Evaluation of Decay Heat Calculation Uncertainties for Spent Fuel from RBMK-1500 Reactor

When handling spent nuclear fuel, the decay heat must be considered to ensure sufficient heat removal. However, the decay heat measurements for spent RBMK fuel assemblies are missing. In this regard, determining accurate spent fuel characteristics with known uncertainties becomes essential for the safety of RBMK spent fuel management. The decay heat uncertainty over the first 100 years after the fuel discharge for the RBMK-1500 fuel was accomplished in this study. Design and nuclear reaction data uncertainties were propagated stochastically through depletion and decay calculations using the Sampler sequence within the SCALE code package. Nuclear reaction data influenced higher uncertainties in decay heat estimations than design data. Cross-section data related uncertainties overshadow uncertainties caused by fission yields and decay data.