VVER-1000 Pin-Cell Nuclear Data UQ Using SANDY/Serpent

Nuclear data uncertainty quantification and propagation is crucial for reactor physics and safety analyses. It involves evaluating uncertainties in fundamental nuclear data, such as cross-sections, resonance parameters, fission yields, decay constants, among others, which impact reactor simulation prediction accuracy. This process is essential for reliable reactor behavior predictions under various conditions and accidents, aiding in reactor design, operation, and licensing [1].
The Best Estimate Plus Uncertainty (BEPU) approach, accepted by the NRC in the 1980s, provides realistic reactor behavior predictions by incorporating uncertainties into best estimate calculations – unlike traditional conservative methods that use worst-case scenarios – resulting in larger safety margins and more economical reactor designs [2]. Figure 1 shows an example of the BEPU approach. Fig. 1. Visualization of the BEPU framework.