Exhibit 10.9.1 First Supplement to 1996 Amendatory Agreement This First Supplement, dated as of February 10, 1997, amends the 1996 Amendatory Agreement, dated as of December 4, 1996, between these parties and is entered into by Connecticut Yankee Atomic Power Company ("Connecticut Yankee") and Central Maine Power Company ("Purchaser"). WHEREAS, terms defined in said 1996 Amendatory Agreement are used herein with the meanings there provided; and WHEREAS, Connecticut Yankee and each of its Purchasers entered into agreements substantially identical to said 1996 Amendatory Agreement to effect certain clarifications in their contractual relationships necessitated by the decision to permanently shut down Connecticut Yankee's generating unit; and WHEREAS, Connecticut Yankee has detected an unintended omission in one section of said 1996 Amendatory Agreement which renders the section meaningless and should be corrected and, concurrently herewith, is entering into agreements with each of its Purchasers substantially identical to this supplement. NOW, THEREFORE, for good and valuable consideration, the receipt of which is hereby acknowledged, it is agreed as follows: 1. Clause C of Section 3 of the 1996 Amendatory Agreement is hereby amended to insert the following after the phrase "but without duplication:" (a) the Total Decommissioning Costs for the month with respect to the Unit, plus (b) Connecticut Yankee's total operating expenses or the month with respect to the Unit, plus (c) an amount equal to one-twelfth of the composite percentage for such month of the net Unit investment as most recently determined in accordance with this Section 7. 2. This First Supplement shall become effective upon receipt by the Purchaser of notice that Connecticut Yankee has entered into identical First Supplements to the 1996 Amendatory Agreements with each of the Purchasers. IN WITNESS WHEREOF, the parties have executed this First Supplement to the 1996 Amendatory Agreement by this respective duly authorized officers as of the day and year first named above. CONNECTICUT YANKEE ATOMIC POWER COMPANY By ________________________________________ Its Address: P.O. Box 270 Hartford, CT 06101 CENTRAL MAINE POWER COMPANY By ________________________________________ Its Address: 83 Edison Drive Augusta, Maine 04336