After , the Federal Energy Regulatory Commission may not issue an original license under Part I of the Federal Power Act [ et seq.] (nor an exemption from such Part) for any new hydroelectric power project located within the boundaries of any unit of the National Park System that would have a direct adverse effect on Federal lands within any such unit. Nothing in this section shall be construed as repealing any existing provision of law (or affecting any treaty) explicitly authorizing a hydroelectric power project.16 U.S.C. 791aOctober 24, 19921992-10-24