Activities from April through June 1981 related to the fluidized-bed boiler used for generating steam for the Georgetown University heating system are described. Boiler operations during the quarter were limited to a single operating period during the first two weeks in May during which a total of 250 h of steam generation were logged. Operations before 1 May were held up for replacement of the three grid plate sections that were damaged in late March by operator error. A scheduled plant shutdown occurred from 13 May through the end of the quarter to permit the major modifications to be made. The thermal efficiency for the quarter averaged 73.1%. This is almost 12% greater than that reported in the previous quarter and was achieved with flyash reinjection from the mechanical collector restricted to the one hopper out of five which was fitted with an airlock. A review of operating data indicates that the quarterly average excess oxygen was at or near design conditions in contrast with high excess oxygen in previous quarters. This would account for some increase in thermal efficiency. A more rigorous determination of continuing efficiency can be made after the above modifications are completed. (LCL)