Abstract
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► We experiment the airborne release of particles during thermal degradation of polymers. ► A “peak of release” was identified during the first instances of thermal stress of Plexiglas. ► The duration of the peak of release was linked to the heat flux applied to the Plexiglas. ► Heat flux has a low influence on the airborne release fraction (ARF). ► The influence of the diameter of particles on the ARF depends on polymer.
Experimental results are reported on the resuspension of particles deposited on polymer samples representative of glove boxes used in the nuclear industry, under thermal degradation. A parametric study was carried out on the effects of heat flux, air flow rate, fuel type and particle size distribution. Small-scale experiments were conducted on 10cm×10cm PolyMethyl MethAcrylate (PMMA) and PolyCarbonate (PC) samples covered with aluminium oxide particles with physical geometric diameters of 0.7 and 3.6μm. It was observed for both polymer (fuel) samples that heat flux has no effect on the airborne release fraction (ARF), whereas particle size is a significant parameter. In the case of the PMMA sample, ARF values for 0.7 and 3.6μm diameter particles range from 12.2% (±6.2%) to 2.1% (±0.6%), respectively, whereas the respective values for the PC sample range from 3.2% (±0.8%) to 6.9% (±3.9%). As the particle diameter increases, a significant decrease in particle release is observed for the PMMA sample, whereas an increase is observed for the PC sample. Furthermore, a peak airborne release rate is observed during the first instants of PMMA exposure to thermal stress. An empirical relationship has been proposed between the duration of this peak release and the external heat flux.