Sodium pool fire phenomena, sodium pool fire modeling in SOFIRE II, and SOFIRE II calculations for the AFR-100

Abstract

The SOFIRE II computer code for the calculation of sodium pool fires has been obtained from the Reactor Safety Information Computational Center and the SOFIRE II ONE CELL version has been implemented at Argonne National Laboratory (ANL). A critical review of literature relevant to sodium pool fires has been carried out with the objectives of understanding sodium pool fire phenomena and how well specific phenomena are modeled or neglected in SOFIRE II. Significant predictions about sodium pool fires can be made on the basis of first principles analyses alone making use of the existing experiment database and knowledge base. In implementing SOFIRE II ONE CELL, minor modifications were necessary to compile and execute the code on a personal computer (PC) and to verify the results of the test case problem. The code was applied to the AFR-100 Sodium-Cooled Fast Reactor (SFR) design to calculate a sodium pool fire following a postulated failure of the sodium storage vessel of one of the four intermediate sodium heat transport circuits and the subsequent release of sodium onto the floor of the steel-lined compartment in which the sodium storage vessel is located. SOFIRE II calculates that only a small fraction of the released sodium burns due to the rapid consumption of the available oxygen inside of the closed compartment. The preliminary results demonstrate the effects of the heat sinks provided by the compartment floor, walls, and ceiling in reducing the temperature of the sodium pool with time.