[en] Various tokamak accident scenarios (e.g. rupture of windows or coolant lines) postulate a pressure transient, possibly to levels exceeding ambient pressure within the reactor. This transient can result in transport into the pumping system of the dust previously deposited in the torus and the exhaust ducts. The objective of this experimental work was to investigate quantitatively the behaviour of dust deposited inside the tokamak. The accident conditions are simulated in a model test facility. The similarity criteria are defined for transferring the experimental results from the model to the tokamak. A theoretical model and the experimental results are presented for the transport of solid particles in rarefied gases. (orig.)