NSUF 22-4426: Micromechanical Testing of LWR-Irradiated Harvested Reactor Internals
Irradiated 304 stainless steel (SS) reactor internals materials were harvested by the Electric Power Research Institute (EPRI), U.S. Nuclear Regulatory Commission (NRC), and international partners from the José Cabrera Nuclear Power Station (also known as Zorita) in Spain. These materials are some of the most representatively aged, high-fluence irradiated SS components that have been studied. An important finding from this prior testing is an increasing susceptibility to high SCC CGRs at higher fluences. Information on the Zorita materials and other high-dose LWR-irradiated SSs suggests that continued irradiation effects at the GBs, such as increased RIS and possibly void accumulation, as dose increases from 10 to 50 dpa is contributing to the increasing susceptibility to high CGRs at higher fluences. Therefore, the objective of this proposal is to investigate, as a function of dose (<1, 15, and 50 dpa), the changes in GB behavior, including potential GB weakening, of the Zorita materials with increasing fluence. Micromechanical testing has been used increasingly in recent years to study the behavior of other materials and has also been applied to irradiated SSs to study irradiation effects.
To study the microstructural and microchemistry changes at the GBs and correlate them to the observed macroscale test results, micromechanical testing will be used to study the change in GB behavior and properties as a function of fluence. Micromechanical test specimens will be prepared using a shielded focused ion beam (FIB) at the Irradiated Materials Characterization Laboratory (IMCL) at INL. Eight days of FIB time in IMCL is required for sample preparation. The specimens will be made along the edge of a polished block of the sample mounted on a Mo stub for high temperature testing. FIB etching will be used to find sample locations containing grain boundaries. These materials are also proposed to be characterized by TEM and atom probe tomography (APT) under another RTE proposal. The data will be compared across the three identified dose levels to improve understanding of the overall research on these materials. The results of this micromechanical testing will help provide improved understanding of the observed behavior in macroscale testing by measuring the local mechanical properties. The local mechanical properties will be correlated with the microstructural and microchemistry changes along the GBs that drive the behavior.
This project is expected to be able to be completed within 6 months of award.
Additional Info
| Field | Value |
|---|---|
| Abstract | Irradiated 304 stainless steel (SS) reactor internals materials were harvested by the Electric Power Research Institute (EPRI), U.S. Nuclear Regulatory Commission (NRC), and international partners from the José Cabrera Nuclear Power Station (also known as Zorita) in Spain. These materials are some of the most representatively aged, high-fluence irradiated SS components that have been studied. An important finding from this prior testing is an increasing susceptibility to high SCC CGRs at higher fluences. Information on the Zorita materials and other high-dose LWR-irradiated SSs suggests that continued irradiation effects at the GBs, such as increased RIS and possibly void accumulation, as dose increases from 10 to 50 dpa is contributing to the increasing susceptibility to high CGRs at higher fluences. Therefore, the objective of this proposal is to investigate, as a function of dose (<1, 15, and 50 dpa), the changes in GB behavior, including potential GB weakening, of the Zorita materials with increasing fluence. Micromechanical testing has been used increasingly in recent years to study the behavior of other materials and has also been applied to irradiated SSs to study irradiation effects. To study the microstructural and microchemistry changes at the GBs and correlate them to the observed macroscale test results, micromechanical testing will be used to study the change in GB behavior and properties as a function of fluence. Micromechanical test specimens will be prepared using a shielded focused ion beam (FIB) at the Irradiated Materials Characterization Laboratory (IMCL) at INL. Eight days of FIB time in IMCL is required for sample preparation. The specimens will be made along the edge of a polished block of the sample mounted on a Mo stub for high temperature testing. FIB etching will be used to find sample locations containing grain boundaries. These materials are also proposed to be characterized by TEM and atom probe tomography (APT) under another RTE proposal. The data will be compared across the three identified dose levels to improve understanding of the overall research on these materials. The results of this micromechanical testing will help provide improved understanding of the observed behavior in macroscale testing by measuring the local mechanical properties. The local mechanical properties will be correlated with the microstructural and microchemistry changes along the GBs that drive the behavior. This project is expected to be able to be completed within 6 months of award. |
| Award Announced Date | 2022-06-14T07:30:53.32 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Alina Zackrone |
| Irradiation Facility | None |
| PI | Matthew Hiser |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | None |