NRC increases oversight of Monticello plant flooding protection violation

The Nuclear Regulatory Commission staff is increasing its oversight of the Monticello Nuclear Generating Plant for failure to maintain an appropriate plan to protect against potential flooding.

“Even though there was no actual flooding event, this issue is of concern because flood protection procedures are extremely important. They require certain safety features be available and built within a specific timeframe to protect equipment from potential flood waters,” stated NRC Region III Administrator Cynthia D. Pederson in a news release issued Aug. 29.

“We know the plant has made corrections to address this violation and we will review those changes to make sure the issues have been fully addressed,” Pederson stated.

As a result of flooding walkdowns directed by the NRC in response to the accident at Fukushima, an NRC inspector identified a violation involving the failure of the plant to demonstrate flood protection features within the required timeframe. After the NRC reviewed details of the plant’s flood protection strategy, the NRC staff concluded that Monticello did not have appropriate procedures in place and would not have been able to construct a protective wall and levee system within the required timeframe.

The NRC staff has classified the violation as yellow, meaning it has substantial safety significance.
The company has taken corrective actions to address the violation by updating plant procedures and by pre-staging the necessary material on-site, so that the protective wall and levee system could now be installed within the required timeframe stated in the plant’s licensing basis.

The NRC will conduct a supplemental inspection to provide assurance that the root cause and contributing causes are identified and understood, and to ensure the corrective actions are sufficient to prevent recurrence. The inspection will also provide an independent determination of whether safety culture issues contributed to this violation.

Tim O’Connor, chief nuclear officer, Xcel Energy’s chief nuclear officer, issued the following statement regarding the NRC’s increased oversight:

“Safety and security at our nuclear generating plants are top priorities for Xcel Energy, and at no time was the public in any danger.  In response to the accident at the Fukushima Daiichi plant, Xcel Energy and the NRC have reassessed the safety of our plants resulting in an even higher level of safety expectations,” O’Connor stated.

Plant officials annually assess the potential for flooding, including monitoring river water levels and snow cover, and they extensively plan for potential floods based on those predictions.

“Flood berm wall construction procedures were in place, and the site had contracts with local suppliers for materials should those have been needed to protect the Monticello plant,” O’Connor stated. “The plant now has procured those flood berm materials and has placed them on site for improved readiness for this worst case scenario. Because the materials are on site the potential safety concern has been resolved.”

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