; and (3) encourage license applicants, agencies, and Indian tribes to develop and use, for the purpose of fostering timely and efficient consideration of license applications, a limited number of open-source methodologies and tools applicable across a wide array of projects, including water balance models and streamflow analyses. (b) Use of studies To the extent practicable, the Commission and other Federal, State, and local government agencies and Indian tribes considering an aspect of an application for Federal authorization (as defined in section 34) shall use studies and data based on current, accepted science in support of their actions. Any participant in a proceeding with respect to such a Federal authorization shall demonstrate that a study requested by the participant is not duplicative of current, existing studies that are applicable to the project. (c) Basin-Wide or regional review The Commission shall establish a program to develop comprehensive plans, at the request of project applicants, on a regional or basin-wide scale, in consultation with the applicants, appropriate Federal agencies, and affected States, local governments, and Indian tribes, in basins or regions with respect to which there are more than one application for a project. Upon such a request, the Commission, in consultation with the applicants, such Federal agencies, and affected States, local governments, and Indian tribes, may conduct or commission regional or basin-wide environmental studies, with the participation of at least 2 applicants. Any study conducted under this subsection shall apply only to a project with respect to which the applicants participate. 37. License amendment improvements (a) Qualifying project upgrades (1) In general As provided in this section, the Commission may approve an application under this section for an amendment to a license issued under this part for a qualifying project upgrade. (2) Application A licensee filing an application for an amendment to a project license under this section shall