The FACE computer code was developed to calculate postulated solvent fire behavior in the extraction process of a nuclear fuel reprocessing plant. The FACE code calculates temperature, pressure, and off-gasflow rate by one- and two-dimensional thermofluid analyses. The code uses this information to evaluate the safety of the associated air ventilation system as demonstrated by its ability to confine the fire-generated radioactive particles by transport, deposition, and filtration of smoke. The mathematical models in FACE were verified by comparison of FACE calculations with the results of Japan Atomic Energy Research Institute fire demonstration tests simulating a hypothetical solvent fire accident in the extraction process.