Cliffs nuclear power plant is a hulking concrete and steel bunker. It is jammed full of new trucks, trailers, portable generators, pumps, hoses, electrical cables and a raft of other emergency equipment.
The plant's owners and workers hope they never have to use any of it.
The FLEX building, as it is called, is the centerpiece of the U.S. nuclear industry's response to the natural disaster that crippled a power plant near Fukushima, Japan, four years ago. Hit by a tsunami after a devastating earthquake, three of the plant's nuclear reactors suffered partial meltdowns, spewing radiation and forcing more than 200,000 people from their homes.
Now every nuclear plant in the United States is gearing up with extra vehicles and equipment for use in an emergency to prevent such disasters.
"The lesson learned from Fukushima was you have to be ready for the unimaginable," said George Gellrich, site vice president for Exelon Corp., owner of the plant 70 miles south of Baltimore on the western shore of the Chesapeake Bay.
Nuclear regulators and the industry took steps after the terrorist attacks of Sept. 11, 2001, to ensure that power plants could withstand a jetliner crashing into them. But with Fukushima, it became clear that nuclear plants faced comparable threats from natural forces possibly beyond what the facilities had been designed to survive.
Ordered by the Nuclear Regulatory Commission to figure out how to deal with such events, the industry proposed a flexible response, adding portable emergency gear stored away from the reactors for use in any type of catastrophe.
So even though Calvert Cliffs is in a seismically stable area, and the plant's reactors and safety equipment are 45 feet above the bay — higher than the Pacific waves that hit Fukushima — Exelon is spending more than $31 million on safety upgrades here. It is beefing up the plant's ability to withstand earthquakes, tornadoes and tropical storms stronger than any ever recorded in Southern Maryland.
Some of that was spent to install remote monitoring of the spent fuel pool, where the highly radioactive used fuel rods are stored. Remote monitors will alert control room operators if there is not enough water covering the rods to keep them from overheating, a serious problem if not quickly corrected.
Nearly one-third of the post-Fukushima investment at Calvert Cliffs has gone into the FLEX building and its contents. The structure's steel-reinforced walls and roof are 21 inches thick. Its three big steel doors, with Kevlar netting on the inside, can stop flying projectiles such as trees and telephone poles uprooted by wind.
"If there is an issue and you wanted to protect your family, the first place I would go is the FLEX building," Gellrich said.
Exelon has completed FLEX buildings at six of its 14 nuclear plants nationwide, according to company spokesman David Tillman. The rest are under construction, including one begun in March at Peach Bottom in Delta, Pa., 45 miles north of Baltimore. The Nuclear Regulatory Commission has ordered that all are to be completed and stocked by the end of next year. The Peach Bottom building should be finished by October, according to plant spokeswoman Krista Connelly.
A little like Noah's ark, the 60-by-140-foot building at Calvert Cliffs holds at least two of every type of equipment that might be needed to restore power and cooling water to the plant's two reactors, should the on-site emergency backup equipment fail. A somewhat less sturdy storage building is to be put up by next year, which will hold a third set of gear, just in case.
At Fukushima, with power to the plant knocked out, workers scrounged for car batteries to try to get enough power to start emergency equipment. In Calvert Cliffs' FLEX building, there are portable generators big enough to restore power to key systems as well as pumps to draw water from various sources, including the bay, for use as emergency cooling water.
"If you really had an ugly day here, everything is there so you could respond," Gellrich said.
There's a trailer full of walkie-talkies, plus 100 spare batteries to keep them working for 24 hours without needing to recharge. Two full tanker trucks are parked inside to refuel emergency generators and vehicles. All the gear is strapped down to steel bolts in the concrete floor, securing it against seismic shaking.
To ensure that the FLEX building's emergency gear can reach the plant, there are Bobcat loaders to remove debris that might block the roads, plus a forklift big enough to move the concrete jersey barriers that now limit vehicular access. Pickup trucks for hauling trailers are fitted with snowplows.
"Whatever time of year, we're ready for anything," said Charles "Chuck" Merritt Jr., the plant's disaster response coordinator.
In case a storm or other disaster cuts the plant off from the outside, Exelon keeps essentials nearby for workers to stay at the plant overnight. According to NRC records, there are 122 gallons of bottled drinking water, 422 power bars, 61 military-style cots, 122 cold-weather sleeping bags and four portable toilets.
Plant officials say they have enough emergency gear and supplies to keep going for the first 24 hours of a crisis. For anything longer, the industry has established two regional response centers in Memphis, Tenn., and Phoenix, stocked with items that can be airlifted to any plant in need.
"The whole goal of this is to add an additional layer of safety," said Tom Kauffman, a spokesman for the Nuclear Energy Institute, an industry group. And beyond that, he noted, the emergency gear is standardized industrywide, so nearby plants could share theirs with one in distress.
David Lochbaum, nuclear safety project director for the watchdog group Union of Concerned Scientists, said it is good that plants no longer rely only on the diesel generators and other emergency systems installed there.
"In the old days," said Lochbaum, a nuclear engineer who spent 17 years in the industry, "we would have said, 'That will get us through the accident,' and we wouldn't have had the cavalry option. Now we recognize that accidents don't always adhere to our rules."
But the FLEX stockpile is no panacea, he said.
The Pilgrim nuclear plant in Massachusetts lost outside power during a severe snowstorm last winter, and when a backup diesel generator would not start, plant workers hauled out the portable air compressor in their FLEX building to reactivate instruments and equipment, Lochbaum said. The compressor started but did not generate enough air pressure for everything to work properly. Pilgrim staff restored pressure hours later after they get another compressor from outside the plant.
"The good news is that even though they came up short at Pilgrim, workers were able to get by without it," Lochbaum said. "And even though it didn't work as needed, the consequences were minor."
But the episode suggests that there is room for improvement, he said. He questioned why the NRC has not set requirements for how often the emergency equipment is tested or how often plant operators should train in how to use it.
Neil Sheehan, an NRC spokesman, acknowledged that the FLEX equipment had not succeeded in restoring air pressure for all of the Pilgrim plant's instruments but said the compressor was only intended for use in restoring air pressure to "certain critical pieces of equipment" in a crisis, not all plant systems.
Jason Paige, an NRC project manager who audited the FLEX setup at Calvert Cliffs, said he is unaware of any specific NRC testing and training requirements for the backup facilities. But he said the plants generally have to show that the equipment works and that personnel know how to use it.
In inspecting other nuclear plants, Paige said, he has seen workers drill by retrieving the equipment from the FLEX building, placing it where needed and doing everything short of hooking it up.
"The plants are much, much better off with the FLEX equipment," Lochbaum said. "But there are some seams [in the safety net] that are perhaps wider than they need to be."