In the current proposal we propose to test Zr-2.5Nb samples cut at a range of angles (0, 22.5, 45, 67.5 and 90°) in the RD-TD plane in in-situ compression at room temperature. In the in-situ experiment the grains pointing into the TD will be oriented so that they diffract into the radial detector bank in order to complete our current RD-ND dataset (RB820197). Additionally we propose to measure 2 samples along the ND in order to get strain response in all three principal directions (ND, TD, RD). Completion of our dataset on the Zr-2.5Nb will enable us to confidently convert the measured elastic phase strains to phase stresses assuming an orthotropic-like behaviour of the alloy. This will further elucidate the load partitioning between the present phases and help us validate the EPSC and FE simulations in the case of twinning in Zr-2.5Nb.