A panel of federal judges has ordered a stricter monitoring plan for Seabrook Nuclear Power Plant’s issues with cracks in its concrete.
The ruling comes from the Atomic Safety and Licensing Board, under the Nuclear Regulatory Commission.
It was issued in late August and made public Friday, about a year after a days-long hearing on the issue in Newburyport, Mass.
The board is upholding, as well as expanding, the part of the plant’s license that lays out how it will manage the aging and cracking of its concrete.
Seabrook is the only nuclear plant in the country known to be experiencing this problem, which is caused by a chemical process known as alkali-silica reaction, or ASR.
The new conditions imposed by the ruling will require the plant’s owner, Florida-based NextEra, to monitor the problem more closely and frequently.
Some tests that would have occurred every five to 10 years will now take place every six months. Concrete cores taken from the plant will also be analyzed more closely for signs of degradation.

“The Board concluded the additional conditions to the license are necessary to provide adequate protection of public health and safety,” the NRC says in a press release.
The watchdog group that spearheaded this case celebrated the ruling, saying it will improve the science and rigor underpinning Seabrook’s concrete management plan.
“Let’s hope that NextEra does the right thing for its neighbors and begins taking steps to strengthen Seabrook’s concrete aging management plan right away, rather than wasting time and resources to fight what was ordered in this carefully-deliberated ruling,” says C-10 Foundation president Natalie Hildt Treat.
NextEra says in a statement that they are pleased their license amendment was upheld and are determining next steps based on the decision.
"Seabrook’s program to monitor and manage ASR is comprehensive and effective," the statement says. "Nothing is more important than the safety of employees and the public, and our robust ASR program is part of that commitment to safety."
Seabrook is one of two nuclear plants left in New England. The other is Millstone Station, in Connecticut. Together, the two facilities supply about a third of the region's power.
