On January 27, 2006 Vermont Yankee applied to the Nuclear Regulatory Commission for a 20 year extension of its operating license. The application was approved on March 21, 2011.
On May 5, 2006 Vermont Yankee completed its power uprate. It is currently producing 650 MW of clean, low cost electricity.
The Nuclear Regulatory Commission and the Vermont Public Service Board were the lead agencies charged with oversight of the approval process that ultimately led to the increase, known as an "uprate."
Storing Spent Fuel/Dry Cask Storage
Nuclear power plants have traditionally stored spent fuel in secure water pools at the reactor site. In the early 1980s, as space in the pools at the reactor sites ran out, the nuclear power industry began to explore alternative storage methods. Today, plants can increase on-site storage capacity by "reracking," or placing fuel rod assemblies closer together in spent fuel pools, or by consolidating the fuel rods themselves. However, both these methods are also constrained by the size of the spent fuel storage pool at the plant.
Dry cask storage is a remarkably simple, yet extremely safe and reliable system that seals used nuclear fuel in massive airtight steel and concrete canisters that provide both structural strength and radiation shielding. The system of concentric cylindrical containers provides above ground, long-term storage of spent nuclear fuel. Casks are placed upright on a concrete pad and are hardened structures capable of withstanding natural disasters and terrorist attacks. The vertical system is referred to as dry because the fuel is surrounded by helium gas rather than water. The canister/cask system is very robust, about 20 feet in height and 11 feet in diameter, with a cask wall that is over 2 feet thick and a total loaded weight of about 360,000 pounds. The inner canisters and outer casks have no operating equipment requiring regular maintenance. The fuel is cooled by passive means, with its heat dissipating via cooling channels in the outer cask that allow air to circulate naturally on the outside of the inner canister. This type of storage is also known as an Independent Spent Fuel Storage System ISFSI.
Entergy moved five casks of fuel to a highly protected dry cask storage pad on site in 2008.
Safety, Security & Environment
The Nuclear Regulatory Commission reviews and approves the designs for spent fuel dry storage systems as well as periodically inspects the design, fabrication and use of dry casks to ensure continued compliance with radiation safety and security requirements. The Nuclear Regulatory Commission requires the spent fuel to be cooled in the spent fuel pool for several years before being transferred to dry fuel storage. Typically, the maximum heat generated from 24 fuel assemblies stored in a dry fuel container is less than that given off by a typical home heating system in an hour. The containers are cooled by the natural circulation of outside air. As the fuel cools further, the heat generated will decrease over time. Dry Cask Storage is an efficient and safe way of adding fuel storage capacity. Dry Cask Storage has been in use at various nuclear facilities in the United States, successfully, since the mid 1980s. It is a proven, safe technology. Dry Cask Storage is safe and environmentally sound, with four decades of exemplary safe performance worldwide. Strict federal regulations pertaining to environmental protection, radiation control, and occupational safety govern the process. The containers used in the dry storage systems are designed to resist floods, tornadoes, projectiles, temperature extremes, and other unusual scenarios.
Over the last 20 years, there have been no radiation releases which have affected the public, no radioactive contamination, and no known or suspected attempts to sabotage spent fuel containers.
For more information please visit http://www.nrc.gov/waste/spent-fuel-