Regulator raises Nuclear One risk

An inspection of the Arkansas Nuclear One facility in Russellville after a fatal 2013 accident yielded two "yellow" findings denoting the second-highest risk, the Nuclear Regulatory Commission said Tuesday. Previously, the regulatory body said it had no safety concerns about the Entergy Corp. plant.

The two findings "of substantial safety significance" at the Entergy plant, discovered after an accident that left one worker dead and injured eight others, were associated with a Unit One stator drop that affected safety-related equipment at both units, according to an inspection report.

The agency, which found in the inspection report that "Entergy did not ensure adequate supervisory and management oversight of the contractors and other supplemental personnel involved with the stator lift," said Tuesday that it "will determine the appropriate level of agency oversight and notify Entergy officials of the decision in a separate letter."

"Because the NRC has not made a final determination in this matter, no Notice of Violation is being issued for these inspection findings at this time," the agency wrote to Entergy on March 24.

The Nuclear Regulatory Commission evaluates commercial nuclear plants' regulatory performance with color-coded classifications ranging from the lowest risk, green, to white, yellow, and the highest risk, red.

On March 31, 2013, a 525-ton component was being moved out of the plant’s turbine building for maintenance when a “temporary lifting assembly collapsed, causing the component to fall,” the regulatory body said. The falling turbine damaged electrical equipment needed to power key systems at both units, increasing risk to the plant because that disabled the alternate means to power safety-related systems in the event the diesels failed, the agency said.

After inspections were performed that day and the next, the agency determined that the collapse resulted from the Entergy's failure to “adequately review the assembly design and ensure an appropriate load test in accordance with its procedures or approved standards,” the agency said. The Nuclear Regulatory Commission said in April 2013 that it had no safety concerns about the plant.

The agency conducted follow-up inspections in February and identified its higher risk findings in a March 24 letter; on May 1, the regulator held a conference with Entergy officials and solidified its "yellow" findings for the two units.

Upcoming Events