The Atlas railcar is designed to carry 17 different Spent Nuclear Fuel (SNF) containers (also known as "casks") weighing between 82 tons and 210 tons. The railcar design process included extensive dynamic computer modeling to simulate how the railcar design would perform with different railcar components, different container attachment mechanisms, and different container weights.

Safety Standards and Testing The Association of American Railroads (AAR) is the standard-setting organization for all of North America's freight railroads. AAR's S-2043 standard is specific to railcars used to transport high-level radioactive material, like SNF.

To gain AAR approval under the rigorous 5-2043 standard, railcars must undergo individual testing, and testing as part of a full train with other S-2043 railcars (multi-railcar testing). DOE estimates it will take about 8 years of railcar development and testing to verify that all of the new railcars meet the S-2043 standard, and receive approval from the AAR.

Atlas was built to fulfill the department's obligation to eventually move and permanently store the growing stockpile of some 92,000 metric tons of spent nuclear fuel produced by the 94 nuclear power plants in the United States, including the US Navy's nuclear fleet.

(Info courtesy Dept of Energy)