High temperature oxidation and room temperature axial strength of pre-oxidized zircaloy-4 cladding after a simulated LOCA

The influence of the nuclear fuel cladding pre-oxidation on post-LOCA quench resistance was experimentally studied and then modeled. Adopting a separate effect approach, quenched high temperature oxidized samples were axially loaded in a mechanical device. The pre-existing oxide layer shows a complex influence that was interpreted and modeled using a simple approach reproducing the main observed phenomena. A new correlation was established to evaluate the oxygen enriched alpha-phase thickness and the zirconia layer growth is analyzed and modeled. These models and correlations were implemented in a failure prediction model finally compared to experimental results. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Experimental studies and modeling have shown that pre-oxidation of nuclear fuel cladding has an impact on post-LOCA quench resistance, with the pre-existing oxide layer exhibiting complex effects that can be modeled using a simple approach. A new correlation was established to evaluate the oxygen enriched alpha-phase thickness, and the growth of the zirconia layer was successfully analyzed and modeled. These models and correlations were implemented in a failure prediction model and compared to experimental results.