Loss-of-Coolant-Accident (LOCA) is a design basis accident considered in LWR safety analyses, and LOCA simulation technique can be used to gain a better understanding of local cladding behaviors. This paper first summarizes equations regarding the oxygen-dissolved metallic Zircaloy-4 which have been implemented into the updated RANNS code. It is then validated using experimental data. The oxidation temperature is about 1473K, the oxidation time is about 182.5s and the quench temperature is about 973K. The difference between the measured axial load and the RANNS computation as the cladding surface temperature reaches about 373K is about 18.7%. In addition, the updated RANNS code is used to examine the influence of the oxygen absorbed into cladding on its axial load under LOCA quench conditions with oxidation time up to 674s. The results suggest that the contributions of both the oxygen-dissolved metallic layer and the oxide layer to the axial load increase with oxidation time. The former corresponds to about a tenth of the computed axial load. These findings are considered useful for improving the accuracy of the analyses of the fuel rod behaviors during LOCA conditions.