Ignitability, Quenching and Deflagration-to-Detonation-Transition (DDT) of hydrogen-air mixtures

Due to radiation and wide use of reactive metals, the nuclear industry has always to be mindful of the generation of flammable gases, principally hydrogen. Hydrogen explosions can lead to deflagration and transition to detonation (DDT) with destructive effects. As NDA estate goes into decommissioning and long term storage new challenges in managing hydrogen are being met where better informed safety cases can be used to remove conservatisms, reduce cost, timescales at Sellafield, Dounreay and Magnox sites.

Leeds detonation map consisting of dimensionless groups is widely used to predict the DDT of flammable gases. This technique offers a convenient means of studying hydrogen detonation in ducts with complex geometries linked to scenarios within nuclear plants. Therefore, with the addition of the ability to study quantitatively a wider range of conditions than the existing work, it is the method adapted for the present proposal.

This project aims to develop current understanding of ignition mechanisms of hydrogen to facilitate ignition source control on nuclear plant, and extend the detonation map with accurate prediction of damage to nuclear process plant, storage containers and structures resulting from hydrogen explosion. The outcomes provide significant improvements to safe operations and safety case development for nuclear decommissioning.