NSUF 23-4668: In situ Synchrotron radiation diffraction study of the Effect of Radiation Damage on the Precipitation and Dissolution of Hydrides in Zircaloy
Hydrogen absorption and hydride particle precipitation in nuclear fuel cladding can cause the cladding tube to become embrittled and reduce its usable life. Despite considerable studies on hydride precipitation, including synchrotron radiation diffraction work by this and other groups, the complexity of the phenomena involved have made a comprehensive understanding of the formation process of specific hydride mesoscale microstructures an elusive goal. The prediction of specific hydride microstructures is important as it is often the orientation connectivity and concentration of hydrides, not overall hydrogen content, that can determine failure. This understanding is crucial to predicting the behavior of nuclear fuel cladding after exposure to the reactor environment, both during service and in dry storage (A.T. Motta et al., Journal of Nuclear Materials, Vol. 518, pg. 440-460, 2019).
The hydride morphology and microstructure formed during hydride precipitation in zirconium alloys is governed by several competing phenomena. Precipitation occurs when the terminal solid solubility in a zirconium alloy is exceeded, or, conversely, when sufficient undercooling is achieved for a given hydrogen concentration. The transformation depends on accommodation of plastic strains, while obeying the orientation relationship between the Zr and the hydride.
When precipitation happens in the presence of irradiation damage, which creates defect clusters in the material matrix, differential scanning calorimetry (DSC) experiments have revealed significant shifts (50-70℃) in the terminal solid solubility due to the presence of irradiation damage (P. Vizcaíno et al., ASTM STP 1529, 754–781, 2011). Earlier work also noted that trapped hydrogen was released between cycles increased due to annihilation of loops (P. Vizcaíno et al., J of Mat. Sci., 6633–6637, 2007). However, microscopic hydrides precipitated with type dislocations in densities orders of magnitude larger than macroscopic hydrides and were stable up to at least 333℃ (Chung et al., ASTM STP 1423, 561–582, 2002). Using in-situ synchrotron radiation diffraction would be a novel application of the technique in order to study the influence of irradiation fluence on hydride precipitation/dissolution. The results can contribute to existing fuel performance codes especially with industrial interest in higher discharge fuel burnups at commercial nuclear power plants.
We propose to use in-situ synchrotron radiation diffraction of hydrided zirconium alloy samples to determine in-situ the influence of irradiation fluence on hydride precipitation/dissolution while undergoing various heat treatment schedules.
Additional Info
| Field | Value |
|---|---|
| Abstract | Hydrogen absorption and hydride particle precipitation in nuclear fuel cladding can cause the cladding tube to become embrittled and reduce its usable life. Despite considerable studies on hydride precipitation, including synchrotron radiation diffraction work by this and other groups, the complexity of the phenomena involved have made a comprehensive understanding of the formation process of specific hydride mesoscale microstructures an elusive goal. The prediction of specific hydride microstructures is important as it is often the orientation connectivity and concentration of hydrides, not overall hydrogen content, that can determine failure. This understanding is crucial to predicting the behavior of nuclear fuel cladding after exposure to the reactor environment, both during service and in dry storage (A.T. Motta et al., Journal of Nuclear Materials, Vol. 518, pg. 440-460, 2019). The hydride morphology and microstructure formed during hydride precipitation in zirconium alloys is governed by several competing phenomena. Precipitation occurs when the terminal solid solubility in a zirconium alloy is exceeded, or, conversely, when sufficient undercooling is achieved for a given hydrogen concentration. The transformation depends on accommodation of plastic strains, while obeying the orientation relationship between the Zr and the hydride. When precipitation happens in the presence of irradiation damage, which creates defect clusters in the material matrix, differential scanning calorimetry (DSC) experiments have revealed significant shifts (50-70℃) in the terminal solid solubility due to the presence of irradiation damage (P. Vizcaíno et al., ASTM STP 1529, 754–781, 2011). Earlier work also noted that trapped hydrogen was released between cycles increased due to annihilation of <a> loops (P. Vizcaíno et al., J of Mat. Sci., 6633–6637, 2007). However, microscopic hydrides precipitated with <c> type dislocations in densities orders of magnitude larger than macroscopic hydrides and were stable up to at least 333℃ (Chung et al., ASTM STP 1423, 561–582, 2002). Using in-situ synchrotron radiation diffraction would be a novel application of the technique in order to study the influence of irradiation fluence on hydride precipitation/dissolution. The results can contribute to existing fuel performance codes especially with industrial interest in higher discharge fuel burnups at commercial nuclear power plants. We propose to use in-situ synchrotron radiation diffraction of hydrided zirconium alloy samples to determine in-situ the influence of irradiation fluence on hydride precipitation/dissolution while undergoing various heat treatment schedules. |
| Award Announced Date | 2023-06-01T09:06:47.16 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Simerjeet Gill |
| Irradiation Facility | None |
| PI | Jonathan Balog |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | None |