This bill, titled the Responsible Containment Reauthorization Act of 2026 , proposes an amendment to the Uranium Mill Tailings Radiation Control Act of 1978. Its primary purpose is to extend the operational authorization for a specific uranium mill tailings disposal site located in Mesa County, Colorado. Currently, the authorization for this site is set to expire on September 30, 2031, or when it reaches its designed capacity, whichever comes first. The proposed amendment removes the fixed date deadline , allowing the site to continue operations solely until it is filled to its designed capacity . This change ensures the continued use of the facility for its intended purpose without an arbitrary time constraint.