Statistical analysis of uranium-hydride (UH3) initiation location was undertaken on an as-received Magnox-U sample using electron back-scattered diffraction (EBSD). Secondary ion mass spectrometry (SIMS) and focused ion beam (FIB) milling were used for UH3 identification and complementary examination of the reacted surface. From the interrogation of 147 hydride sites on the electrochemically etched sample it was found that hydride formation occurred predominantly around grain and twin boundaries. Clear preference of hydride attack was observed around grains with high rotational mismatch. Crown Copyright (C) 2016 Published by Elsevier B.V.