Defending Against Rosatom Exports Act This bill extends limits on the importation of Russian low-enriched uranium, a fuel for nuclear reactors, and contains other related provisions. (These limits stem from a 1992 agreement with Russia to end a Department of Commerce antidumping investigation into Russian uranium imports.) The bill extends these limits, which are currently set to expire in 2020, to 2035. The bill also specifies the maximum amounts of qualifying uranium that may be imported each year for 2021-2035. Currently, qualifying uranium imported for use in the initial core of a new reactor or for the Department of Energy inventory does not count against these limits. The bill eliminates these two exceptions but maintains an exception for uranium imported for reprocessing and reexportation. No more than 25% of qualifying uranium may be imported each year under a contract other than a contract exclusively for separative work units. (A separative work unit is the standard unit of measurement for effort expended to enrich uranium.)