The UK nuclear industry is involved in a large effort to decommission nuclear power reactors and safely store radioactive waste. A key process is the vitrification of high level waste by adding it to a base glass to make a waste form. Some key base glass compositions have been chosen for intense scientific study. This proposal is to collect high quality neutron diffraction structure factors from these base glasses using the design capability of GEM. The data will be of great use to improve simulations of base glasses, where detailed information on short range order is present in the pair distribution functions. The simulation methodology will then be used to study further phenomena in glass waste forms such as radiation damage.