| About this Abstract |
| Meeting |
Materials in Nuclear Energy Systems (MiNES) 2021
|
| Symposium
|
Materials in Nuclear Energy Systems (MiNES) 2021
|
| Presentation Title |
Modeling the Mechanisms of Fuel Pulverization Using Cluster and Molecular Dynamics |
| Author(s) |
Michael W. Cooper, Christopher Matthews, Robert Daum, David Andersson |
| On-Site Speaker (Planned) |
Michael W. Cooper |
| Abstract Scope |
Reactor operators in the US would like to extend the refueling cycle length in PWRs from 18 to 24 months, which requires an increase in the peak rod average burnup from 62 GWd/tU to 75 GWd/tU. The high burnup structure (HBS) that forms in UO2 under such conditions is susceptible to fragmentation and pulverization when it experiences a temperature ramp (e.g., during a LOCA). The resultant relocation/dispersal of fuel particles represents a significant safety concern. In this work, we use cluster dynamics to examine the over-pressurization of Xe bubbles through irradiation-enhanced diffusion processes relevant to the cooler temperatures found in the periphery of the pellet, where HBS forms. Then, we employ MD simulations to examine the impact of over-pressurized inter-granular bubbles on the fracture of grain boundaries during temperature ramps, as a proposed mechanism for fuel pulverization. The peak temperature, bubble size, bubble number, and bubble pressure are all examined. |
| Proceedings Inclusion? |
Undecided |