The engineering analysis group is responsible for all nuclear plant systems analysis and reactor analysis activities, excluding fuel management analysis, at Pennsylvania Power & Light Company. These activities include making pretest and posttest predictions of startup tests; analyzing unplanned or unexpected transient events; providing technical training to plant personnel; assisting in the development of emergency drill scenarios; providing engineering evaluations to support design and technical specification changes, and evaluating, assessing, and resolving a number of license conditions. Many of these activities have required the direct use of RETRAN models. Two RETRAN analyses that were completed to support plant operations—a pretest analysis of the turbine trip startup test, and a posttest analysis of the loss of startup transformer event—are investigated. For each case, RETRAN results are compared with available plant data and comparisons are drawn on the acceptability of the performance of the plant systems.