The proposing team has a well established experience in the use of neutron scattering on samples containing molecular hydrogen, and has recently studied some aspects of the physical behaviour of hydrogen molecules trapped in the cages of simple and binary clathrate hydrates. These systems might have a relevance as new materials for hydrogen storage applications. This proposal aims to study in detail the diffusion of hydrogen molecules into a pre-formed (solid) tetrahydrofuran-water clathrate. For the experiment we will exploit a new and promising technique, namely neutron radiography, recently available on INES. The diffusion coefficient will be measured directly analysing a series of radiographies, taken at constant time intervals, of a bulk solid sample of heavy water and perdeuterated tetrahydrofuran (TDF) clathrate hydrate, exposed to H2 gas at a pressure of about 200 bar.