Dry cask storage allows spent fuel already cooled in a spent fuel pool for several years to be stored inside a container, called a cask, filled with inert gas. Each cask is surrounded by steel, concrete, or other material to provide shielding from radiation. All spent fuel storage is regulated by the U.
Nuclear Regulatory Commission. Approximately two-thirds of total spent nuclear fuel is from pressurized-water reactors , and about one-third is from boiling-water reactors. In the United States, nearly all spent nuclear fuel is currently stored on-site at commercial nuclear power plants.
The survey data contain information on the quantity and characteristics of spent nuclear fuel at the time when a reactor discharges it. The Nuclear Fuel Data Survey shows that between and , more than , bundles of spent fuel rods fuel rod assemblies , which contained a little less than 80, metric tons of uranium, were stored in the United States. The inventory of spent fuel assemblies has grown by about The nuclear fuel used in nuclear reactors requires concentrated uranium known as enriched uranium , which is further processed to create nuclear fuel.
Each fuel assembly is typically used for a cycle of 18 to 24 months. The discharged spent nuclear fuel rods are stored in one of two ways.
Over the last 55 years, more than 2, cask shipments of used fuel have been transported across the United States without any radiological releases to the environment or harm to the public. The fuel is shipped in transportation casks that are designed to withstand more than 99 percent of vehicle accidents, including water immersion, impact, punctures and fires. The United States does not currently recycle used nuclear fuel but foreign countries, such as France, do.
There are also some advanced reactor designs in development that could consume or run on used nuclear fuel in the future. Learn more about our work with spent nuclear fuel. The border between Croatia and Slovenia, for example, shifted 7 times between to Accordingly, when considering the long timelines of spent fuel storage and disposal, we must also consider that the ownership of SNF buried underground may be affected, and so might SNF management.
Potential changes in spent fuel ownership and management strategies also need to be considered when countries jointly operate nuclear power plants and therefore share the responsibility for waste management. In June , Croatia and Slovenia declared their independence from Yugoslavia. The Krsko nuclear power plant , which came online in October and is still the sole plant in Slovenia, is now jointly owned by companies in Croatia and Slovenia. SNF is entirely stored onsite at the plant. When Germany united on October 3, , there were 16 nuclear power plants in operation, two of which were permanently shut down in East Germany right before unification.
At the time of the change, there were two nuclear power plants within Czechoslovakia, Dukovany and Bohunice. They began operation in and , respectively. To date, there are SNF sites located in 39 countries. Of these, there are 6 countries France, Germany, Hungary, Sweden, Switzerland, Ukraine that have operational central storage facilities. As efforts towards finding long-term solutions for isolation and permanent disposal of SNF continue around the world, a global picture of the current status of SNF distribution provides context for spent fuel management strategies.
But the trajectory is clear. Understanding a trend in the change of SNF over time could help countries determine their long-term strategies for SNF management.
How spent fuel is managed, and the types of nuclear reactors used by a country can affect how rapidly the amount of spent fuel in storage increases. For example, Russia, France, UK, and Japan partially reprocess their civilian spent fuel, extracting uranium and plutonium from it for reuse, and leaving less in storage.
Others, such as Canada, Finland, and Sweden, have chosen to store spent fuel since it was produced. The amount of SNF also depends on the types of nuclear reactors. Canada has pressurized heavy-water reactors CANDU reactors that produce more spent fuel than other types due to a low burn-up rate. To move around the interactive map, refer to the tools in the top left corner.
Zoom in for a closer look at the SNF sites and hover over a site point or region for more information. This map shows the spread of relevant facilities in 17 countries around the world and visualizes the concentration of SNF inventories in subnational regions of interest. By displaying SNF inventory in subnational regions rather than at specific facilities or in countries as a whole, it provides a more useful look at how SNF is concentrated in larger areas and distributed within countries.
The degree of subnational regional division differs between some countries to account for the wide range of inventory masses present in the selected countries.
Divisions are also dependent on the specific pre-set country divisions available in the Tableau visualization tool. Based on these specifications, the U. Canada is divided regionally with the exception of Ontario, in part due to the large inventory in Ontario, which houses the majority of Canadian reactors and is the focus for disposal efforts.
The SNF regions, therefore, are intended to harmonize different geographical boundaries while maintaining easy visualization of wide-ranging SNF inventories in our selected countries.
This approach synthesizes different methods of national reporting while maintaining a degree of sensitivity around the data national authorities provide. This might also help foster international collaborations for those countries that share the same interest in long-term SNF solutions.
Current wet and dry spent fuel storage systems on the surface can operate for between 50 and years. But as the volume of fuel grows, current storage facilities will soon reach their capacity. This intensifies the need to develop new facilities to handle storage and permanent disposal of nuclear waste. A few models for future deep geological repositories have been proposed and examined during the past decades using a traditional tunneling method.
KBS-3 and Multi-barrier designs, as described below, are examples of this method. Lately, a deep horizontal drillhole repository design, which is based on innovative directional drilling method, also has been proposed for permanent disposal of spent nuclear fuel. In this concept, geological disposal provides safety through a combination of man-made engineered and natural barriers that work together to provide isolation and containment of radioactive waste.
The barriers in the multibarrier concept include solid-only waste form, waste container, a buffer or backfill, access seals, and host rock.
Together, these barriers will provide multiple levels of protection from the waste for many thousands of years.
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