SEABROOK — A recent inspection report by the Nuclear Regulatory Commission finds that NextEra Energy Seabrook has shown that the nuclear power plant’s staff is taking necessary steps to address the plant’s concrete degradation, leading the NRC to close all of the remaining action items first issued by the commission to address the situation.
By closing the last of the items ordered to address the alkali-silica reaction concrete degradation evaluation at the power plant, the commission has found that appropriate corrective actions are being carried out, according to an NRC spokesman.
However, the results of more testing, ongoing at the University of Texas, are necessary to determine a long-term solution for the problem as it relates to the NextEra’s request for a 20-year extension of the plant’s operating license. The result of that testing isn’t expected until some time in 2014.
On June 27, a team from the NRC completed a weeks-long inspection at Seabrook Station. The team reviewed procedures and records, observed activities and interviewed station personnel regarding the adequacy of NextEra’s actions to address the impact of alkali-silica reaction on reinforced concrete structures, according to the letter written by Raymond Lorson, director of reactor safety for the NRC.
The team also examined the plant’s safety and compliance with agency rules and regulations.
Alkali-silica reaction is a slow chemical reaction among water, the alkaline cement and reactive silica found in some aggregates used to make concrete. ASR forms a gel that expands, causing cracks that affect concrete properties, but which can take five to 15 years to show up.
More commonly found in transportation structures like dams, bridges and roads, where it has been successfully mitigated, Seabrook Station was the first nuclear power plant to discover and report the presence of ASR in 2009. It was found in an electrical conduit tunnel located about 40 feet below ground level, in one of the deepest sections of the plant. The tunnel contains wires that lead from the control room to the rest of the plant. The tunnel holds wiring that connects the plant’s controls to machinery throughout the facility.