NSUF 22-4397: Synchrotron characterization of corrosion growth on gamma irradiated aluminum nuclear spent fuel alloys
The U.S. Department of Energy is currently evaluating options for the safe extended storage of almost 18 metric tons of aluminum-clad spent nuclear fuel (ASNF) . One of the technical challenges associated with this task is understanding the extent of molecular hydrogen gas (H2) produced by ASNF cask materials stored in inert He environments to mitigate the corrosion process. Unfortunately, the presence of helium (He) alongside the corrosion products appears to facilitate H2 production, increasing the risk of embrittlement/pressurization, which ultimately may result in cask rupture from explosive and/or flammable gas mixtures. It is critical to understand the generation of H2, from the radiation-induced decomposition of hydrated (oxy)hydroxide aluminum corrosion layers, and synchrotron-based x-ray methods offer a fast, non-destructive probe for detailed understanding of H2 generation. The transition point for steady-state H2 yield is necessary for an accurate depiction of H2 production over ASNF storage period and needs to be correlated to structural changes and corrosion products under different environmental conditions to assess the accuracy of complementary modeling efforts. Furthermore, the H2 yield may be impacted by the aluminum (oxy)hydroxide polymorphs that comprise the corroded surface. To address this knowledge gap, we propose a 9-month experiment performing a multi-modal post-irradiation examination study on Al-based alloys that have been subjected to different temperatures, gamma irradiation doses, and humidity levels. In this proposal, changes in polymorphs of aluminum (oxy)hydroxide and microstructure will be characterized by synchrotron-based x-ray diffraction (XRD) through the development of a proof-of-concept in-situ accelerated surface radiolysis study using synchrotron x-ray powder diffraction beamline at Brookhaven National Laboratory. These studies will be complemented by ex-situ electron microscopy and Raman spectroscopy techniques at Idaho National Laboratory to validate corrosion products detected by XRD and elucidate the mechanism correlating the corrosion product to H2 yield. There are very limited studies focusing on the relationship between H2 yield and the structural changes including polymorphic composition of surface corrosion of ASNF cask alloys. The significance of this investigation is to generate empirical data simulating relevant conditions for optimizing predictive computational tools to support technical and logistical considerations for extensive (>50 years) storage of ASNF safely and effectively.
Additional Info
| Field | Value |
|---|---|
| Abstract | The U.S. Department of Energy is currently evaluating options for the safe extended storage of almost 18 metric tons of aluminum-clad spent nuclear fuel (ASNF) . One of the technical challenges associated with this task is understanding the extent of molecular hydrogen gas (H2) produced by ASNF cask materials stored in inert He environments to mitigate the corrosion process. Unfortunately, the presence of helium (He) alongside the corrosion products appears to facilitate H2 production, increasing the risk of embrittlement/pressurization, which ultimately may result in cask rupture from explosive and/or flammable gas mixtures. It is critical to understand the generation of H2, from the radiation-induced decomposition of hydrated (oxy)hydroxide aluminum corrosion layers, and synchrotron-based x-ray methods offer a fast, non-destructive probe for detailed understanding of H2 generation. The transition point for steady-state H2 yield is necessary for an accurate depiction of H2 production over ASNF storage period and needs to be correlated to structural changes and corrosion products under different environmental conditions to assess the accuracy of complementary modeling efforts. Furthermore, the H2 yield may be impacted by the aluminum (oxy)hydroxide polymorphs that comprise the corroded surface. To address this knowledge gap, we propose a 9-month experiment performing a multi-modal post-irradiation examination study on Al-based alloys that have been subjected to different temperatures, gamma irradiation doses, and humidity levels. In this proposal, changes in polymorphs of aluminum (oxy)hydroxide and microstructure will be characterized by synchrotron-based x-ray diffraction (XRD) through the development of a proof-of-concept in-situ accelerated surface radiolysis study using synchrotron x-ray powder diffraction beamline at Brookhaven National Laboratory. These studies will be complemented by ex-situ electron microscopy and Raman spectroscopy techniques at Idaho National Laboratory to validate corrosion products detected by XRD and elucidate the mechanism correlating the corrosion product to H2 yield. There are very limited studies focusing on the relationship between H2 yield and the structural changes including polymorphic composition of surface corrosion of ASNF cask alloys. The significance of this investigation is to generate empirical data simulating relevant conditions for optimizing predictive computational tools to support technical and logistical considerations for extensive (>50 years) storage of ASNF safely and effectively. |
| Award Announced Date | 2022-06-14T07:29:30.7 |
| Awarded Institution | Idaho National Laboratory |
| Facility | Advanced Test Reactor |
| Facility Tech Lead | Alina Zackrone, Simerjeet Gill |
| Irradiation Facility | None |
| PI | Trishelle Copeland-Johnson |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 4397 |