Nuclear plants in Carolinas brace for Hurricane Florence, may shut in advance

Washington — US nuclear plants in several Southeastern states are readying for Hurricane Florence and may have to shut ahead of the arrival of hurricane-force winds, utilities said Tuesday.

The Category 4 hurricane is on track to make landfall late Thursday or early Friday, and if it retains current wind speeds, it would be the most powerful storm to hit that far north in the US ever, Accuweather said in a statement early Tuesday. The storm may slow and stall around the coast, increasing potential rainfall and wind damage, its forecasters said.

Hurricane-force winds could extend along much of the coast of North Carolina and parts of Maryland, South Carolina and Virginia depending on the exact track of the storm, it said.

Duke Energy's nuclear plants in the Carolinas would be required to shut in advance of the arrival of winds of more than 73 miles per hour, Karen Williams, a spokeswoman for the coastal 1,978-MW Brunswick plant 30 miles south of Wilmington, North Carolina, said. The units would have to be shut at least two hours before the arrival of hurricane-force winds, meaning the process of shutting the reactor would have to begin even earlier, she said.

The same requirements apply to most US nuclear units. Nuclear reactors are protected against extreme winds, including tornado-strength gusts, but shut as a protective measure in case off-site power is lost.

The Carolinas have a heavy concentration of power reactors, with 12 of the country's 99 nuclear units. In addition, four units are in Virginia and five in coastal Delaware and Maryland.

Preparations for the storm are already underway at all 11 Duke nuclear units in North and South Carolina, including the two-unit Brunswick and Duke's one-unit 820-MW Robinson-2 near Florence, South Carolina, Williams said.

The timing of the potential shutdown of Duke's nuclear plants will depend on the exact track of the storm, which is hard to predict, she said. As part of preparations, personnel not vital to plant operations are sent home, food, water and other necessities are kept onsite to prepare for potential isolation of the site, and staff needed during the storm are brought in to ensure proper resources are available for an extended period, Duke said.

Portable back-up equipment is already in place, the company said.

South Carolina Electric & Gas is also prepared to shut its 1,006-MW Summer station in Jenkinsville, South Carolina, should hurricane-force winds be expected at the site, company spokeswoman Rhonda O'Banion said Tuesday. The utility is evaluating whether it will need to increase staffing levels in advance of the storm, she said.

Florida Power & Light last year shut three of the four nuclear reactors at its Turkey Point and St. Lucie nuclear plants in southern Florida when Hurricane Irma made landfall there in early September. -- William Freebairn, william.freebairn@spglobal.com

-- Edited by Pankti Mehta, newsdesk@spglobal.com