NSUF 18-1455: Novel Microstructure Characterization of Pre-Hydrided ZIRLO® at Low Neutron Doses

Hydride precipitation is one of the major embrittling mechanisms which is elevated by the neutron irradiation for zirconium-based nuclear fuel cladding alloys during in-pile service and out-pile storage/transportation conditions. To assess the influence of neutron radiation damage in d-hydride platelets, high-resolution microstructural characterization techniques become essential to facilitate continued alloy development and increase the mechanical performance of current cladding during nuclear fuel cycle. The characterization of the d-hydride platelets using the highly complementary S/TEM-EDS and tKD will enable us to understand the nature of early stages of the radiation damage in d-hydrides in initially pre-hydrided ZIRLO samples irradiated up to dose level of 2.9 dpa and develop informed mesoscale models that depict hydride formation and the irradiation effects. In this study, we propose to perform post-irradiation S/TEM and tKD characterization of neutron-irradiated pre-hydrided ZIRLOTM nuclear fuel cladding tube segments. Samples are located inside an irradiation capsule. The irradiation capsule will be disassembled for sample removal and the samples will be sectioned for TEM sample preparation using FIB milling at cryogenic temperatures. Three specimens will be prepared using dual-beam FIB with a liquid-nitrogen-cooled sample stage. For microstructural characterization, we will use the FEI Talos S/TEM with its high-efficiency EDS detector including dislocation density analysis and elemental mapping through EDX spectroscopy. The FEI Versa SEM will be used for the tKD data acquisition and analysis as well. The combined data will enable a greater understanding of how hydride microstructure is affected in ZIRLOTM cladding at low neutron doses.

Additional Info

Field	Value
Abstract	Hydride precipitation is one of the major embrittling mechanisms which is elevated by the neutron irradiation for zirconium-based nuclear fuel cladding alloys during in-pile service and out-pile storage/transportation conditions. To assess the influence of neutron radiation damage in d-hydride platelets, high-resolution microstructural characterization techniques become essential to facilitate continued alloy development and increase the mechanical performance of current cladding during nuclear fuel cycle. The characterization of the d-hydride platelets using the highly complementary S/TEM-EDS and tKD will enable us to understand the nature of early stages of the radiation damage in d-hydrides in initially pre-hydrided ZIRLO samples irradiated up to dose level of 2.9 dpa and develop informed mesoscale models that depict hydride formation and the irradiation effects. In this study, we propose to perform post-irradiation S/TEM and tKD characterization of neutron-irradiated pre-hydrided ZIRLOTM nuclear fuel cladding tube segments. Samples are located inside an irradiation capsule. The irradiation capsule will be disassembled for sample removal and the samples will be sectioned for TEM sample preparation using FIB milling at cryogenic temperatures. Three specimens will be prepared using dual-beam FIB with a liquid-nitrogen-cooled sample stage. For microstructural characterization, we will use the FEI Talos S/TEM with its high-efficiency EDS detector including dislocation density analysis and elemental mapping through EDX spectroscopy. The FEI Versa SEM will be used for the tKD data acquisition and analysis as well. The combined data will enable a greater understanding of how hydride microstructure is affected in ZIRLOTM cladding at low neutron doses.
Award Announced Date	2018-05-17T11:11:40.44
Awarded Institution	None
Facility	None
Facility Tech Lead	Kory Linton
Irradiation Facility	None
PI	Nicholas Brown
PI Email	[email protected]
Project Type	RTE
RTE Number	1455