A probabilistic model for flammable pool fire damage in nuclear power plants

Abstract

A new code, called VULCAN/STADIC-2, has been developed to aid the probabilistic risk of the spread of fire damage within a large enclosure. By combining simplified theoretical and empirical physical models (VULCAN) with the Monte Carlo simulation technique in STADIC-2, the code is able to estimate the conditional frequency of fire suppression before damage can occur to equipment near a fire. The code was developed principally for situations in which a fire ignites over a pool of flammable liquid within a room in a nuclear power plant. The room may contain overhead cables, cabinets housing electrical equipment or both. The models in the code utilize contemporary empirical and analytical information on equipment damage criteria, fire thermal modeling, fire damage spreading, and fire suppression. Results of an application to oil pool fires in the relay room of the Shoreham Nuclear Power Station and results of sensitivity studies are presented. An overview of fire analysis methodology used in probabilistic risk assessments is also presented to provide perspective.