Pellet compliance model based on out-of-pile simulation☆

摘要: Abstract The thermal and mechanical behavior of fuel rods is significantly influenced by the extent their relocation compliance cracked pellets. Movement pellet pieces towards cladding results in softer pellets with crack voids which accommodate some fraction thermoelastic deformation make more compliant under restraint cladding. It difficult to model such a independently experimental observations because uncertain nature. Electrically heated simulation pellet-cladding interaction (PCMI) facilitates much quicker flexible experimentation than actual in-pile tests. Testing apparatus consists simulated rod hollow UO 2 tungsten center, diameter measuring device including three pairs sensors. Test parameters include gap thickness. Results show that smaller have larger increasing rate diameter. This suggests group induced stress has an apparent increases gap. also sensitivity thickness those calculated assuming having intrinsic stiffness. nature Such can almost be described reducing elasticity pellet. A simple was obtained fitting calculations measurements describe as uniform axisymmetric body elasticity.