Creep in polycrystalline engineering alloys occurs differently along different crystalline orientations. This is because external loading distributes lattice strains non-linearly between the crystal planes. However, it is not well understood how this occurs for the mixed boundary conditions created during elastic follow-up. To gain this understanding it is proposed that neutron diffraction is used to measure lattice strains distributions at different crystal orientations during stress relaxation (with elastic follow-up). This proposal is an integral part of the Bristol-Open Universities Long Term Proposal on Measuring and Monitoring the Internal State of Steels for Nuclear Steels. In particular, we will undertake a feasibility study, in the ENGIN-X facility, using a specially developed and unique experimental system to obtain measurements of lattice strains using neutron diffraction.