An independent group of scientists says they believe the concrete cracks at Seabrook Nuclear Power Plant are under control.
The report from the Advisory Committee on Reactor Safeguards agrees with earlier findings from the Nuclear Regulatory Commission.
The groups conclude that Seabrook's owner, NextEra, has a sufficient plan in place to monitor changes in and effects from the cracks over time.
"We concur with the staff conclusion that, while some of the structures are degraded, they are fully capable of performing their credited function through the requested PEO [period of extended operation] under the committed enhanced monitoring and evaluations," the advisory committee writes in its report.
The concrete cracks, caused by a chemical reaction known as ASR, were first found nearly a decade ago. Seabrook is the only plant in the country known to have this problem.
NextEra wants to extend its license to operate the plant through 2050. But activists say the cracks and other potential hazards mean it should close.
“The fact remains that ASR is a progressive, irreversible condition that is degrading concrete throughout important safety structures at Seabrook," says C-10 Foundation executive director Natalie Hildt Treat in a statement. "No one really knows how bad it is — or will get — and while it is being monitored, there is no ‘cure’ for ASR.”
C-10 will participate in hearings on the license renewal next summer. The reactor safeguards advisory committee will also issue a report on the renewal request "sometime in the near future," the NRC says.
Seabrook will be one of two nuclear plants left in New England after next year, when Pilgrim Station in Massachusetts is set to close.
This story has been updated to include a statement from the C-10 Foundation.