40 CFR 61.221 - Definitions.
(a)Long term stabilization means the addition of material on a uranium mill tailings pile for the purpose of ensuring compliance with the requirements of 40 CFR 192.02(a). These actions shall be considered complete when the Nuclear Regulatory Commission determines that the requirements of 40 CFR 192.02(a) have been met.
(b)Operational means a uranium mill tailings pile that is licensed to accept additional tailings, and those tailings can be added without violating subpart W or any other Federal, state or local rule or law. A pile cannot be considered operational if it is filled to capacity or the mill it accepts tailings from has been dismantled or otherwise decommissioned.
(e)In significant part means in a manner that is not reasonably expected to materially (i.e., more than de minimis) interfere with compliance with the 20 pCi/m 2-s flux standard as expeditiously as practicable considering technological feasibility (including factors beyond the control of the licensee).