Comparative study of Cr-coating and Zr-lining method on inner surface of HT9 cladding to mitigate Fuel-Cladding chemical interaction

A comparative study was conducted between electroplated Cr coatings and Zr linings as inner-surface barriers to mitigate chemical interactions in metallic nuclear fuel claddings. The comparison involved microstructural analysis and micro-CT examination to analyze their inner-surface morphology, along with an evaluation of their mechanical properties. Furthermore, diffusion couple tests were conducted to determine the fuel-cladding chemical interaction (FCCI) resistance. Both barrier processes demonstrated superior FCCI resistance compared with untreated HT9; however, several limitations were identified. Although potential improvements were expected for the Cr-coating process through modifications of the applied pulsed current waveforms, the Zr-lining process presented major process-related dilemmas that were challenging to overcome.