Methods for Determining the Irradiation Response of Structural Materials for Nuclear Reactor Core Structural Materials Development
EMSL Project ID
50087
Abstract
Current reactor concepts call for fuel cladding and duct to withstand up to as much as 500 dpa of neutron irradiation. Achieving such dose levels using neutrons is totally impractical due to the unavailability of suitable irradiation sources. As an alternative approach to study high dose irradiation effects in materials, self-ion irradiation techniques are becoming widely employed due to the high displacement per atom (dpa) rate. While ion irradiations are already in-use to serve as a screening tool, the correspondence between neutron and ion irradiations is still being investigated. To date, differences in microstructures and void swelling between ion and neutron irradiated materials are still not well understood. In this research, we seek to study the microstructural correlation among ion irradiated and neutron irradiated ferritic/martensitic steels, and the injected interstitials effects on void swelling. Microstructures such as irradiation-induced second phases, precipitates, elemental segregation will be using atom probe tomography (APT). Specimens will be fabricated using standard FIB lift out procedures from site of interests. Investigating the correspondence among ion and neutron irradiated microstructures systematically will not only provide a baseline for optimizing future ion irradiation experimental conditions, but also help us to understand key aspects that governs materials performance and safety under extreme conditions. Imaging injected interstitials will be accomplished by irradiating the materials using cathodes composed almost entirely of low natural abundance isotopes and then mapping the fate of the isotopic atoms time of flight secondary ion mass spectrometry (ToF-SIMS), and NanoSIMS. Tracking the fate of injected atoms will provide insights into how ion irradiations affect microstructural evolution differently than neutron irradiations not only due to the effect of adding additional atoms, but it will also provide insights into other aspects of ion irradiations such as the presence of the unirradiated substrate and the exposed free surface on alter point defect migration and concentrations.
Project Details
Start Date
2017-11-28
End Date
2018-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members