NEWBURYPORT — Concerned about growing cracks in the concrete containment dome and in other critical parts of the sprawling complex at the Seabrook Nuclear Power Plant, a group of activists here has been urging federal regulators to postpone a planned extension of the aging plant’s operating license.
With the help of lawmakers from Massachusetts and New Hampshire, they recently won a reprieve.
Officials at the Nuclear Regulatory Commission agreed last month to delay their renewal decision and meet with local residents on Wednesday in Hampton, N.H., to discuss whether the plant should be allowed to continue producing electricity 20 more years after its current license ends in 2030.
Now, the activists are planning to file an emergency petition with the government, seeking immediate action “to ensure that the NRC will uphold its duty to protect the public,” said Natalie Hildt Treat, executive director of the C-10 Research & Education Foundation, which for years has been monitoring any radiation from the plant.
The petition, which the group plans to file this week, demands that regulators further delay their decision on the license extension. “We think the NRC made a mistake when it concluded that [extending the license] would pose no significant hazard to public safety,” she said.
Seabrook has 11 more years before its license expires, and Treat said it would be “crazy” to rush the decision.
“What’s the hurry?” she asked from her office, a nondescript building in Newburyport some 7 miles downwind from Seabrook, where instruments are constantly tracking the air for radioactive particles and other signs of danger. “We believe [extending the license] could undermine the safety of the American citizens that NRC is charged with protecting.”
Federal regulators say the protective concrete, which was designed to prevent the release of radiation, is “operable but degraded,” meaning that the plant can continue to operate if the cracks are monitored closely. The three-decade-old reactor, which looms over marshlands on New Hampshire’s seacoast, just across the Massachusetts border, provides power to roughly 1.2 million homes and businesses.
“The NRC staff sees no reason at this point to not issue the renewed license,” said Neil Sheehan, a spokesman for the NRC, adding that the plant’s concrete has been “intensively studied.”
But the commission agreed to delay its approval of the extension after Massachusetts Senators Edward J. Markey and Elizabeth Warren and US Representative Seth Moulton raised concerns about how NextEra Energy, the Florida company that owns the plant, planned to address the structural degradation and accused regulators of ignoring local concerns.
“This timeline will effectively silence local stakeholders and minimize their critical role,” they wrote in a letter last month to the commission, referring to its plan to renew the license.
The lawmakers also urged the agency to delay its decision until C-10’s concerns are formally heard this summer by the Atomic Safety and Licensing Board, a NRC panel that adjudicates a range of issues about nuclear power.
“It is unacceptable that the NRC plans to . . . grant a 20-year license renewal before the community publicly shares its concerns,” the lawmakers wrote to the NRC.
Sheehan said the NRC isn’t required to wait for the hearing. If the board affirms C-10’s concerns, the NRC could amend the plant’s renewed license and require further action to correct the problem, he said.
NextEra first reported the problems in 2009, when operators found that moisture in the plant’s walls was degrading the concrete and producing something called an alkali silica reaction, which generates an expanding gel that causes small cracks.
More recently, the plant’s staff reported that the gel was contributing to significantly larger cracks that could be causing structural damage.
Degraded concrete has been found throughout the plant, including near the spent-fuel pool, the water-cooling tower, and the buildings that contain turbines, diesel generators, and fire pumps. About 170,000 people live within 10 miles of the plant.
The unusual reaction, which hasn’t been found at any other nuclear plant in the United States, spurred a host of federal inspections and testing of concrete samples throughout the plant. The commission has also deferred NextEra’s requests to extend the plant’s license until the company proved that its staff could manage the problem.
Treat’s foundation, which receives funding from Massachusetts to monitor the region’s radiation levels, argues that NextEra’s testing of the concrete has been insufficient and that the commission’s analysis has relied on samples that aren’t representative of degradation throughout the plant. Similar kinds of concrete degradation were factors in the closing of nuclear plants in Europe and Canada, Treat said.
Officials at NextEra said the commission’s conclusions about the plant’s safety rebut C-10’s assertions.
In a statement, company officials added that alkali silica reactions, known as ASR, are a “manageable condition common in critical infrastructure like bridges, runways, and dams.”
“Seabrook’s opponents refuse to acknowledge that there has never been a documented case of structural failure due to ASR, even in structures far less robust than Seabrook,” said Peter Robbins, a spokesman for NextEra. “We have extracted and tested more than 100 core samples . . . to validate that our structures are capable of performing as required.”
Robbins added that nuclear power is vital to reducing the region’s dependency on fossil fuels. Without power from Seabrook, Massachusetts would struggle to comply with its legal requirement to cut carbon emissions 25 percent below 1990 levels by 2020.
“People produce more greenhouse gases driving to work each day than Seabrook has produced in 30 years of power production,” Robbins said.
At C-10’s office, which receives data every minute from 14 radiation detectors deployed throughout the area, Treat and her colleagues are planning to make the case that their analysis of the concrete reflects far more danger than regulators have acknowledged.
“Because this atomic plant’s concrete must continue to serve as the primary barrier between our environment and some of the deadliest toxins known,” said Chris Nord, who serves on the group’s board of directors, “one would think an agency that regards their mission seriously would not rush to extend the operating license of this compromised facility.”
David Abel can be reached at email@example.com. Follow him on Twitter @davabel.