Analysis for fuel rod performance under LOCA based on the FROBA-ROD 2.0 code

Abstract Loss of Coolant Accident (LOCA) is one of the major design-basis accidents in LWRs. Fuel rod may fail due to the rupture of the cladding. By developing a LOCA simulation module, the steady-state fuel rod performance analysis code, FROBA-ROD, is now capable to predict fuel rod behaviors under a LOCA transient. The relevant models and the code was verified and validated by comparing with authoritative commercial codes and with the experimental measurements. Comprehensive calculations and analyses of fuel rod behaviors under different LOCA transients were performed by the new version of FROBA-ROD. Compared the failure conditions to the non-failure conditions through the simulation results, a cladding failure threshold equation was found for a better estimate of the integrity of high burnup fuel rods under LOCA transients.