Seabrook Owner Must Conduct Tests Assessing Potential Concrete Damage in Containment Buildings, Nuclear Safety Groups Say

The C-10 Research and Education Foundation and the Union of Concerned Scientists (UCS) today asked the Nuclear Regulatory Commission (NRC) to require the owner of the Seabrook nuclear plant in New Hampshire to address potentially serious concrete degradation problems at the facility.

The letter from the two nuclear safety groups specifically calls on the NRC to compel NextEra, Seabrook's owner, to launch a thorough evaluation of the plant's concrete structures during its scheduled September 23 refueling outage to determine the extent of degradation of the concrete in the facility's containment building as well as any accompanying corrosion of steel structures--including the reinforcing rods embedded in the concrete walls--that could undermine structural integrity.

Plant workers first discovered cracks in the concrete in some of Seabrook's buildings in 2009, which prompted the NRC to suspend the plant's relicensing process. That degradation reportedly is extensive with moderate-to-severe mechanical consequences. A key, unanswered question is to what extent such degradation has affected the reactor's containment building and reduced its structural strength, which could compromise its ability to withstand earthquakes and other stresses.

Parts of the containment building are known to have been exposed for many years to water containing chemicals that trigger a process called alkali-silica reaction (ASR). This reaction causes the concrete to swell and crack.

"Systematic testing and assessment of the containment is needed to determine the current status of the plant and predict the consequences of future degradation of the concrete or corrosion of steel reinforcement," said Deborah Grinnell, a C10 Foundation spokeswoman. "Two years into the Seabrook relicensing process, that has still not been done."