Study of the Aging Impact on the Extinction Efficiency of an Extinguishing Powder for Sodium Fire

The French Atomic and alternatives Energy Commission (CEA) developed an effective powder capable of extinguishing sodium fire. However, ever since the dismantling of several old sodium installations facilities, CEA has at its disposal an important stock of unused powder batches, some of which have not been kept in suitable conditions. The idea of reutilizing these powders initiates the question about their efficiency to extinguish a sodium fire after long term storage. The various physicochemical analyses that have been carried out to characterize these stocked powder batches highlight the presence of lithium sodium carbonate (LiNaCO3), which is not a product of aging, and trona that, contrarily, formed because of aging during storage. This study presents the first experimental results of small sodium pool fire extinction using the powder samples previously characterized. The presence of trna did not affect significantly the extinction. Moreover, it did not affect the fusion temperature of the powders due to its decomposition at low temperature. On the contrary, the powder having high percentage of LiNaCO3 encountered a difficulty in extinguishing the fire. This happened because of their difficulty to flow, which enhanced by the external condition of the tests. These first results show that this facility allows us to test the extinguishing powders on sodium fires, with temperature monitoring at different positions and video recording. Improvements suggested from these preliminary tests should permit to discriminate the extinguishing efficiency of the powders as a function of their chemical composition.