SN0398 : Hypothetical Deflagration of P10 from the STAR TPC: Maximum Plausible Effect

Author(s):R. Bossingham
Date:May. 7, 1999
Abstract:The STAR TPC holds 50 m^3 of P10 (90 % argon, 10 % methane); P10 is not normally considered flammable, but can burn in air under certain conditions. We consider the impacts of a worst plausible case accident: the entire volume of P10 pre-mixed with air stoichiometrically and ignited at the center of the gas cloud. A flame front in P10-air is relatively cool and progresses slowly, so there would be no significant pressure wave. Instead, the dominant damage mechanism would be a slow, 0.4 PSI overpressuring of the assembly hall. Thermal injuries could occur within the ~5 m combusion radius, and first-degree flash burns on exposed flesh would be possible out to ~6.5 m.
For comparison only, we also discuss the deflagration of 50 m^3 of pure methane stochiometrically pre-mixed with air. Since the energy release is an order of magnitude higher, it is not surprising that the potential for damage and injury is found to be much greater in this case.