When increasing the power of an energy unit it is necessary to ensure strict adherence to the specified normal operation limits, and limits for power density. This is made possible by using new types of nuclear fuel with enhanced operating characteristics and advanced methods of fuel loading formation. Operation of fuel types using burnable absorber needs more detailed analysis during development of core fuel loading pattern, because the change of multiplication properties during burn-up becomes nonmonotonic. Due to this reason, it is often impossible to provide significant margins for peaking factors to design limits during development of fuel loading pattern. In this case analysis of sensitivity and uncertainty of the calculation results is advantageous. A simple estimate of the possibility of design limit violation can be used in the process of optimization The paper investigates the methods of sensitivity and uncertainty analysis and provides a number of examples from the experience of core loading selection.
Monte-Carlo method, neutronic model, VVER-type reactor, reactor core, nuclear fuel, fuel loading, operation limit, sensitivity estimation, fuel cycle
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