The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) Version 8 is a software application developed for performing a complete probabilistic risk assessment using a personal computer running the Microsoft Windows™ operating system. SAPHIRE 8 is funded by the U.S. Nuclear Regulatory Commission (NRC). The role of the Idaho National Laboratory (INL) in this project is that of software developer and tester. In older versions of SAPHIRE, the model creation and analysis functions were intermingled. However, in SAPHIRE 8, the act of creating a model has been separated from the analysis of that model in order to improve the quality of both the model (e.g., by avoiding inadvertent changes) and the analysis. Consequently, in SAPHIRE 8, the analysis of models is performed by using what are called Workspaces. Currently, there are Workspaces for three types of analyses: (1) the Events and Condition Assessment (ECA), (2) the NRC's Significance Determination Process (SDP), and (3) the General Analysis (GA) workspace. Workspaces for each type are created and saved separately from the base model which keeps the original database intact. Workspaces are independent of each other and modifications or calculations made within one workspace will not affect another. In addition, each workspace has a user interface and reports tailored for their intended uses. iv v FOREWORD The U.S. Nuclear Regulatory Commission (NRC) has developed the Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) software that is used to perform probabilistic risk assessments (PRAs) on a personal computer. SAPHIRE enables users to supply basic event data, create and solve fault and event trees, perform uncertainty analyses, and generate reports. In that way, analysts can perform PRAs for any complex system, facility, or process. For nuclear power plant PRAs, SAPHIRE can be used to model a plant's response to initiating events, quantify core damage frequencies, and identify important contributors to core damage (Level 1 PRA). The program also can be used to evaluate containment failure and release models for severe accident conditions given that core damage has occurred (Level 2 PRA). In so doing, the analyst could build the PRA model assuming that the reactor is initially at full power, low power, or shutdown. In addition, SAPHIRE can be used to analyze both internal and external events and, in a limited manner, to quantify the frequency of release consequences (Level 3 PRA). Because this software is a very detailed technical tool, users should be familiar with PRA concepts and methods used to perform such analyses. SAPHIRE has evolved with advances in computer technology and users' needs. Starting with Version 5, SAPHIRE operated in the Microsoft Windows™ environment. Versions 6 and 7 included features and capabilities for developing and using larger, more complex models. SAPHIRE Version 8 includes significant new features and capabilities to meet user needs for NRC risk-informed programs. In gener...