Moreover, some future Generation III+ reactor designs such as advanced boiling water reactor (ABWR) or economic simplified boiling water reactor (ESBWR) [10] are based on BWR technology. The most recent extensive research regarding burnup credit application to transport and storage of BWR spent fuel was performed by Oak Ridge National Laboratory (ORNL) as a part of their five-year program with the US Nuclear Regulatory Commission (NRC) [11]. The project had two phases: (1) burnup credit analysis for BWR spent fuel near the peak reactivity; and (2) for the burnups beyond peak reactivity or so-called extended BUC. The authors investigated the effect of design and operating parameters of BWR systems on the final storage and transport task criticality, along with verification and validation of the utilised tools [11]. Although the effect of axial burnup and moderator densities profiles were studied during the project, the limitation of the tools did not allow to track changes of these profiles over the cycle, so analysis was performed using the cycle-averaged data [12]. The different modules and versions of SCALE [13] nuclear code were used for the project. Another recent study [14], investigated the compound effect: the effect of the variation of the several operating parameters on burnup credit for various assembly burnups. The authors showed the correlation between effective multiplication factor (k\({}_{\text{eff}}\)) of the storage cask and fuel burnup for single and compound effects of the operating parameters variation. However, the study included a range of assumptions and simplifications regarding fuel assembly design and operating parameters. Other research on the BWR BUC is presented in a series of works [15; 16]. In the first part of the study [15], the authors created an advanced 3D model of the BWR fuel assembly with complex design and compounding operating parameters for depletion analysis and compared it to the simplified 2D lattice models. The results showed substantial changes in the criticality curve and U-235 and Gd-155 depletion when using the advanced model. The second part of this research [16] was focused on the criticality analysis and uncertainty quantification (UQ) for the cask loaded with BWR spent fuel discharged at the peak reactivity using depletion models developed in the first part of the research [15]. Authors concluded that the advanced 3D model of the BWR fuel assembly is highly beneficial for the burnup credit since it can incorporate parameters which significantly affect the cask criticality such as axial burnup or coolant density profiles. Uncertainty analysis is an essential part of the burnup credit method. Fuel depletion in criticality analysis leads to many additional uncertainties in comparison with the fresh fuel approach. The isotopic prediction is viewed as a possible primary source of uncertainties related to the fuel burnup [17]. There have been several studies on uncertainty analysis associated with BWRs in recent years [18; 19; 20; 21]. The work [18] related to the isotopic uncertainty, comparing two approaches for the uncertainty analysis: (1) computational (uncertainty in the input parameters), and (2) data-driven (usage of the experimental data and previous expertise in the criticality assessment). The authors identified that the data-driven approach provides a larger contribution to the uncertainty value than the computational approach. The present study is an extension of the work [22] which was focused on creating the BWR reactor core model for the nodal analysis using the Advanced BWR design [23] to get the spent fuel (SF) data for further criticality analysis of the BWR transport and storage cask. The nodal calculations were performed for various core loading strategies to estimate the possible range of the assemblies' discharge burnups. In this part of the study, the authors will focus on applying the results of the full-core simulations to the extended burnup credit for BWR spent fuel.