Verification of fuel pin performance code MIPEC against PNC irradiation data

A fuel pin performance code MIPEC is verified against LMFBR irradiation data. Six PNC fuel pins irradiated in DFR and Rapsodie are included in the verification analysis. Review of the verification results are focused on the MIPEC capability of prediction for clad inelastic strain due to fuel-clad mechanical interaction (FCMI). The following conclusions are obtained from the verification analyses. Assumption of an early-life fuel-clad gap closure results in fairly good prediction for clad inelastic strains due to FCMI in all of the fuel pins analyzed in this study. Use of stress dependent fuel swelling rate is important in predicting FCMI. Use of the modified elastic moduli defined in MIPEC gives higher clad inelastic strain than does the use of LIFE modified elastic moduli model for cracked fuel region