The nuclear fuel cladding temperatures of the HANARO fuel test loop have been calculated by MARS code for the large break loss-of-coolant accidents. Conservative method was used for the analysis of the loss-of-coolant accidents. Consequently, the maximum peak cladding temperature was predicted as 1235K, which was lower than the design limit temperature (1477K) of nuclear fuels for the HANARO fuel test loop. This means that the cooling capability of the emergency cooling water system for the HANARO fuel test loop is sufficient for the large break loss-of-coolant accidents.

The conservative method on the analysis of loss-of-coolant accidents for the HANARO fuel test loop was established based on the guide of evaluation method for the emergency core cooling systems of pressurized light water reactors. The evaluation models, the Moody model for discharge rate calculation and the Baker-Just model for water-metal reaction calculation, were used. In order to calculate conservative peak cladding temperatures for accidents the multipliers to the correlations of heat transfer coefficients in the MARS were also introduced. Consequently it is found that the maximum peak cladding temperature predicted by using the conservative method is sufficiently greater than that calculated by using the best-estimated models.