Key Facts
- Nuclear power plants generate electricity for one in five U.S. homes and businesses, collectively producing about 2,000 metric tons of used nuclear fuel rods each year. A golf ball of uranium provides a lifetime’s supply of energy for a typical person.
- All the high-level nuclear waste produced by the U.S. nuclear energy industry in more than 50 years of operation would, if stacked end to end, cover a football field to a depth of approximately 12 yards.
- Used nuclear fuel rods are stored safely and securely at reactor and storage sites around the country, either in enclosed, steel-lined concrete pools filled with water or in steel-reinforced concrete containers. The U.S. Nuclear Regulatory Commission has determined that it is technically feasible to continue to store used nuclear fuel safely at power plant sites or consolidated interim storage facilities for an indefinite period.
- On-site storage of used nuclear fuel was never intended to be permanent. In 1998, Congress mandated that the U.S. Department of Energy develop a deep geologic repository for used nuclear fuel and some defense program wastes at a site in the Nevada desert. Given that the repository Congress mandated to be built by 1998 still does not exist, containers are safely and securely stored at plant sites until such time as a repository is ready.
- Globally, the development of geologic repositories for used nuclear fuel is becoming common. A repository is under construction in Finland. Sweden has approved a repository design that will begin construction in the near future. France has identified a repository location and is conducting public consultation on a pilot phase. Canada and Switzerland are progressing on a decision-making process to choose a repository site from a list of proposed candidate locations.
Water Storage Provides Cool-Down Period for Used Fuel
Nuclear power plant fuel storage pools are designed to provide a temporary place to cool used fuel before it is placed in containers for storage and subsequent transport to a permanent repository.
Water is an effective natural shield that protects workers and the environment from the radioactivity and heat produced by used fuel rods. To maintain radiation levels near the pool below the limits specified in NRC regulations, the used fuel at least 20 feet below the water’s surface. The water is filtered and purified. It circulates through a heat exchanger for cooling and then is returned to the top of the pool.
Used fuel storage pools are robust concrete and steel structures that are designed—like the nuclear plants they are part of—to withstand extreme events such as earthquakes, floods, hurricanes and tornadoes. A 2013 NRC report said that an extremely powerful earthquake has a low probability of damaging a pool to the extent that it would lose water. In the event that pools lost water, the report said that “existing emergency procedures would keep the population around the plant safe.”
The safety of used fuel storage pools was proven under severe conditions in 2011. Despite the strongest earthquake in modern Japanese history, a tsunami estimated at 45 feet in height, loss of all off-site electric power for weeks and explosions resulting from hydrogen buildup in containment structures, all seven pools at the Fukushima Daiichi power plant in Japan remained intact and the used fuel in the pools remained safely covered with cooling water.
It is standard practice to store used fuel in a pool until it has cooled sufficiently that it no longer needs to be stored under water. At that point, fuel may be moved from the pool and placed in dry storage containers.
Dry Storage Is Final Step Before Permanent Repository
Nearly all U.S. nuclear plants are storing used fuel in large, rugged containers made of steel-reinforced concrete. Depending on the design, a container can hold up to 37 pressurized water reactor fuel assemblies or 87 boiling water reactor fuel assemblies. The containers have either a 20-year or 40-year license with an option to extend the license term for up to 40 years. Over a period spanning more than three decades, industry has safely loaded and placed into storage over 3600 of these containers. Industry is applying this considerable experience in the implementation of aging management programs that will continue to assure the long-term safety of this form of storage. This experience also informs the U.S. Nuclear Regulatory Commission in its rigorous oversight of storage facilities including enhancement of the regulations where beneficial. Given that the geologic repository Congress mandated to be built by 1998 still does not exist, containers will remain safely stored at plant sites until such time as a repository is ready.
Consolidated Interim Storage
An additional option now being considered is to move these storage systems—they are designed to be transportable—to one or two sites where the security, inspection, and maintenance of these systems can be more efficiently managed. Commercially operated interim sites have been proposed in Southeast New Mexico and Western Texas. The Texas facility has been licensed by the NRC and the license application for the New Mexico facility is under NRC review. The US Department of Energy has also recently begun the process of working with local communities to identify a federal interim storage site.
Transportation
Used nuclear fuel has been routinely transported across the US on over 1300 occasions over the past 50 years for reasons other than consolidation and disposal. In transit, every ton of spent fuel is typically surrounded by 7 tons of protective material for containment, radiation shielding, and impact absorption. These systems can withstand impacts, drops, fires, and immersion in water. There has never been any release of radioactive material to the public from used fuel in transportation. To see how this is done, watch this video.