Analysis of Fire Barriers Within Nuclear Power Plants

A review of the analysis techniques currently available for evaluating the adequacy of fire barriers revealed several shortcomings that may render these techniques inappropriate for nuclear power plant applications.In particular, current fire barrier analysis methods are either cumbersome or unconservative. An alternative to these methods was developed using a knowledge of the influences on fire severity of fuel load, room size, and available air for combustion. By performing a parametric heat balance for a room, temperature changes versus time were calculated as a function of fuel load, room size, and airflow rate. When combined with time-temperature criteria used in fire barrier testing, the parametric heat balance equations defined those combinations of fuel load and airflow for which barriers can be expected to survive under the most severe fire conditions. The results of this calculational model were simplified into several plots for convenience of analysis. These plots were used to demonstrate the analysis technique with parameters taken from several actual power plant areas.