The paper addresses the use of nuclear power plant simulators for Human Reliability Assessment (HRA) purposes as an extension of the normal training of control room personnel. The paper opens with a brief history of the use of simulators for this purpose, starting with the US Nuclear Regulatory Commission (USNRC) program in the early 80s and continuing with projects undertaken by the Electric Power Research Institute (EPRI), Electricité de France and later by other countries. The USNRC program lead to the use of Time Reliability Curves (TRC) in the HRA field and to the development of the Human Cognitive Reliability...