North Anna Power Station Units 1 and 2 are located in Louisa, Virginia approximately 40 miles northwest of Richmond, Virginia. The Westinghouse PWRs are operated by Dominion Generation. Virginia Electric & Power Co., a wholly owned subsidiary of Dominion Resources, Inc. owns 88.4% of both units, and Old Dominion Electric Cooperative owns the remaining 11.6% of both units. Unit 1 is licensed to operate until April 1, 2038. Unit 2 is licensed to operate until August 21, 2040.
The ISFSI for North Anna began accepting SNF from both units in 1998 pursuant to both a general license and a site-specific license. The ISFSI consists of two concrete storage pads. As of the end of 2011, there were 1,280 SNF assemblies stored in 40 dry casks. All of the casks are manufactured by Transnuclear. As of the end of 2010, there were 2,400 metric tons of SNF stored at the 2 nuclear power plant sites located in the Commonwealth of Virginia — North Anna and Surry.
As of the end of 2011, there are 27 vertical TN-32 metal casks storing 864 SNF assemblies under the site-specific license on Concrete Storage Pad #1. These casks appear on the left side of the above photo and are shown in the top photo to the right. The vertical TN-32 metal cask were the first to be used at North Anna. In addition, there are 26 horizontal NUHOM HD-32PTH storage modules (although only 13 are loaded) storing 416 SNF assemblies under the general license on Concrete Storage Pad #2. These casks appear on the right side of the above photo and are shown in the bottom photo to the right. The NUHOM storage modules are the current casks being used.
On August 23, 2011, a magnitude 5.8 earthquake occurred near Mineral, Virginia. The epicenter of the earthquake was approximately 11 miles southwest of North Anna. As a result of the earthquake, 25 of the 27 free-standing, vertical TN-32 metal casks located on Concrete Storage Pad #1 slid up to 4.5 inches. The top photo to the left shows the result of the movement. For the horizontal NUHOMS storage modules, some slight damage occurred around the outlet vents on the roof of the modules. This is shown in the second and third photos to the left. Some surface cracking of the modules also occurred. In addition, some of the horizontal storage modules showed gaps between them of 1.5 inches instead of the originally required 1 inch maximum. The bottom photo to the left shows the result of this movement. Subsequent inspections by Dominion Generation and the U.S. Nuclear Regulatory Commission concluded that the damage to the concrete ISFSI components was cosmetic, did not impact structural integrity or radiation shielding capability, and was not an immediate safety issue. These photos illustrate, however, that dry casks loaded with SNF and weighing in excess of 150 tons can be moved by the force associated with a significant earthquake.