A viscoplastic approach to corium spreading during a severe nuclear accident

Thomas Schiano (1, 2) , Barbara Bigot (1) , Jean-François Haquet (1) , Pierre Saramito (2) , Claude Smutek (3, 4)

1 SMTA - Service Mesures et modélisation des Transferts et des Accidents graves
2 EDP - Equations aux Dérivées Partielles
3 IPGP (UMR_7154) - Institut de Physique du Globe de Paris
4 LGSR - Laboratoire GéoSciences Réunion

A viscoplastic model for lava is presented, and its use for corium spreading is argued with dimensionless numbers. It describes the tridimensional flow as non-Newtonian and non-isothermal. Using an adaptive finite element method based on C++ library Rheolef, simulations are ran and compared to the VEU7 corium spreading test. A sensitivity analysis on the viscoplastic parameters of corium that are not well-known is conducted. Tridimensional solution of the problem is computed from the bidimensional height-averaged solution.

Mots clés: Spreading; Corium; Lava; Severe accidents; Simulation

Domaines: Analyse numérique [math.NA]

Thomas Schiano, Barbara Bigot, Jean-François Haquet, Pierre Saramito, Claude Smutek. A viscoplastic approach to corium spreading during a severe nuclear accident. Nuclear Engineering and Design, 2023, 401, pp.112045. ⟨10.1016/j.nucengdes.2022.112045⟩. ⟨hal-03893285⟩