Mechanistic verification of empirical UO2 fuel fracture models

Standard UO2 fuel pellets used in light-water reactors fracture during irradiation due to the large thermal gradient radial direction. Over decades, numerous researchers have explored cracking from experimental and modeling points of view. To date, there been both empirical mechanistic approaches predict number fragments that form UO2. The models only consider maximum power burnup as inputs. Existing for normal operation not accounted effects. This work employs a model using extended finite element method explore crack formation while including sensitivity analysis accounts randomization tensile strength within fuel, criteria (uniform or volume-weighted Weibull), ramping rates, computational mesh density, level, (burnup) results indicate uncertainty this approach envelopes predicted values three different correlations almost all cases. means that, computationally intensive analyses involving fragmentation, can be used. However, since calculations bound those correlations, is confidence applicability developed generate correlation types where limited data exists (e.g., doped-UO2, U3Si2).