A degrading concrete wall at Seabrook Station and the nuclear crisis in Japan were the chief topics of concern during a public hearing held by the Nuclear Regulatory Commission on June 8 in Hampton.

At the meeting, held at the Galley Hatch Conference Center at the Best Western Inn, NRC officials discussed their annual assessment of safety performance at Seabrook Station, which is owned and operated by NextEra Energy. NextEra is seeking a 20-year extension to its operating license, which expires in 2030. 

An NRC report published in May revealed that groundwater had been seeping into an underground electric tunnel at Seabrook Station. A portion of the tunnel wall has lost about 22 percent of its strength due to water saturating an aggregate in the concrete, according to the report.

NRC officials assured the public the water had not compromised the plant’s electrical systems or impacted safety. They gave Seabrook Station a positive safety assessment for 2010.

“NextEra operated Seabrook safely and in a manner that met all safety cornerstone objectives,” said William Raymond, senior resident inspector for the NRC.

But several area residents expressed concerns about the concrete, especially as the plant seeks a license renewal that would keep it operating for another 40 years.

“That’s of concern to people that live here and want to know whether the plant’s going to be functional 30 or 40 years from now,” said Doug Bogen, a Barrington resident and director of the Seacoast Anti-Pollution League. 

NRC representatives said the weakened wall in Seabrook marked the first time such degradation had been observed at a nuclear plant in the United States. But they reiterated that the situation did not pose a safety threat. 

“The building still performs its design function, even though there has been some degradation with its ability to resist various stresses,” said NRC branch chief Arthur Burritt. “It is still functional.”

He acknowledged that NextEra was slow to identify the problem, despite the fact that groundwater has been saturating the concrete for many years. He said the NRC is still working with NextEra to address the issue going forward.

“We have not been able to draw conclusions on Seabrook’s ability to manage and maintain the building at this point. That is an issue that still needs to be resolved,” Burritt said. “We are holding the utility accountable.”

Burritt also sought to ease fears stemming from the nuclear crisis in Japan, where an earthquake and tsunami in March caused explosions and radiation leaks at the Fukushima Daiichi Nuclear Power Station. The NRC has established a task force to conduct a “methodical and systematic review of the events in Japan,” he said.

“Our current assessment is the U.S. nuclear fleet is safe and will continue to be operated safely,” Burritt said. “The key reasons for our continuing confidence are that every plant is designed and constructed to withstand the most significant natural events,” including earthquakes, tsunamis, hurricanes, floods and tornadoes.

Only two nuclear plants in the United States, both located on the coast of California, could be directly affected by a tsunami, Burritt said, and they have design features to protect against such events. 

The most significant threat to Seabrook Station is hurricane storm surges, but the plant is prepared for those, as well, he added.

A team of safety experts from the International Atomic Energy Agency is currently conducting a safety review at Seabrook Station and will share its findings with NextEra and the NRC, Burritt noted.