CFD simulations of a detonation of a hydrogen/air mixture in a hydrogen production facility coupled with a nuclear reactor

The report presents a safety study performed with the CFD tool CALIF3S, developedat IRSN, to evaluate the consequences of a potential accident of hydrogen release on the combined plant. The selectedscenario is the detonation of a stoichiometric hydrogen/air cloud.The explosive cloud is determined with the Multi Energy Method (MEM), reconstructed for hydrogen/air mixtures.The volume of the cloud is obtained, assuming that the reactor buildings are designed to withstand a 100 mbar overpressure wave (same value as for recent PWRs).Several numerical computations of detonation are performed and the impact of the blast waves on the reactor building is studied.A safety distance for the reactor building is also evaluated: the reactor should be located at around 470m from the leak to prevent damagesto its structure. Finally, the impact of the addition of a wall in front of the reactor building as safety barrier is carried out.