During a severe accident, in a water-cooled nuclear reactor, the release of large quantities of hydrogen occurs due to the exothermal oxidation of fuel claddings. The hydrogen mixed with the air contained in the power plant containment can potentially ignite. The acceleration caused by the interaction of the flame with the equipment in the containment produces a large dynamic pressure load, which is detrimental for the structural integrity of the containment and the equipment. Therefore, the prediction of flame acceleration and dynamic pressure loads is an important safety issue. This thesis work, developed at the Nuclear Research Group(NRG), follows the broad research framework of the SAMHYCO-NET project concerning hydrogen explosions.