This bill, titled the Responsible Containment Reauthorization Act , amends 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 . The legislation achieves this by striking the existing expiration date of September 30, 2031, from the original Act. Consequently, the disposal site's authorization will now continue indefinitely until it is filled to its designed capacity , rather than being subject to a fixed calendar deadline.