NRC to hold public meeting, open house on Dec. 11 to update public on reviews of concrete degradation at Seabrook nuke

Nuclear Regulatory Commission staff will hold a meeting and open house on Tuesday, Dec. 11, to update the public regarding its ongoing reviews of concrete degradation at the Seabrook nuclear power plant. Seabrook is a single pressurized-water reactor located in Seabrook, N.H., and operated by NextEra Energy Seabrook, LLC.

The open house will take place from 5:30 to 6:45 p.m. at the One Liberty Lane Conference Center, at 1 Liberty Lane East in Hampton, N.H. (Directions to the center are available at: During the open house, members of the public will have an opportunity to talk on a one-on-one basis with NRC staff involved with the reviews. The open house will be immediately followed by a public meeting, beginning at 7 p.m., during which NRC staff will provide a presentation on the reviews and take questions from audience members.

Seabrook’s concrete degradation is caused by alkali silica reaction. This chemically combines reactive silica from the concrete aggregate with the alkali from the cement paste in the presence of moisture. (Aggregates are inert granular materials, such as sand, gravel or crushed stone that, along with water and cement paste, are an essential ingredient in concrete.) This reaction forms a gel, which can expand and may cause micro-cracks in the concrete.

While the extent of the problem at Seabrook is still being evaluated, the NRC has determined that the structures identified to be affected by the degradation are able to continue to perform their safety function.