Bunding of Large LH2 Spills

For scaling up supply infrastructures, liquid hydrogen (LH2) will be increasingly stored in large decentralised cryostats. Loss of containment and massive spills of LH2 have been considered credible scenarios. Bunding can limit the associated pool formation. However, there is no consistent view on the risk reducing effect of bund walls for large LH2 storage, although they are consistently used for liquefied natural gas (LNG). The paper presents a simple model to conservatively estimate the maximum pressure loads resulting from a late ignition of a cloud formed above the boiling LH2 pool, using only the pool surface area. The model is then applied to a prototypical LH2 storage device designed for a large hydrogen refuelling station. The results are used to suggest a bunding concept, minimising the risk associated with the considered worst-case scenario. The proposed concept resembles the secondary containment applied for modern LNG storage.