Press Release-IV-12-040, NRC Issues a Yellow Finding to Wolf Creek Nuclear Plant in Connection with Loss of Off-Site Power Event

Press Release-IV-12-040: NRC Issues a Yellow Finding to Wolf Creek Nuclear Plant in Connection with Loss of Off-Site Power Event

ML12265A279
Person / Time
Site:	Wolf Creek
Issue date:	09/21/2012
From:	Office of Public Affairs Region IV
To:
Category:Press Release
References
Press Release-IV-12-040
Download: ML12265A279 (2)

Text

NRC NEWS U.S. NUCLEAR REGULATORY COMMISSION Office of Public Affairs Region IV 1600 E. Lamar Blvd.

Arlington, TX 76011 - 4125 Site: www.nrc.gov Blog: http://public-blog.nrc-gateway.gov No. IV-12-040 Sept. 21, 2012

Contact:

Victor Dricks (817) 200-1128 E-Mail: OPA4.Resource@nrc.gov Lara Uselding (817) 200-1519 NRC ISSUES A YELLOW FINDING TO WOLF CREEK NUCLEAR PLANT IN CONNECTION WITH LOSS OF OFF-SITE POWER EVENT The Nuclear Regulatory Commission staff has determined that an inspection finding at the Wolf Creek nuclear power plant related to a loss of off-site power event is yellow, meaning the issue has substantial safety significance and will result in additional NRC inspections and oversight. The plant, located near Burlington, Kan., is operated by Wolf Creek Nuclear Operating Corp.

On Jan. 13, operators at the plant declared an Unusual Event, the lowest of four levels of nuclear emergency, after the failure of a main generator electrical breaker, followed by an unexplained loss of power to a transformer. This caused the switchyard to lose power, which removed the plants connection to the electrical power grid. All safety systems responded as expected and emergency diesel generators automatically powered safety-related equipment.

The NRC conducted an Augmented Inspection and determined that actions by the licensee set the stage for the incident because the company failed to provide adequate oversight of contractors while they performed work that could affect safety-related equipment in April 2011. As a result, the licensee failed to identify that electrical maintenance contractors had improperly connected wires on an electrical component. This allowed an electrical short to prevent transfer of power to a transformer on Jan. 13.

The NRC held a public meeting on March 6 in New Strawn, Kan., to discuss the preliminary results of the Augmented Inspection. Following further review, the NRC staff has concluded that the inspection finding is appropriately characterized as yellow, which has been accepted by the licensee.

Under the NRC reactor oversight process, inspection findings are evaluated using a significance determination process and assigned a color indicating its safety significance.

Findings with very low safety significance are labeled "green." "White" findings have low to moderate safety significance, "yellow" findings have substantial safety significance, and "red" findings have high safety significance.

The yellow finding moves Wolf Creek into the degraded cornerstone column of the NRC action matrix, resulting in a higher level of NRC oversight. This is the third highest level of NRC oversight and Wolf Creek joins six other U.S. nuclear units in that column. The position of all nuclear units within the NRC Action Matrix is available on the NRC web site at:

http://www.nrc.gov/NRR/OVERSIGHT/ASSESS/actionmatrix_summary.html#am_summary .

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