Press Release-IV-14-014, NRC Issues Two Yellow Findings to Arkansas Nuclear One

Press Release-IV-14-014: NRC Issues Two Yellow Findings to Arkansas Nuclear One

ML14175B146
Person / Time
Site:	Arkansas Nuclear
Issue date:	06/24/2014
From:	Office of Public Affairs Region IV
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Category:Press Release
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Press Release-IV-14-014
Download: ML14175B146 (2)

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No: IV-14-014 June 24, 2014 CONTACT: Victor Dricks 817-200-1128 Lara Uselding 817-200-1519 NRC Issues Two Yellow Findings to Arkansas Nuclear One The Nuclear Regulatory Commission has determined that two inspection findings at the Arkansas Nuclear One facility in Russellville, Ark., issued in connection with a 2013 heavy equipment handling incident are yellow, or of substantial safety significance. The plant is operated by Entergy Operations, Inc.

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.

Workers were moving a 525-ton component out of the plants turbine building during a maintenance activity when a temporary lifting assembly collapsed on March 31, 2013, causing the component to fall, damaging plant equipment, killing one person and injuring eight others. Unit 1 was in a refueling outage at the time, with all of the fuel still in the reactor vessel, safely cooled. Entergy officials declared a Notice of Unusual Event, the lowest of four emergency classifications used by the NRC, because the incident caused a small explosion inside electrical cabinets. The damaged equipment caused a loss of off-site power. Emergency diesel generators were relied upon for six days to supply power to cooling systems.

The falling turbine component damaged electrical cables and equipment needed to route power from an alternate AC power source to key plant systems at both units. This condition increased risk to the plant because alternate means of providing electrical power to key safety-related systems was not available using installed plant equipment in the event the diesels failed.

Unit 2, which was operating at full power, automatically shut down when a reactor coolant pump tripped due to vibrations caused by the heavy component hitting the turbine building floor when it fell. Unit 2 never completely lost off-site power, and means existed to provide emergency power using the diesel generators.

NRC Resident Inspectors responded to the site the day the incident occurred. The NRC conducted an Augmented Team Inspection, prepared a detailed chronology of the event, evaluated the adequacy of licensee actions in response to the incident, and assessed the factors which may have contributed to the incident. Worker safety issues are the responsibility of the Occupational Safety and Health Administration, which conducted an independent inspection of the incident. The NRC determined that the lifting assembly collapse resulted from the licensees failure to adequately review

the assembly design and ensure an appropriate load test in accordance with its procedures or approved standards.

The Augmented Team Inspection report documented information gathered from the initial inspection and identified areas for further inspection follow-up. The NRC held a public meeting in Russellville on May 9, 2013, to discuss the teams findings.

From its follow-up inspections, the NRC identified the preliminary red and yellow findings documented in a March 24 inspection report. NRC held a regulatory conference with Entergy officials on May 1, and after considering information provided by the licensee determined that yellow findings were appropriate to characterize the risk significance of the event for both Unit 1 and 2.

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

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