Thick, localized, “non-native” corrosion plumes have been identified on Advanced Test Reactor fuel elements, raising concern on their impact on the radiolytic formation of molecular hydrogen gas (H2) from aluminum-clad spent nuclear fuel (ASNF) under proposed extended (> 50 years) dry storage conditions. Here, we report our findings on H2 generation from the gamma irradiation (up to 52 MGy) of surrogate “non-native” corrosion plume coupons: ambient-temperature-corroded (~350 days in water) aluminum alloy 6061 (AA6061) coupons in helium gas environments with ~0% added relative humidity. Additionally, we provide a comparison of proposed ASNF drying techniques— vacuum drying only, vacuum drying + 100 oC for 4 hr, and vacuum drying + 220 oC for 4 hr—on the yield of H2 from these surrogate systems. The presented data indicates that similar amounts of H2 (~2 × 10–3 µmol J–1) are formed from gamma irradiated AA6061 coupons corroded under different temperature regimes, i.e., ambient/350 days vs. 90 oC/30 days. These findings validate current, complimentary modelling predictions based on high-temperature-corrosion irradiation data only. Further, the application of a heat treatment procedure (100 and 220 oC), in conjunction with vacuum drying, accelerated the rate at which a steady-state H2 yield was attained, in comparison to vacuum only, due to the removal of H2 precursors in the form of adsorbed waters. Interestingly, within the confidence limits of our measurements, negligible difference in total H2 yield was found between the two investigated heat treatment procedures.
