Already in the low temperature region of the water adsorption behaviour in faujasite NaX at different hydration levels, an important question that requires further research is kept open: what is the possible role and type of nuclear quantum tunnelling (NQT) in the dynamics of confined water molecules. This proposal aims to shed more light on this question by conducting experiments of Neutron Compton Scattering (NCS) experiments on H2O confined in the NaX faujasite network at temperatures between 30 and 70 K, to investigate the probability of proton NQT inside the water clusters in zeolite cages and modelling the ADPs of the zeolite framework atoms to get the predictions for the nuclear momentum distributions (NMD)