Oxidation kinetics and oxygen diffusion in low-tin Zircaloy-4 up to 1523K

Numerical modeling of oxygen diffusion in the wall thickness of Low-Tin Zircaloy-4 fuel cladding tube during high temperature (1100–1250°C) steam oxidation

“…This author used an analytical resolution with the assumption of a steady-state regime and semi-infinite conditions. More recently, this analytical approach has been revisited and applied to steam oxidation of Low-Tin Zircaloy-4 in the 1100-1250°C oxidizing temperature range [3]. However, the required steady-state hypothesis for analytical treatment limits this model to semi-infinite samples.…”

“…In the previous analytical model [3], the set of equation, from Eqs. (1)-(6), was analytically solved adding a quasi-steady-state hypothesis, and assuming parabolic rate constants for interfaces motions.…”

“…For the ZrO 2 and b phase, the diffusion coefficients have been calculated from the diffusion parameters of the Ma et al [3]. These parameters were deduced from [23] (beta-phase) and from [24,25] (ZrO 2 -phase).…”

“…Thus, knowing accurately the kinetics growth of the a Zr(O) phase and the oxygen concentration profiles in the b Zr phase are a key issue to predict the amount of ductile phase remaining in the cladding tube after a LOCA scenario. Analytical oxygen diffusion models [3], used previously, are limited to semi-infinite samples, consequently, the oxygen concentration prediction in the b phase and the simulation of the b ? a phase transformation need to be improved.…”

Oxygen segregation in pre-hydrided Zircaloy-4 cladding during a simulated LOCA transient

“…In the open literature, analytical oxygen diffusion models are restricted to samples having simple geometry that is usually not satisfactory for analyzing tubular geometry [9]. A finite-difference software solving the oxygen diffusion equations named DIFFOX (for DIFFusion of OXygen) has been developed by Institut de Radioprotection et de Sûreté Nucléaire (IRSN) [10].…”