NSUF 18-1211: Investigation of radiation-generated phases in FeCrSi alloys for multimetallic layered composite (MMLC) for LWR fuel cladding
A team of researchers led by MIT are developing a multimetallic layered composite (MMLC) fuel cladding for LWRs, as a way to impart both improved steady state performance and accident tolerance. This MMLC hinges upon a FeCrSi outer layer (chosen to improve upon FeCrAl in terms of weldability) to protect the underlying Zircaloy against steam attack in a severe accident. However, despite the microstructural stability of Fe-12Cr-2Si in out-of-pile experiments, its radiation performance has not yet been tested. In this study, we will determine the rates, mechanisms, and morphologies of radiation-induced microstructural changes from the neutron irradiation of FeCrSi alloys to 0.5 DPA. Three materials with different Cr contents are studied: Fe-12Cr-2Si, Fe-16Cr-2Si, and Fe-20Cr-2Si, as higher Cr content both improves severe oxidation resistance but also may form brittle sigma or alpha prime phases. In addition, the -2Si was chosen to just barely avoid the formation of Fe3Si intermetallics on dislocation cores and grain boundaries, which must be experimentally tested. Analyses by atom probe tomography (APT) and transmission electron microscopy (TEM) will reveal which phases form specifically due to neutron irradiation at PWR conditions (irradiation is already complete). Specimens will be sectioned using the FIB at CAES or the new plasma focused ion beam (P-FIB) at the IMCL laboratory in the MFC at INL, while APT analysis will take place in the CAES laboratories. The project will last nine months, and the specimens are ready for size reduction, shipping to INL, and subsequent analysis by FIB, TEM, and APT. The scientific outcomes include the first knowledge of the radiation stability of FeCrSi alloys, originally developed in a DOE-NERI project for lead-bismuth fast reactor cladding coatings, and will therefore simultaneously wrap up long-awaited “future work” in the NERI project plus determine whether the outer MMLC layer is fit for in-reactor service.
Additional Info
| Field | Value |
|---|---|
| Abstract | A team of researchers led by MIT are developing a multimetallic layered composite (MMLC) fuel cladding for LWRs, as a way to impart both improved steady state performance and accident tolerance. This MMLC hinges upon a FeCrSi outer layer (chosen to improve upon FeCrAl in terms of weldability) to protect the underlying Zircaloy against steam attack in a severe accident. However, despite the microstructural stability of Fe-12Cr-2Si in out-of-pile experiments, its radiation performance has not yet been tested. In this study, we will determine the rates, mechanisms, and morphologies of radiation-induced microstructural changes from the neutron irradiation of FeCrSi alloys to 0.5 DPA. Three materials with different Cr contents are studied: Fe-12Cr-2Si, Fe-16Cr-2Si, and Fe-20Cr-2Si, as higher Cr content both improves severe oxidation resistance but also may form brittle sigma or alpha prime phases. In addition, the -2Si was chosen to just barely avoid the formation of Fe3Si intermetallics on dislocation cores and grain boundaries, which must be experimentally tested. Analyses by atom probe tomography (APT) and transmission electron microscopy (TEM) will reveal which phases form specifically due to neutron irradiation at PWR conditions (irradiation is already complete). Specimens will be sectioned using the FIB at CAES or the new plasma focused ion beam (P-FIB) at the IMCL laboratory in the MFC at INL, while APT analysis will take place in the CAES laboratories. The project will last nine months, and the specimens are ready for size reduction, shipping to INL, and subsequent analysis by FIB, TEM, and APT. The scientific outcomes include the first knowledge of the radiation stability of FeCrSi alloys, originally developed in a DOE-NERI project for lead-bismuth fast reactor cladding coatings, and will therefore simultaneously wrap up long-awaited “future work” in the NERI project plus determine whether the outer MMLC layer is fit for in-reactor service. |
| Award Announced Date | 2018-02-01T14:15:34.563 |
| Awarded Institution | Center for Advanced Energy Studies |
| Facility | Microscopy and Characterization Suite |
| Facility Tech Lead | Yaqiao Wu |
| Irradiation Facility | None |
| PI | Michael Short |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 1211 |