NRC issues two yellow findings to Entergy’s Arkansas Nuclear One

The Nuclear Regulatory Commission has determined that two violations associated with flood protection at Arkansas Nuclear One are of substantial safety significance. The plant, located in Russellville, Ark., is operated by Entergy Operations, Inc.

“Problems existed with the condition of some flood protection barriers at the plant.” NRC Region IV Administrator Marc Dapas said. “This created the potential for water to enter the auxiliary building in the unlikely event of extreme flooding, potentially compromising safety-related equipment. While the deficiencies have been corrected they were of substantial safety significance and as such we will now reassess the appropriate level of oversight for the plant.”

A comprehensive inspection of flood barriers by the licensee and the NRC during 2013 and 2014 identified numerous deficiencies documented in an NRC inspection report issued on Sept. 9.

The licensee has replaced the degraded seals or parts, implemented compensatory measures, and added appropriate instructions to procedures to ensure the protection of vital safety-related equipment. The NRC has inspected these corrective measures to ensure their adequacy.

The NRC evaluates regulatory performance at commercial nuclear plants with a color-coded process that classifies inspection findings as green, white, yellow or red in order of increasing safety significance. NRC held a regulatory conference with Entergy officials on Oct. 28, 2014, and after thoroughly considering information provided by the licensee, determined that the violations related to flood protection have substantial safety significance, or are “yellow” for both units.

The NRC will determine the appropriate level of agency oversight and notify Entergy officials of that decision in a separate letter.