Notwithstanding anything to the contrary in § 56-234, the rates and charges for service to any federal governmental facility that is a retail customer of any electric utility prior to January 1, 1996, and which ceases, in whole or in part, to be a retail customer of that electric utility after January 1, 1996, because of its purchase of electricity from another supplier shall be subject to the jurisdiction of the Commission for the limited purpose of determining the proper rate, if any, to be paid by the federal government to the electric utility for any and all costs stranded due to the cessation of such retail service, and payments of such costs shall be made pursuant to a tariff filed and approved by the Commission; provided, however, the Commission’s jurisdiction shall not arise unless and until the effective date of any federal action that allows any federal governmental facility to purchase electricity from a supplier other than the electric public service company now providing electric service to such federal facility.