Photo: Columbia's Independent Used Fuel Storage Installaion
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Used Nuclear Fuel Storage

Photo: Columbia's Independent Used Fuel Storage Installaion

​​Columbia Generating Station's used nuclear fuel is a solid dry material, safely stored on site in a secure Independent Spent Fuel Storage Installation, or ISFSI.

Columbia began operations in 1984. Until 2002, all of the used fuel from the reactor was stored in a specially designed, temperature-controlled, water-filled fuel pool in the reactor building. The pool, able to accommodate 2,658 fuel assemblies, was designed as a short-term storage option until a national repository could be built. Used fuel is safely stored on-site at nuclear power plants across the county.

Learn more about used nuclear fuel in this video with Dr. James Conca.

Planning for Energy Northwest’s dry cask storage project began in the late 1990s. Construction followed in 2001 and loading and storage of the first five casks was completed in April 2002. Additional campaigns were successfully completed in 2004, 2008, 2014, 2018, and 2022 bringing the total number to 54.

Phot: Fuel Storage Casks

Each concrete and steel storage cylinder stands about 19 feet tall and measures 11 feet in diameter. The outer concrete cask encases a stainless steel canister. Heat is transferred from the fuel to the walls of the helium-filled canister. Space between the canister and cask allows air flow to cool the used fuel and canister. The casks rest on a large, two-foot-thick reinforced concrete pad in a fenced secure area adjacent to the plant.

Integrated Used Fuel Management

Under the integrated management approach, used nuclear fuel is stored on site at plants in steel-lined water-filled concrete pools, and above ground in massive airtight steel or concrete-and-steel dry canisters. The dry storage system allows for the safe and efficient storage of Columbia Generating Station’s used fuel until such time as it can be transported to a national repository. Although the Nuclear Regulatory Commission determined used fuel could remain in safe storage at plant sites for 100 years, such storage was never intended to be permanent.​

National Repository Development

In 1983, Energy Northwest and other U.S. nuclear utilities entered into an agreement with the Department of Energy for disposal of used nuclear fuel beginning on or before January 1998. The agreement was established under the Nuclear Waste Policy Acts of 1982, and required Energy Northwest and other nuclear operators to pay DOE an annual fee.

The fees, paid to the Nuclear Waste Fund, equal one-tenth of a cent for every nuclear-generated kilowatt-hour of electricity produced, amounting to many billions of dollars. Energy Northwest alone has paid more than $100 million in fees since 1983.

In 2002, Congress approved Yucca Mountain, Nev., a remote desert location, as the site for a centralized deep geologic repository for used nuclear fuel and other high-level radioactive waste. The DOE planned to apply for a Nuclear Regulatory Commission license for the Yucca Mountain by the end of 2004. DOE has subsequently notified Energy Northwest and other nuclear utilities of an indefinite delay in fulfilling their contractual obligations to provide safe methods of long-term storage for used fuel.

Photo: Cask Storage Transport Crawler

(Right) A used nuclear fuel storage cask is transported to the ISFSI. Each cask weighs about 185 tons. The crawler, which moves at 0.3 mph, is affectionately known as "greased lightning."

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