BACO (BArra COmbustible) code version 2.20: a thermo-mechanical description of a nuclear fuel rod

Simulation with DIONISIO 1.0 of thermal and mechanical pellet-cladding interaction in nuclear fuel rods

“…The creep and irradiation growth models for Zircaloy included in DIONISIO were taken from Refs. [16] and [17], respectively. The models for swelling and densification were taken from Refs.…”

“…Cladding irradiation growth [17] de Ig zz =dt ¼ 4:942 Â 10 À20 / /: fast neutrons flux (n/m 2 s) de Ig rr =dt ¼ À0:941 de Ig zz =dt de Ig hh =dt ¼ À0:059 de Ig zz =dt Swelling due to intragranular bubbles [1,4,5] C B : concentration of intragranular bubbles; R B : bubble radius [1,4,5] P ext : external pressure (Pa); 2c/r f : stress due to surface tension; a: grain radius (m); r f : radius of curvature of the bubble's face (m); N: surface concentration of gas atoms (at/m 2 ); k: Boltzmann constant (J/K)…”

“…Swelling due to fission products in the fuel lattice [11] Bup: burnup (at%U 235 consumed) DV V l:f:p: ¼ 0:0032 Bup Densification [17] b: rate of bubbles resolution (s À1 ); P 0 : initial porosity…”

Simulation of irradiation hardening of Zircaloy within plate-type dispersion nuclear fuel elements

“…The irradiation growth of the cladding is anisotropic, namely the cladding stretches in one dimension while shrinks in other two dimensions. In this study, the model of the irradiation growth strain has been adopted from [28] de gr e gr z are the components in the direction of length, width and thickness respectively; / depicts the fast neutron flux (n/m 2 s).…”

Elastic and viscoplastic pellets fragmentation modeling using an axisymmetrical 1D finite element code

“…The relocation of fragments can be treated only on an empirical way (Oguma, 1983;Walton and Matheson, 1984;Ito et al, 1983). The relaxation of stresses and strains can be treated through the mechanical laws by considering the fragmentation using a material approach (Ito et al, 1983;Jankus and Weeks, 1972;Rashid, 1974;Williford et al, 1982;Riktzhaupt-Kleissl and Heck, 1993;Garcia et al, 2002) or an inelastic strain approach (Jernkvist, 1997;Marino et al, 1996;Harriague et al, 1980;Lassmann and Moreno, 1977). The first solution, consisting in the modification of material characteristics, seems to be the most used method.…”