The nuclear industry is required to analyze its facilities for hazardous fire conditions, and a national laboratory has developed a computer code called FIRAC to aid in this process. FIRAC can predict the temperature, pressure, density, and mass or volumetric flow of air through a facifity. The code is oriented primarily toward transport through the ventilation system, but it can be adapted to model any airflow passageway. The code includes a compartment fire model to simulate the burning of both radioactive and nonradioactive material. This model generates the smoke that subsequently is transported throughout the facility.

The FIRAC code and material transport modules are described in detail. An example hypothetical facility and fire scenario are used to illustrate the code’s abilities to model smoke generation and movement.