[en] Experiments in a pipe of the original scale, original material, and original quality control were carried out to study the maximum possible loads potentially arising in the combustion of radiolysis gas / nitrogen mixtures in BWR relief pipes with full lowering of the water level. Peak pipe loads resulted for narrow ranges of concentration around 43% N₂ (for 0.8 bar initial pressure) and 50% N₂ (for 1.6 bar initial pressure), respectively. With these mixtures, ignition of the homogeneous H₂/O₂/N₂ mixture is followed by a deflagration - detonation transition in pre-compressed unburnt gas only a short distance upstream of the end flange. This phenomenon generally occurs when, in the combustion gas studied, the starting distance for detonation transition becomes comparable to the pipe length. No strains higher than 0.2% were measured in any of the experiments. The dynamic pipe load remained in the elastic range in all experiments performed, which also prevented the pipe from being damaged in the course of a test series. The pipe was not subjected to any major axial forces and accelerations in the experiments. This constitutes experimental proof, under conservative boundary conditions, of the integrity of relief pipes even in the case of assumed complete filling with the most adverse radiolysis gas mixture and subsequent combustion. (orig.)