| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Seaborg Institutes: Emerging Topics in Actinide Sciences
|
| Presentation Title |
Lattice Distortions and Swelling Resilience in Aged δ-phase Plutonium |
| Author(s) |
Jason Jeffries |
| On-Site Speaker (Planned) |
Jason Jeffries |
| Abstract Scope |
As δ-plutonium ages, Pu atoms split into uranium ions and alpha particles. While mass is conserved in this process, volume is not: the size of a Pu-239 atom is smaller than the size of a U-235 atom plus a He-4 atom. This simple fact, absent other microstructural factors, would predict an age-dependent swelling in plutonium, which is indeed observed. He bubbles sizes and the lattice volume evolution have been measured, and point and cluster defect volumes have been calculated. When these predominant effects are summed, the expected volume of aged Pu exceeds the directly measured volume. This contradiction implies that there is an unaccounted for "contracting force," and high-resolution x-ray diffraction implicates a culprit: a time-dependent lattice distortion towards a new body-centered tetragonal crystal structure.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Nuclear Materials, Phase Transformations, |