A modified model predicting fire power in closed compartment of nuclear power plant and validation experiments

CFAST(Consolidated Model of Fire Growth and Smoke Transport) predicts fire growth without taking account of increased pyrolysis attributable to radiative feedback from the flame or compartment. To provide a possible solution to this drawback of CFAST, a modified model to predict fire heat release rate is developed for fire risk analysis in Nuclear Power Plant. The model couples the interaction of fire source and upper hot gas layer. In order to validate the modified model?Four-layer cable tray fire in closed room and open space were conducted and the arrangement of cables are based on the conservation principle in Nuclear Power Plant. By comparing the predictions with experimental data, it is found that the accuracy is increased by 11% for the new model predicting the heat release rate. Especially, for the phase of cable flame spread in horizontal direction, the accuracy of new model is improved by 24.7%. The temperature of upper hot gas layer is underestimated by the CFAST, because it ignores the external heat flux. Apparently, it does not conform to the conservative principle of fire risky analysis in Nuclear Power Plant. Based on the modified model, the predicted upper gas layer temperature is greater than the experimental data, which is more conservative and accurate. (authors)