On May 29, 2018, Byron Station successfully completed the loading and transporting of five used fuel casks to the site's storage pad within its Protected Area. Each cask holds 32 nuclear fuel assemblies that were once used in a reactor on site as part of the process of generating electricity.
Like most nuclear plants in the country, Exelon's Byron Generating Station implemented a dry cask storage program to increase the plant's capacity to safely store used nuclear fuel. Dry cask storage is a safe, alternative method for storing used, solid nuclear fuel material and is a proven technology that is utilized across the nuclear industry.
Used fuel, also referred to as spent fuel, is a byproduct of nuclear power plant operations. Nuclear plants use uranium-enriched fuel in the form of small ceramic pellets to generate electricity. These pellets are inserted into sealed tubes, which make up a fuel assembly. Used fuel remains once the fuel's energy has been consumed through the reactor process. The Nuclear Waste Policy Act of 1982 required the federal government to properly dispose of spent nuclear fuel in 1998 by constructing a national repository, which to date has not been completed.
The outer cask awaits the arrival of the inner container, which contains the used fuel.
In the interim, Byron Station is storing some of its used nuclear fuel on its property until a more permanent storage facility is opened by the U.S. Department of Energy. Exelon Generation is committed to ensuring the safety of Byron Generating Station employees, neighbors and the surrounding environment. All aspects of the dry cask spent fuel storage program are designed and implemented with this as the top priority.
The initiative to add more storage space for spent fuel at Byron is necessary due to limited remaining space in the station's current fuel storage pool — the steel-lined, concrete water pools located within the plant where spent fuel is currently stored safely. The additional storage at Byron will also ensure the continued long-term operation of the plant to produce clean, low-cost electricity for future generations.
Dry Cask Storage: Safety & Security
Dry cask storage is approved and regulated by the U.S. Nuclear Regulatory Commission — the federal agency responsible for regulating the nation's commercial nuclear plants. The dry cask storage process has been proven to be an extremely safe, secure and reliable method of storing spent nuclear fuel.
The foremost safety feature is the robust storage cask design and construction. These containers are extremely rugged steel-lined and concrete-enclosed structures designed to protect the fuel in the event of severe weather or other destructive forces and provide radiation shielding to workers and members of the public. The technology has been tested and proven safe under the most extreme conditions.
Moving the Fuel: The Process
The movement of spent fuel and the dry casks to the on-site storage space is safely managed by highly-trained and qualified Exelon employees who have performed this work at Exelon's other sites.
Used nuclear fuel is loaded into the primary storage cask under water in the plant's fuel pool. Once the fuel has been loaded into the cask, it is sealed and all atmosphere and water inside the cask is removed creating the 'dry cask' name. Through a very regulated process, the primary cask is welded closed and placed inside the outer storage cask. Then, the outer cask is bolted closed. The dry cask is transported via a specially designed slow-moving crawler that moves approximately one mile per hour to the site's used fuel storage facility located on plant property.
Byron Generating Station currently has 31 Dry Casks on its pad, protected by stringent security barriers and regularly patrolled by the station's paramilitary force.