The Development of Thermal Models for a UF6 Transport Container in a Fully Engulfing Fire.

In 1987 the IAEA, as part of its review of transport regulations for UF6 containers, recommended that further work into the response of containers to a fire test should be undertaken. The IAEA regulations concerning fires, specify that the thermal test should consist of exposure to a fully engulfing hydrocarbon fire with an average flame temperature of soooc for a period of thirty minutes. Originally it was expected that the heat transfer processes in a UF6 container were sufficiently well-known to allow a theoretical analysis to verify that the container would pass the fire test. However, it now appears that there are several uncertainties in the physics and heat transfer parameters assumed, leading to variations in the predictions produced by several workers. These predictions are sufficient to indicate either survival of the test or failure at some time during the last 10 minutes of the fire period. It is desirable therefore to have a single thermal model that is accepted by all interested parties.