NSUF 16-835: Radiation Response and Microstructure of Accident Tolerant U3Si2 Fuels by Ion Beam Irradiation
U3Si2 fuel is the leading candidate of the accident tolerant fuels (ATFs), alternative to the current UO2 fuel form for light water reactors, due to its significantly higher thermal conductivity and higher fissile element density. Extensive development of U3Si2 as a dispersion fuel for research reactors has been performed; however, the behavior of U3Si2 under relevant LWR reactor conditions is largely unknown. Limited ion irradiation data reported radiation damage-induced amorphization at a relatively low temperature. The silicide fuel may experience grain subdivision through recrystallization at high temperature, similar to UO2 fuels. Grain coarsening of the silicide fuels may also occur at higher temperature due to the thermally or radiation-induced grain coarsening. Various experiments are planned to investigate the fuel characteristics and behavior by the FCRD and ATF programs, e.g., silicide fuel fabrication, properties characterization and fuel performance evaluation. However, data for ATR irradiation will not be available for at least a few years. Potentially-important behaviors in U3Si2 that are not being investigated by FCRD including radiation-induced amorphization, grain growth, and possible grain subdivision. U3Si2 fuel is also identified as a high impact program (HIP) under the Nuclear Energy Advanced Modeling & Simulation (NEAMS) in developing high fidelity multi-physics models to predict fuel performance, and critical experiment data are needed in order to validate fuel modeling. Upon the support of a newly-awarded DOE NEUP project (16-10667, PI participated), a coupled experimental and theoretical approach was proposed to investigate radiation-induced amorphization, grain subdivision and grain coarsening of U3Si2 fuels at relevant LWR conditions. The unique capability of IVEM-tandem facility at Argonne National Laboratory enables an in-situ TEM observation of radiation damage and microstructure evolution, providing critical data for evaluating the performance of silicide fuels as the leading ATF candidate. Preliminary experiments of heavy ion beam irradiation on U3Si2 lamellas prepared by focused ion beam (FIB) were conducted at 350 oC using IVEM-Tandem facility recently, and very promising results were obtained in which U3Si2 maintains crystallinity and structural integrity at a dose as high as 60 dpa. In this NSUF RTE project, we proposed to continue ion beam irradiation by IVEM-Tandem facility at ANL in order to gain complete understanding of the radiation response and microstructure evolution of silicide fuels under relevant reactor conditions, prepare. The U3Si2 TEM samples for ion beam irradiations will be prepared and characterized by FIB and TEM, respectively, at CAES of Idaho National Laboratory. Key components of this RTE proposal include: (1) temperature dependence of critical doses for amorphization; (2) critical amorphization temperature above which U3Si2 remains crystalline regardless of irradiation levels; and (3) radiation-induced microstructure evolution under relevant LWR working temperature (300 ~ 800 oC) including accumulation and evolution of atomic damage on the crystal structure, possible grain subdivision and grain coarsening processes as functions of irradiation dose and temperature.
Additional Info
| Field | Value |
|---|---|
| Abstract | U3Si2 fuel is the leading candidate of the accident tolerant fuels (ATFs), alternative to the current UO2 fuel form for light water reactors, due to its significantly higher thermal conductivity and higher fissile element density. Extensive development of U3Si2 as a dispersion fuel for research reactors has been performed; however, the behavior of U3Si2 under relevant LWR reactor conditions is largely unknown. Limited ion irradiation data reported radiation damage-induced amorphization at a relatively low temperature. The silicide fuel may experience grain subdivision through recrystallization at high temperature, similar to UO2 fuels. Grain coarsening of the silicide fuels may also occur at higher temperature due to the thermally or radiation-induced grain coarsening. Various experiments are planned to investigate the fuel characteristics and behavior by the FCRD and ATF programs, e.g., silicide fuel fabrication, properties characterization and fuel performance evaluation. However, data for ATR irradiation will not be available for at least a few years. Potentially-important behaviors in U3Si2 that are not being investigated by FCRD including radiation-induced amorphization, grain growth, and possible grain subdivision. U3Si2 fuel is also identified as a high impact program (HIP) under the Nuclear Energy Advanced Modeling & Simulation (NEAMS) in developing high fidelity multi-physics models to predict fuel performance, and critical experiment data are needed in order to validate fuel modeling. Upon the support of a newly-awarded DOE NEUP project (16-10667, PI participated), a coupled experimental and theoretical approach was proposed to investigate radiation-induced amorphization, grain subdivision and grain coarsening of U3Si2 fuels at relevant LWR conditions. The unique capability of IVEM-tandem facility at Argonne National Laboratory enables an in-situ TEM observation of radiation damage and microstructure evolution, providing critical data for evaluating the performance of silicide fuels as the leading ATF candidate. Preliminary experiments of heavy ion beam irradiation on U3Si2 lamellas prepared by focused ion beam (FIB) were conducted at 350 oC using IVEM-Tandem facility recently, and very promising results were obtained in which U3Si2 maintains crystallinity and structural integrity at a dose as high as 60 dpa. In this NSUF RTE project, we proposed to continue ion beam irradiation by IVEM-Tandem facility at ANL in order to gain complete understanding of the radiation response and microstructure evolution of silicide fuels under relevant reactor conditions, prepare. The U3Si2 TEM samples for ion beam irradiations will be prepared and characterized by FIB and TEM, respectively, at CAES of Idaho National Laboratory. Key components of this RTE proposal include: (1) temperature dependence of critical doses for amorphization; (2) critical amorphization temperature above which U3Si2 remains crystalline regardless of irradiation levels; and (3) radiation-induced microstructure evolution under relevant LWR working temperature (300 ~ 800 oC) including accumulation and evolution of atomic damage on the crystal structure, possible grain subdivision and grain coarsening processes as functions of irradiation dose and temperature. |
| Award Announced Date | 2016-12-16T07:47:05.523 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Wei-Ying Chen |
| Irradiation Facility | None |
| PI | Jie Lian |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 835 |