Modeling of Pellet Cladding Interaction

Analysis of fabrication and crack-induced porosity migration in mixed oxide fuels for sodium fast reactors by the finite element method

“…The second one, which considers both as-fabricated and crack-induced porosity, has a geometry similar to that reported in the previous section, i.e., to the circular section representative for the fuel pellet is added a surface representative for the crack. The crack pattern is again those considered at the beginning of irradiation (e.g., see [37])…”

“…The crack pattern considered is a simplification of that developing in real conditions. The related assumptions are taken according to [37], i.e., only radial cracks developing under the first rise to power are considered, and axial and circumferential cracks are not accounted. The pellet is supposed to split in 8 fragments spanning 22.5 degrees in the angular direction.…”

Investigation of clad ballooning during NSRR RIA tests using ALCYONE fuel performance code

“…ALCYONE pulse-irradiation simulation capability includes (see details in [1,2,4,5]):  the solving of the transient thermal heat balance equation and of the mechanical equilibrium for the pellet-gap-cladding system, based on the finite element method [42],  the solving of the axial transient heat and mass balance equations for both sodium and water coolants. For NSRR stagnant water conditions under various pressure and temperature, the post-DNB stage is considered as will be detailed in the next part,  material laws describing the non linear mechanical behavior of irradiated claddings (Zircaloy-4, M5® 2 ) based on the extensive PROMETRA program performed on irradiated cladding samples submitted to high strain rates and high temperatures [43,44,45].…”

“…Co-developed within the PLEIADES software environment by CEA, EDF and Framatome, ALCYONE is a multidimensional finite element-based nuclear fuel performance code dedicated to the analysis of the behavior of fuel rods during irradiation in commercial Pressurized Water Reactors (PWRs), power ramps in experimental reactors or accidental conditions, including Reactivity-Initiated Accidents (RIAs). Capable of steady state and transient thermal modeling, ALCYONE solves fully-coupled equations of thermo-mechanics together with sophisticated models for fission gas swelling and release [1] [2]. As regards RIA experiments, ALCYONE is capable of modeling the Pellet-Cladding Mechanical Interaction (PCMI) [2][3] and post-Departure from Nucleate Boiling (DNB) phases as well as various fuel/cladding material types.…”

Modeling of fission product release during severe accidents with the fuel performance code ALCYONE

“…ALCYONE is a fuel performance code co-developed by the CEA, EDF and FRAMATOME within the PLEIADES computational environment [26] [28]. Multi-dimensional modeling (1.5D, 2D, 3D) of a fuel rod in normal and accidental conditions (Reactivity Initiated Accident [29], Loss of Coolant Accident [30]) is available in the code.…”