NRC to address concrete degradation at Seabrook nuclear plantBy GRETYL MACALASTER
Union Leader Correspondent
December 15. 2013 6:36PM
HAMPTON — Nuclear Regulatory Commission staff will once again discuss the issue of concrete degradation at Seabrook nuclear power plant during a public open house and meeting on Wednesday.
The open house will begin at the Best Western Plus–The Inn at Hampton, 815 Lafayette Road in Hampton at 5 p.m. followed by a formal meeting beginning at 6 p.m. during which NRC and NextEra Energy officials will discuss work being performed to address concrete degradation at the nuclear power plant. Members of the public will also have the opportunity to ask questions.
NextEra Energy, owners and operator of the plant, first reported the concrete degradation issue in May 2010.
It is caused by Alkali-Silica Reaction, which is not uncommon in concrete structures, but it is the first time the problem has been discovered at a nuclear power plant in the United States.
ASR is a chemical combining of reactive silica from the concrete aggregate with the alkali from the cement paste in the presence of moisture. The result of the reaction is a gel, which can expand and cause micro-cracks in the concrete.
In May 2012, the NRC issued a “confirmatory action letter” to NextEra confirming that it would complete a variety of actions in response to the condition.
On Oct. 9, the NRC announced that the action letter was being closed out after the agency confirmed through inspections that the actions committed to by the company were being met.While NRC inspections have determined that ASR-affected structures at the plant remain capable of performing their safety functions, the NRC has said it will continue to provide focused oversight of the company’s ongoing actions to resolve the issue. This includes NRC review of the results of an ongoing testing program being conducted at the University of Texas-Austin, as well as of the on-site monitoring of ASR progression in the plant’s concrete structures.