[en] JNES is developing severe accident analysis codes in order to apply to the probability safety analysis (PSA) for a typical fast breeder reactor (FBR). AZORES code analyzes the severe accident phenomena in the reactor containment that reactor coolant (sodium) and molten core debris are released from the primary cooling system boundary, and the discharge rate to the environment of fission products (FP). This report summarizes analysis results using the AZORES code for a PLOHS (loss of decay heat removal function) accident sequence with the actual plant system about the containment bypass scenario (CVBP) and the containment failure scenario by hydrogen deflagration or detonation. The coolant temperature of the primary system and the secondary system in the PLOHS sequence increases at the almost same temperature, and the creep damage to the reactor coolant boundary will become remarkable if coolant temperature exceeds about 1,100 K. In the CVBP scenario, when an intermediate heat exchanger is ruptured by creep and the boundary of the secondary system is failed, the path from the primary system to environment is formed. Then, the reactor vessel (RV) is failed and sodium in the primary coolant system releases into the reactor vessel room (RV room). Sodium of high temperature which fell in the RV room damages the floor liner, and generates hydrogen by a reaction with concrete. In addition the reactor core is exposed into atmosphere and the core temperature increases with decay heat and then volatile FP and non-volatile FP are released to the environment through the secondary system from the primary system. In the non-CVBP scenario which the intermediate heat exchanger does not fail by creep, core debris falls into the RV room after reactor vessel failure or evaporation of sodium coolant molten. FPs released from the reactor vessel are retained in the RV room, the primary system room, the containment dome and so on. The hydrogen generated by sodium-concrete reaction and debris concrete reaction moves to the reactor containment dome with sodium aerosol. Although the diffusion flame combustion of hydrogen occurs by igniting with sodium aerosol, since the flame velocity is slow, the reactor containment vessel is not damaged. However, if ignition of hydrogen is considerably delayed, the containment vessel may fail by deflagration or detonation of hydrogen although possibility is small enough. The CVBP scenario and hydrogen burning scenario were analyzed in the AZORES code, and FPs released to environment were calculated as ratios to the initial core inventory. The release ratios of CVBP case were obtained to be 2x10^-4 about the rare gas (Xe), 1x10^-5 about the volatile FP (I), and 1x10^-6 about the non-volatile FP (Ce). The release ratios of containment vessel failure case by hydrogen burning were obtained to be 0.82 about the rare gas (Xe), 0.06 about volatile FP (I), and 0.003 about non-volatile FP (Ce). These analyses by the AZORES clarified quantitatively the release ratio to the environment of FP in both case of CVBP and non-CVBP for the PLOHS sequence of a typical FBR plant