The technical quality of procedures governing integrated nuclear power plant operation is influenced by knowledge of system, component, and operator interactions. This knowledge includes, in part, operating plant data and realistic simulations of plant operation. This same information can be used to develop training materials for teaching plant dynamic response to plant operators and engineering staffs. Realistic simulations of plant performance have been used to supplement existing plant data or to provide data where none existed. The simulations may cover events with durations in hours and may be required to consider unique plant conditions including actual core physics conditions, valve leakage, and auxiliary steam loads. In addition, it should be possible for the simulation to account for operator interaction and to provide the information operators would have available through plant instrumentation. Simulations using the RETRAN computer code have been used in the development of procedures and training materials. Procedure applications have included development and validation of general control philosophy and establishment of specific test conditions and setpoints. Training applications include development of materials for teaching general plant response, specific plant response during tests, and analysis of plant performance.