Determination of leak integrity and behaviour of 'standard' 205 litre UN drum lids when subject to differential pressures

Work was conducted in late 2012 by Onet Technologies UK on behalf of a UK client to determine how the 'standard' 205 litre UN drum used for the transport of solid radioactive materials (typically SCO II/LSA II) behaves when subjected to pressure differentials that would be encountered in transport by road. The 'standard' drums are used widely in the transport of solid radioactive waste material by road in the UK, and by the wider community globally. For road transport most drums will never be subject to pressure differentials of greater than 25kPa. Drums, which are similar in material thickness and geometry to these 'standard' drums, when transporting hazardous liquids are subject to a 'leakproofness test' and tested to a pressure differential of 30kPa as part of gaining the UN approval. Should these drums be used by air they are required to withstand a pressure differential of 95kPa plus MNOP to meet the requirements of TS-R-1. Drums are not tested to that pressure for UN approval unless they are to be approved specifically for the carriage of liquids. This poster paper reports on the findings of the work, completed early in 2013. It defines the leak integrity (as measured using Helium mass spectrometry and pressure drop) and describes the failure mode of the drum lid together with the pressure and lid deflection leading up to the time of failure. The work also explores how the drum behaves with its lid supported and determines the pressure at which leakage occurs in that configuration.