Flammability limits thermal structures

The limited amount of eiectricai wiring in Room 109 is embedded in the concrete shield walls. Other than the mules which are used to push barrels into Room 109 there are no active mechanical or electrical devices in the room that could become an ignition source. Even in the event of the presence of a source, the flammable materials are physically separated from the source by metallic barriers. Based on separation of the ignition sources from the combustible material, the possibility of an internally initiated fire is considered remote. It may be somewhat more probable that the hydraulic fluid is ignited externally to Room 109 and combustion products of such a fire heat the waste. As noted above, an external thermal environment cannot ignite the combustible materials in the waste barrels due to oxygen depletion in the barrel. Additionally, the contents of Room 109 are separated from external environments by massive concrete structures, which would limit the effects of an external fire. 

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