NSUF 20-2986: Atom Probe characterization of neutron irradiated commercial ZIRLO® and AXIOM X2® alloys
We propose to use atom probe tomography (APT) to study the evolution of microchemistry of neutron irradiated ZIRLO® and AXIOM X2® alloys at different irradiation doses (1 cycle and 4 cycles). The major research objective of this study is to provide knowledge on neutron irradiation induced Nb redistribution in Zr-Nb alloys to understand the effect of Nb redistribution on corrosion kinetics. The overall research program aims at precisely characterizing the Nb concentration in irradiation induced platelet/nanoclusters and in the solid solution of neutron irradiated samples both in metal and oxides, which would provide quantitative data to model the in-reactor corrosion behavior of Zr-Nb alloys. The main hypothesis tested is that the precipitation of irradiation induced platelets, and the associated change in Nb solute concentration is responsible for the low corrosion rates experienced by Zr-Nb alloys in-reactor conditions, resulting in lower corrosion rate at high burnup. Our recent publication on proton irradiated samples has already partially proved this hypothesis. The next step is to examine whether neutron irradiated samples behave similar to proton irradiated samples and indeed have lower Nb concentration in solid solution as function of irradiated doses. This study will utilize shielded FIB at IMCL to fabricate APT needles of neutron irradiated X2 and ZIRLO samples. The samples contains both metallic and oxide regions. Since it is essential to study the Nb redistribution in solid solution in metal and in oxides, APT needles would be taken from both metallic and oxide regions. The APT experiment will be performed at CAES under laser mode to generate higher atomic yield. Since Zr APT needles are very easy to fracture during APT experiment, higher numbers of APT needles would ensure greater success to have higher quality datasets (>10 million atoms). In total, we are requesting 1 week of FIB at IMCL and 10 days APT at CAES instruments time to finish this RTE. IVAS software will be used to analyze the structural and compositional information in the 3D reconstructed APT needles. Since nanoclusters are expected to be present in the analyzed volume, iso-surface and maximum separation methods will be applied to identity nanoclusters. Proximity histogram will be used to analyze chemistry of nanoclusters
Additional Info
| Field | Value |
|---|---|
| Abstract | We propose to use atom probe tomography (APT) to study the evolution of microchemistry of neutron irradiated ZIRLO® and AXIOM X2® alloys at different irradiation doses (1 cycle and 4 cycles). The major research objective of this study is to provide knowledge on neutron irradiation induced Nb redistribution in Zr-Nb alloys to understand the effect of Nb redistribution on corrosion kinetics. The overall research program aims at precisely characterizing the Nb concentration in irradiation induced platelet/nanoclusters and in the solid solution of neutron irradiated samples both in metal and oxides, which would provide quantitative data to model the in-reactor corrosion behavior of Zr-Nb alloys. The main hypothesis tested is that the precipitation of irradiation induced platelets, and the associated change in Nb solute concentration is responsible for the low corrosion rates experienced by Zr-Nb alloys in-reactor conditions, resulting in lower corrosion rate at high burnup. Our recent publication on proton irradiated samples has already partially proved this hypothesis. The next step is to examine whether neutron irradiated samples behave similar to proton irradiated samples and indeed have lower Nb concentration in solid solution as function of irradiated doses. This study will utilize shielded FIB at IMCL to fabricate APT needles of neutron irradiated X2 and ZIRLO samples. The samples contains both metallic and oxide regions. Since it is essential to study the Nb redistribution in solid solution in metal and in oxides, APT needles would be taken from both metallic and oxide regions. The APT experiment will be performed at CAES under laser mode to generate higher atomic yield. Since Zr APT needles are very easy to fracture during APT experiment, higher numbers of APT needles would ensure greater success to have higher quality datasets (>10 million atoms). In total, we are requesting 1 week of FIB at IMCL and 10 days APT at CAES instruments time to finish this RTE. IVAS software will be used to analyze the structural and compositional information in the 3D reconstructed APT needles. Since nanoclusters are expected to be present in the analyzed volume, iso-surface and maximum separation methods will be applied to identity nanoclusters. Proximity histogram will be used to analyze chemistry of nanoclusters |
| Award Announced Date | 2020-02-05T14:14:31.68 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Alina Zackrone, Yaqiao Wu |
| Irradiation Facility | None |
| PI | Mukesh Bachhav |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 2986 |