During the 1990s, the Electric Power Research Institute (EPRI) developed methods for fire risk analysis to support its utility members in the preparation of responses to Generic Letter 88-20, Supplement 4, Individual Plant Examination of External Events (IPEEE). This effort produced a fire risk assessment methodology for operations at power plants that was used by the majority of U.S. nuclear power plants (NPPs) in support of the IPEEE program and by several NPPs overseas. Although these methods were acceptable for accomplishing the objectives of the IPEEE, EPRI and the U.S. Nuclear Regulatory Commission (NRC) recognized that the methods needed to be improved to support current requirements for risk-informed, performance-based (RI/PB) applications.