This report summarizes the work performed July 1, 1984 through September 30, 1984. The overall objective of this program is to develop and verify the design of a prototype molten carbonate fuel cell stack which meets the requirements of a 1990's-competitive, coal-fired, electrical utility central station, or industrial cogeneration power plant. Compressive creep testing and evaluation of the anti-sintering stability of the anode continued with accrued 2180 hours of testing at 1300/sup 0/F. They continue to demonstrate a creep rate that is believed acceptable for stack use. The anti-sintering stability of the anode has been measured following 1700 hours of testing at 1300/sup 0/F. The thickness change of the anode speciments is believed acceptable for stack use. A single piece cathode current collector configuration was selected for evaluation in Subscale Stack No. 4. This configuration is functionally equivalent to the two-piece current collector design being tested in Subscale Stack No. 3. The lower cost configuration is being evaluated in single cell tests. The design of a lower cost separator plate was selected for Subscale Stack No. 4 and is also being evaluated in single cell tests. Single cell testing focused on evaluation of cell operating conditions on NiO dissolution. This program consists of three activities: measuring the effect of CO/sub 2/ partial pressure on cell performance, determining the allowable amount of nickel dissolution before excessive performance decay occurs, and verifying the dissolution rates obtained from accelerated testing. Testing of the 20-cell Subscale Stack No. 3 was initiated. The principle objectives of this stack are to evaluate electrolyte management and end cell short protection improvements. The test has been in progress for 980 hours and continues to demonstrate acceptable electrolyte management and end-cell short protection. 30 figs., 35 tabs.