While nuclear power has become the major source of electricity in many countries, its safety remains an important issue for many nuclear researchers and technologists. In this study, an advanced boiling water reactor (ABWR) monitoring system is presented using the Modular Accident Analysis Program (MAAP) as a reactor simulator. The ABWR monitoring system was designed with a user-friendly graphical interface and computer processing that allows nuclear engineers and operators to "visualize" many MAAP parameters of the reactor and containment. Computer animations are also applied with respect to preselected MAAP parameters and six reactor scenarios that are of particular interest to nuclear technologists. Simulated results are presented to demonstrate the system using the six reactor/containment scenarios, and these six scenarios are typical as far as the progression of the events for the severe accidents is concerned. The preliminary results show that our ABWR monitoring system not only indicates if the reactor is under normal operations but also yields several warning messages if the reactor is under various conditions of concern. Therefore, our ABWR monitoring system could offer an effective and efficient display of plant data that helps nuclear engineers and operators maintain the steady state of the ABWR and provide plant data for the accident conditions, ultimately bringing the nuclear power plant to a safe-stable state.